1. Field of the Invention
The invention relates in general to apparatus and methods for controlling the delivery of a fluid, and to mixing of two or more fluids, and in particular, to methods and apparatus wherein the mixing of two or more fluids create and/or control physical and/or chemical changes in those fluids.
2. Description of the Related Art
Many physical and chemical processes require the delivery of a first fluid, and of mixing of two or more fluids together. The effectiveness of the mixing in such processes is dependent upon many physical phenomena. Mixing may depend upon the surface area of a liquid or the interfacial area between the fluids (e.g., a liquid, a vapor, and/or a gas) that are to be mixed. For heat exchange between two fluids in direct contact, the process depends in part on the interfacial area between the two fluids and thus on the specific interfacial area (surface area per mass). In another example, chemical reactions between a liquid and a gaseous fluid typically occur between the vapor evaporated from the liquid, and the surrounding gaseous fluid.
Traditional methods for mixing two fluids together rely on relatively few injection nozzles, which are arranged to inject a first fluid into a second fluid. Such methods produce areas where local concentrations may be higher or lower than the desired average concentration. Such discontinuities may adversely effect the desired physical or chemical processes. There is a general need for an apparatus and method for improving the mixing of two or more fluids together.
Accordingly, one exemplary embodiment of the invention involves an apparatus for mixing a first fluid with a second fluid. The apparatus comprises a fluid distribution portion comprising at least one tubular portion having an outer surface and an inner surface, the inner surface defining a first flow path for the first fluid, a duct that defines a second flow path for the second fluid, the duct having an axial direction and a first and second transverse directions mutually distinct from the axial direction, the first and second transverse directions defining a plane through an axial location and containing a cross-sectional area of the duct, a first fluid delivery system for supplying the first fluid to the fluid distribution portion a second fluid delivery system for supplying the second fluid to the duct; the tubular portion comprising a plurality of orifices each forming a third flow path along which the first fluid can be injected into the second fluid within the duct; and wherein the outer surface of the tubular portion comprising the orifices is positioned within the duct in the second flow path and the orifices when projected onto a plane containing the first and second transverse directions have an average spatial density of at least about 10,000 orifices per square meter of duct cross sectional area.
Another exemplary embodiment of the invention involves a method of mixing a first fluid with a second fluid. The method comprises providing a fluid distribution portion comprising at least one tubular portion having an outer surface and an inner surface, the inner surface defining a first flow path for the first fluid, providing a duct that defines a second flow path for the second fluid, the duct having an axial direction and a first transverse direction and a second transverse directions perpendicular to the axial direction, the first and second transverse directions at an axial location defining a plane comprising a cross-sectional area of the duct, positioning the at least one tubular portion in the duct such that it extends in a direction having a component in the first transverse direction; providing a plurality of orifices on the at least one tubular portion, each orifice forming a third flow path along which the first fluid can be delivered into the second fluid within the duct; providing a first fluid delivery system for providing the first fluid to the first flow path; controlling a delivery pressure of the first fluid; configuring at least one of the (i) the size of the plurality of orifices in the transverse direction, (ii) the linear density of the plurality of orifices in the transverse direction or (iii) the delivery pressure of the first fluid to deliver a non-uniform amount, with respect to the first transverse direction, of the first fluid into the second fluid to achieve a desired distribution of the first fluid in the second fluid in the first transverse direction downstream of the fluid distribution portion.
Another exemplary embodiment of the invention relates to method of mixing and exchanging heat between a first fluid and a second fluid. The method comprises providing a delivery member for a first fluid, the delivery member comprising tubular portions with a plurality of orifices; providing a duct for a second fluid through, the duct having a duct axis and encompassing the orifices; configuring a non-uniform transverse distribution of orifice sizes along at least one of a first direction transverse to the duct axis, and controlling the differential ejection pressure between the first fluid within the orifices and the second fluid outside the orifices along at least a first direction transverse to the duct axis; providing a non-uniform density in the transverse direction of the orifices on the delivery member, delivering the second fluid through the duct; and and delivering the first fluid through the delivery member to control the temperature of the second fluid exiting the duct.
Another exemplary embodiment relates to a method of radiatively exchanging heat with a first fluid. The method comprising providing tubular portions comprising numerous orifices within a duct; configuring the orifices to have a non-uniform spatial distribution with respect to a transverse axis of the duct; configuring the orifices to have a non-uniform size distribution with respect to the transverse axis of the duct; delivering a first fluid to the tubular portions with a non-uniform differential ejection pressure with respect to the transverse axis; controlling the temperature of the first fluid delivered to the tubular portions, controlling the temperature of a wall of the duct, and controlling the radiation flux from the duct wall to the first fluid being delivered from the tubular portions to the duct.
Another exemplary embodiment relates to a method of mixing a first fluid with a second fluid. The method comprises providing a fluid distribution portion comprising at least one tubular portion having an outer surface and an inner surface, the inner surface defining a first flow path for the first fluid, providing a duct that defines a second flow path for the second fluid, the duct having an axial direction and a first transverse direction and a second transverse directions perpendicular to the axial direction, the first and second transverse directions at an axial location defining a plane comprising a cross-sectional area of the duct, positioning the at least one tubular portion in the duct such that it extends in a direction having a component in the first transverse direction; and dynamically controlling the distribution of the first fluid into the second fluid with respect to the first transverse direction downstream of the fluid distribution portion by controlling the pressures at both ends of the fluid distribution portion.
For purposes of summarizing the invention, certain aspects, advantages and novel features of the invention have been described herein above. Of course, it is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or increases one advantage or group of advantages as taught or suggested herein without necessarily achieving other advantages as may be taught or suggested herein.
All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed.
Having thus summarized the general nature of the invention and some of its features and advantages, certain preferred embodiments and modifications thereof will become apparent to those skilled in the art from the detailed description herein having reference to the figures that follow, of which:
A list of some components and certain nomenclature utilized in describing and explaining the preferred embodiments of the invention follow:
The following detailed description of the preferred embodiments uses many technical terms. In an effort to improve clarity, several of these terms will be first described in this section. It should be appreciated that these technical terms are broad terms and are also used in their ordinary sense in addition to the definitions provided below.
First Fluid, commonly comprising one or more of a First Reactant Fluid, a Fluid Fuel, and a Thermal Diluent, herein also generically called a “Fuel Fluid”. (e.g. a gaseous, liquid or fluidized powdered fuel or a mixture comprising fuel and thermal diluent typically passing through a Fuel Perforated Tube or Duct and moving out Orifices)
Second Fluid, commonly a Fluid comprising a second Reactant or an Oxidant, optionally comprising a thermal diluent fluid, herein also generically called an “Oxidant Fluid”. (e.g. humid air or oxygen enriched air optionally mixed with steam, typically passing through a Fluid Duct across one or more perforated tubes, or else passing through an Oxidant Perforated Tube)
Third Fluid, commonly a “Thermal Diluent” or “Diluent Fluid” comprising an inert fluid or fluid with low reactivity such as a mild oxidant, capable of absorbing or giving off heat and changing enthalpy and temperature, herein also generically called a “Thermal Diluent” “Diluent Fluid” or “Cooling Diluent”, sometimes distinguished as “Vapor Diluent” and “Liquid Diluent” when the diluent fluid is vaporizable. (e.g. water, steam, excess air, carbon dioxide, or recirculated products of combustion, typically passing through a Thermal Diluent Perforated Tube and out Orifices)
Energetic Fluid, a fluid capable of delivering energy, commonly a hot pressurized fluid comprising products of reaction and residual portions of the First Fluid and Second Fluid, and commonly comprising Thermal Diluent (e.g. a hot pressurized fluid formed by combusting a fuel fluid with oxidant fluid such as compressed air and diluted with steam and excess air)
Expanded Fluid, fluid downstream of an expander or work engine such as a turbine or reciprocating engine, may also be termed Exhaust Fluid or Spent Fluid
Flue Gas, expanded energetic fluid exhausting through a flue
Cooled Fluid, a fluid with heat withdrawn such as downstream of a cooling heat exchanger or condensor
Distribution member, a member having a fluid passage through which fluid is delivered to orifices through which the fluid is distributed, such as a tube comprising orifices in a wall.
Orifice—a mouth or aperture of a tube, cavity etc.; opening
Opening—open place or part; hole; gap; aperture
Aperture—(1) an opening; hole; gap (2) the opening, or the diameter of the opening, in a camera, telescope, etc. through which light passes into the lens
Hole—an opening in or through a solid body, a fabric, etc.; a perforation; a rent; a fissure; a hollow place or cavity; an excavation; a pit; Webster 1913 rearranged
Duct—(1) a tube, channel, or canal through which a gas or liquid moves; . . . (4) a pipe or conduit through which wires or cables are run, air is circulated or exhausted etc.
Tube—a distributed member having an inner surface forming a passage defining a first flow path to deliver a first fluid, often having an elongated walled member.
Prescribed—herein generally refers to a parameter that is desired or needed, prescribed, predetermined, pre-selected or otherwise selected.
Curvilinear—the shape of a generic line comprising one or more linear and/or curvaceous sections as desired. E.g. comprising linear, polynomial and/or transcendent functions comprising conic sections, parabolic, elliptical, hyperbolic, sinusoidal, logarithmetic, exponential curves.
Coordinate system—system used to configure planar or spatial ducts or other fluid delivery system, comprising Cartesian, cylindrical, spherical, annular, or other suitable curvilinear co-ordinate systems or combinations thereof.
Differential Ejection Pressure—differential pressure across the orifice in the tube wall that ejects the first fluid as a jet.
All Orifice Differential Fluid Pressure Poda—the differential pressure across an array of orifices sufficient to eject fluid from all the orifices, including the smallest orifices 80.
Equivalence Ratio or Phi—the ratio of first reactant flow to second reactant flow or fuel fluid flow to oxidant fluid flow relative to the stoichiometric ratio of first reactant to second reactant or fuel fluid to oxidant fluid. I.e. the inverse of Lambda (E.g. diesel fuel to air ratio relative to stoichiometric diesel fuel to air ratio.)
Excess Oxidant Ratio, Lambda, or excess air ratio—the ratio of the second reactant or oxidant fluid flow to first reactant or fuel fluid flow relative to the stoichiometric ratio of second reactant to first reactant or stoichiometric oxidant fluid to fuel fluid. I.e. the inverse of Phi.
Lambda Distribution—the distribution of Lambda or relative stoichiometric ratio of oxidant fluid to fuel fluid (e.g. oxygen to fuel ratio relative to the stoichiometric ratio of oxygen to fuel.)
Rich mixture or composition—a fluid comprising more fuel (or less oxidant) than the stoichiometric ratio i.e. Lambda less than one or Phi greater than one.
Lean mixture or composition—a fluid comprising less fuel (or more oxidant) then the stoichiometric ratio. I.e. Lambda greater than one or Phi less than one.
Diluent enthalpy change—the change in enthalpy of a diluent between two states, including one or more of change due to heat capacity, latent heat of vaporization, and chemical dissociation.
Specific diluent enthalpy change—the change in enthalpy per unit mass between two states.
Total diluent enthalpy change—the diluent enthalpy change of all fluid components including excess oxidant fluid (in lean mixtures), excess fuel fluid (in rich mixtures), thermal diluent vapor, thermal diluent liquid and any other non constituents.
Excess heat generation—heat of combustion in excess of the heat required to increase combustion products to the desired energetic gas exit temperature.
Combustion cooling—the reduction in enthalpy of hot combustion gases equal to the excess heat generation and equal to the total increase in enthalpy of the total thermal diluent components.
Distribution—a function describing the variation of a parameter. Herein frequently used to describe the variation of the parameter along one or both transverse directions (e.g., radial and circumferential) or an axial direction. Also used for number distributions.
Profile—a function or distribution describing the variation of a parameter along a direction, such as in a radial direction in a cylindrical or annular duct. Herein may also be used for a ratio of two distributions, or to describe a “pattern” along a direction such as a circumferential direction. Sometimes used to emphasize spatial rather than number distributions.
Jet Discharge Cross Area—net cross-sectional area of the fluid jet as it exits the orifice.
Orifice Flow Factor—ratio of jet discharge cross-sectional area to total orifice discharge cross-sectional area
Fluid flow—the rate of flow of fluid on a mass basis, or the mol or volumetric rate if so stated.
Fluid flow distribution—the variation of the fluid flow along a direction, or along a curvilinear line as specified.
Fluid flow ratio—the variation in the ratio of two fluid flows, sometimes the distribution of this ratio.
Fluid flow ratio profile—the distribution of the ratio of two fluids along a transverse direction or along an axial direction or curvilinear line if so specified.
Fluid Flow Ratio Profile Range—the distribution of the range of upper and lower fluid flow ratios along a transverse direction or along an axial direction or curvilinear line if so specified.
Minimum Orifice Differential Pressure Podm—the differential ejection pressure across an array of orifices sufficient to eject fluid from the largest orifices 80.
Partial Orifice Differential Fluid Pressure Podp—the differential ejection pressure across an array of orifices sufficient to eject fluid from some of the larger orifices 80 but not from the smallest orifices.
Temperature—the thermodynamic temperature of a fluid at a point or the mean temperature of the fluid,
Temperature distribution—the variation of temperature in a fluid along a transverse direction or along an axial direction or curvilinear line as specified.
Temperature distribution range—the variation in upper and lower temperatures along a transverse direction or an axial direction or curvilinear line as specified.
Uncertainty—the uncertainty evaluated according to international definitions. Eg See NIST TN 1287.
Temperature uncertainty—the uncertainty in the temperature of the fluid or component.
Flow uncertainty—the uncertainty in fluid flow rate.
Ratio uncertainty—the uncertainty in ratio of fluid flow rates.
Turn Down—the ratio of minimum to maximum fluid flow rates, or described as reduction in flow divided by the maximum to minimum flow rates. E.g., 10% minimum to maximum flow ratio; 90% turn down; or a turn down of 10:1.
8.2 Direct Contactor Perforated Tubes with Numerous Orifices
Some preferred embodiments of the present invention relate to apparatus and methods for delivering a first fluid and for mixing two or more fluids and together. As will be described below, one embodiment utilizes a distribution member comprising a tube that is positioned within a duct forming a flow path. The tube comprises a large number of small orifices. The first fluid is injected through the orifices into the second flow path of a second fluid. By positioning the numerous small orifices across the flow path, very efficient mixing between the first and second fluids can be achieved.
As shown in the cross section view
With reference to
As will be explained in more detail, below, in some embodiments, users create a differential ejection pressure across the perforated tube 10 sufficient to force the first fluid 901 through orifices 80 and form drops (or bubbles) 902 or micro-jets 903 of the first fluid 901 in the second fluid 904. In modified embodiments, the second fluid flows across the orifices 80 to entrain the micro-flows, micro-jets, drops or bubbles of the first fluid 901 delivered with a desired differential ejection pressure into that second fluid 904.
It should be appreciated that although dictionary definitions of “tube” refer to a “cylindrically walled member”. Applicants do not intend for tube to have such a limited definition. Instead, Applicant has used “tube” to refer to a distributed member which has an inner surface forming a passage that defines a first flow path to deliver a first fluid. The distributed member is often an elongated walled member. It may have a variety of cross-sectional shapes as will be apparent from the description below. The distributed member comprises orifices which are often round but which may be elongated or form slots etc.
8.2.1 Number of Orifices or Jets
Conventional systems typically only use a few orifices in a plate or at the end of an injector. In contrast, users provided one or more contactor tubes with a lineal orifice density of at least hundreds of orifices per meter of tube length, more preferably with thousands of orifices per meter of tube length, and still more preferably optionally tens to hundreds of thousands of orifices per meter of tube length depending on the application. In other words, with respect to
The orifices 80 are distributed across the second flow path 4 to achieve a desired transverse flow distribution of the first fluid 901, or flow ratio profile of the first fluid flow divided by the mean first fluid flow, preferably on a mass basis, or alternatively on mol or a volume basis. The flow distribution and orifice distribution provide a desired mixing distribution of the two fluids. For example, to produce a uniform ratio of second fluid to first fluid flow, the orifices 80 are distributed with a substantially non-uniform distribution across the second flow path 4 within the duct 130 to accommodate the non-uniform flow of the second fluid. In such configurations, the orifices are configured in arrays of perforated tubes 10 across the flow path 4 thereby distributing hundreds and preferably thousands to hundreds of thousands of orifices or more across the second flow path 4.
Typical ranges of orifice specific number density (number of orifices per duct cross sectional area) are shown in Table 1 Orifice Specific Number Density for typical ranges of orifice lineal density along contactor tubes and for typical ranges of tube to tube spacing.
Ranges of Duct to Orifice Area ratios are shown in Table 2 for a range of orifice specific number density, the orifice sizes. This demonstrates the very wide range of duct to orifice areas that can be configured with various embodiments of the direct contactor arrays.
8.2.2 Tube Supports
As shown in
The supports 37 are preferably configured to provide sufficient flexure to accommodate any differential thermal expansion during operation and are designed to accommodate vibration, pressure oscillation, gravity, acceleration and other forces using techniques well known in the art. In some embodiments, the distributed tubes 10 may form in part the structural supports 37.
8.2.3 Differential Ejection Pressure with Numerous Orifices
With a large number of orifices, a large cumulative cross-sectional area of orifices 80 is provided for the first fluid to flow through. An advantage of this arrangement is that in some embodiments a large differential ejection pressure is not required to deliver the first fluid 901 through the orifices 80 into the second fluid 901. e.g., compare the relevant art which often uses pressures of about 750 bar to 3000 bar (about 10,000 psi to 40,000 psi).
In contrast, in one embodiment, a relatively low positive differential (e.g, about 0.001 bar to 750 bar or about 0.01 psi to 10,000 psi) pressure may be used to force the first fluid 901 within the tube 10 out through the orifices 80 to form drops 902 (See, e.g.,
In various embodiments, (referring to
Alternatively, the full range of differential ejection pressure is sometimes used to increase fluid delivery turn-down ratio (such as in
8.2.4 Uniform or Prescribed Distribution through Many Orifices
As mentioned above, the distributed contactor system 2 preferably includes perforated tubes 10 with a large number of small, orifices. It is also advantageous to distribute these orifices 80 across the second flow path 4 to efficiently mix the first fluid 901 flowing through orifices 80 with the second fluid 904 flowing across those orifices 80. This arrangement causes more efficient distribution and mixing of the fluids 901, 904. This results in more locally homogeneous compositions which may vary in composition as desired transversely across the duct.
In various embodiments, the distributed fluid contactor 2 may be used distribute drops of a first liquid into a second gas, distribute a first gas into a second gas, distribute a first liquid into a second liquid, or distribute a first gas (e.g., bubbles) into a second liquid. That is, the first fluid 901 may be a liquid, gas or a combination of liquid and gas (e.g., water droplets, mist, solution, suspension, fluidized powder, nucleated bubbles of vapor in a liquid, etc.). Similarly the second fluid 904 may also be a liquid, gas or combination of liquid and gas (e.g., water droplets, mist, nucleated bubbles of vapor in a liquid, etc.) In some configurations, the second fluid 904 may comprise a fluidized powder.
8.3 Numerous Orifice Array Configuration Linear Array
As mentioned above, rather then a high pressure spray from one or a few nozzles, in some embodiments the distributed contactor system 2 utilizes large number of orifices 80 in an array along the tube wall 30 to provide a more effective, uniform or desired mixing of the first fluid 901 emitted from the perforated tube 10 with the second fluid 904. With reference to
When forming drops by gravity or fluid pressure extrusion, pendant drops are formed with a nominal diameter “d” which are typically of the order of twice the diameter “d” of the orifice or hole 80. Thus, holes of about 2 micrometer (μm) diameter nominally create droplets of about 4 micrcometer (μm) in diameter at low pressures or velocities.
As will be explained below, the arrangement of the orifices 80 on the tube 10 may be varied in a variety of ways to achieve different results. For example with reference to
8.3.2 Column or Arc
In other embodiments, the orifices 80 are distributed in a columns or arcs 93 about the tube wall 30 as shown in the exemplary embodiment of
8.3.3 Curvilinear Spatial Orifice Array
In other embodiments, users preferably form a spatial array of orifices by creating an curvilinear array comprising lines, columns, arcs, or other curvilinear orientations of orifices.
Hexagonal orifice array: For example, as show in
Cartesian orifice array: In some embodiments, as shown in
Areal Orifice Density: As mentioned above with reference to
8.3.4 Orifice Spacing
To prevent drop coalescence during formation, the hole interval h is preferably significantly greater than the drop size formed. It is preferable to provide significant gaps “g′” between drops, to prevent droplet coalescence.
With reference back to
8.3.5 Columnar or Rectangular Arrays
In some embodiments, as shown in
8.4 Spatial Orifice Density
In various embodiments, users of the fluid contactor 10 (see
This design parameter is approximately equal to the effective orifice area per length of contactor tube divided by the tube to tube spacing h. (Note that this may count multiple rows of orifices along the tube and orifices of differing size.) The effective orifice area is obtained by the gross cross-sectional area of the orifices adjusted for net fluid flow area exiting the orifice due to the necking down of fluid flow within the orifice variously caused by roughness, geometry, turbulence, cavitation and/or entrained bubbles.
