The present invention relates generally to the field of contacting systems and methods. In particular, the invention relates to systems and methods of contacting two or more fluids and uses thereof, such as removing contaminants from or adding supplements to liquids, such as fuels.
Removal of a material from or addition of a material to a liquid can be useful in many applications. For example, adding a gas to a liquid is required for the production of carbonated beverages. Removal of a gas from a liquid may be desirable to produce a purified liquid, for example. Purified liquids are desirable in many applications. In particular, removal of contaminants from a liquid may be required in many industrial and commercial applications. For example, in the case of fuels, such as diesel or jet fuels, impurities in the fuel can result in high maintenance costs and poor performance. For example, the presence of oxygen in fuels can result in poor performance of a machine using the fuel, such as a jet engine. Further, oxygen-saturated fuels can inhibit a coolant or heat-sink function served by fuels when the oxygen-saturated fuel causes coking, thereby restricting fuel flow.
Conventional methods of removing contaminants, such as oxygen, from liquids, such as fuels, have considerable drawbacks. For example, use of reducing agents to chemically bind the oxygen results in further contamination issues related to the active metals which may be used. Further, the large volume and weight of such systems prohibits their use on aircraft in-flight purification systems. Accordingly, there is a need for improved systems and methods of purifying liquids while eliminating such drawbacks.
The present invention provides systems and methods for purifying or infusing a liquid which allow efficient and/or uniform addition of components to or removal of components from the liquid. The components may be undesirable components to be removed from a liquid or a desired component or components to be added to the liquid, for example, each of which is referred to herein as “component.”. In this regard, the disclosed embodiments provide for the purification or infusion of a liquid by passing the liquid and a fluid through a porous medium. The porous medium facilitates mixing of the liquid and the fluid. A differential of partial pressure, activity, fugacity or concentration of the components between the liquid and the fluid facilitates the transfer of the components between the liquid and the fluid in the mixed liquid and fluid.
One embodiment of the invention relates to a method of transferring a component between a liquid and a fluid. The method includes passing a liquid, such as a fuel, and a fluid, such as a gas, through a porous medium, at least one of the liquid and the fluid containing a component, such as oxygen gas, therein. Within the porous medium, the liquid and the fluid mixture has a component partial pressure differential. The passing causes mixing of the liquid and the fluid and transfer of at least some of the component between the liquid and the fluid. The method may also include, separating the liquid and the fluid after the transfer of the component.
In another embodiment, the invention includes a system for transferring a component between a liquid and a fluid. The system includes a porous medium adapted to cause mixing of a liquid and a fluid and transfer of at least some of a component between the liquid and the fluid, and a separator for separating the liquid and the fluid.
In another embodiment, the invention includes a porous medium for facilitating mixing of a liquid and a fluid. The porous medium includes a porous body and pores being adapted to cause surface mixing of a fluid flowing therethrough with a liquid having a component flowing therethrough. In a particular embodiment, the pores have sufficiently small pore sizes and sufficiently complex shape to cause surface mixing.
In another embodiment, the invention includes a mixing body adapted to mix a liquid and a fluid. The mixing body includes a plurality of axial channels for passing a liquid therethrough into a path substantially aligned with the axial channels. The mixing body also includes a porous body for diffusing a fluid into the path.
One embodiment of the invention includes a system for transferring a component between a liquid and a fluid. The system includes a porous medium adapted to cause mixing of a liquid and a fluid, at least one of the liquid and the fluid having a component therein. The porous medium is further adapted to cause transfer of at least some of the component from the liquid to the fluid. The system may also include a separator for separating the liquid and the fluid.
A “component” may be mixed, absorbed, suspended or dissolved in the liquid or the fluid.
“Fluid” may be a liquid, a gas or a material in any phase which allows the material to flow readily.
In one embodiment, the system also includes a fluid purification module adapted to remove the component from the fluid. In a particular embodiment, the fluid purification module includes a pressure swing adsorption module. In other embodiments, the purification module may include membranes. A recirculation line may be provided to transfer the fluid from the fluid purification module to the porous medium.