Detailed designs will involve other parameters as desired or needed such as orifice size, orientation and configuration, the pressure difference across the tube wall, the pressure drop of the second fluid flowing across the tubes, the relative fluid densities, viscosities, surface energies, pressures, temperatures, tube configurations and relative positions etc. These may further use full CFD modeling to best position and orient the orifices.
8.4.1 Axi-symmetric Flow Distribution for Uniform Ratio of Fluid Flows
As is well known in the art, the fluid flow in ducts commonly displays a substantial velocity distribution being faster near the duct axis 133 or center and slower near the duct wall 132 (see
In one embodiment, the contactor is configured to achieve a uniform or prescribed ratio of the second fluid to first fluid across a duct with such a non-uniform velocity profile. Referring to
For example,
In a similar manner, the embodiment illustrated in
8.4.2 Radial Variation in Ratio of Fluid Flows
With continued reference to
Each contactor ring or perforated tube 10A-C comprising orifices 80 having an net specific orifice spatial density of the net area of orifices divided by the relevant cross-sectional duct area. i.e. the relevant area is the mean tube to tube spacing multiplied by the mean incremental orifice spacing distance along the tube 10 at that location. Furthermore, in some configurations the lineal orifice density varies from one side of each tubular ring 10A-C to the other side to adjust the net orifice density in the radial direction transverse to the duct axis or perpendicular to the tube arcs. In such cases, the area is the half the tube to tube spacing on that side of the arc multiplied by the orifice spacing along that side of the tube. Users preferably adjust the net spatial orifice density along each contactor ring 10A-C to achieve a radial distribution of spatial orifice density that varies radially as desired in a circular fluid duct 144, an elliptical fluid duct (not shown) or annular fluid duct 146 (such as shown in
8.4.3 Circumferential Variation in Ratio of Fluid Flows
In some embodiments, to obtain a desired circumferential profile (or “pattern”) in the ratio of fluid flows such as around an annular duct, users preferably adjust the orifice spatial density in the circumferential direction around the fluid duct 130. E.g., in the embodiment of
8.4.4 Transverse Variation in Ratio of Fluid Flows
8.4.5 Spatial Variation in Ratio of Fluid Flows
To achieve a multidimensional spatial variation in fluid ratio, users preferably vary both the spatial density of orifices along each tube in one dimension (or parameter) as well as the spatial density or variation in a second direction (or parameter) such as from tube to tube across the array in some configurations. E.g., along the major transverse coordinates in cylindrical or Cartesian coordinates.
For example, in rectangular arrays 266 as shown in
8.4.6 Varying Spatial Fluid Delivery Profiles
To dynamically vary spatial fluid delivery distributions and profiles, users adjust the differential ejection pressure distribution along the longitudinal axis of the contactor tubes by adjusting the pressure in one or both sub-manifolds 254 or manifolds 240 to which the contactor tubes 10 are connected. The pressure is preferably adjusted using one or more pressure flow modulator 370 or sub-manifold valve 233.
8.5 Orifice Size
8.5.1 Magnitude of Orifice Size
In various embodiments, users preferably form the orifices 80 on the fluid contactor (See
As examples, in other embodiments, the contactor 10 may have 2 micrometer diameter holes to about 60 μm holes in 200 μm thick walls of the thin-walled tube 10. In other embodiments, the contactor 10 may have about 0.3 to 10 micrometer diameter holes in an ultra-thin walled sheet or foil etc. of about 30 micrometer thick. For applications involving direct contactors with physical changes such as condensing, the contactor may have orifices ranging from 50 micrometers to 5 mm, and preferably from 200 μm to 2 mm.
8.5.2 Orifice Size Uniformity
Orifices 80 of differing size typically create drops (or bubbles) of differing size, given sufficient pressure to emit such drops. To form drops of uniform size and at a uniform rate, the orifices 80 are preferably provided with uniform dimensions within a prescribed statistical distribution parameter. For example, with a relative standard deviation (RSD)<0.1, preferably<0.01 and more preferably with the RSD<0.001. Of course, other suitable RSDs may be efficaciously utilized, as needed or desired.
8.5.3 Pressure Drop Adjusted Orifice Size
Liquid flow within small diameter tubes 10 may cause a significant pressure drop along the tube. Conversely, any heating (or cooling) of the fluid along the tube will reduce (or increase) the surface tension. To compensate for such effects, as shown schematically in
8.5.4 Stepped Orifice Sizes
In other embodiments users make the orifice gradations in substantially discrete sizes. The orifices may be arranged arranged in discrete sizes such that the drop size formed or micro-jet diameter and drop size distribution are significantly varied as desired.
With such configurations in low flow with short penetration distances, users may control which orifices through which drops are expelled by controlling the positive differential ejection pressure applied. Accordingly, users can cause drops to be formed from larger sized orifices and not from smaller orifices by controlling the differential ejection pressure of the first fluid relative to the second in relation to differential ejection pressure required to overcome the interfacial surface energy relative to the given orifice size.
8.5.5 Graded Orifices
In some embodiments where users need or desire to control drop size and location of drops, the direct contactor 2 includes graded orifice arrays. The orifices 80 may have diameters changing in curvilinear fashion with a prescribed systematic method. In one embodiment, the orifice area may be systematically varied e.g., the diameter of the orifices 80 is varied as the square root of the desired orifice area. The orifices may be formed using lasers or other suitable orifice forming methods. The desired orifice area in turn is preferably configured as a function of spatial location. In this manner, users can control the positive differential ejection pressure across the tube to control the portion of the orifices through which fluids or liquids flow.
They similarly configure gradation in orifice areas and diameters for arithmetic, geometric, polynomial or other desired spatial functions E.g., by varying the orifice diameter as the half power of a transverse dimension, user obtain a generally linear variation in drop size along that dimension. Similarly, varying the orifice diameter according to the first power of a transverse direction gives a generally parabolic variation in drop size along that direction etc.
8.5.6 Tailored Orifice Distribution
Flow through an orifice is generally proportional to the square root of the differential ejection pressure across the orifice. A 100:1 turn down ratio of flow rate would conventionally or typically require a pressure difference of 10,000:1. To compensate for this phenomena, in some embodiments, the direct contactor may be configured to utilize the effect that at low differential ejection pressures, orifices of different sizes will selectively pass fluid through some passages and not thru others. Accordingly, the contactor may be configured such that the orifices are varied with respect to both their size distribution or profile, number distribution, lineal net jet area distribution, and/or spatial net jet area distribution to obtain a desired flow rate versus differential ejection pressure distribution while achieving a prescribed micro-jet or drop size distribution. For instance users can obtain a linear, quadratic or other variation of flow vs differential ejection pressure instead of (or in combination with) the default square root relationship. This can expand the relative control at low differential ejection pressure. This can be used to expand the overall turndown ratio.
8.5.7 Configuring Orifice Size Distribution
In other embodiments, users form orifices with various prescribed sizes to correspondingly form drops or micro-jets of various sizes or with more desired transverse distribution of a measure of drop size such as the Sauter Mean Diameter (SMD), along one or more of the axial, first or second transverse directions.
8.5.8 Non-curvilinear, Random & Pseudo-random Arrays
Random or non-curvilinear arrays: In some embodiments, the orifices may be formed in a random spatial array in a tube wall as needed or desired. (Not shown.) E.g., In some configurations, users randomize the location of orifices. The size of orifices is randomized in some configurations. In other variations, both the location and size of the orifices is randomized. In situations where regular orifice arrays and periodic pulsing cause pressure oscillations, these oscillations might advantageously be reduced by shifting to or providing such randomized arrays of orifices.
Pseudo-random arrays: In another embodiment, the orifices form pseudo-random or non-curvilinear arrays by combining “random” placement and/or size of orifices with net variations in the net orifice spatial density. I.e. the net area of orifices per unit cross-sectional area of fluid duct. These methods include varying the net orifice spatial density as desired or needed. E.g., increasing and then decreasing the spatial density transversely across the fluid duct 130. An example of such an embodiment is illustrated in
Non-Curvilinear arrays: Of course, in other embodiments, the orifices may be oriented other non-curvilinear arrays other than those explicitly described, as desired or needed.
8.5.9 Orifice Cone Angle
In some embodiments, users adjust one or both of the thickness of the tube wall and the orifice diameter to adjust the thickness to diameter ratio (t/d). This in turn is adjusted to achieve desired micro-jet spray angle which varies by this ratio.
8.5.10 Generalized Orifice Configuration
Of course, in other embodiments, the orifices may be located, spaced and/or sized in other suitable manners with efficacy, to achieve net spatial densities or other parameters or to avoid certain configurations as desired or needed.
8.6 Location of Orifices
With reference to
8.6.1 Circumferential Angle of Orifices
As shown schematically in
As shown in
8.6.2 Orifice Circumferential Location
Again with reference to
8.6.3 Combined Orifice Angle, Radial Location and Size
With reference to
In some configurations, users set the circumferential angle of the longitudinal axis of the orifice to one angle, while separately varying the orifice circumferential location around the tube. This adjusts the transverse location of the jet relative to the tube to tube gap while keeping the same angle of attack between the jet 903 and the duct axis. Conversely, users may orient the orifices with differing circumferential angles while maintaining the same circumferential location around the tube.
Orifice positions and orientations are preferably adjusted according to the relative speed of the transverse flows and tube dimensions. These parameters will vary according to how laminar or turbulent the flow becomes and affect the flow velocity profiles.
In accordance with some embodiments, by forming uniform orifices and forming laminar jets, users form fairly uniform drops (or bubbles) of the first fluid that will penetrate a fairly uniform distance into the second fluid.
8.6.4 Orifices at Tube Corners
For very low flow rates of the first fluid, drops may not be ejected as the fluid flows out from the tube, but might “dribble” or “weep” across the tube surface, wetting the tube. Certain flows of the second fluid flowing transversely across the contactor tube 10 could also influence such wetting. Drops could then aggregate resulting in larger drops breaking off the tube.
To reduce the tendency for drops to “dribble” or “weep” across the outer tube surface at low pressures and with turbulence, in some embodiments as shown in
8.6.5 Orifice Axial Location
With reference to
8.6.6 Orifices in Tube Ends
As shown in
8.7 Orifice Configuration, Spacing and Orientation
In various embodiments, users preferably adjust the orifice spacing, circumferential and longitudinal orientation, circumferential and longitudinal position, and array configuration to position and mix drops and/or micro-jets of the first fluid into a second fluid with desired transverse distributions along one or more of the axial, first and second transverse directions. These are detailed as follows.
8.7.1 Conical Orifice Orientation
Laser drilling typically forms truncated conical holes through a tube wall, forming a larger orifice opening nearest the laser and a smaller orifice opening farthest away from the laser. With reference to
Where fluid differential ejection pressure is sufficient to cause the fluid 901 to cavitate as it flows through the orifice 80, the fluid jet forms an outwardly reducing flow cross section resulting in a jet exiting the outer orifice 90 that is significantly smaller than the smaller orifice 89 even though it forms the inner orifice 88 at the tube inner surface 6.
With reference to
8.7.2 Orifice Array Width
With reference now to
With continued reference to
In embodiments having compound tubes which will be described below this gives a total downstream tube section circumference of about 9 mm. In such compound tubes, users preferably allow at least another 0.5 mm to 1.0 mm on each edge to attach to the stiffening tube. This results in a total strip width of at least about 10 mm to about 11 mm to form these downstream tube sections. Alternatively, as shown in
Note that these dimensions are illustrative taking a convenient thin walled tube. Similar effects are obtained in selecting larger or smaller dimensions. Users may select the tube size, shape and spacing according to the orifice diameter and maximum micro-jet distance desired or needed relative to the tube spacing.
8.8 Orifice Angular Orientation to 2nd Fluid Flow
In some embodiments, in addition to, or instead of, positioning orifices transversely around the tube, users preferably orient the orifices at various predetermined or pre-selected angles relative to the second fluid flow path to adjust the terminal position of the fine drops injected into the transverse flow. By such measures, users form drops of substantially uniform size and position them fairly close to some desired distribution across the transverse fluid flow in configurations using low differential ejection pressures to create fairly laminar jets. E.g., uniform, or proportional to the gas velocity. Similarly with higher pressures, users form turbulent micro-jets oriented at different angles to deliver the jet into desired locations across the tube gap.
This technique or methodology is preferably further refined to compensate for the variation in velocity of the transverse flow across the gap between the tubes and for the changes in differential ejection pressure across tube wall due to the Bernoulli effect. Accordingly, in some embodiments, users preferably position drops between and along tubes to achieve fairly uniform number of drops of the first fluid per unit mass of the second fluid in the transverse flow.
8.9 Orifice Angular Orientation to Tube Axis
With reference to
For example, as shown in
As shown in
As shown in
In other configurations, as shown in
8.9.1 Fluid-Droplet Vortex Mixing
In most embodiments, by providing a distributed tubular array of tubes, users generate vortices in the second fluid flow downstream of each of the tubes and manifolds. This distributed turbulence creates fairly uniform mixing of the first fluid flowing through the tube orifices with the second fluid flowing over the contactor tubes 10. The first fluid droplets and second fluid are mixed in the stream of vortices created immediately downstream of each tube.
8.10 Micro-Jet Penetration & Mixing
As mentioned above, in various embodiments, users preferably design, configure and/or control the system so that the micro-jets and droplets of the first fluid exit orifices 80 on perforated tubes 10 and penetrate a desired distance into the adjoining tube to tube gap G.
8.10.1 Micro-Jet Penetration Distance
Users preferably use jet penetration correlations appropriate to the pressure of the second fluid, and the respective fluid velocities. As shown in
To calculate these penetration distances, users use the most effective appropriate correlations of jet penetration distances, such as summarized by Heywood, Internal Combustion Engines. For example, Holdeman (ASME, NASA 1997) has published jet penetration correlations. In integrated design calculations, the desired correlation of spray distance to orifice diameter is preferably normalized by the other side of the equation to obtain ratios near unity.
8.10.2 Turn-down Ratio, Mixing & Pumping Work
Referring to
It could also be designed to penetrate to about the far side of contactor tube 10, where the jet will extend downstream of the adjacent tube at peak flow conditions. The jet may be configured to spray across the tube into the next gap such as such as to 200% of the tube to tube spacing H. Opposing orifices are preferably displaced by about half the orifice spacing h. Consequently opposing micro-jets nominally fill the gap between the tubes when viewed from a plan view when the orifices are configured at the jet width of the sprays axially in line with that opposing jet wall.
The contactor tubes 10 may further be angled giving a varying tube to tube spacing H or tube gap G. As shown in
As shown in
To further improve mixing in either of the arrangements of FIGS. 26 or 28, users preferably reduce the tube to tube gap G and increase the number of orifices and micro-jets. As shown in
To achieve these features, the orifice size, location and orientation, array configuration, gap between tubes, fluid differential ejection pressure, temperature, and external electrical field (as discussed further below) are designed or controlled relative to the flow, density and viscosity of the second fluid. The droplets will generally follow an approximately parabolic arc compounded by oscillating vortices formed by tubes.
For example, in the embodiments of
8.10.3 Tube to Tube Transverse Fluid Delivery Distributions & Ratios
With continued reference to
To achieve a desired degree composition of the second fluid 904 relative to the first fluid 901, users preferably evaluate the axial velocity of the second fluid 904 transversely across the tube to tube gap G. They then configure the orifice area, orifice orientation and differential ejection pressure across the tube wall to configure the micro-jets across the tube to achieve the desired first fluid flows distribution relative to the second fluid flow distribution in the tube to tube or second transverse direction across the duct. These are configured such that the mean composite second transverse delivery distribution of the first fluid 901 is desirably proportional to the second fluid flow delivery distribution to achieve a desired ratio profile of the second to first fluid flows in this second transverse direction.
8.10.4 Uniform Tube to Tube Fluid Profiles
For the most uniform fluid distribution across the gap, users expect to configure the jets to penetrate about 35% to 45% of the tube gap G from either side. Similarly the jets penetrate about 60% to 90% of the tube gap G from each side of the gap providing overlapping jets and overlapping transverse fluid delivery distributions. In modified embodiments, users preferably provide a combination of penetrations using radial and upstream orifices to provide desired combinations of mixing and tube to tube flow profile of the first fluid relative to the second fluid.
To configure the delivered fluid 901 to more closely match a peaked velocity profile and fluid delivery profile of the second fluid 904 flowing between the tubes, users preferably configure the jets to penetrate about 40% to 50% of the tube to tube gap G from either side. Similar results are obtained by configuring jets to penetrate about 55% to 65% of the tube to tube gap G. Such configurations provide transverse fluid flow distributions and profiles between the tubes that are greatest about mid gap, and fall off towards the tubes.
8.10.5 Assymetric Tube-Tube Fluid Profiles
Users configure the circumferential orientation of the orifices about the tube to selectively direct the micro-jet spray to a desired portion of the tube to tube gap G. To achieve an asymmetric distribution, for example, they orient the orifices on opposite of the Gap and adjust the orifice areas and differential ejection pressure to deliver the micro-jet upstream (or down-stream) so that they are delivered asymetrically across the gap G.
With reference to
With reference to
These methods of asymmetrically orienting tubes on adjacent tubes about a Gap can be used together with methods of adjusting the orifice area and jet penetration distance to taylor the mean intra-gap fluid distribution to a desired asymmetric fluid delivery distribution. The angle of the orifice longitudinal axis to the tube longitudinal axis can similarly be varied to adjust the fluid distribution distance across the gap G.
8.10.6 Part Load Operations
With continued reference to
8.11 Modifying Tube Shape
In some embodiments, users preferably adjust tube shape to affect the pressure drop and flow across a contactor tube or contactor tube array or bank. They change tube shape to affect the vortex intensity and turbulence downstream of the tubes. Tube shape is also be used to influence the direction of flow and momentum of fluid flowing across tubes in some configurations. Flow induced differential ejection pressure across a contactor tube also causes bending forces and moments on the tubes.
In some embodiments, users selectively adjust the cross section shape of the contactor tubes to streamline a cylindrical tube 10 and orient perforated tube arrays to adjust these parameters, as needed or desired. (See e.g., compare
By forming a more bluff body shape on the downstream side of the tube, users increase the turbulence downstream of the tube, eventually forming two vortices downstream of the two outer edges. By such methods, users change parameters to improve present value of total system costs including capital, assembly and operating costs.
8.11.1 Circular Tubes
In some common configurations, users use generally circular tubes to form distribution tubes to deliver first fluid, such as, fuel or thermal diluent. A circular tube shape provides more turbulent vortex mixing than tube streamlined shapes. (See, e.g.,
8.11.2 Streamlined Non-circular Tubes
In some embodiments, users reduce the pressure drop across the contactor tube array while increasing the surface heat transfer coefficient by configuring the contactor fluid tubes and manifolds to a non-circular shape with the narrower cross section facing into the fluid flow. This reduces the parasitic pressure drop, reducing the pumping work to move the second fluid across the distributed contactor, but it reduces vortex mixing.
Elliptical or Oval Tubes: As shown in
Symmetric Streamlined Aerodynamic Shape: As shown in
Flattened Tubes: Gases have substantially higher volume than liquids for the same mass. The necessary liquid flow cross-sectional area through the distribution tube 10 is often much smaller than that of the gas flowing across the tube. Consequently, in still further embodiments as shown in
Dual Channel Internally Bonded Flattened Tubes: A flattened tube 10 will expand given sufficient internal pressure. In some embodiments, as shown in
Single Channel Flattened Tube: In some embodiments as shown in
Asymmetric Aerodynamic Shape: In some embodiments as shown in
8.11.3 Anti-streamlined Bluff Tubes
In some embodiments, users form the tubes into less streamlined shapes to increase the inherent turbulent mixing downstream of the tubes as needed or desired.
Transverse Elliptical Tubes: In some embodiments (compare,
Hemispherical or Triangular Shapes: Users may use shapes that are somewhat streamlined upstream but bluff downstream in some embodiments to reduce pressure drop while creating flow separation with multiple vortices to improve mixing. E.g., as shown in
Cusped Bluff Tube: In some configurations, as shown in
8.12 Design Configuration
As users narrow and streamline the distributed tubes, users reduce the drag of the second fluid flowing across the tube arrays. Conversely this increases the capital cost of the tube arrays. Similarly as users increasing the tube-tube spacing H, users reduce the drag across the tube arrays. At the same time, users increase the length of the fluid duct and pressure vessel, as well as the pumping work to deliver the first fluid through micro-jets. These parameters will vary with the viscosity and thus the orifice size and temperature of both the injected first fluid and the transverse second fluid.
In some embodiments, users adjust the diameter, shape, spacing of tubes, the delivery velocity of fluids size of orifices, and differential delivery pressures to improve drop formation and/or micro-jet penetration and mixing of fluids while reducing the parasitic fluid pressure drop and fluid pumping losses, fluid filtration and associated costs.
8.13 Fluid Pressure Drop Ratios
With reference back to
For many embodiments, the corresponding primary control parameters are the pressure drop across the tube array relative to the differential ejection pressure drop across the contactor tube wall. The second fluid flow rate and pressure drop across the tube array is often held constant or varies relatively slowly in proportion to the pressure drop across the fluid duct 130 between the inlet 134 and outlet 136. Users generally primarily control the differential ejection pressure drop across the orifices of the respective distribution tubes to rapidly control the delivery of first fluid 901.
In some embodiments, users preferably form the perforated distribution tubes described above into various two or three dimensional arrays ranging from a circular (or elliptical) planar tube array 265 in a circular duct 144 as shown in
9.2 Tube Orientation to Duct Flow Tubes Perpendicular to the Duct or Flow Axis
With particular reference to
9.2.2 Tubes Parallel to the Duct or Flow Axis
As shown in
9.2.3 Tubes at an Angle to the Duct or Flow Axis
In some embodiments, users efficaciously orient the contactor tubes at some angle to the fluid duct and flow axis as needed or desired. This typically varies according to the two or three dimensional array configuration desired. For example, as shown in
Users preferably adjust the angle of the contactor tube 10 relative to the axis of the fluid duct 145 according to the relative degree of control over the axial fluid delivery distributions and profiles and the transverse fluid delivery distributions and profiles. These in turn affect the relative control over the transverse distributions and profiles compared to axial distributions and profiles of the respective fluid ratios.
9.3 Axial Profile Control
With continued reference to
9.4 Two Dimensional Tube Array Configurations
9.4.1 Elliptical/Circular/Spiral Arc Contactor Arrays
For elliptical or circular ducts, in some embodiments, users preferably form curvilinear sections 21 of perforated tubes into elliptical or circular arcs. For example, as shown
In other embodiments, users connect the contactor tubes to one radial manifold or sub-manifold. In modified embodiments, users further form a perforated tube into a single spiral and form a helical or pseudo circular contactor array. A spiral perforated tube is typically simple to form. As mentioned above, users preferably adjust the orifice diameter to compensate for the progressive pressure drop along the contactor tube from the manifold to the end of the contactor tube or to the center (e.g., outside to inside) resulting in more non-uniform micro-jet penetration or drop formation along the contactor tube.
9.4.2 Rectangular/Trapezoidal Contactor Arrays
With reference to
9.4.3 Annular Contactor Arrays
As shown in
9.5 Three Dimensional Spatial Arrays of Perforated Tubes With reference to
9.5.1 Conical Array of Helical Wound Tubes
With reference to
In a modified embodiment, shown in
9.5.2 Tent Shaped Tube Array
As shown in
9.5.3 Polygonal Pyramid:
In some embodiments users form a pyramid array of contactor tubes for rectangular ducts. Conceptually, users take the rectangular array formed from four triangular arrays of perforated tubes as described above and extend that array to three dimensional pyramid such as a trilateral pyramid or quadrilateral pyramid.
As with
9.5.4 Annular Tent Tube Array
Annular ducts are often encountered in industry. E.g., between a compressor and a gas turbine. These annular ducts are often divided into multiple annular duct sections. Accordingly, as shown in
As shown in
9.5.5 Cylindrical Tube Array or “Can” array
In yet other embodiments, as shown in
9.5.6 “Top Hat” Tube Array
In modified embodiments, as shown in
9.5.7 Bulbuous or “Dandelion” Tube Array
In some embodiments, as shown in
9.5.8 Extended Arrays Tube Arrays
For large fluid flows, in some embodiments, users preferably form larger extended arrays of perforated tubes by taking two or more of the two or three dimensional (“3-D”) contactor array structures described herein and arranging them into extended arrays of such array structures as desired or needed. Accordingly, users take tubular arrays with circular, hexagonal, Cartesian or similar footprints and replicate them in linear, circular, spatial arrays as desired or needed to fit into the corresponding fluid ducts or similar regions.
Similarly in various embodiments, users replicate sections of annular tube array to form part or all of an annular array. For circular or polygonal tube arrays are used that do not fill the desired fluid duct or spatial surface, users preferably provide blocking structures to fill the inter-array gaps and prevent fluid from flowing between the tube arrays without being desirably contacted by contactor tubes.
9.5.9 Array Opening Orientation
“Horn” Orientation: In some embodiments, as shown in
With Reference to
“Funnel” Array Orientation: In other embodiments, as shown in
9.6 Flow Direction Tube Offset
A planar tube array, such as the circular array 265 shown in
9.6.1 Offsetting Adjacent Tubes
For instance, in some configurations users offset adjacent contactor tubes 10 (See e.g.,
In other embodiments, users similarly offset tubes 10 to increase the gaps between the tubes. While there is still significant drag across the tubes, offsetting adjacent tubes significantly reduces the flow constriction and consequent pressure drop. (See, e.g.,
9.6.2 Conical Arrays
As shown in
Similarly, the flow area can be increased by increasing the cone angle to much greater than 180 degrees in the “funnel” configuration as shown in
9.6.3 Pleated Array
At the other extreme, in some embodiments, users may increase gap area between tubes by offsetting alternating tubes upstream and downstream in a zig zag pattern to form a pleated array. For example,
Similarly
9.6.4 Compound Arrays
In further embodiments, users combine and adapt these contactor array formations. For example, users use a conical tube array (See e.g., 68) in the center portion of the flow. They then take the pleated contactor array and form it into a circular pleated array to surround the conical tube array. (Compare
9.6.5 Tube Spacing
In various embodiments, users space the tubes across the flow at intervals as needed or desired. With reference to
Where users perforate the tube 10 about a portion of the circumference of the tube, the tube spacing H is preferably equal to about the total width of the perforated area about the circumference. For example, the tube spacing may be nominally configured about 175% of the tube diameter D, preferably in the range of about 101% to 500% of the tube diameter D. Similarly, users may set the gap G between the tubes at about 1% to 400% of the tube diameter D. E.g., users may configure the tube spacing H to about 7 mm. This in a gap between tubes G of about 3 mm in the above example for tubes with diameter D of about 4 mm.
9.7 Drilling Orifices
In some embodiments, users preferably use laser drilling technology with a high Thickness to Diameter (T/D) drilling ratio to create numerous small orifices in tube walls 30. E.g., using technology with about 100:1 thickness/diameter drilling capability with 200 μm thick walls nominally enables formation of about 2 μm diameter orifices using suitable wavelength lasers. Such orifice drilling desirably combines a structural tube wall 30 with numerous fine orifices 80. With reference to
With reference to
9.8 Drop Array Formation
Using such measures, users typically configure orifices to form micro-jets in a suitable array to desirably distribute droplets across the transverse flow. They similarly configure orifices along and/or about the tubes. In some embodiments, users direct orifices longitudinally relative to the cross flow. For example, configuring 10 μm orifices would nominally form droplets about 20 μm in diameter giving a specific surface area (surface area/volume) of about 2,500−1. Similarly a finer array of about 2 μm orifices, nominally forms about 4 μm droplets. Ignoring droplet coalescence, this would nominally create a specific surface area of about 125,000−1.
9.9 Manifolds
In various embodiments described above, users preferably connect multiple distribution tubes to one or more manifolds. For example, as shown in
9.9.1 Streamlined or “Thin” Manifolds
By flattening the manifold(s) transverse to the fluid duct 130, in some embodiments, users form a “thin” or streamlined manifold. This reduces the drag or pressure drop for second fluid 904 flowing across the manifold, similarly to flattening the distribution tubes 10. Users also desirably increase the bending strength of the manifold 240 crosswise to the flow 904.
9.9.2 Sub-Manifold
In some configurations, as shown in
9.9.3 Sub-Manifold Valves or Flow Modulators
With continued reference to
By these measures, users preferably control the first fluid flow 901 relative to the second fluid flow 904 over one or more flow sub-regions as selected by the configuration of sub-manifold valves 233 allowing fluid to flow through select combinations of sub-manifolds. They similarly preferably control the flow through those selected sub-manifolds by controlling the pressure flow modulators 370.
9.9.4 Sub-manifold Arrays
As will be apparent to one of skill in the art, in various configurations, users preferably connect contactor tubes to sub-manifolds and/or manifolds to achieve desired or needed groupings of orifices in a contactor array section relative to the flow of the second fluid through the contactor array section. They similarly configure the contactor array sections together with corresponding combinations of sub-manifold valves and/or pressure flow modulators. These arrays are variously configured in arithmetic, geometric arrays as desired to give the flexibility and turn-down ratio desired in the controls. Redundancy and/or degeneracy in these configurations is also provided in some configurations.
Arithmetic ratios: For example, users configure areas of contactor array sections in an arithmetic ratio of second fluid flow 904 through those sections. E.g., 1:1, 1:2, 1:3, 1:4, 1:5 etc. according to the respective turn-down ratios needed or desired.
Geometric ratios: Similarly, they configure contactor arrays in geometric ratios such as binary, 1:2:4, ternary 1:3:9, quaternary 1:4:16 etc.
Hybrid ratios: In other configurations, they configure arrays in combinations of such arrays or with degenerate combinations. E.g., such as 1:1:1, 1:1:2, 1:1:1:1, or 1:1:2:4.
9.9.5 Sub-manifold Tube Configurations
In configuring such contactor array sections, users preferably configure contactor tubes 10 in proportion to the desired contactor array sections areas. For example, preferably configure contactor tubes 10 in a radial or spoked configuration connected to sub-manifolds 254 configured along the inner and outer circumferences of the annular duct 146. They similarly configure tubes to sub-manifolds S1, S2 and S3 respectively in a repeated pattern: #1, #2, #1, #3, #1, #2, #1. (See, e.g.,
This configuration provides four tubes #1 to sub-manifold S1, interspersed with two tubes #2 connected to sub-manifold S2, interspersed with one tube#3 connected to sub-manifold S3. Where each of these radial contactor tubes 10 are of similar size and length, with about an equal number of orifices, users obtain orifices in the proportion of about 4:2:1. These deliver flows of first fluid 901 in proportion to flows of second fluid 904 by array sections.
9.9.6 Varying Internal Manifold Cross-sectional Area
In some embodiments, manifolds 240 are varied in cross-sectional area with distance to compensate for the fluid delivered to the perforated tubes 10. The manifold's internal cross-sectional area preferably varies proportional to the remaining first fluid flow rate as the distance along the manifold. E.g., as distance along a radius, an edge, or similar parameter.
9.10 Contactor Tube and Fluid Delivery Profiles
To provide desired flexibility on fluid delivery, users preferably control transverse or axial distributions and profiles of one or more parameters along the tube contactors or contactor arrays in some embodiments.
9.10.1 Orifice Size & Jet Penetration Distance
In some configurations, users adjust the orifice size and differential ejection pressure across the tube wall to achieve desired micro-jet penetration distances. For example, as shown in
9.10.2 Orifice Spacing Profile
In some configurations users preferably configure the transverse distribution of the spacing of the orifices 80 along one or both transverse directions and/or axial directions, to provide a spatial orifice density to achieve a desired orifice area distribution and profile along that transverse or axial direction.
9.10.3 Spatial Area Density Profile
In some embodiments, users combine one or more features of changing orifice size, orifice spacing, and tube spacing to achieve a desired spatial area density of orifices 80 delivering the first fluid 901 along one or more directions transverse to the fluid duct 130 and the second fluid flow direction 904.
9.10.4 Spatial Fluid Delivery Profiles
Users combine the prescribed spatial area density distributions and profiles with controlling the differential fluid pressure distribution across the tube walls to provide a desired first fluid delivery distribution in some configurations. For example, to accommodate varying transverse profiles of axial velocity in the second fluid 904, users combine the profiles of orifice size, orifice spacing, tube gap and differential ejection pressure to achieve a desired first fluid delivery distribution relative to the transverse flow distributions of the second fluid 904 and one or more of the first and second transverse directions and the axial direction.
9.11 Tube Ribs or Stiffening Supports
Flow of the second fluid 904 over the perforated distribution tubes 10 causes turbulence, pressure drops and a flow drag force in the direction of the second flow or fluid duct 130. Contactor tubes 10 oriented transverse to the flow of the second fluid 904 are also subject to bending forces by the flow drag. Accordingly, as shown in
9.11.1 Structural Supports
In some embodiments, as shown in
9.12 Tube Surface
9.12.2 Tube Surface Energy
With reference back to
9.12.3 Tube Surface Roughness
In some embodiments, users preferably create very small scale roughness or texture on the exterior of the tube 10 about and downstream of the orifices 80. This helps repel drops and prevent a liquid 901 from wetting the tube outer surface and so assist in drop formation and avoid “wetting” or dribbling” down the outer surface of the contactor tube 10.
10.3 Smaller Orifices
As shown in
10.3.1 Laser Drilling for Smaller Orifices
Various techniques may be used to create the small orifices describe above. For example, users may use several different technologies to create orifices, such as laser drilling, photo-lithographic etching, x-ray lithographic etching, among others. Users preferably select the laser power, frequency and optics according to the orifice diameter and uniformity required. Common CO2 lasers can achieve about 20 μm diameter orifices. To achieve smaller diameters, users sometimes utilize lasers with smaller wavelengths (higher frequencies.) Eximer lasers can drill orifices of about 1 μm to about 2 μm in diameter with Thickness to Diameter ratios (t/d) of up to 100 or even 200. E.g., in ink jet orifice arrays. Ultraviolet lasers can achieve sub micrometer orifice sizes.
Users may also utilize other drilling methods. For example, friction drilling, mechanical punching, electro drilling. Users typically use these for larger orifices such as forming orifices in manifold ducts where tubes are connected.
10.3.2 Tube Wall Thickness vs Tube Diameter
Table 3 shows an exemplary embodiment of the variation in the thickness of the tube wall 30 as a function of tube wall thickness to diameter ratios for a range of tube diameters from 1 mm to 16 mm.
10.3.3 Wall Thickness to Orifice Diameter Ratio
Laser drilling can typically achieve a given Wall Thickness (“depth” or orifice “length”) to Orifice Diameter ratios (t/d). E.g., Common laser drilling technology can achieve Wall Thickness/Orifice Diameter ratios of 10:1. Some technologies can achieve Wall Thickness/Orifice Diameter ratios of 100:1 to 200:1 with Eximer lasers, depending on wavelength. With laser drilling, the orifice size is thus limited to the thickness of the sheet drilled, divided by the Wall Thickness/Orifice Diameter (t/d) ratio for a given wavelength. e.g., about 20 μm to 1 μm diameter holes in a 200 μm wall for Wall Thickness/Orifice Diameter ratios of 0:1 to 200:1.
Table 4 shows embodiments of the consequent orifice diameters for various thicknesses of the tube wall 30 as a function of wall thickness to orifice diameter ratio of the drilling technology used.
10.3.4 Many Orifices
As mentioned above, some embodiments of the invention form direct contactors 10 using a few to tens to hundreds of orifices 80 per mm of tube length. E.g., selecting about 80 orifices per mm typically of 50 μm in diameter, with 3 meters of thin walled tube would provide about 3,000 orifices. Similarly, by making about 20 μm orifices 80 every 60 μm along a thin walled tube, users create about 17 orifices/mm tube length. By wrapping about 3 meters (m) of such thin walled perforated tubing into a direct contactor perforated tube array 260, users provide up to about 50,000 orifices distributed across the flow. E.g as shown in
These methods provide far greater number of nozzles than conventional systems which provide just a few nozzles with one or a few orifices per nozzle. E.g., a large bore Diesel engine may use three nozzles each with six orifices, forming a total of 18 orifices.
10.4 Thin Wall Perforated Tubes
Conventional Diesel injectors may use 10 micrometer (μm) to 60 micrometer (μm) diameter orifices with high pressure heavy walled tubing. By preferably using many smaller orifices users significantly reduce the injection pressure and pumping work to create numerous small drops or droplets while significantly improving the spatial control over transverse distribution of flows and flow rate profiles in the first and second transverse and axial directions. Modified configurations could also use many conventional nozzles or injectors distributed across the flow, though at higher expense and without as precise control over spacing.
10.4.1 Thin Walled Tubes
Thin-walled tubes with diameter to wall thickness ratios (D/t) of 8 to 10 are available (e.g., with 760 μm or 0.030″ OD, and 500 μm or 0.020″ ID). Users nominally consider “thin wall tubes” as having wall thicknesses of 1,000 micrometer (μm) to 200 μm.
Users preferably use such thin wall tubing to make 100 micrometer (μm(to 20 μm diameter orifices (0.004″ to 0.000,8″ diameter orifices) directly in the thin tube wall 30 using an orifice forming technology such as laser drilling. Users preferably use technologies which can form orifices with a 10:1 Wall Thickness/Orifice Diameter (t/d) ratio and more preferably with a thickness/diameter ratio (t/d) of 100:1 to 200:1. With such orifices 80, users advantageously form simple drops with diameters in the range from about 200 (μm) to 40 μm with low differential positive pressures and flows. With such thin walls, users can further reduce the orifice sizes down to a range of about 10 micrometer (μm) to 2 μm by using laser drilling technology capable of Wall Thickness to Orifice Diameter (t/d) ratios of 100:1 etc.
Of course, as the skilled artisan will appreciate, other suitable nominal thicknesses for the thin wall tubes may be efficaciously utilized, as needed or desired, giving due consideration to the goals of achieving one or more of the benefits and advantages as taught or suggested herein.
10.4.2 Ultra-Thin Wall Perforated Tubes
For still smaller orifices, in some embodiments such as with low differential ejection pressures, users select thinner walled tubing or use orifice forming technologies capable of higher Thickness/Diameter (t/d) ratios. Ultra-thin walled tubes are commonly available with wall thicknesses from about 200 micrometer (μm) down to about 125 μm (about 0.008″ to 0.005″) or even to about 75 μm (about 0.003″). With such ultra-thin walled tubing, users readily form orifices with diameters down to about 20 micrometer (μm) to 8 μm using laser hole drilling technology capable of Thickness/Diameter ratios of 10:1. With 100:1 laser drilling technology using short wavelength (high frequency) lasers, users could potentially form orifices of 2 micrometer (μm) to 0.8 μm in diameter with such ultra-thin wall tubing.
10.5 Thinning Walls for Smaller Orifices in Thin Walled Tubes
The size of holes formed in tubing is nominally limited by the thickness of the tubing and the Length/Diameter capabilities of the hole forming method. As shown in
10.5.1 Grind Arcs on Tubing
To form thinner walls, in some embodiments as shown in
CNC Industries of Fort Wayne ind. USA, and Alpha Technologie company of Thyez France, are two companies for example specializing in precision surface grinding. They claim to nominally hold the surface tolerance to 2.5 micrometers (0.0001″) with precision grinding. This is about 10% of the desired final wall thickness.
10.5.2 Forming Thin Sheet into Thin Walled Tubing
To further improve on the uniformity of forming thin walled tubing, in another embodiment as shown in
10.5.3 Drilling Holes in Thin Walls
In configurations using an ultra thin wall thickness of about 25 micrometers, users can drill holes of about 2.5 μm to 0.25 μm, using a drilling technology with a thickness/diameter ratios of about 10:1 to 100:1. Thus, the hole diameter achievable is of the order of the precision of the thickness of the thin wall 32. e.g., forming foils or surface grinding tolerance. Users may drill multiple holes 80 transversely around the perimeter of the tube 10 in this thin wall section 32. Users may then replicate such linear arrays along the length of the tube, or vice versa.
10.5.4 Multiple Arcs or Flats Around Tubing
As shown in
10.6 Micro-Orifices in Compound Thin Walled Perforated Tubes
With reference now to
Practical ultra-thin wall tube systems may require structural support to withstand the bending forces of the external second fluid flow across the tube as well as to handle forces due to gravity and vibration. To support these bending forces, in some embodiments users take a thicker upstream tube stiffener portion 36 formed from strips thick enough to provide structural support. Users make the small orifices through one or more thin perforated strips and form them into the downstream portion of the tube 36.
Users preferably form an ultra-thin walled compound perforated tube by bonding the downstream thin tube wall 33 to the upstream structural tube portion 36. E.g users bond thin strips 32, of about 500 micrometer (μm) to 50 μm thick, onto thicker tube structural support wall sections 36, either within or without the upstream support. With this construction method, users advantageously create compound contactor tubes 10 with effectively larger tube diameter/wall thickness ratio.
10.6.1 Forming Small Orifices in Thin Sheets or Foils
With a range of Thickness/Diameter orifice forming technologies and thin sheet or foil thicknesses available, users variously achieve orifice diameters of about 25 micrometer (μm) down to sub-micron sizes for a range of sheet thickness from about 1000 micrometer (μm) to 1 μm. (Smaller orifices can be formed with deep ultra-violet, electron or x-ray forming technologies as these technologies progress.) Assuming pendant drops are formed with sizes twice the orifice diameter, users nominally form uniform drops from about 50 micrometer (μm) to 0.5 μm in diameter from an array of orifices of substantially uniform size.