As used herein, “purification” and “purifying” refer to the removal from a fluid of one or more components. The removal may be partial, complete or to a desired level and may include removal of only some or all components.
In one embodiment, the system may also include a recirculation line adapted to transfer the fluid from the separator to the porous medium.
In one embodiment, the system also includes a vapor trap adapted to separate vaporized liquid mixed with the fluid from the separator.
In a particular embodiment, the porous medium includes pores having a pore size of less than 500 microns. In a further particular embodiment, the pore size is between about 350 and about 450 microns. In a still further embodiment, the pore size is approximately 400 microns.
In one embodiment, the system also includes a pre-mixer adapted to provide a mixture of the fluid and the liquid to the porous medium. In a particular embodiment, the pre-mixer includes a plurality of axial channels for passing the liquid therethrough into an axial path directed toward the porous medium and a porous body for diffusing the fluid into the axial path. The pre-mixer may also include an annular passage along a circumferential perimeter of the pre-mixer for receiving the fluid and directing the fluid to the porous body.
The porous medium may be made of an inert material, such as metals, ceramics, plastic, glass or other organic or inorganic solid materials.
In one embodiment, the separator includes at least one centrifugal separator.
In a particular embodiment, the liquid is a fuel and the component is a gas. The fuel may be diesel, kerosene or jet fuel, for example. The gas may be oxygen.
In a particular embodiment, the component is a gas that is dissolved in the liquid prior to passing the liquid and the fluid through the porous medium.
In one embodiment, the fluid is a gas. In a particular embodiment, the gas is a non-reactive gas under operating conditions, such as nitrogen, argon, helium or carbon dioxide, that is substantially free of the component. In other embodiments, the gas may be a noble gas.
Another embodiment of the invention includes a method of transferring a component between a liquid and a fluid. The method includes passing a liquid and a fluid through a porous medium, at least one of the liquid and the fluid containing a component therein, the passing causing mixing of the liquid and the fluid and transfer of at least some of the component between the liquid and the fluid. The method may further include separating the liquid and the fluid, at least one of the separated fluid and the separated liquid including at least some of the component.
In a particular embodiment, the method also includes removing the component from the fluid if the component has been transferred from the liquid to the fluid. Removing the component may include pressure swing adsorption. In a further particular embodiment, the purified fluid may be recirculated for use in any continuation of passing the fluid through the porous medium.
In a particular embodiment, the method also includes recovering any vaporized liquid mixed with the fluid after separation of the fluid from the liquid.
In one embodiment, the method also includes passing the liquid and the fluid through a pre-mixer before passing through the porous medium. In a particular embodiment, the pre-mixer includes a plurality of axial channels for passing the liquid therethrough into an axial path directed toward the porous medium and a porous body for diffusing the fluid into the axial path. The pre-mixer may further include an annular passage along a circumferential perimeter of the pre-mixer for receiving the fluid and directing the fluid to the porous body.
In one embodiment, separating the liquid and the fluid includes passing the fluid and the liquid through at least one centrifugal separator.
Another embodiment of the invention includes a porous medium for facilitating mixing of a liquid and a fluid. The porous medium includes a porous body and pores formed in the porous body. The pores are adapted to cause surface mixing of a fluid with a liquid having a component flowing through the porous body. The pores have pore sizes sufficiently small and pore shapes sufficiently complex to cause surface mixing.
Still another embodiment of the invention includes a method of purifying a liquid. The method includes passing a liquid and a fluid through a porous medium, the liquid containing a component therein, the passing causing mixing of the liquid and the fluid and transfer of at least some of the component from the liquid to the fluid. The method also includes separating the liquid and the fluid, the separated fluid including at least some of the component, and removing the component from the fluid. The fluid with the component removed is recirculated for use in any continuation of passing the liquid and fluid through the porous medium.