10.6.2 Compound Foil-Walled Perforated Tubes
In further embodiments, users form ultra-thin walled compound tubes using even thinner sheets or “foil” to create thin walls 32 with still smaller orifices. e.g., walls less than about 50 m thick. Stainless steel structural foils are available at least in about 30 micrometer (μm), 25 μm, and 20 μm thin sheets. E.g., Metal Foils, LLC provides stainless steel foils from 250 micrometer (μm) down to 25 μm (0.010″ down to 0.001″). Emitec Inc. of Auburn Hills, Mich., and Lohmar in Germany, manufacturer heat exchangers using foils of such thicknesses which they purchase from at least three reliable manufacturers.
Given the thinnest acceptable thin wall (e.g., metal foil thickness), users preferably divide by the Wall Thickness/Orifice Diameter ratio of the drilling technology used to arrive at the orifice diameter. (e.g., divide wall thickness by 10 for common laser drilling technologies.) To achieve smaller orifices, users can select shorter wavelength (higher frequency) lasers and/or use lasers capable of higher Wall Thickness/Orifice Diameter ratios as needed or desired. (Some companies claim Wall Thickness/Orifice Diameter ratios of 100 or higher for eximer laser drilling etc.) Thus, users can laser drill about 2 m to 0.2 μm diameter orifices through 20 μm thick stainless steel foil. (Conversely, given a desired orifice diameter and the Wall Thickness/Orifice Diameter limit of a drilling technique, users can calculate the desired thickness of the thin tube wall 32 e.g., sheet or foil.)
In modified configurations users utilize even thinner foils. E.g., ACF Metals of Tucson Ariz. makes ultra-thin metal foils with thicknesses of about 5 micrometers (μm) down to about 1 nanometer (nm).
10.7 Two Section Compound Perforated Tube Cut Structural Strip
With reference back to
10.7.2 Thin Wall Strip
In other embodiments, the downstream thin wall portion 32 is formed by cutting a thin strip 32 from thin sheet material or foil. For example, users select the stainless steel foil with thin commercially available thickness, preferably about the desired diameter of the orifices times the length/diameter ratio of the hole forming method. E.g., about 20 to 30 μm (about 0.02 mm to about 0.03 mm) thick to prepare small holes about 2 μm to 3 μm in diameter, using a laser capable of drilling holes with a 10:1 length/diameter ratio.
10.7.3 Thin Foil Downstream Perforated Wall Section
Wrapped downstream portion: In still other embodiments, the ultra-thin sheet is cut into a strip about equal to the circumference of the desired tube. This is formed into the desired shape and wrapped around the upper structural tube portion to form the thin tube wall.
Part downstream portion: As shown in
10.7.4 Indented Attachment Edges
In some modified embodiments, as shown in
10.8 Perforate Thin Strip or Foil
In various embodiments, the thin wall 32 (strip or foil strip) is perforated with a pattern of fine holes 80 in one or two dimensional arrays or patterns as desired.
Laser drilling: The preferred method of forming orifices 80 is to use lasers to drill fine orifices proportional to the thickness of the material limited by the length/diameter capability of the laser. E.g., the Department of Defense sought a Small Business Innovative Research (SBIR) project #AF02-003 to drill large numbers of 170 μm holes with very high precision. High power lasers evaporate material rapidly, leaving clean uniform holes. Shorter wavelength higher frequency lasers may be used to drill smaller holes. E.g., Ultra-violet lasers can prepare holes down to micrometer or sub-micrometer capability.
Mechanical punch: In other embodiments, users may form linear or spatial arrays of micro-punches to press holes 80 through thin foils.
Electro drill: In further embodiments, users may form holes 80 using an electrode type removal process.
Resist Etch: In some embodiments, users may form holes 80 using a photo-etch method with a resist, similar to methods of forming circuit boards.
Form Longitudinal perforated array: In various embodiments, users preferably form an array of orifices 80 longitudinally along the thin wall 32. In other embodiments, users may form two parallel arrays, leaving a solid section in the middle and on either edge. The width of the array is preferably about 1.0 to about 1.5 times the diameter of the tube.
As an example, in some embodiments, users form two parallel arrays about 3.5 mm wide on either side of a solid center band about 1.5 mm wide, leaving a solid strip on either edge of about 0.75 mm wide to which to bond the foil to the tube. This results in perforating about 7 mm of a foil strip of about 10 mm width.
10.8.1 Bond Perforated Downstream Portion to Structural Portion
In various embodiments, users preferably wrap the lower perforated tube portion 32 around the upper structural portion 36 as shown in
In other embodiments, users form the downstream portion 32 and position it to overlap the upper structural portion 36. Where indents 256 are formed, the edges of the lower thin side wall section 32 are preferably positioned into the indents 256 in the upper portion.
Both edges of the perforated downstream half tube are bonded to the supporting half tube support 36. E.g., by induction welding, friction welding, brazing, soldering or gluing according to the temperature and strength required.
10.9 Supported Compound Foil-Wall Perforated Tubes
Thin walls 32 limit the differential ejection pressure that a perforated wall can support. The thinner the tube wall 32 (or foil), the lower the differential ejection pressure or span that the tube can typically tolerate.
As shown in
In alternative embodiments, users form thin perforated wall or foil around the large holed structural support 202. They then bond the thin wall 32 to the supporting large holed perforated tube 202.
10.10 Centrally Stiffened Compound Perforated Tube
Thin perforated foil (e.g., about 20 micrometer (μm) to about 30 μm thick) is relatively weak and deformable. As shown in
10.10.1 Attach Central Stiffening Strip
With reference to
10.10.2 Form Support Tube into Upstream Streamlined Shape
As shown in
10.10.3 Form Stiffened Perforated Foil into Downstream Streamlined Shape
In other embodiments, users form the stiffened perforated foil wall strip 33 into a desired downstream streamlined shape as shown in
10.10.4 Fit Perforated Foil Tube to Structural Support Half Tube
To assemble the embodiment illustrated in
10.10.5 Bond Foil to Tube
With continued reference to
10.11 Transversely Stiffened Compound Tube
In some embodiments, users form a compound perforated tube 200 from a thin wall section 32 over structural support 202 formed from components. E.g., they form the support 202 using periodic curvilinear circumferential tube structural supports 38 between the upstream tube support 36 and the downstream stiffener 36 to which the thin perforated walls 32 are attached. Large openings in the structural support 202 may be variously formed as circles, slots, rectangular holes and other openings.
10.11.1 Assemble Skeleton Tube from Components
As shown in
10.11.2 Attach Perforated Foil(s)
As shown in
10.12 Forming Curved Perforated Tubes
When tubes are bent into a curve, there is a danger of flattening or crinkling the tube side walls 33. Users may use relevant art bending methods, such as filling the tube with a liquid and then cool the liquid to a solid. E.g., with beeswax, a hydrocarbon with a high melting point, or with a fusible metal (preferably gallium, historically lead). After the tube is bent into shape, the tube is heated and evacuated to remove the forming solid.
10.12.1 Forming Curved Compound Tube Sections
It should be appreciated that the compound tubes described above may be formed into arcs, helices or other non-linear curves and formed into the various arrays described above (See e.g.,
10.12.2 Assembling Curved Tube Sections
The upstream tube portion 36, and downstream tube portion 36 are then assembled and bonded together into or near the desired final shape. This method significantly reduces the likelihood that the thin perforated walls 32 will tear or wrinkle compared to the damage that could happen if linear compound tubes 200 are assembled and then formed into an arc, helix or other non-linear curve.
10.13 Skeleton Compound Tube Formation
In some embodiments, as shown in
10.13.1 Remove Gaps Between Stiffener Arcs
With continued reference to
10.13.2 Herringbone Compound Perforated Tube Assembly
In modified embodiments users attach circumferential tube support sections 38 approximately perpendicular to the central tube stiffener 36 on the perforated thin tube wall 32 (sheet or foil) like a covered herringbone. The stiffened perforated thin wall 32 is then formed into the desired cross-sectional shape (e.g., streamlined or bluff). This downstream stiffened perforated wall section is then bonded to the upper support tube section 36.
10.14 Compound Wire Tubes
As shown in
10.14.1 Modified Wire Sizes and Shape
As shown in
Conversely, such configurations may be used to increase turbulence by orienting the bluff side of the contactor 10 or 200 towards the flow (i.e. the longer axis perpendicular to the flow.) As shown in
10.14.2 Thin Strip Assembly
In another embodiment illustrated in
In some configurations, the strip(s) 32 are preferably perforated after assembly of the compound tube 200 to facilitate assembly. These methods commonly form outwardly increasing orifices. (See, e.g.,
In some embodiments, the thin wall strip(s) 32 are formed into a desired curve prior to assembling and bonding them to the support wires 36. Alternatively, in some assembly methods, the wall strip(s) 32 are assembled flat and the fluid within the compound tubes 200 is pressurized to a desired forming or proof pressure to curve the strips.
In some embodiments, the stiffening wires 36 are moderately flattened to improve bending stiffness and provide a greater surface to bond to the thin strip, though circular wires may be used. In other embodiments, trapezoidal shaped wires may be used to improve bonding while still providing some streamlining. In modified embodiments, the upstream or downstream end of the supporting wire 36 may similarly be formed to improve streamlining. Similarly, in some embodiments the edges of the thin strips 32 may be cut at an angle, thinned, beveled, pressed, ground or otherwise smoothed to improve aerodynamics.
10.14.3 Polygonal Wired Tubes
In embodiments utilizing triangular or other polygonal shaped contactor tubes 10, this method may be used to provide a wire support at each vertex of the polygonal tube.
10.15 Alternative Assembly of Compound Perforated Tube
After forming the structural strip and the stiffened perforated foil as described above, the following modified or other techniques or steps are used in some embodiments. (See, for example,
10.15.1 Attach Perforated Foil to Structural Strip
Overlap and align one edge of the perforated foil over the indented edge of the structural strip. Users preferably reduce hole blockage and facilitate cleaning by using the “horn” configuration. I.e. by orienting the smaller hole diameter inward with the hole size increasing outward (as discussed above and illustrated in
10.15.2 Form Stiffened Perforated Foil into Downstream Streamlined Shape
Both sides of the compound strip are bent up about the tube-foil joint and formed into the desired streamlined shape. This will be similar to an elliptical shape but with a wider shorter upstream width and longer narrower downstream section similar to aircraft strut faring.
10.15.3 Align Perforated Foil to Structural Strip
The free edge of the formed perforated strip is aligned to the indent in the formed structural strip.
10.15.4 Attach Outer Foil Edge to Strip Edge
The perforated foil edge is attached or bonded to the structural strip edge to complete the streamlined compound perforated tube.
10.16 Alternative Elliptical Tube Construction
With reference to FIGS. 43 and
10.16.1 Form Elliptical Tube
A stainless steel tubing of diameter D is pressed into an approximately elliptical shape. E.g., a tube with about a 4 mm outer diameter is selected with wall thickness about in the range 0.20 mm to 1.0 mm. This will have a circumference of πD of about 12.6 mm with a half circumference of about 6.3 mm.
10.16.2 Cut into Half Elliptical Tube
This elliptical tube is then cut in half along the short axis (normal to and half way along the long axis). E.g., using an abrasive water jet or a power laser. In other embodiments the tube is machined about in half to remove one half along this line.
10.16.3 Form Elliptical Foil
The thin perforated stainless steel foil is then formed approximately into the shape of half an ellipse with the ends forming the short axis of the ellipse. (In modified embodiments the tube is formed into a similar parabolic shape). This downstream tube section is formed slightly wider than the net width of the supporting upstream half tube.
10.16.4 Prepare Attachment Indent
A thin indent is then ground a little greater than the thickness of the perforated foil on each outer side of the half tube e.g., about 25 to 35 micrometers. This is extended a little greater than the desired attachment width of the foil. E.g., about 0.6 mm to about 1.1 mm up both outer edges of the tube.
10.16.5 Fit Foil to Tube
The perforated foil half ellipse is fitted up over the half ellipse supporting tube to form an approximate ellipse.
10.16.6 Bond Foil to Tube
The thin foil half tube is then bonded to the supporting half tube. E.g., by induction welding, friction welding, brazing, soldering or gluing among other methods, according to the temperature and strength required.
10.17 Hybrid Compound Tubes
Users may combine the various embodiments and assembly methods described herein.
10.17.1 Compound Tubes from Ground Strips
In some embodiments, users may take a tube wall strip 30 and grid a thin wall section 32 along a portion of the strip. The thin strip section 32 is preferably perforated and then the strip 30 is assembled to form compound perforated tubes by the methods described herein. This method provides benefits of achieving more uniform thinned strip thickness. Correspondingly this results in more precisely sized orifices or uniform orifices being formed by the laser drilling or other orifice forming technology. Alternatively, the thin sheet ground walls 32 may be perforated after assembling the tube.
10.17.2 Wire Tubes from Ground Strips
With reference to
10.18 Combination Thinning & Drilling
With continued reference to
10.19 Other Configurations
Of course, as the skilled artisan will appreciate, other suitable nominal thicknesses and shapes may be efficaciously provided for the upstream and downstream structural components 36, 38 (or “wires”) used to form the compound perforated tubes. Similarly, as the skilled artisan will recognize, a variety of curved, curvilinear, angular or flat strips 32 may be used to form the side walls 33 of the compound perforated tubes 200. Various combinations of the thinning and/or forming holes may similarly be used, as desired or needed. Furthermore, orifices 80 may be positioned in a variety of locations and orientations about a thin-walled tube 8 or compound perforated tube 200 depending on the pressure drop and degree of mixing desired or needed.
11.2 Fluid Filters
Further referring to
Besides filtration, water treatment such as by mixed-bed demineralizers may be required. Other types of treatment such as reverse osmosis and other types of demineralizers can be used where the chemistry is suitable. These treatment methods can remove any chemicals that are incompatible with the components into which it will be injected, e.g., turbine hot path.
11.2.1 Coarse Fluid Filter
For example, in the illustrated embodiment in
11.2.2 Fine Fluid Filter
In the exemplary embodiment, users further preferably follow the initial filter 380 with finer filter(s) 380 capable of filtering off smaller particulates, preferably capable of filtering particulates smaller than the diameter d of orifices 80. This provides an inexpensive means to protect the orifices and any subsequent filters. E.g., fine filters appropriately configured to filter the first fluid. Media filters (e.g., sand, anthracite) may also be used to filter particulates out down to around 10 microns.
11.2.3 Maximum Orifice Fluid Filters
With continued reference to
Users preferably form this maximum orifice fine filter 386 using a filter membrane or sheet with a large number of accurately controlled uniformly sized orifices. This can be formed by suitable hole drilling technology, e.g., laser orifice drilling or photo etching similar to making the tube orifices. Users preferably configure large numbers of uniform orifices in large thin flat sheets to achieve a low pressure drop across the filter sheet. The number of orifices and net orifice area in this filter sheet are preferably in the range of 1.1 to 200 times that of the orifices in the direct contactor array 260. More preferably these are in the range of 5 to 50 times, to reduce the total costs of filtration and the filtration pumping costs.
In some embodiments, users then preferably support the sheet with a porous backing that permits the liquid to flow through while supporting the filter membrane. These uniform orifice filter sheets may be variously configured into maximum orifice filters 386. These may be configured like plate heat exchangers or wrapped into spiral formats similar to reverse osmosis filters.
11.2.4 Recirculating “Bypass” Filter(s)
With continued reference to
11.2.5 First Fluid Delivery System: e.g., Liquid Pump
With further reference to
Conventional horizontal centrifugal or vertical turbine type pumps are readily available in the flow and pressure range required and can be used as one or more pumps 364 where appropriate. Where the pressure or flow control or both is needed, flow control valves on the pump discharge may be used. In some embodiments, users preferably use a continuous positive displacement pump that creates very low pressure fluctuations for the pump 364 to improve fluid delivery performance. (E.g., Kraütler GmbH & Co. of Lustenau, Austria makes precision continuous positive displacement equipment (“KRAL”) that can be used as a pump or as a flow meter.)
Two pumps are preferred. The first is a low developed head pump. It takes suction from the source of the recycled water (a tank or other vessel) and pumps the water through the filter(s), water treatment equipment, and heat recovery equipment etc. to the suction of the second pump. The piping, pump, and equipment from the water source through to the second pump, are of low pressure rating and hence low cost. The second pump preferably has a high developed head (e.g., 165 bar) to produce the pressure needed at the first fluid orifices and associated intermediate heat recovery components as needed. The piping and equipment downstream of the second pump are of high pressure ratings. Piping is kept as short as possible to minimize the cost of the heavier piping and to minimize pressure losses in the pipe.
11.2.6 Pump Pressure Fluctuation Dampers
With reference to
11.2.7 Fluid Flow Transducer
As shown in
11.2.8 Further Fluid Treatment
In some configurations, users provide further fluid treatment beyond filtration as desired or required by system components. E.g., water treatment such as by mixed-bed deimineralizers may be provided. Other types of treatment such as reverse osmosis and other types of demineralizers can be used to achieve desirable composition and fluid purity as appropriate. Such fluid treatment removes chemicals that are incompatible with the components into which the fluid will be injected, e.g., turbine hot path.
11.3 Second Fluid Delivery System
In many embodiments, the second fluid 904 delivered is commonly a gas. (In other embodiments these methods may apply to delivering a first fluid into a second liquid.) Accordingly, in such systems as shown in
11.3.1 Blower(s)
As shown in
11.3.2 Compressor(s)
In energy conversion systems, with reference to
In some power embodiments, turbomachinery is commonly used to compress the gaseous fluid 904, e.g., using centrifugal or axial compressors. These are preferably for applications operating at high duty levels over relatively narrow speed and flow ranges.
11.3.3 Moving Cavity Compressors
As shown in
11.3.4 Natural Draft Device
In other embodiments users may configure the second delivery system 400 to provide the motive power to deliver and move this second fluid 904 through the fluid contactor 10 by use of device or system that generates a natural draft such as a stack, chimney or flare.
11.4 Fluid Delivery System Control
With reference to
In various embodiments, pumps, blowers and/or compressors 407 are variously driven by work engines, synchronous or asynchronous motors with fairly constant or varying speed. Where the pressure or flow control or both is needed, flow control valves on the pump discharge may be used. Variations in drive speed, atmospheric pressure and/or humidity cause small but significant differences in composition and/or the pressure and/or temperature to which the second fluid is compressed. In various embodiments, users preferably improve control over the compressor speed to improve control of the pressure, flow rate and/or temperature of the second fluid supplied to the fluid contactor.
11.4.1 Variable Speed Drive
In some embodiments, users preferably drive the fluid supply system by a electrical, mechanical, hydraulic or pneumatic variable speed drive and/or the pump stroke. Users preferably provide a synchronous motor and use variable frequency drive and control system to reduce the variation in drive speed with variations in pressure differential between atmospheric pressure and the pump head or pressure supplied. Electronic speed control with induction motors may similarly be used. In other embodiments users provide an asynchronous motor or work engine such as a gas turbine or an internal combustion engine.
Alternatively, standard pumps with flow control valves may be used where more economical than variable speed drives. Flow sensors such as venturies, nozzles, or orifice plates with differential pressure transducers would be used with single loop or other types of controllers to vary the flow according to demand, automatically or manually.
11.4.2 Drive Speed Transducer
Users preferably provide a speed meter 580 as shown in
High resolution speed meters 580 such as rotary encoders are available. E.g., optical encoders with 10,000 optical pulses per revolution are preferably used. Electronic conditioners are available to multiply that pulse rate 2 times to 20 times. In some embodiments, users preferably use such rotary encoders 580 to provide about 200,000 pulses per revolution for design speeds of about 20 Hz (1200 RPM). They preferably utilize dithering electronics to reduce errors due to vibration. (e.g., (E.g., such equipment is provided by BEI Electronics with a 10,000 pulse per revolution encoder and a 20×pulse multiplier). Such pulse resolution is reduced as needed to accommodate the desired design rotational speed. E.g., for 4 MHz electronics with 100 Hz pump speed (6,000 RPM), users preferably keep the electronic frequency to about 40,000 pulses/revolution such as by using 10,000 pulses/revolution with a four times electronic multiplier.
Similarly, users preferably provide a high resolution speed meter 580 for one or more compressors 407 to assist in monitoring the flow rate of the second fluid 904 (e.g., the oxidant fluid). They preferably add a differential pressure sensor monitor across the second fluid compressor(s) and the first fluid pump(s) between the fluid intake and fluid delivery ports, and an absolute pressure intake sensor, or equivalently two absolute pressure sensors. Corresponding temperature sensors are also provided. These assist in precisely controlling the delivery fluid flow rates.
11.4.3 Drive Controller
As shown in
11.5 Selective Orifice Fluid Control via Intra-Tube Fluid Pulsation
In some applications desiring low flows with low differential ejection pressures, users control the differential orifice pressure across the tube wall 30 to selectively control when the first fluid 901 is delivered and through which orifices 80. Such control is selectively combined at the low end of flow control to improve the turn down ratio and range of flow control in some embodiments.
11.5.1 Minimum Orifice Differential Fluid Pressure to Overcome Surface Energy
With small orifices, surface tension becomes a significant factor in determining drop (or bubble) formation out of orifices 80. A differential ejection pressure (or acceleration) is typically needed to form liquid drops or micro-jets (in a gas or liquid) or conversely gas bubbles in a liquid, due to increasing the interfacial surface energy (“surface tension”). The higher the interfacial curvature (the smaller the orifice diameter), the greater the differential ejection pressure needed to form the interfacial surface energy. When orifices vary in diameter, there is a Minimum Orifice Differential ejection pressure needed to expel liquid from the largest holes 80. This will typically be insufficient to expel fluid from smaller orifices 80.
Accordingly, as shown in
11.5.2 Partial Orifice Differential Fluid Pressure
In other embodiments, as shown in
11.5.3 All Orifice Differential Fluid Pressure
When orifices 80 differ in size about the distribution tubes 10, then to create drops or micro-jets (or bubbles) users preferably control the differential ejection pressures or accelerations applied across the orifices 80 (or tube wall 30) between the fluid 901 within the tubes 10 and the surrounding fluid 904 to selectively create drops or micro-jets (or bubbles) from differing sized orifices 80. As shown in
11.5.4 Control by Graded Differential Ejection Pressure
In other embodiments, users form orifices 80 with a small but generally uniform gradient in size e.g., large at the center to smaller at the periphery. (See, e.g.,
11.5.5 Control by Pressure with Discrete Orifice Sizes
In some embodiments, users form orifices 80 of varying size for contactor tubes 10 bent to different radii, arcs or helices. As shown in
11.5.6 Control by Digital Fluid Pulsation
With fairly uniform orifices, in some embodiments, users use a differential ejection pressure pulse as a pressure “switch” to form one or more drops or micro-jets of a first fluid 901 out of each of a prescribed range of orifices 80 as shown in
11.5.7 Control by Frequency Modulation
By varying the frequency of fluid pulses of a given magnitude to the fluid 901 within the contactor tubes 10, in some embodiments as shown in
In another variation users provide pulse width modulation (PWM) control of the differential ejection pressure and thus of the delivery of the first fluid through the orifices, as shown in
11.5.8 Control by Amplitude Modulation
By varying the amplitude of the differential ejection pressure across the contactor tubes 10, in some embodiments users create a form of amplitude modulation. With intermediate differential fluid pressures, the higher the pressure the more orifices 80 emit liquid. As shown in
Users further vary the width of pressure pulses to provide some degree of amplitude modulation because of fluid inertia and the time it takes to accelerate and expel liquid through the orifices 80 in some configurations. I.e. using pulse width modulation (PWM).
11.5.9 Higher Pressure Jet Control
By increasing the differential ejection pressure across the tube wall 30 above that required to form fluid drops or micro-jets, in some embodiments as shown in
11.5.10 Maximum Operating Design Pressure
The strength of the thin wall strip or foil, orifice fraction and wall curvature, will have effect on the limit of the usable differential ejection pressure across the perforated wall. Accordingly, in some embodiments, users generally limit the upper differential ejection pressure within suitable safety factors of the maximum burst pressure, accounting for long term cyclic fatigue of the contactor tube 10 or compound contactor tube 200. (See, for example,
11.5.11 Pressure Difference in Compound Perforated Tubes
With compound tubes, the thin walls will be the limiting factor on the pressure difference across the tube walls. However, much of the bending strength is preferably taken up by the structural tube portion. For thin perforated walls users preferably provide reinforcing supports outside of the thin perforated walls. This transfers much of the internal fluid load to the reinforcing supports.
Users preferably conduct a full finite element analysis to adjust the dimensions for the required flow and pressure differences. In other embodiments, other suitable modeling and/or computation techniques empirical or semi-empirical studies and/or correlations, and the like may be efficaciously utilized to adjust dimensions, as need or desired.
11.6 Control by Spatial Phase Modulation
In some configurations, users configure orifices 80 with periodic spacing along a contactor tube 10. Where orifices are configured circumferentially around the tube, users preferably configure such orifices in a columnar arc around the contactor tube 10. Users further provide high frequency mechanical excitation to the first fluid 901 near the juncture of the tube to the manifold 240 or sub-manifold 254. (e.g., ultrasonic or acoustic.) They form a standing wave in the fluid within the contactor tubes 10. They preferably control the orifice spacing and the frequency of the mechanical excitation such that the orifice spacing H is equal to the wavelength of the fluid within the contactor tube 10, or some multiple of it.
Users then preferably control the relative phase of the excited standing wave in the first fluid 901 within the contactor tube 10. For maximum ejection, users adjust the phase of the standing wave is such that the fluid anti-node approximately matches the orifice locations. This causes the differential ejection pressure to be at a maximum at the orifice and a minimum at the node between the orifices. This results in a maximum differential ejection pressure and fluid ejection rate.
Similarly by adjusting the phase by about +/−90 degrees, users adjust the relative phase of the excited standing wave in the first fluid within the tube 10 is adjusted to position the fluid pressure nodes at the orifices. This creates a minimum differential ejection pressure across the orifices. Accordingly this gives the minimum ejection flow for variations in pressure oscillation phase.
These measures provide rapid amplitude control over the fluid flow by control of fluid excitation wavelength and amplitude using the mechanical fluid excitation. The control resolution and speed are adjusted by the excitation frequency and orifice spacing, and excitation (amplitude or pressure) relative to the total differential pressure desired. These measures are preferably combined with one or more other pressure flow control measures to provide enhanced control flexibility.
11.7 Tube Stress and Differential ejection pressure Control
In various embodiments, users preferably control the maximum pressure difference across the tube wall 30 to stay within the design stress for the perforated tube 10, and prevent the tube 10 from bursting. The hoop stress generated in the tube walls 30 is preferably kept below the design working stress of the tube material accounting for the desired the operating temperature, the operating life and operating pressure oscillations. These are preferably adjusted for the stress concentrations of the orifices 80, and for tube forming and bonding methods and the drag of transverse flows across the tube. Users preferably maintain the fluid pressure to maintain a maximum tolerable design differential fluid pressure and pressure fluctuation rate within the contactor tube 10, based on the curvature, stress concentrations, temperature and operating strength of the tube wall 33.
11.7.1 Maximum Differential Ejection Pressure in Perforated Tubes
In general users preferably constrain the internal fluid force within the tube 10 to less than the tensile force in the tube walls 10 adjusted for operating and safety parameters. Users preferably use the Lame burst formula incorporating both internal and external tube radii to account for the influence of relatively thick walls. Alternatively, they use the Barlow burst formula for thin wall tubes. E.g., approximating by calculating the tensile force is about equal to the hoop stress in the tube wall 33 multiplied by the cross-sectional area of both tube wall sections in that longitudinal plane, where the internal fluid force is about equal to the fluid pressure times the longitudinal cross-sectional area of a tube section in a plane through the tube axis.
In doing so, users preferably account for the stress, creep and fatigue components. These include stress concentrations due to orifices, non-circular shapes, bending forces of gases traversing the flow, vibration due to turbulence and vortex generation, pressurization to control flow, and cyclic pressurization to vary flow rates or digitally control the liquid flow.
Under some circumstances and embodiments, users control differential ejection pressures to higher than the nominal design limits, but which remain below the tube burst pressure, when emergency flow rates higher than nominal design rates are desired or needed. They then replace the distribution tubes more frequently to accommodate the greater damage rates.
11.7.2 Maximum Thin Wall Tube Diameter for Orifice Size
A given drilling technology (such as laser drilling) typically has a design Wall Thickness/Orifice Diameter (T/D) ratio. E.g., about 10:1. In various embodiments, users preferably select a desired orifice size. This in turn limits the maximum wall thickness through which users can create the needed or desired orifices using that orifice forming technology. E.g., about 100 micrometer (μm) wall thickness to form about 10 μm orifices with 10:1 T/D, or about 2 mm wall thickness with a 200:1 T/D etc.
11.7.3 Minimum Pressure for Liquid and Orifice
Conversely, users preferably determine a minimum pressure needed to force the liquid out through the orifices 80 based on the orifice size and the fluids 901 used. This is a function of the differential surface energy between the first liquid being expelled from the tube 10 and the second fluid 904 flowing across the tube 10.
In accordance with some preferred embodiments, users establish a minimum and a Maximum Differential ejection pressure within which embodiments of the distributed direct contactors 10 can be safely and/or desirably operated. They further preferably evaluate design minimum and maximum absolute or gauge pressures based on the operating pressure within of the distributed fluid contactor system 2. These are configured according to the fluid dynamics and system geometry including variations in pressure due to the fluid flows.
11.7.4 Maximum Over Pressure
In some circumstances, the pressure around the perforated tube 80 may fluctuate. It could be possible for the pressure around the contactor tube 80 to become greater than the pressure within the tube. In other embodiments the pressure within the perforated tube 80 might be decreased below the pressure around the tube 80. In such circumstances there is potential for a negative differential ejection pressure on the perforated tube 80.
Accordingly, in some embodiments, users preferably control the Maximum Negative Differential ejection pressure to prevent damage to a perforated tube 10 and/or compound perforated tube 200 from collapse or bending the tube wall 33 inward. This is particularly applicable for tubes 80 within the pressurized chamber 170 with large oscillating pressures. e.g., such as within an internal combustion engine.
11.7.5 Tube End-end Differential Pressure Profile Control
To increase control over the fluid delivery distributions and profiles along the contactor tubes 10, in some configurations as shown in
In a similar configuration, users provide a differential manifold pump to differentially pressurize fluid between the two sub-manifolds 254 (or manifolds) connected across or to the ends of contactor tubes 10. The differential manifold pump is preferably configured as a reversible pump with corresponding bidirectional controls so as to be able to generate an internal fluid gradient along the contactor tube 10 in either direction between the two adjoining sub-manifolds 254. In similar configurations, users provide controllable valves to control the flow through the two adjoining sub-manifolds 254.
Users accordingly configure the controller 590 to suitably control the Pressure/Flow Modulators 370 (or similarly the differential manifold pump, controllable valves) or as desired or needed, such as the control methods shown in
By controlling the differential pressure in the connecting manifolds 240 or sub-manifolds 254, users control the internal pressure gradient along a contactor tube 10. They accordingly control the longitudinal distribution and profile along the tube 10 of the differential ejection pressure across the tube wall and associated orifices 80. Accordingly, they achieve a dynamic gradient in fluid delivery distribution and profile along the axis of the tube section 260 from one end of the tube 10 to another. By controlling the differential pressure between the two connecting sub-manifolds 254, users preferably control the gradient of the first fluid 901 delivery distribution and profile within and along the direct contactor 10 delivering that fluid. E.g fuel fluid 901, and/or oxidant fluid 904.
11.7.6 Combined Pressure Profile Control
Preferably, in some embodiments, users combine such methods and variously control one or more of the mean differential ejection pressure amplitude across the tube wall 33, the gradient of the differential ejection pressure along the tube section 260, the dynamic fluctuating mean differential ejection pressure the fluid (e.g., the Root Mean Square value) in analog or discrete fashions, and the dynamic fluctuating gradient of the differential ejection pressure (RMS value) along the tube section 260.
Such control enables users to flexibly and precisely control the static and/or dynamic distribution and profile of the rate of fluid issuing from the tubes relative to the distribution and profile of the rate of fluid flow across the tubes 80. These can cover common turn down ratios or extend to very wide turn down ranges. For example, users may use pulse width, pulse amplitude, pulse frequency, analog and/or discrete variations in one or more of these differential ejection pressures such as depicted in
With such controls 590, they dynamically adjust the flow rates to provide a wide range of methods to modulate the fluid flow and precisely control or meter one or both of the fluid flows, including digital, frequency, amplitude, pulse width or other modulation methods. In some embodiments, these are similarly used to modulate the relative fluid mixing as well as higher pressure fluid control.
11.8 Control of Fluid Ratio Profiles
With reference to
In some configurations, users seek to form a fairly uniform fluid ratio profile along one or both of these transverse directions. E.g., to form a uniform ratio in the circumferential direction in an annular array. In other configurations, users will seek some other desired fluid ratio profile such as along the second transverse direction.
11.8.1 Oxidant to Fuel Ratio Profile
For example, users preferably control the delivery distribution and/or profile of the fuel fluid 901 compared to the delivery distribution and/or profile of the oxidant fluid 904 to control the distribution and/or profile of the oxidant to fuel ratio across the contactors 10 or contactor arrays 260 in one or two transverse directions. Where users provide substantial excess oxidant containing fluid, controlling the oxidant to fuel ratio will correspondingly control the temperature of the combustion and resulting combustion gases or energetic fluid.
11.8.2 Water to Air Ratio Profile
In another example, users preferably control the delivery distributions and/or profiles of water as a first fluid 901 compared to air flow as the second fluid 904 to control the distribution and/or profile of the water to air ratio across the contactors 10 or contactor arrays 260. This beneficially controls the relative humidity profile in the delivered air.
11.9 Vibrate Tubes-Orifices
With reference to
The vibrator 50 may be mechanically and/or electrically excited such as using a pneumatic, hydraulic, or electromagnetic excitators. Correspondingly, users configure curvilinear flexible fluid supply tubes 54 that can deliver one or more of the first fluid 901 while flexibly accommodating the vibrations generated in the contactor tubes 10. The vibrator 50 may be inertially driven relative to a suspended mass. Alternatively, it may be supported between the surrounding structure and the contactor tubes 10 with tube supports 37 or similar supporting structures. Similarly the direct contactor array 260 is preferably supported by two or more flexible array supports 72 to the surrounding fluid duct 130 to permit the contactor array 260 to vibrate relative to the duct.
The vibrator 50 is preferably configured to excite vibrations generally perpendicular to the plane of the outlets of the orifices 80. E.g., preferably using axial excitation parallel to the fluid duct 130. This vibration preferably causes a sessile drop and then a pendant drop or liquid jet to oscillate at or near the vibrator excitation frequency. This vibration encourages drops to form with greater precision and uniformity than by natural turbulence driven oscillation.
11.9.1 Orifice Vibration Frequency & Direction
In some embodiments, users preferably oscillate one or both of the perforated tubes 10 or tube arrays 260 at or close to the natural frequency of the liquid micro-jet oscillation. In some embodiments, users preferably oscillate one or more the contactor tubes 10 along the axis of the axis of the fluid duct 130 or the predominant flow direction of the second fluid 904. This vibration axis is preferably selected when the orifices 80 are oriented predominantly perpendicular (normal) to that duct axis. In this mode, preferably all the orifices 80 are vibrated to desirably obtain more uniform drop size. In some embodiments, orifices expelling liquid drops or micro-jets are preferably vibrated transversely to the a vector predominantly parallel to the axis of the orifices 80 (e.g., the flow axis of the first fluid 901), especially when the orifice orientation is preferably perpendicular to the mean flow of the second fluid 904. This maximizes the formation of the capillary waves in the micro-jets and consequently encourages formation of drops or micro-jets of uniform size or more narrow size distribution.
In various embodiments, users preferably use a frequency Omega of wavelength lambda with a characteristic capillary speed Vc where Omega=Vc/lambda=Vc*0.56/(2*Pi*ro).
In other embodiments, users preferably oscillate the tubes 10 transversely to the fluid flow direction of the second fluid 904 to create symmetric liquid oscillations. For example, when the orifices 80 are oriented parallel to the axis of the second fluid flow 904. In other embodiments, users vibrate the orifice array 260 in the azimuthal direction about the flow axis of the second fluid 904. As the orifice vibration magnitude is proportional to radial distance from that axis, this azimuthal excitation is most effective with annular array configurations 267, 269.
11.10 Differential Pressure Modulation System
As shown in
In other embodiments, users move diaphragms or walls of the fluid enclosure or duct, or pistons 197 or motion actuation members such as ultrasonic transducers connected to fluid manifolds and/or fluid ducts to modulate or fluctuate the pressure. In further embodiments, users combine such methods of pressure variation in the pressure modulation system 370.
By so doing, users preferably provide systems to control the differential ejection pressures across the perforated tubes and thus to control the fluid delivery rates through those perforated tubes.
11.11 Electrostatic Jet Reduction
Some embodiments of a direct fluid contactor incorporate electrostatic and/or electrodynamic jet reduction. In such embodiments, users preferably apply an static and/or dynamic electric field generally in line with the orifice axes. These arrangements may result in a substantial reduction in the diameter of liquid jets (such as liquid fuel or liquid diluent jets) exiting the orifices. Consequently, the surface energy with this electrostatic deformation or modulation causes the jets breaks up into substantially smaller and/or more precise droplets than are typically formed from jets exiting those orifices under similar differential ejection pressures.
11.11.1 Electrical Field Excitation
For example, as schematically shown in
In this example, users position a conical electric grid 326 positioned downstream of a conical distribution tube array 262 formed into a fuel fluid array electrode 322. By applying a differential high voltage between the downstream grid electrode 326 and the upstream fluid array electrode 322 will draw micro-jets from the tube orifices towards the electrode grid 326. The high voltage causes the jets to neck down and form smaller droplets. With sufficient voltage and small orifices, the droplets will be small enough to generally flow around the downstream grid 326 between the inlet 134 and the outlet 136.
As shown in
As shown in
This high voltage excitation method requires relatively high voltages, but relatively low power. In some embodiments, the electric power supplies providing these voltages may be controlled to vary one or more of the electric voltages and/or currents. Both the mean and fluctuating amplitude, frequency and/or phase of the voltage are preferably controlled.
11.12 Electric Field Excitation Control
11.12.2 Base Electric Field Excitation
As mentioned above with reference to
Users preferably apply such electric fields to reduce the size of liquid columns to smaller in diameter than the orifices 80 through which the fluids are delivered. Accordingly, they preferably break up the liquid column of first fluid 901 into micro droplets that are smaller than conventional drops, and preferably smaller than the diameter of the orifice 80. (This contrasts with sessile or “pendant” drops which form at about twice the size of the orifice 80. It also differs from high velocity jets which initially break up into drops of similar size to the orifice. The differential fluid velocity then variously breaks these drops into smaller droplets.) In such configurations, users preferably utilize one or more conductive manifolds 240 to electrically connect distribution tubes 10 to respective voltage sources at electrodes 302-312.
In some embodiments, users preferably apply a prescribed, pre-selected or pre-determined excitation voltage(s) from the high voltage power supply 300 according to the electric field gradient desired or required, liquid surface tension and viscosity gas pressure and flow rates. They further account for the influence of the tube to tube gaps G, liquid composition and temperature(s). By using such electric field excitation, users seek to provide the benefits of using larger orifices 80 that are less susceptible to clogging while creating smaller drops and micro-jets. They can also use such methods to create drops or micro-jets from more viscous fuels such as bunker fuel or crude oil.
11.12.3 Control by Oscillating or Pulsing Electric Fields
In some embodiments, users pulse or oscillate the applied high voltage between two or more tubes 10 or tube sets 260, or between such tubes or arrays and electrodes 302-312, 320, 326-334. This provides an oscillating excitation to the first liquid 901 being delivered or expelled from the perforated tube orifices 80. This electric field oscillation in turn generates oscillations in the liquid column and initiates column breakup and droplet formation. The liquid excitation will be generally synchronous with the field excitation and may result in liquid oscillations synchronous with the electric field. Accordingly, users use the oscillating electric field excitation to generally create more uniform droplets according to the precision of pulsing the electric field in magnitude and frequency. The electric field and the fluid pressure modulation are preferably controlled together to have the greatest benefit in controlling the physical pressure oscillations and the precision of drop formation.
In some embodiments, users preferably tune the electric field pulsation or oscillation frequency to the natural liquid jet oscillation frequency in the presence of the average electrical field established. This further achieves more uniform drop formation.
11.12.4 Control by Field-Drop Frequency Modulation
As with pressure modulation, in some embodiments, users preferably modulate the electrical field to vary drop size and delivery rate with a prescribed frequency modulation.
11.12.5 Control by Field-Drop Amplitude Modulation
In some embodiments, users preferably modulate the amplitude of the electric field to expand or reduce the liquid jet as desired to create drops or micro-jets of differing size, resulting in a general drop amplitude modulation. Similarly, users can use Pulse Width Modulation (PWM) to control the time over which the fluid is ejected. By using such amplitude modulation and pulse width modulation methods, they provide benefits of varying drop size and/or micro-jet flow in systems where drop size is generally controlled by the size of the orifices 80 and the surface energy of the first fluid 901 relative to the second fluid 904.
11.12.6 Control by Combined Frequency and Amplitude Field Modulation
In some embodiments, users combine frequency and amplitude modulation of the applied electric field from the power supply 300. This enables users to vary both drop size and drop delivery frequency and thus liquid delivery rate. In some configurations, users further combine electric field control with differential fluid pressure to desirably control drop size, drop or micro-jet delivery rates.
11.13 Electrostatic Homogenization
To more homogeneously distribute drops of a first fluid in a second fluid, users preferably use high voltage electrostatic excitation in some configurations. They preferably provide a high voltage power supply 300 and at least sufficient voltage and current between the direct contactors 10 or between contactors 10 and electrostatic grids 326, to charge at least 10% of the droplets formed, preferably more than 50%, and more preferably at least 90% of the droplets formed downstream of the direct contactors 10 within a prescribed drop formation residence time. By so charging the droplets and providing a desired residence time, they preferably cause the droplets to accelerate by mutual electrostatic repulsion caused by nearby drops having similar electrical charges. By charging the drops, users further shatter and disperse the drops of the first fluid 901 within the second fluid 904 when the charged droplets evaporate and reach a critical charge to mass condition.