Another embodiment of the invention includes a mixing body adapted to mix a liquid and a fluid. The mixing body includes a plurality of axial channels for passing a liquid therethrough into a path substantially aligned with the axial channels and a porous body for diffusing a fluid into the path. In a particular embodiment, the mixing body also includes an annular passage along a circumferential perimeter of the porous body for receiving the fluid and directing the fluid to the porous body.
In this regard, “a path substantially aligned with the axial channels” refers to the general direction of flow. The path may include a conical or radial component. For example, in certain regions, the path may include only a radial component which transitions or diffuses into an axial flow.
Referring to
The system 100a includes a purification module, such as a deoxygenation module 110, which is described in greater detail below. The deoxygenation module 110 is adapted to receive a liquid fuel and gaseous nitrogen. The liquid fuel may have a component, such as gaseous oxygen, absorbed therein. The gaseous nitrogen is preferably substantially oxygen-free. The operation of the deoxygenation module 110 causes the gaseous oxygen to be transferred from the fuel to the nitrogen. Thus, the outputs of the deoxygenation module 110 in the system 100a are de-oxygenated fuel and gaseous nitrogen with oxygen absorbed therein. A limited amount of fuel vapor may be output with the nitrogen/oxygen stream.
Referring now to
The deoxygenation module 110 is also adapted to receive a supply of a fluid, such as a gas, to mix with the fuel. In certain embodiments, the fluid is a non-reactive gas, such as nitrogen, argon, or the like. In the illustrated example, the fluid is nitrogen gas. The nitrogen may be received from a pressurized nitrogen bottle. In other embodiments, the nitrogen is received from a fluid purification module, such as a highly optimized pressure swing adsorption (PSA) system 120, which supplies substantially oxygen-free nitrogen (e.g., 99.9% N2). The flow of nitrogen into the deoxygenation module 110 may be regulated using a flow meter 122, for example. In one embodiment, the deoxygenation module 110 is adapted to receive nitrogen and fuel at a rate based on the desired fuel output. For example, the large fluid-to-fuel ratio may be used to obtain a more purified fuel while a smaller fluid-to-fuel ratio may be used to obtain a less purified fuel. In particular embodiments, the fluid-to-fuel ratio may be 10:1, 4:1, 2:1, 1:1, 1:2, 1:4, or 1:10.
The deoxygenation module 110 is adapted to transfer the component, such as oxygen gas, from the fuel to the nitrogen gas. This aspect of the deoxygenation module is described in greater detail below with reference to
In many cases, certain amounts of the liquid fuel may evaporate either in the deoxygenation module 110 or prior to entering the deoxygenation module 110. In this regard, the system 100b includes a fuel vapor recovery module 150 through which the nitrogen stream is processed. The fuel vapor recovery module 150 may be a vapor trap including a coalescing filter adapted to separate the fuel vapor from the nitrogen stream, producing condensed fuel. The condensed fuel is then routed to the fuel stream 140 exiting the deoxygenation module 110, as shown in
The stream of nitrogen with oxygen from the fuel vapor recovery module 150 can then be directed to the PSA system 120, which separates the oxygen from the nitrogen. The purified nitrogen can then be used for deoxygenation of additional fuel, while the oxygen can be vented to the atmosphere. In cases where the system 100b is operating in a closed environment, such as a laboratory or an operational application in a closed area, the stream of nitrogen and oxygen may be further treated prior to being directed to the PSA system 120. The stream of nitrogen and oxygen may be similarly treated in systems without a PSA system. For example, the stream of nitrogen and oxygen may be treated through an active carbon filter to remove components prior to either PSA processing or venting to the atmosphere. In other embodiments, the active carbon filter may be positioned upstream of the PSA system 120. Thus, the components may be removed from the nitrogen as well.
The exemplary purification system 100 is illustrated in further detail in
Further, a fuel thermal regulator 136 may be provided to control the temperature of the fuel. The temperature may require regulation based on the requirements of the machine for which the fuel is deoxygenated. The fuel thermal regulator 136 may include a heater for increasing the fuel temperature and/or a heat exchanger for increasing or decreasing the fuel temperature. In certain embodiments, the temperature of the fuel may be increased to facilitate removal of a component.