Users preferably provide a desired drop homogenization residence time over which the droplets move driven by self-repulsion towards a smoother mass distribution and profile in one or both transverse directions, and in the axial direction relative to the fluid duct 130. By adding electrostatically charging the drops, users effectively provide a high frequency filter to at least one of the droplet distributions and/or profiles about the fluid duct 130. Users preferably select the drop homogenization residence time to achieve a desired degree of high frequency filtering or smoothing of at least one of the droplet distribution profiles along a direction as well as the number distribution at a point. They preferably provide sufficient charging and homogenization residence time to effect at least about 10% smoothing preferably about 50% smoothing, and more preferably more than about 90% smoothing of the droplet spatial distribution and profile measured across about 20% of the respective duct dimension, e.g., radius, circumference, transverse width, transverse height, fluid duct length, bulbuous diameter as appropriate to the configuration of the contactor array 260.
By such high frequency electrostatic profile filtration, users advantageously improve the profile of the desired ratio of mass flow distributions of a liquid delivered through the contactor array 260, relative to a second fluid flowing within the fluid duct. E.g., the ratio of the mass flow distribution of fuel fluid 901 or diluent fluid 907 relative to the mass flow distribution of oxidant fluid 904. While this method most commonly applies to charging liquid fuel fluid 901 or liquid diluent fluid 907 through their respective contactors, it can also be used to charge and influence gaseous fluids.
11.14 Electrically Heating Contactors
In some embodiments, users electrically heat contactor tubes. In such embodiments, in reference to
The thermal cleaning is preferably performed when the system off duty with low flow rates of the second fluid to minimize the heating required. It may also be performed on duty with higher currents to compensate for higher cooling loads.
Similarly, in embodiments of contactor arrays 260 comprising multiple distribution tubes between manifolds, electrical contacts can be made symmetrically or asymmetrically across the manifolds so that the current generally flows uniformly from the power supply 301 through the contactor tubes. E.g., connecting voltages to manifolds on opposite comers of rectangular distribution arrays or annular arrays. In other embodiments non-uniform heating is also used. With these various embodiments, the control system 588 preferably utilizes temperature sensors to control the heating to control the temperatures to which the distribution tubes are heated and the heating duration.
11.14.1 High Temperature Thermal Tube Cleaning
In some embodiments, users preferably make the perforated tubes 80 of high temperature materials capable of sustaining temperatures substantially greater than the pyrolysis temperatures of for example liquid fuels and blocking biomass materials. E.g., substantially higher than about 900 K (about 623° C. or 1153° F.). Correspondingly, users preferably keep the tube temperature below temperatures at which entrained ash and particulars melt to form slag that might block the orifices.
These measures preferably assist in removing fibers and other materials in the second fluid that come through the filtration system and build up on the contactor tubes and block the tube to tube gaps. Similarly unfiltered materials within the first fluid can block tube orifices.
In some embodiments with lower stress and temperature applications, users form the contactor tubes using high temperature stainless steel. In other embodiments, with higher stress and temperature applications, users preferably select Incolonel or Hastalloy or similar high temperature materials to form the contactor tubes.
11.14.2 High Temperature Cleaning Operation
In some preferred embodiments, further referring to
In some embodiments, users preferably provide a flow of a reactive cleaning first fluid such as hot water or steam, through one or more perforated tubes in addition to or instead of electrically heating the tubes, to assist cleaning the orifices by the water gas shift reaction.
Here are disclosed preferred methods of forming perforated distribution tubes. In some configurations, users further assemble these perforated tubes into contactor arrays and connect them to manifolds to duct the fluid to the tubes as described above.
12.2 Materials
In various configurations described above, the perforated tubes 10 and manifolds 240 may be formed from a wide variety of materials according to the applications, temperatures, and desired or needed design life. Embodiments commonly use corrosion resistant materials such as stainless steel. High temperature applications preferably use suitable high temperature materials such as Inconel or Hastalloy. Other embodiments can use quartz, glass, sapphire or ceramic. Other embodiments utilize a variety of structural plastics.
12.3 Cutting Tubes and Forming Holes
Following are preferred ways of forming contactor tubes and manifolds, which may be used to form the embodiments described above. Other methods may also used.
12.3.1 Cut Tubes
In one embodiment, users cut long lengths of tube into suitable shorter lengths. Technology is available to rapidly and precisely shear or separate tubes into shorter tubular lengths sections without sawing them and with minimal burr formation. E.g., Production Tube Cutting Inc. of Dayton Ohio.
12.3.2 Form Manifold Holes & Shape Tube Ends
Referring to
In other embodiments, users may extend the manifold hole 250 to variously form round ended slots, or elliptically shaped holes etc. as needed or desired. Users correspondingly form the tube ends into shapes the conveniently fit into such elongated holes.
12.3.3 Friction Drilling
Further referring to
12.4 Bond Tubes onto Manifolds
Further referring to
In other embodiments, users braze, solder, glue, thermo-form or use other suitable techniques to join the tubes 10 to one or more manifold walls 250.
12.5 Structural Supports Manifold Tube Supports
With reference to
12.5.2 Additional Supports
As needed or desired, users add further tube supports 37 at the end of tubes 10, or attach the tube supports 37 in between tube ends, preferably transversely to the tubes 10. In some embodiments, these support sections 37 are preferably positioned upstream of the tubes 10 so that liquid does not impact and build up on downstream supports. In other embodiments users attach tube supports 37 both above and below tubes 10 to form a three dimensional structurally supported array or space frame.
12.6 Three Dimensional Structural Supports
As the tubes 10 are offset along the axis of the fluid duct 130, so the manifolds 240 and structural tube supports 37 are also generally offset. Axially offsetting the tubes 10 and tube supports 37 advantageously forms a three dimensional structural support or space frame configuration that is stiffer and generally stronger than planar arrays.
12.6.1 Conical Ray Supports
As described above with respect to
12.6.2 Space Structure
In some embodiments, with reference to
12.7 Axially Multi-Plane Distribution Array
With reference to
These multiple contactor arrays 267 are then spaced axially along the duct to form an axially multi-plane distribution array. With further reference to
As shown in
Contactor tubes in each axially distinct array set 267 are preferably connected to corresponding sub-manifolds. Each sub-manifold 254 in turn is connected via pressure-flow modulators or valves to one or more manifolds 240. This permits at least on/off control of flow through the differing sets of axial contactor arrays. More preferably, each axially distinct contactor array set is preferably individually controlled to provide the greatest control flexibility and off design performance.
12.7.1 Jet Penetration Configurations
By varying the circumferential orientation of the orifices 80 about the perforated tube 10, users achieve differing jet penetrations across the tube-tube gap in some configurations. By starting with jet penetrations of about 10% to 200% of the tube-tube gap, fairly uniform mixing is achieved in the second transverse direction perpendicular to the tubes across a wide range of varying jet penetrations with varying fluid delivery flow ranges. Similarly, users vary the orifice size and consequently the relative jet penetrations in configuring the spatial orifice area density in some configurations.
12.7.2 Ranges of Varying Differential Ejection Pressure
The pressure-flow modulators may be configured to control the differential ejection pressure for a range of varying pressures. For example, where a precise narrow range of control is desired the pressure could be varied over about a 1.04:1 range giving about a 1.02:1 (i.e. 2%) variation in fluid flow. In another example, the differential ejection pressure range can be configured for a range of about 2700 bar to 0.27 bar (40,000 psi to 4 psi) or 10,000 times pressure ratio. This gives an mass flow turndown ratio of about 100:1. Numerous pressure ranges within this range can be configured. The variation in mass flow ratio in relation to pressure flow ratio is shown for example in Table 5.
12.8 Hybrid Turn-down Ratios
By such combinations of varying spatial orifice density distributions, profiles and controls, users configure contactor arrays 260 which provide very wide turndown ratios of fluid flow profiles of the first fluid relative to the second fluid. For example, users may provide a 10:1 ratio in spatial orifice densities between one array and the next. They may further use a 10:1 flow turn-down ratio in each array by varying the differential ejection pressure by 100:1. The combination of two such arrays provides an effective 100:1 turn down ratio. By similarly adding a third array in like proportions, users achieve a 1000:1 turn down ratio for the combined array while only requiring a 100:1 pressure ratio range across each individual array. Similarly controlling the pressure range to 10,000 for a mass flow turn-down of 100 with three arrays of 10:1 range each gives a combined turndown ratio of 100×10×10×10 or 100,000. Such very wide turn-down ratios are achieved while generally preserving the transverse mass flow profiles of the delivered fluid. Other ratios may be readily used, as shown in Table 5.
In various embodiments, users preferably configure one or more direct fluid contactor arrays to deliver a first fluid to mix with a second fluid to accomplish desired heat exchange processes comprising cooling, condensation, heating, and evaporation. Users preferably adjust one or more of the transverse distributions of contactor parameters of orifice size, position, orientation, tube spacing and fluid delivery pressure, to achieve corresponding desired transverse distributions of drop size distributions, jet penetration, and jet orientation. These in turn achieve desired transverse distributions of heat transfer rates, heat transfer distances, fluid flow delivery and fluid composition or second to first fluid ratio profiles. These are variously configured in one or more of the first and second transverse directions and the axial direction.
For example, in various embodiments such as shown in
13.2 Distributed Contactor Modeling Method
With reference to
They further form equations to model the desired configurations. These include design equations for the tube parameters of tube length, tube to tube spacing, tube wall thickness/orifice diameter, orifice cone angle, etc. The spatial distribution of orifice parameters about the tube and across and along the duct are similarly modeled.
They further form the flow equations for the first and second fluids. These preferably include models of the flow through the tubes, through the orifices, spray penetration correlations and spray cone angle correlations. The equations include the desired composition mass or mol (or volume) flow rate relations either in the mean flows, or more particularly the spatial distributions of compositions as desired or prescribed.
Users further apply desired or required constraints. For example, the desired transverse distribution(s) of spray penetration such as the degree of penetration across the tube to tube gap. Similarly the spatial profiles of the ratio of second to first fluid flow rates or equivalent spatial composition distributions. These may also include spatial constraints on the time to achieve desired fractions of heat transfer and/or on the corresponding distance distributions needed to achieve those fractions of heat transfer. For example, these may include the spatial distributions of evaporation time and/or evaporation distance. They further apply the constraints of tube strength and maximum burst pressure, realizable tube diameters, maximum orifice length/diameter ratios in drilling etc.
With these models, users then initialize parameters as needed by the computational methods. They further normalize or configure the equations into ratios to assist in convergence etc. In some configurations, the equations are configured into non-linear search programs as desired or needed to provide convergence.
Users then configure the programs to produce the desired output values and figures. For example, these include the spatial distribution(s) of fluid pressure, orifice number, orifice spacing, orifice diameter, orifice orientation, and orifice length/diameter ratio profiles. Similarly they obtain the spatial distributions of spray cone angle, spray penetration, injection velocity, differential ejection pressure and fluid compositions or profiles of the ratios of second to first fluid flow rates. They similarly obtain the desired distributions of tube to tube gap, wall thickness, diameter and length. These methods are further exemplified in the following discussions of configuring heat exchangers.
13.3 Residence Time
13.3.2 Residence Time vs Drop Size Distribution
The speed of many physical phenomena and chemical reactions depends on the surface area of a fluid, or the interfacial area between two fluids. The time for the process to finish in turn depends on change in a process through the drop and thus on the drop size. Drop formation in most prior art systems results in a broad distribution of drop sizes. Disadvantageously, this results in a broad distribution of corresponding drop reaction residence times. In the relevant art, systems are commonly sized for the largest drops or micro-jets and longest acceptable residence times with large spatial variations resulting from a few jets.
In some embodiments, users advantageously configure a direct contact heat exchanger 483 or direct contact condensor 484 to form drops or micro-jets with prescribed distributions and/or profiles of orifice sizes in the transverse and/or axial directions relative to the fluid duct 130. Using the preferred methods described with respect to
In other configurations, users can configure the fluid delivery and orifice size distribution(s) and/or profile(s) to achieve substantially non-uniform distribution(s) and profile(s) to achieve particular transverse or axial distribution(s) and/or profile(s) of fluid composition and transformation times etc.
13.3.3 Evaporation Residence Time
Users preferably configure the direct fluid contactor 483 with desired or prescribed transverse distribution(s) and/or profile(s) of orifice size and spatial orifice density. These are variously configured to provide desired transverse distributions of orifice size with corresponding transverse distributions of drop size or micro-jet size 903 of the first fluid. E.g., by configuring fairly uniform transverse distributions of distributed orifices these form provide fairly uniform drops or micro-jets 903 with fairly narrow drop size distribution of a first fluid 901 in perforated tube arrays 260 in various embodiments of the invention. With continuing reference to
Users consequently obtain evaporation time transverse distribution(s) for the fluid drops or micro-jets to evaporate within desired transverse distribution(s) of evaporation distance in flows of the second fluid 904 with various transverse distributions of unsaturated fluids. Similarly, users may form micro-jets from fairly uniform transverse distributions of orifice size with fairly uniform transverse distribution(s) of differential ejection pressure across the orifices 80, resulting in fairly narrow transverse distribution(s) of a measure of drop size such as the Sauter Mean Diameter (SMD). Consequently, these form narrower transverse distribution(s) of evaporation time and more controlled transverse distribution(s) of evaporation distance.
Since the time to evaporate drops strongly depends on the largest drops in a spray, users significantly reduce the portions of large drops in the spatial and number fluid delivery distribution(s) and/or profile(s). Accordingly they significantly reduce the size and cost of the evaporation equipment. William Sirignano (1999) reviews droplet evaporation rates including transient effects due to changing temperature in combustion, and the effects of neighboring drops in sprays or drop arrays. Davis & Schweiger (2002) further review the evaporation of drops. The vapor pressure of the first fluid 904 and the diffusion coefficient in turn depend on the effective temperatures of both the liquid and gas. The evaporation rate of a drop is generally proportional to its surface area, the difference between local and remote vapor pressures and a diffusion coefficient. Users utilize such methods in evaluating and configuring the parameters described herein.
To ensure substantially complete evaporation, users control the drop size or size distribution and residence time sufficient to generally limit the maximum evaporation time with a suitable statistical probability.
Accordingly, users create orifices with about the desired diameter distribution and/or profile and prescribed uniformity, adjust tube oscillation frequency, control the pressure pulsation pattern of the first fluid 901 and/or the external electric field outside the orifice, and the temperature of the two fluids and vapor pressure of the first liquid 901 in the second fluid 904 as appropriate, needed or desired. Then users select the area and length of the fluid duct 130, and the velocity (or pressure drop) of the second fluid 904 in a prescribed manner to control the first fluid residence time for evaporation. This similarly applies to using direct contactor arrays 260 to evaporate the first fluid 901.
13.3.4 Heat Exchanger Residence Time
Drops (or bubbles) of a first fluid 901 traveling in a second fluid 904 change in temperature with evaporation, condensation and/or heat transfer and time. To achieve a given proportional change in temperature compared to the total temperature difference, users preferably configure a direct fluid contactor 483 of
13.3.5 Condensation Residence Time
Cooler drops of a first fluid 901 contacting a second fluid 904 saturated with some vapor of a fluid will cool the second fluid 904 and condense some of that vapor. In some embodiments, users preferably configure the direct fluid contactor system 483 as a direct contact condensor 484. They preferably configure distributed contactor arrays 260 to distribute a cooler first fluid 901 in a second fluid 904 with desired transverse delivery distributions and/or profiles. The temperature of the first fluid 901 is preferably kept below a generally prescribed temperature. The contactor array 260 is configured with transverse orifice size distributions and/or profiles to achieve desired transverse drop size spatial and number distributions and/or profiles. E.g., in some configurations, these may be fairly uniform drops of the first fluid 901 or drops with a narrow size distribution.
They may further distribute those drops or with one or more desired transverse delivery distributions and/or profiles to achieve desired transverse profile ratios of the second fluid 904 to first fluid 901. E.g., These can be configured for fairly uniform ratios of the second to first fluids where there are distinctly non-uniform transverse flow distributions and/or profiles of the second fluid 904 in the fluid duct 130. The contactor array 260 is commonly positioned across and within the fluid duct 130. The contactor 260 may also be arrayed near the upstream end, or across the inlet 134 to the fluid duct 130.
Users preferably provide a residence time distributions and/or profiles for the coolant fluid generally sufficient to achieve a desired or prescribed distributions and/or profiles of the fraction of the desired total temperature change. This achieves a certain amount of cooling of the second fluid 904 by the first fluid 901. This in turn will generally condense a certain fraction of the vapor in the second fluid 904. By controlling the uniformity or narrowness of drop size distributions, and the ratio profile of the distributions of first fluid 901 to the distributions of the second fluid 904 transversely across the fluid duct 130, (and/or axially) and the distributions in the difference in temperature between the first fluid 901 and the second fluid 904, users generally achieve a given condensation fraction.
13.4 Counter-Flow Direct Contact Heat Exchanger
Exhausting hot products of combustion to the atmosphere results in significant energy losses. Surface heat exchangers are typically used to recover such exhausted energy. Using sprays with a wide distribution of drops results in a portion of the smallest droplets being entrained in the exhaust plume with consequent loss of water.
With reference to
Users preferably configure a generally vertical duct 130. They preferably select a mean drop size or narrow size distribution and design the transverse inlet fluid velocity distributions so that the drops of cooling first fluid 901 fall through the counter flowing fluid. I.e. most coolant fluid drops 901 are formed larger and heavier than those that are entrained by the cooled fluid flow 928 exiting the duct. The force of gravity on the drops is greater than the sum of the hot fluid drag on the coolant drops and the buoyancy of drops in the counter flowing hot fluid. Conventional sprays generate “drafting” or coordinated drop motion. This increases drop entrainment. With distributed drop contactors, users preferably adjust drop velocity to compensate for the small drafting component.
As the drops fall through the counter flow of hot flue gas 904, they cool the flue gas. The hot gas in turn heats the drops. As a result, users recover hot liquid drops at the fluid collector 481 at the bottom of the flue 130, and deliver cold flue gas exiting the top 136 of the flue duct 130.
In some embodiments, users provide a particle separator 520 (e.g., gas-liquid separator) to separate the hot water near the bottom of the flue duct 130 from the hot flue gas 926 (See
13.4.1 Direct Contact Fluid Condensor
Further referring to
In other embodiments, users use a preferably fairly inert liquid as the liquid coolant first fluid 904. For example users can use a low vapor oil such as is used in vacuum pumps, or a synthetic fluid or refrigerant. In modified embodiments users efficaciously use a liquid metal such as gallium which has a low vapor pressure and a very wide liquid range, as needed or desired.
Further referring to
13.5 Cross-Flow Contactor
In some embodiments, users configure the direct fluid contactor heat exchanger as a cross-flow contactor.
13.5.1 Cross-Flow
Further referring to
Users preferably generate fairly uniformly sized drops or drops with a desired narrow spatial and number size distributions in transverse or axial directions with embodiments of distributed contactors 260. Users thus preferably increase the first fluid flow 901 and reduce the duct size while still achieving a very high droplet recovery. Even when users provide fairly uniform orifices 80 to obtain smaller more uniform droplets, there will typically be a bimodal distribution of drop size with narrow peaks. The users preferably size orifices or transverse orifice size distributions for a prescribed fraction of droplets recovered. Similarly users use a range of orifices in some configurations to increase turn down range. This provides narrower range of drop sizes than conventional spray systems. Again users preferably determine the desired fluid flow velocity distribution and size the ducts 130 accordingly to achieve the desired droplet recovery.
13.5.2 Multiple Horizontal Plates
With reference to
Users preferably use fairly uniformly sized orifices or with a narrow desired size distribution to form fairly uniform drops or micro-jets to give fairly uniform drop velocities and residence times. Similarly users form micro-jets forming a fairly narrow drop size distribution and which are fairly uniformly configured transversely across the sub-duct 130 to provide fairly narrow distributions in drop velocities and transverse spatial drop distributions and/or profiles. The orifice size, spacing and differential delivery pressure are preferably configured so that adjacent micro-jets overlap. Users preferably size the duct height relative to the second fluid flow velocity so that the fluid flow is generally laminar within the thin sub-ducts 131.
Fluid Residence Times: With further reference to
Spray flushing: Users preferably configure the spray cleaning system 498 to clean each thin duct and periodically flush and wash out the accumulated particulates. Users preferably provide numerous spray orifices along the contactor tube 80 for the first fluid 901 with a high pressure delivery pump to provide a flushing spray across the full width of the sub-duct 131. In other embodiments, users provide a moveable spray cleaning system 498 that periodically moves across the sub-ducts 131 and sprays each sub-duct in turn. In modified embodiments, users use a narrow high pressure spray system to sequentially traverse across each sub-duct to clean it.
Duct Angle: To reduce the tendency for the contacting fluid such as water to stand in the sub-duct, with further reference to
To further assist the fluid flow, users preferably tilt the sub-ducts 131 downwards transverse to the fluid flow 904. This assists in flowing the fluid 901 to one downstream corner of the fluid duct 130. Users provide a collector duct 481 to collect the fluid 901 flowing out the sub-ducts 131.
In other embodiments, users further tilt the sub-ducts downwards towards the upstream direction so that the resulting collected contacting liquid at the bottom of the duct flows counter flow to the fluid flow towards the duct inlet 134.
Sizing: Users preferably size and configure the number of sub-ducts 131 and their width and length to reduce net present value of the life cycle costs of the fluid contactor system. (See
13.5.3 Direct Contact Co-Flow Heat Exchanger
In some embodiments, with further reference to
In embodiments where users desire or need to recover the first fluid, various liquid retrieval methods may be used, such as electrostatic precipitators, cyclones, impingement separators, etc. The fairly uniform size drops used will result in much greater recovery of the injected liquid.
13.6 Fluid Scrubber
In other embodiments, users configure the direct fluid contactor 483 as a fluid scrubber to remove various contaminants, such as shown in
13.6.1 Intake Water Scrubber
Intake air or compressed oxidant containing fluid is commonly filtered through a porous intake filter to remove particulates. This reduces the compressor 407 and turbine fouling thus preventing efficiency losses at the expense of a pressure drop with consequent pumping losses. By using a multi-duct direct contactor 483, users achieve both wet scrubbing to remove particulates and fibers from the intake air, as well as cooling the intake second fluid 904. (See, e.g.,
13.6.2 Exhaust Water Scrubber
Users similarly configure a direct fluid contactor 483 with numerous in a desired size distribution to scrub the exhaust fluids from combustion or power generation system. (See, e.g.,
13.6.3 Solution Scrubber
With further reference to
13.7 Direct Contact Thermal Fluid Control
With reference to
13.7.1 Cooling by Cold or Refrigerated Liquid
With reference to
With reference to
13.8 Distributed Direct Contact Fluid Heater
With reference to
13.8.1 Low Vapor Pressure Liquid
When users wish to heat a cool fluid without vaporizing a significant portion of the hot first fluid, users preferably use a liquid with a very low vapor pressure. High molecular weight hydrocarbons such as vacuum pump oil may be used for moderate temperatures up to a few hundred degrees C. For higher temperatures, users preferably use the liquid metal gallium which has a very low vapor pressure and a very wide liquid temperature range.
13.8.2 High Vapor Pressure Liquid
With reference to
Where heating is associated with a demand for power, users preferably use a direct contact heat exchanger 483 as a direct contact condensor to cool the exhaust fluid 926 and condense the thermal diluent first fluid vapor 901 (e.g., steam and water vapor) while recovering high purity hot thermal diluent first fluid 901 (e.g., hot water). Users then pass that high purity hot water through a liquid-liquid surface heat exchanger 470 to preheat common water. Users preferably recycle the high purity cooled water first fluid 901. Users take the heated common water and use it for district heating applications.
13.8.3 Hot Contact Liquid Recovery
With reference to
In some embodiments, with further reference to
For example, the direct contactor 2 may be configured to preferably form direct contactors to deliver a first fluid 901 through numerous orifices 80 with a desired distribution within a combustor. In such an embodiment, the first fluid 901 may be gaseous or liquid fuel, such as natural gas or diesel fuel, or a thermal diluent fluid such as steam or water. Users preferably select combinations of one or more orifice diameters, number of orifices, orifice configurations, orifice distributions, differential fluid pressure, fluid temperature and electric field magnitude and gradient to achieve the desired or needed delivery drop size and distribution as described herein. Users correspondingly select the thickness and diameter of the tube wall and/or orifice forming technology with suitable Thickness/Diameter capabilities to cost effectively form the number of orifices 80 with the desired parameters. In some configurations, they provide protective coatings to protect against high thermal fluxes, erosion, oxidation and corrosion.
14.2 Narrow Size & Residence Time Distributions
Fairly large distributions in drop size cause corresponding differences in evaporation time with the residence time having to be selected for the longest evaporation times caused by the largest drops. To improve evaporation times of the first liquid 901 within the second fluid 904 within prescribed dimensions of a fluid duct 130, users preferably position a distributed contactor array 260 with a desired size distribution of orifices 80, in one or both directions transverse to the axis of the fluid duct 130 containing the second fluid 904 with further reference to
14.2.1 Static or Uniform Flows & Evaporation Times & Distances
For example, referring to
These drops of the first liquid 901 evaporate within a fairly narrow range of time. In similar flow velocities, this narrow spatial distribution of residence times results in fairly narrow axial distribution of locations where the drops evaporate. The evaporation residence times and evaporation locations are broadened somewhat by turbulence within the flow. Users thus obtain a fairly narrow transverse spatial variation of the cumulative distribution of evaporation distances. Users preferably adjust the orifice size 80 and applied differential ejection pressure to adjust the drop size to obtain the desired cumulative probability of evaporation and/or cumulative probability of drop size at a desired distance from the contactor array 260.
Similarly, with higher differential ejection pressures, users provide numerous larger micro-jets along the contactor array 260. They achieve a fairly narrow size distribution of drops with a fairly narrow distribution of evaporation residence times. 14.3 Orifice size profiles, evaporation time & distance distributions In other configurations, with reference to
14.4 Transverse Flow Distribution Profiles & Ratios
With further reference to
Users similarly adjust the transverse fluid flow distributions and/or profiles of the first fluid 901 relative to the fluid flow distributions and/or profile of the second fluid 904 accounting for the tube to tube gap distribution and upstream to downstream spatial distribution of pressure drop across the contactor array 260 to achieve the desired ratio of mass flow distributions (or profiles) of first fluid 901 relative to the mass flow distributions (or profiles) of the second fluid 904. Accordingly, users preferably control the spatial transverse and axial flow distributions and/or profiles of the first fluid 901 relative to the transverse flow profiles of the second fluid 904 to achieve desired spatial transverse and axial flow profile ratios of the second fluid to first fluid.
14.5 Distributed Evaporator or Cooler
Users preferably use embodiments of distributed contactor arrays where users wish to evaporate a first liquid (e.g., water) to cool and/or increase that vapor concentration in a second fluid. E.g., evaporate water to cool or humidify air. Water is being introduced to cool intake air in power generation systems to increase power and reduce NOx emissions. Users preferably use distributed contactor arrays, as described herein, in such applications to provide substantial benefits over prior art. Some embodiments are detailed as examples of these applications as follows.
14.6 Quasi-isothermal compression
As schematically shown in
This thermal diluent 901 is preferably a vaporizable liquid (such as water) to provide evaporative cooling of the second fluid 904 when mixing the diluent. The latent heat of vaporization of the vaporizable first fluid 901 absorbs heat, reducing the temperature of both the second fluid 904 and the first fluid 901. This in turn beneficially reduces the net work of compressing that second fluid.
As shown in
For example, users preferably spray water as the first fluid 901 into the flow of an oxygen containing second fluid 904 such as air, after, between, within or before the compressor(s) 407 to evaporatively cool the gaseous fluid 904 being compressed and reduce the work of raising the pressure of the second fluid 904. They preferably configure the spatial orifice spatial density distributions and profiles and/or spatial orifice area profile to provide prescribed or desired profile ratios of the transverse delivery profiles of the second fluid to the first fluid e.g. in transverse and/or axial directions. By adjusting these ratios users beneficially achieve more controlled fluid composition and temperature than in relevant art methods.
In some configurations users configure the precooler to deliver non-uniform distributions of the first fluid to accommodate the centripetal motion of droplets and their evaporation patterns within the compressor. These may be weighted more towards the compressor radius than in conventional methods. In other configurations, users provide more uniform transverse fluid compositions and temperatures than are obtained in the relevant art.
14.6.1 Inter-Compressor Diluent Drop Delivery
With continuing reference to
They preferably configure one (or both) spatial or transverse spatial distributions of orifice area and the profile ratio of second to first fluid flows, to desirably provide one or more spatial or transverse profile(s) of the rate of liquid evaporation, transverse profile(s) of the droplet evaporation residence time, and spatial (e.g. transverse) distribution(s) and/or profile(s) of the evaporation distance. For example,
Users preferably desire evaporation distance spatial distribution(s) or profile(s) for the vaporizable diluent. E.g., to provide desired composition, or temperature distributions or profiles, and/or to reduce impact erosion from large drops. A conceptual evaporation distance transverse distribution is shown in
From the desired evaporation distance transverse distribution(s) and the second fluid boundary conditions, users preferably evaluate the available transverse distribution of the allowable maximum residence time or maximum evaporation for the first fluid. This maximum evaporation time transverse distribution is shown schematically in
E.g., these calculations incorporate the spatial (e.g. transverse) velocity distributions or profiles of the two fluids, their temperature and pressure distributions or profiles, the relative saturation pressure distributions, diluent vapor pressure distributions, and drag distributions on the diluent drops. From the desired evaporation time and the relevant parameters, users obtain the desired spatial (e.g., transverse) distributions of measures of the first fluid drop size such as the Sauter Mean Diameter (SMD) or similar measures of drop size number distribution.
Users similarly evaluate the ratio of transverse fluid mass flow profile(s) desired to obtain desired transverse composition or ratio profile(s). E.g., they take the second fluid spatial or transverse flow velocity, pressure and temperature distributions and/or profiles to evaluate the desired spatial or transverse density and mass flow distributions. From these, they evaluate the desired first fluid spatial or transverse mass flow distribution(s) needed to achieve the desired spatial or transverse composition ratio profile(s).
Combining the desired spatial or transverse drop size profile(s) (as needed to achieve the evaporation distance distribution), with the desired first fluid spatial flow distribution(s) (to achieve the composition distribution(s) or flow ratio profile(s), users preferably solve the relevant simultaneous equations obtain the desired spatial or transverse orifice spacing distribution(s) (or the inverse lineal orifice density), and the spatial or transverse net orifice spatial density distribution(s) (per duct cross section area).
From the orifice size and first fluid flow rates, users obtain the desired jet penetration spatial distributions or profiles and the spatial differential ejection pressure distributions required to achieve those flows, and the desired tube gap distributions. Where there are constraints among these parameters, users adjust some of the parameters to achieve other parameters within desired ranges. E.g., by adjusting tradeoffs in evaporation distance, tube size and tube gaps and their spatial distributions.
In a similar embodiment, users select the desired tube to tube gap size distribution. E.g., as a increasing gap between two radial direct contactor “spokes”, or as a uniform spacing between two circumferential direct contactor arcs. Users preferably select a desired spray penetration distance relative to these tube to tube gaps to provide a more uniform transverse distribution of the second to first fluids across the tube to tube gap, downstream of the contactor array. E.g., equal to about 90% of the tube to tube gap at the design conditions. The transverse distribution of tube gap and jet penetration are conceptually shown from the inner radius to the outer radius in
From the constraints of the transverse distribution of the jet penetration distance (eg as a function of the tube to tube gap distribution), and the transverse distribution of the first fluid drop size measure (e.g., SMD), they calculate the required fluid delivery pressure required to achieve the transverse distribution of differential ejection pressures and the transverse distribution(s) of orifice size required to achieve those drop sizes and penetration distances.
With these parameters, users further constrain the local desired transverse distribution of composition or second fluid to first fluid flow ratio profiles. From these constraints and parameters, they calculate the orifice spacing or lineal density, and the net orifice spatial density required to achieve the first fluid flows to give the desired local transverse distribution of fluid composition or second fluid to first fluid flows.
In performing these calculations, users preferably account for the pressure drops along the contactor tubes as well as the friction losses and pressure drops for the flows through the orifices. The pressure drops through orifices are particularly significant for higher orifice thickness to diameter ratios resulting from small orifices and thick tube walls, and for long contactor tubes relative to the tube hydraulic diameter. For example, as shown in
These substantially non-linear transverse distributions of orifice size, orifice spacing, pressure and mass flow per orifice are required to achieve the uniform transverse ratio profile of second fluid to first fluid shown in
In a similar fashion, the constraints and parameters can be evaluated the corresponding transverse distributions of orifice size, effective net orifice spatial density (including orifice spacing and tube to tube gap) and fluid delivery pressures. These can be configured as before to achieve the desired transverse distributions of evaporation distance, jet penetration, and locally averaged composition or second to first fluid flow ratio profiles, whether uniform or non-uniform as desired.
14.6.2 Post-cooler Compressor Diluent Drop Delivery
In some embodiments or power systems, users preferably provide embodiments of distributed contactors as a post-cooler 417 to introduce the first fluid 901 thermal diluent (e.g., water) into the compressed second oxidant containing fluid 904 after the sequence of one or more compressors 407 and before the downstream utilization device such as a turbine 440. The evaporation after the compressor cools the compressed second fluid 904, reducing the back pressure on the compressor 407 (compared to adding a non-evaporating fluid). Evaporation after the compressors (407) further reduces the temperature and volume of the second fluid while increasing the total mass of the fluid flowing through the utilization device 440. These parameters reduce the work of the compressor compressing the second fluid 904 compared to systems without post diluent delivery and evaporative cooling.
The second fluid 904 exiting the compressor 407 commonly has spatial or transverse flow velocity distributions or profiles that vary markedly from the mean flow. The transverse flow distributions or profiles exiting the high pressure compressor 407 often vary substantially from the transverse flow distributions or profiles exiting the low pressure compressor 407. Users preferably apply the methods described above in reference to
In doing so, they preferably account for the hotter temperature, higher pressure, increased diluent content and higher density of the second fluid 904, and more non-uniform transverse velocity distribution than within the compressor 407, resulting in faster evaporation and lower evaporation residence time than within or between compressors.
Where substantially non-uniform velocity distributions exist, users preferably adjust the spatial or transverse orifice size distributions relative to the velocity to achieve fairly uniform spatial distributions of drop evaporation distances. They further preferably configure the orifice spacing relative to gap spacing and velocity to configure one or more spatial or transverse distributions or profiles of net spatial orifice specific density and deliver the first fluid with flow distributions to achieve prescribed spatial or transverse profile ratios of the second fluid relative the first fluid flows.
In some embodiments, users preferably deliver the first fluid 901 through streamlined direct fluid contactor arrays 417 and mix it with the second fluid 904. For the same amount of evaporative cooling, water delivered and evaporated after the compressor 407 and before the turbine appears to give lower fluid pumping and turbo-machinery parasitic losses from turbulence, wall friction etc in the second fluid 904 by reducing the compressor back pressure than the same amount of water evaporated prior to or within compressors 407.
With continuing reference to
Users preferably deliver the diluent water through distributed contactor arrays with numerous orifices forming small drop sizes of less than about 100 μm in diameter, preferably less than about 30 μm, and more preferably less than about 10 μm. Users preferably use streamlined water distribution contactors to reduce the pressure drop across the array. By more uniformly delivering the first fluid 901 (e.g., water) throughout the second fluid 904 with smaller drop size and greater surface area than conventionally, users reduce the energy and entropy loss required for mixing compared to conventional water spray systems. Such combinations provide significantly faster evaporation, smaller volume and pressure vessel cost, and lower pressure drop than relevant art systems. (E.g., compare Humidified Air Turbine (HAT®) or the Evaporated Gas Turbine (EvGT) power systems.)
14.6.3 Intra-Compressor Drop Delivery
In some configurations, users similarly preferably apply this distributed water delivery method to intra-compression to deliver a diluent liquid first fluid 901 into the second fluid 904 being compressed within a compressor 407. They preferably configure direct contactor tubes 10 to distribute vaporizable diluent from near the hub or along compressor vanes as direct contactor tubes 10 to deliver the vaporizable thermal diluent fluid 901 with a desired flow distribution relative to the flow of second fluid 904 being compressed, using the methods described herein. In some configurations, they further provide contactor tubes along the compressor blades. These may be further combined into the vane and blade shapes with orifices exiting the vane or blade surfaces. These measures provide the benefit of more uniformly cooling the compressed flow and reducing its volume (compared to using excess air as diluent) and thus reducing the compression work required compared to the relevant art.
14.6.4 Pre-compressor Drop Entrainment
With continued reference to
With numerous orifices in the streamlined fluid contactor 260 users provide numerous micro-jets. These achieve narrower spatial and number drop size distributions across the intake. Improving the spatial distributions and profiles of drop size resulting in a smaller fraction of large drops significantly reduces blade erosion within the compressor 407.
Users preferably configure the orifice net spatial density distributions and differential ejection pressure distributions to achieve one or both desired spatial profiles of the ratio the second fluid 904 to first fluid 901. These profiles are preferably configured to provide more uniform profiles of the second to first fluids (e.g., air to water.) Where users entrain vaporizable diluent into the compressor, they preferably provide fairly uniform spatial delivery distributions in proportion to the fairly uniform velocity distributions for the oxidant fluid entering the compressor 407. Users preferably utilize the methods of configuring the contactor array parameters as above, but with reference to the much more uniform velocity distributions, lower pressures and lower diluent content at the entrance to the low pressure compressor 407.
Improving these transverse distributions of fluid ratios significantly improves the uniformity of fluid cooling, fluid density and fluid velocity within the compressor 407. This reduces propensity for compressor surge and improves compressor efficiency compared to the relevant art, giving significant cost advantages. The improved evaporation and fluid ratio profile uniformity further improves downstream combustion temperature uniformity, combustion stability, and turbine efficiency.
Evaporation prior to compression results in an additional volume of water vapor that is compressed with corresponding parasitic flow losses. Providing distributed contactor arrays 260 to entrain or deliver fairly uniform water drops into the compressor(s) 407, between compressors 407 or after the compressor(s) is significantly more efficient than “fogging” before the compressor 407.
14.6.5 Cooling Gas by “Fogging”
Evaporative air cooling is being added to the air intake systems for power plants to cool the air, increase air density and mass flow into the energy conversion system, increasing its power, and to add thermal diluent to reduce nitrogen oxides formed by combustion. Conventional systems create wide drop size distributions. Unevaporated drops impacting on blades can cause blade erosion. Wide drop size distributions require long residence times and distances to evaporate the largest drops or to let them fall out. This requires a large volume duct prior to the compressor 407.
In some embodiments, users provide distributed contactors with numerous orifices in the fluid duct upstream of the compressor 407. In some configurations they preferably form fairly uniform orifices to provide fairly uniform size transverse profiles of drop sizes or micro-jets with transverse size profiles of narrow drop size distributions.
With one or more of these measures, users configure desirable transverse distributions of drop evaporation residence times to evaporate the drops and correspondingly narrower spatial profiles of evaporation distances.
They further preferably configure a fairly uniform ratio of second to first fluid flow profiles. Where “fogging” is desired, users position the distributed contactor upstream of the compressor 407 sufficiently far to evaporate a desired fraction of the water drops prior to entrainment into the compressor 407.
Users may also position a multi-duct cooler 483 (as shown in
14.7 Counter Flow Evaporator
In some embodiments, users configure a direct fluid contactor 483 as a highly counter flow evaporator. The fluid duct 130 is preferably configured vertically. Users configure a direct contactor array 260 across the duct 130 near the top of the fluid duct 136. They size orifices 80 to form drops of the first fluid 901 generally of sufficient size and velocity so that they will fall or move against the second fluid flow 904. They typically provide a means of recovering the drops near the bottom or inlet 134 of the duct 130. Where fluid drops 901 are formed that are entrained with the second fluid flow 904, users preferably position the contactor array 260 a suitable distance below the top of the duct 136 so that the entrained drops 901 are evaporated to a desired degree before exiting the duct.
14.8 Hybrid Counter-Co Flow Evaporator
To more efficiently evaporate a liquid 901 in a fluid duct 130 with a vertical updraft flow, users preferably provide a direct contactor 260 across the duct 130 and form numerous drops or micro-jets with a fairly narrow size distribution to form a hybrid counter-co flow evaporator. Drops of fluid 901 below a critical size will be entrained by the vertical counter flow 904, while larger drops will initially fall as they evaporate. The contactor array 260 is preferably sized to form fairly uniform drops which will initially fall against the counter-flowing fluid 904.
Users preferably size the drops 901, height of the contactor array 260 above the inlet 134 to the evaporator, and velocity of the second fluid 904 such that when the drops have partially evaporated, the drag of the counter-flowing fluid 904 will then reverse the droplet velocity and entrain the drops 901 vertically upward along with the flow before the droplets fall to the bottom inlet 134 to the evaporator. This results in drops evaporating while they twice traverse the same region within the fluid duct 130. Consequently users have about twice as many drops within the fluid duct 130 for a given number and size of orifices 80 as compared with a co-flow configuration. This significantly increases the evaporation rate within a given duct 130, while permitting larger orifice sizes 80, thus reducing filtration requirements.
Users similarly configure the location of the contactor array 260 below the top (outlet) of the evaporator 136 sufficient to evaporate most of the droplets entrained vertically upward to a desired degree before exiting the evaporator. Users preferably size the size distribution of first fluid drops delivered relative to the second fluid flow so that a prescribed fraction of the drop mass will evaporate within the period when they are falling, entrained upward through the contactor array 260 and before they leave through the evaporator exit 136. (E.g., 99.97%.)