The control system 400 includes control modules for controlling the various modules of the system 100. A flow control module 410 is provided to control the flow rates of the fuel and the nitrogen gas. In this regard, the flow control module 410 may be adapted to communicate with and control the flow meter 122 and the pump 132 described above and shown in
As illustrated in
An embodiment of a pre-mixer 210 will now be described with reference to
The illustrated embodiment of the pre-mixer 210 includes a porous body 212 which allows the nitrogen gas to deliver a relatively even discharge adjacent to the contactor. An annular channel 214 is provided to receive the nitrogen gas from, for example, the PSA system, and distribute the gas across the cross-section of the porous body 212 through a set of non-axial channels 216. The non-axial channels 216 guide the gas from the annular channel 214 into various sections of the porous body 212 for diffusion through the porous body along an axial path.
Axial channels 218 are provided through the pre-mixer 210 and are substantially evenly distributed, avoiding any non-axial gas channels 216. The axial channels 218 allow the liquid fuel to pass through the pre-mixer 210. In a particular embodiment, a large number of axial channels 218 are provided to facilitate even distribution of the fuel. In one embodiment, the size of the axial channels 218 is sufficiently large so a particulate will not block passage of the liquid fuel with minimal back pressure.
The porous body 212 of the pre-mixer 210 is preferably made from a porous material with channels for the liquid, as described above. In other embodiments, the pre-mixer can be made from a solid piece or multi piece assembly of solid materials. In this regard, the pre-mixer may include channels for the liquid as well as channels for the fluid. The channels for the fluid may be substantially smaller than the channels for the liquid. However, the cost to manufacture a pre-mixer with solid materials can be substantially higher compared to the cost of using porous materials.
Porosity of the pre-mixer can be chosen with certain basic parameters satisfied. For example, the gas used in the process (e.g., nitrogen gas) should flow through the porous body 212 with minimal flow restriction, such as approximately 1%-6% pressure drop under operating conditions. Further, the liquid being processed (e.g., liquid fuel) may pass through the porous material under pressure closely above operating liquid pressure. The porous material should be chemically compatible or resistant to the fluid and liquid being processed.
The porous body may be designed to accommodate various flow patterns for the liquid. For example, in one embodiment, the flow of the liquid may be substantially axial and linear. In other embodiments, the flow may be non-linear through the porous body. Still in other embodiments, the flow may be substantially radial in certain regions.
A small distance may be provided between the pre-mixer 210 and the contactor 220 to allow the pressure across the contactor to equalize. In one embodiment, this distance is approximately 0.25 to 1.25 mm. In another embodiment, direct mating of the pre-mixer 210a and the contactor 220 may be facilitated by providing a subsectioned pre-mixer, as illustrated in
It is noted that the fuel-gas contactor 200 may operate without the pre-mixer. The pre-mixer is provided to reduce the effects of orientation and external forces upon the fuel-gas contactor 200.
An embodiments of the contactor 220 will now be described with reference to
The fine porosity of the porous body 222 creates a pressure differential across the length of the porous medium and results in a highly sheared flow. In this environment, the high-shear mixing of the fuel and nitrogen allows transfer of the oxygen due to a differential in the oxygen partial pressure in the fuel versus the nitrogen. This concept is illustrated in
Similarly,
By contrast, as illustrated conceptually in
While the exemplary embodiments illustrated in the Figures and described above are presently preferred, it should be understood that these embodiments are offered by way of example only. Other embodiments may include, for example, different techniques for performing the same operations. The invention is not limited to a particular embodiment, but extends to various modifications, combinations, and permutations that nevertheless fall within the scope and spirit of the appended claims.
This invention was made with Government support under government contract no. FA8650-04-C-2457 awarded by the U.S. Department of Defense to Phyre Technologies, Inc. The Government has certain rights in the invention, including a paid-up license and the right, in limited circumstances, to require the owner of any patent issuing in this invention to license others on reasonable terms.