More preferably, users adjust the spatial orifice size distributions to achieve desired spatial distributions of evaporation residence times, and spatial distributions of evaporation distances as described herein. They further adjust the net spatial density distributions to achieve desired spatial profiles of the ratio of second fluid flow 904 to first fluid flow 901, and associated transverse evaporation time and distance distributions and spatial saturation distributions.
14.9 Co-flow Evaporator
In other configurations, to evaporate a first liquid 901 in a second fluid 904, users configure a co-flow evaporator system with a direct contactor array 260. Users preferably size orifices 80 to generate drops of sufficiently small size that the drops are entrained in the flow and carried away from the contactor array 260.
14.9.1 Upward Co-Flow Evaporator
When users have a temperature differential, users preferably orient the evaporator duct 130 in the vertical direction to benefit from natural updrafts. To achieve a highly co-flow configuration, users preferably size the orifices to form drops of the first fluid 901 that are sufficiently small to be generally entrained by the second fluid 904 against gravity. I.e. the drag on those drops is less than the force of gravity on them. Gravity reduces the velocity of the entrained drops 901 to less than the velocity of the second fluid 904. Such a vertical updraft configuration provides a desirably longer evaporation residence time and shorter length of the evaporator 130 than a downdraft configuration.
14.9.2 Downward Co-Flow Evaporator
In alternative embodiments, users configure a co-flow evaporator with a downward flow of the second fluid and corresponding downward flow of the first liquid drops. Here gravity accelerates the first liquid 901 as well as the flow of the second fluid 904 resulting in higher velocity and lower residence time than the hybrid counter-co flow and the upward co-flow configurations.
14.10 Radial Co-Flow Evaporator
Where a second fluid 904 flows radially into or out of a duct, users preferably configure and position a distributed contactor 260 across the opening of that fluid duct 130. The first fluid 901 is then desirably mixed with the second fluid 904 as it flows radially into or out of that duct. Users preferably size the orifices 80 such that when liquid drops are formed, they are entrained by the second fluid 904. In other embodiments, where some of the first liquid drops 901 settle out, users preferably provide a liquid collector 481 to recover that liquid 901 and recycle it.
14.11 Cross-Flow Evaporator
In other embodiments users configure a direct fluid contactor 483 in a cross-flow configuration with horizontal ducts. This is similar to the configuration shown in
14.11.1 Layered cross-flow saturator
In other embodiments, users preferably enhance the evaporation and saturation uniformity by forming a multi-duct cross-flow evaporator 483. (See, for example,
In this case, users size the orifices 80, length and height and number of thin ducts 130 to form numerous micro-jets and drops that do not completely evaporate by the time they reaching the bottom duct wall 132 near the exit 136. Users so size the number and size of orifices 80 and dimensions of the contactor array 260 and duct 130 to provide at least a prescribed mass flow rate, surface area formation rate and residence time of the first fluid 901 falling through the fluid duct 130 per mass flow of the second fluid 904 flowing through the fluid duct 130 for prescribed temperatures and composition of those fluids. By so doing, users can achieve a prescribed degree of saturation with a prescribed probability more efficiently and compactly than with the prior art. Users can similarly apply this methodology to the simpler cases of the other evaporator configurations.
14.12 Distributed Hydrocarbon Evaporator
Users preferably configure various evaporator embodiments 483 to evaporate hydrocarbon liquids including various petroleum distillate fractions, vegetable oils and liquid chemicals. These configurations are variously used to evaporate fuels 901 in oxygen containing second fluids 904 such as in combustion systems, to evaporate chemicals in petroleum refining or chemical processing, to evaporate potable liquids in food processing, or to concentrate liquids in biochemical processing systems.
14.13 Delivering Fluids into Work Engines
In some embodiments, users use direct contactor arrays 260 or direct fluid contactors 483 to deliver one or more first fluids 901 into second fluid 904 to be used in work engines. For example, users preferably deliver one or more fuel fluids as the first fluid 901 into a second fluid 904 containing oxygen to form a mixed fluid comprising fuel and oxygen. (e.g., delivering fuel fluids such as natural gas or diesel fuel into oxygen containing fluids ranging from air to oxygen enriched air to oxygen).
14.13.1 Entraining through Cylindrical Wall Opening
In the relevant art, work engines are shown which draw their air in through openings, slots or perforations in or around a fluid duct 130, or in or around a fluid sub-duct 131 connected to such a fluid duct 130. E.g., a fluid delivery duct 131 connected to a cylinder, or within the cylinder itself As shown in
As shown in
Where a reciprocating compressor or piston moves over such wall openings 196, users preferably provide cylinder slider wear bars 198 for the piston to ride on. The perforated tubes 10 are configured upstream of the slider wear bars 198 and preferably in line with them.
14.13.2 Delivering a Fluid through an Intake Duct or Port
As exhibited in
In other configurations using arc or circular contactor tubes 10 about a cylindrical duct, users configure radial orifices 85 with multiple diameters to provide micro-jets with multiple penetration distances as desired. These are configured to penetrate a desired fraction of the radius from the peripheral fluid duct wall 132 towards the axis of the fluid duct 130.
They correspondingly configure the frequency and spacing of the orifices areas and micro-jet penetration distances to desirably fill the cross-sectional area to be covered at the respective jet penetration distances. For example, as shown in
Users further configure combinations of contactor tubes 10 across the fluid duct 130, about or along the periphery of the duct 130 or 131, or about or along an axial hub of the fluid duct 130 in some embodiments.
As shown in
14.13.3 Delivering a Fluid into a Prechamber
With further reference to
Where flow of the second fluid 904 through such sub-ducts or prechambers 131 into main chambers 130 is controlled by sub-duct valves 231, users preferably configure the contactor arrays 260 to desirably control the transverse evaporation time distributions and evaporation distance distributions relative to those sub-duct valves 231. These are desirably controlled to achieve desired degrees of fluid evaporation and mixing within the sub-ducts 131 and/or to control the level of splashing on the sub-duct valve 231 controlling that second fluid flow 904.
14.13.4 Delivering a Fluid into a Chamber
In some embodiments, with further reference to
This method permits the first fluid 901 (e.g., fuel) to penetrate and evaporate to a desired degree by the time the oxygen containing fluid 904 is compressed within the combustion chamber. This provides smaller more uniform drops with more uniform residence time. The results in significantly improved charge uniformity.
14.14 Delivery of Other Liquids
In some configurations, users use the direct contactor array deliver a fine spray of drops or “mist” of a lubricant into a transversely flowing fluid or gas. E.g., to add a suitable hydrocarbon, or hydro-fluorocarbon, water or other lubricant with desired transverse distributions of fluid flows to achieve the desired transverse distributions of composition or ratio of the first fluid to the second fluid. Some configurations deliver a fine mist of lubricants into refrigerants.
In a similar fashion users deliver cleaning fluids, refrigerants, fertilizers such as ammonia or other fluid with a desired transverse distribution of drop size and relative mass flows. In such configurations, achieving the desired transverse composition distributions are often more important than any heat transfer involved.
In further embodiments, users preferably form powders using one or more methods of liquid solidification, evaporation or chemical reaction.
15.2 Forming Uniform Liquid Drops
The contactor 2 of
Users preferably control the temperature of the liquid being delivered within a narrow prescribed range. This helps control the variation in surface energy, viscosity and density which affect drop size. Users preferably also control the temperature of the structure around the distributed orifices which helps control the solidification rate and solidification time.
15.2.1 Uniform Micro-jets
In a similar fashion, users preferably form uniform micro-jets of fluid and adjust the differential ejection pressure to form drops with fairly narrow size distributions. E.g., by preferably maintaining the liquid jets in the laminar region and forming single micro-jets rather than sprays whose oscillations form fairly uniform drops.
15.3 Distributed Direct Contact Drier
Spraying a fluid with slurried or dissolved materials into a hot gas is a common method of evaporating the carrier liquid, drying and recovering the solid materials such as milk powder. Users preferably deliver such compound fluids through embodiments of distributed perforated tube arrays to create drops with a desired transverse drop size distribution relative to a flow of second fluid flowing through the drier such as a heated gas. These drops are configured to evaporate within desired transverse distribution of residence times enabling much more controlled transverse distributions of evaporation distance. These measures of controlling drop size and evaporation distance further reduce the frequency of very small drops and particles, thus increasing product recovery. The narrow drop and particle distribution further reduces or prevents the formation of large drops. This reduces residence time and liquid carrier liquid carryover into the product. Users preferably utilize the methods described with respect to
As before, users preferably filter the compound fluid using a filter with a fairly uniform orifice size smaller than the product delivery orifices. With solids that tend to agglomerate, users preferably provide a wiper to remove solids built up on the filter. Users further provide a back flushing system to clear the filter.
15.4 Melt Drop Powder Former
In a similar fashion, users form powders from liquid melts, giving respectively more attention to radiation heat transfer than to evaporation. Users preferably hold the first fluid or “melt” temperature within a narrow prescribed range near the freezing point. With reference to
As shown in the enlarged view
With further reference to
As before users preferably control the transverse distributions of contactor parameters of orifice size, position, orientation and fluid delivery pressure and temperature to achieve the desired transverse distributions of drop size and solidification distance. Users preferably use orifices smaller than about 50 μm to obtain rapid cooling and small drop size. E.g., Reducing drop size from about 500 μm to about 50 μm achieves about 100 times faster equilibrium for the same mass. This method provides a significantly shorter drop height, faster production with associated benefits than the prior art.
15.4.1 Extended Cool Walls
With further reference to
In some embodiments, users form the tubes, drop passageways and cooling walls in spiral or concentric forms. In other embodiments, users form cooling walls by using cooling vertical tubes carrying coolant interspersed across the drop space, preferably in a hexagonal pattern.
15.4.2 Drop through a Vacuum
Molten metals often react with oxygen to form oxides. Many organic compounds similarly react with oxygen. To prevent or mitigate such reactions, users preferably evacuate the vessel through which the drops fall. The vacuum also eliminates convective cooling. The residence time for drops falling within the vessel is based on gravity caused acceleration. The dispersed cooling wall methods described above become even more advantageous with this configuration.
Users preferably use pipes for cooling surfaces as they can easily handle the pressure differences. In other embodiments, users can use coolant containing cooling walls where the walls are periodically bonded together to accommodate the pressure difference.
15.4.3 Drop through an Inert Gas
As a modification to falling liquid drops through a vacuum, users preferably deliver liquid drops to fall through an inert gas such as argon or possibly nitrogen. In calculating the drop velocity falling within the gas users preferably account for velocity dependent differential drag on the drop and buoyancy from differential density. In calculating the thermal residence time users preferably account for the influence of internal drop circulation on increasing heat transfer to the surface such as developed by Sirignano (1999) and others.
15.5 Uniform Powder Former by Reactive Liquids
15.5.2 Ultra Violet Solidification
Some chemicals are formed by exposing a reactive compound to Ultra Violet (UV) radiation. Users preferably form fine drops of the reactive compound with embodiments of direct contactor systems 2. Users then preferably send the drops through or exposed to an ultra violet radiation field. Users preferably form this UV radiation field with banks of UV lamps, preferably located at the foci of parabolic or similar reflectors to direct all the radiation across the falling drops. Users can also use vertical UV lamps with drops falling between them.
Often the UV radiation lamps are more intense and narrow. Consequently much of the UV radiation is poorly or non-uniformly intercepted by drops. Users preferably distribute the UV radiation more uniformly along the drop cavity. Users preferably provide reflective surfaces, linear Fresnel mirrors, or Fresnel lenses in a normal V or inverted V configuration in parallel with the UV lamps. In other embodiments, the UV lamps are interspersed among the perforated tubes, preferably above the drop space, but may also be below that drop space.
15.5.3 Drop through Reactive Gas
For liquids that react with a gas to form solids, users preferably form the drops with distributed perforated tube arrays 2. The reactive gas is flowed across the perforated tubes 10. The gas flow is preferably vertical to improve product uniformity. The drop residence time is preferably controlled to ensure a prescribed portion of the reactive liquid in the drops reacts with the surrounding gas.
Direct contactor arrays may be used to assist in recovering droplets and particles in some configurations. See, for example,
16.2 Gravity Settling
In some embodiments, users configure a gravity separator in a very similar fashion to the direct contact heat exchanger 483 shown in
In some embodiments, users preferably select duct dimensions to provide a smooth laminar flow. Steps, baffles and other flow changes that cause eddies are preferably avoided. Users preferably utilize numerous fairly uniform orifices 80 to form fairly uniform micro-jets or fairly uniform drops of a first fluid 901 and deliver them to the fluid duct 130 to effectively contact the second fluid 904.
Where users form fairly uniform sized drops of the first fluid 901, this results in a generally uniform settling velocity across the second fluid flow 904. Fairly uniform drops have a fairly predictable residence time depending on where they are released, the relative uniformity of the flow, the difference in density, the viscosity of the second fluid, and the maximum duct height through which the drops settle. Users then select a length of fluid duct 130 long enough and/or the duct area large enough or reduce the velocity slow enough to provide the desired residence time so that they recover at least a prescribed portion of the drops.
16.3 Settling Planes
As in the discussion herein on using multiple planes in layered cross-flow contactors and heat exchangers, users preferably provide multiple settling planes or duct walls 132 to form multiple sub-ducts 131 to recover the fluid 901 in some embodiments. (See, for example,
Suitable methods are further described above in the discussion of the cross-flow contactor, heat exchanger 483 and/or evaporator. As before, users preferably adjust the transverse distributions of direct contact parameters to achieve desired transverse distributions of settling time according to the respective second fluid parameters and duct parameters.
16.4 Cyclones
Cyclones are commonly used to recover drops and solid particles. However, conventional drop or particulate formation results in a wide distribution of drop or particulate sizes. The efficiency of cyclones drops off dramatically for smaller drop or particulate sizes. E.g., Kim and Lee (1990) measured the efficiency of a small cyclone 3.11 cm diameter by 9.5 cm high (barrel and cone). They found the efficiency drop off from 80% at about 7 microns to less than 10% at about 4.5 microns. Griffiths and Boysan (1996) obtained very close correlation with those experimental results by modeling the cyclone with Computational Fluid Dynamics using a Randomized Normal Grouping (RNG) based k-ε turbulence model to account for the swirling flow.
With a broad distribution, a cyclone will typically only recover a portion of the drops or powders. Often cyclones are sized much smaller and more numerous than needed for mean drops to recover smaller drops or particles. This undesirably requires many more cyclones. It also requires much higher pressure drops with higher pumping costs.
In some embodiments of distributed direct contactor arrays, users preferably generate fairly uniform sized drops or a narrow prescribed distribution of drop sizes. By using the analysis methods of Griffiths and Boysan (1996) users preferably obtain a cumulative distribution of drops recovered vs size. In modified embodiments, other suitable analysis methods may be efficaciously used, as needed or desired.
As shown schematically in
Using such methods, users preferably size the cyclone dimensions and flow parameters to achieve a prescribed cumulative distribution of drops recovered. By such methods, users preferably achieve greater than about 99% drop recovery at significantly lower rates of flow of the fluid per cyclone. This improves recovery and revenues and lowers pumping costs compared to conventional systems. In other embodiments, for the same gas flow rate, users can use larger or fewer cyclones and thus reduce operating and/or capital costs.
In modified embodiments, users use the experimental methods of Kim and Lee (1990) to obtain recovery efficiency versus drop size. Users then extrapolate the recovery efficiency versus size to identify the drop size at nominally 100% recovery. Users then select the drop size to be greater than the size needed to achieve greater than this nominal 100% recovery with the cyclone under consideration.
16.5 Electrostatic Precipitators
Electrostatic precipitation technology is used to remove droplets or particulates from a gas stream. Prior art sprays result in a wide distribution of droplet or particulate sizes. Consequently, and disadvantageously, the electrostatic precipitation equipment are sized to remove the smallest particulates or droplets tolerable. Particulates smaller than that are undesirably lost with the exhaust gas flow.
16.5.1 Recovering Liquid Drops
In some embodiments, distributed direct contactors are used to form drops of the first fluid of fairly uniform size. This enables users to size the electrostatic precipitators and the voltages provided by the high voltage power supply used to remove these generally uniform drops. This provides a substantial reduction in size of the electrostatic precipitator and/or power required to recover a prescribed fraction of particles.
16.5.2 Recovering Solidified Powders
Users preferably utilize distributed direct contactors to form fairly uniform drops. Users solidify these drops to form fairly uniform powders. To recover these powders, an electrostatic precipitator is then provided. Users adjust the dimensions gas flow and power to efficiently recover these fairly uniform particles. Users obtain greater recovery efficiency with associated benefits than the prior art.
16.5.3 Recovering Evaporated Powders
Users similarly apply this method with driers to recover the powders formed by drying fluids containing slurries or dissolved solids. By creating fairly uniform drops, users form much more uniformly sized powders. Users then recover these powders with this electrostatic precipitator method with greater efficiency and associated benefits than the prior art.
16.6 Impingement Separators
Another common method of separating entrained droplets from the second fluid is to direct the flow through a tortuous passage which changes the fluid flow direction. A fluted array is commonly used to force the gas to change direction by traversing the flutes. Particles with a drop size and mass to drag ratio greater than certain values will impinge on the passage wall. Particles with smaller drop size and smaller mass to drag ratios will be carried on through by the gas.
By generating fairly uniform drops, users significantly improve recovery of impingement separators. Users preferably size the impingement passages, orifice size drop size and gas velocity such that most of the particles will impinge on the impingement separator with very few carried past the separator. Correspondingly users adjust the gas velocity and passage size to reduce the pressure drop and pumping cost of forcing the fluid through the impingement separator.
As with steam generation, heat recovery in concentrated solar collectors in prior art is typically limited by the material thermal stress limits. The solar flux is focused on tubes containing a fluid that is heated such as water or helium, or liquid sodium. In some embodiments, users preferably use distributed perforated tube arrays 260 to provide a dense “rain” of very small drops across the duct 130 receiving the high intensity concentrated solar flux, as shown in
With reference to
In other embodiments, users form the wall of the cavity with an array of sapphire contactor tubes. Users then pass the absorbing heat transfer fluid through the tubes and numerous surrounding micro-jets to absorb the heat from the solar flux. This helps cool the tubes as well as increase the optical absorption density within the duct 130.
From the foregoing description, it will be appreciated that a novel approach for distributed contacting, mixing and/or reacting of two or more fluids has been disclosed using one or more methods described herein. While the components, techniques and aspects of the invention have been described with a certain degree of particularity, it is manifest that many changes may be made in the specific designs, constructions and methodology herein above described without departing from the spirit and scope of this disclosure. Where dimensions are given they are generally for illustrative purpose and are not prescriptive. Of course, as the skilled artisan will appreciate, other suitable nominal thicknesses, diameters, spacings and other dimensions and parameters for perforated tubes, tube arrays, and other components may be efficaciously utilized, as needed or desired, giving due consideration to the goals of achieving one or more of the benefits and advantages as taught or suggested herein.
Where tube or array configurations are provided, similar two or three dimensional configurations or combinations of those configurations may be efficaciously utilized. Where the terms fuel, diluent, water, air, oxygen, and oxidant have been used, the methods are generally applicable to other combinations of those fluids or to other combinations of other fluids. Where assembly methods are described, various alternative assembly methods may be efficaciously utilized to achieve configurations to achieve the benefits and advantages of one or more of the embodiments as taught or suggested herein.
Where transverse, axial, radial, circumferential or other directions are referred to, it will be appreciated that any general coordinate system using curvilinear coordinates may be utilized including Cartesian, cylindrical, spherical or other specialized system such as an annular system. Similarly when one or more transverse or axial distributions or profiles are referred to, it will be appreciated that the configurations and methods similarly apply to spatial control in one or more curvilinear directions as desired or prescribed. Similarly, the contactor, array, device or duct orientations may be generally rearranged to achieve other beneficial combinations of the features and methods described.
Where fluid delivery controls refer to controlling the size and flow rate of ejecting drops or micro-jets, it will be appreciated that the control measures may utilize one or more measures to control the differential ejection pressure distributions across the orifices 80, vibrate the orifices, and/or control the electric field outside the orifices 80 using one or more measures described herein or using similar means of modulating the orifices location, the fluid pressure and the surrounding electric field.
While the components, techniques and aspects of the invention have been described with a certain degree of particularity, it is manifest that many changes may be made in the specific designs, constructions and methodology herein above described without departing from the spirit and scope of this disclosure.
Various modifications and applications of the invention may occur to those who are skilled in the art, without departing from the true spirit or scope of the invention. It should be understood that the invention is not limited to the embodiments set forth herein for purposes of exemplification, but includes the full range of equivalency to which each element is entitled.
This application is a continuation-in-part of U.S. patent application Ser. No. ______, filed Sep. 12, 2003, which is a conversion of U.S. Provisional Application No. 60/418,989, filed Oct. 15, 2002, this application claims the benefit of the earlier filed applications under 35 U.S.C. § 119(e) and 35 U.S.C. §120 which are also incorporated by reference herein.
Number | Date | Country | |
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Parent | 10713899 | Sep 2003 | US |
Child | 10686191 | Oct 2003 | US |