Patent Application
20090323460
The present invention relates to systems and methods for mixing components using turbulence. More specifically, the present invention is a system and method for using turbulence to thoroughly and rapidly mix and blend components, thereby maximizing the evenness and degree of mixing and blending while minimizing reduction in flow rate.
Mechanical mechanisms, both active and passive, exist for mixing and blending components. However, many of these methods have problems and limitations. Most processes require a thorough mixing and blending of components, some of which can benefit from a finer-scale and more-complete, in-stream, continuous-flow mixing. For example, it is sometimes desirable to mix fuel and water for consumption by a diesel engine. Such a mixture reduces pollutants, including oxides of nitrogen and emissions of particulates.
Other obstacles to mixing diesel fuel and water include diesel fuel and water are immiscible, i.e., will not remain homogenized for long once mixed; the presence of water corrodes most metal; and the presence of water in diesel fuel facilitates the growth of microbes which can clog fuel lines.
The present invention overcomes the above-described and other problems and limitations by providing a system and method for mixing flowing components using turbulence created by manipulating the flows to maximize the evenness and degree of mixing while minimizing reduction in flow rate. The present invention does this by creating vortices, in one or both components, parallel to the stream at the interface between the components.
In one embodiment, in which first and second components are flowing in a generally downstream direction, the system broadly comprises at least one first opening; at least one second opening located downstream of the first opening, wherein the first opening is offset from the second opening; and an intermediate structure having a larger first end presenting a mouth, a smaller second end, and at least one exit opening located between the first and second ends, wherein the first end is positioned substantially over a downstream side of the first opening, and the second end is positioned substantially adjacent to an upstream side of the second opening, and wherein the second component flows into the first opening, into the mouth of the intermediate structure, and out the exit opening, the first component flows past the first opening and interacts with the second component flowing out the exit opening such that turbulence is created which mixes the first and second components, and the mixed first and second components flow out the second opening.
In various applications, the system may further comprise any one or more of the following features. The first component may be a fuel; the second component may be an additive, such as water. The first and second openings may be polygonal, such as hexagonal. The edges of the first and second openings may be contoured to reduce both cavitation and resistance to flow. A vane may be located in the flowpath of at least one of the first or second components for creating additional turbulation in the flow thereof. A twisted structure may be located within at least one of the first or second openings for creating additional turbulation in the flow of the component therethrough. The intermediate structure may generally taper along its length between the first end and the second end. The intermediate structure may vibrate. The exit opening may include a first end and a second end located downstream of the first end, and the first end may be offset from the second end, such that the exit opening is angled. The intermediate structure may include a mesh material presenting a plurality of exit openings. The exit opening may vibrate. The intermediate structure may be twisted along at least a portion of its length for creating additional turbulation in the flow of the second component therethrough. The system may include a sensor located downstream of the second opening and operable to sense a property of the mixed first and second flows and to provide a sensor signal indicative thereof to a control mechanism for controlling an upstream activity to optimize the sensed property. The first and second components may be diesel fuel and water, and the sensor may be operable to detect the amount of water in the mixed first and second flows. A shut-off mechanism may be included for stopping the flow of the second component before the flow of the first component is shut off. The size and distribution of the openings is adjusted to produce a Reynolds number sufficient to produce a turbulent flow. Depending on the particular application, the Reynolds number may be approximately between 2000 to 3000.
These and other features of the present invention are described in greater detail below in the section titled DETAILED DESCRIPTION OF THE INVENTION.
The present invention is described herein with reference to the following drawing figures, which are not necessarily to scale:
With reference to the drawing figures, a system and method are herein described, shown, and otherwise disclosed in accordance with various embodiments, including a preferred embodiment, and implementations of the present invention. Broadly characterized, the present invention is a system and method for mixing and blending components. The present invention controls turbulence to thoroughly and rapidly mix and blend components, maximizing the evenness and degree of mixing and blending while minimizing reduction in flow rate.
More specifically, the present invention advantageously allows for maximizing the rate and intimacy of mixing continuous flow, variable proportion component streams while minimizing the flow resistance to those streams. This is accomplished by introducing turbulence at multiple scales in both the radial (across the flow) and longitudinal (with the flow) directions. The components may be substantially any components susceptible to turbulation, including fluids, gasses, and powders; compressible and incompressible components; reactants, catalysts, or additives; pure and previously mixed components; and miscible and immiscible components. If the components are immiscible, the resultant mixture may be an emulsion. Potential applications for the present invention include processing chemicals, petroleum products, foods, drugs, synthetic materials, and resins, as well as processing fuels for engines, burners, and furnaces. For example, as discussed below, one of the components may be diesel fuel and the other may be water.
Referring to
In operation, the second component flows into the first opening 22, into the mouth of the intermediate structure 26, and out the exit opening 32. The first component interacts with the second component flowing out the exit opening 32 such that turbulence is created which mixes the first and second components. The mixed first and second components flow out the second opening 24.
The shapes, sizes, and numbers of the openings 22,24 and exit openings 32 may depend on the particular components and application, as well as the desired performance of the system, including the desired Reynolds number, i.e., the ratio of inertial forces to viscous forces. For example, for at least some applications, at least one of the openings 22,24 may be either substantially circular or polygonal. For at least some applications, a hexagonal shape may be desirable as providing the maximum packing density and resulting in the least amount of wasted space and material. For at least one application, in which the components are diesel fuel and water, there may be at least nineteen first openings 22 arranged in three approximately concentric rings, with each first opening 22 being substantially hexagonal in shape, and at least nineteen second openings 24 arranged in three approximately concentric rings, with each second opening 24 being substantially hexagonal in shape. Depending on the particular application, the Reynolds number may be approximately between 2000 and 3000 in order to achieve sufficient turbulation.
Also, for at least some applications, it may be desirable to contour the edges or other surfaces of the first or second openings 22,24 using, e.g., an airfoil shape, in order to minimize both cavitation and resistance to flow.
The shapes, sizes, and number of the intermediate structures 26 may also depend on the particular components and application, as well as the desired performance of the system 20. In at least some applications, the intermediate structure 26 may generally taper between the first end and the second end. For example, the intermediate structure 26 may be substantially conical, frustoconical, parabolic, or hyperbolic. In at least some applications, the intermediate structure 26 may be shaped so as to draw the components in the downstream direction, including through a mutual induction effect, thereby compensating, at least to some degree, for any flow resistance introduced at other points in the system 20.
For some applications, the intermediate structure 26 may be constructed, in whole or in part, from a mesh material presenting a plurality of exit openings 32. In one implementation, the mesh material may be screen or screen-like material. In one application, the intermediate structure 26 may vibrate to further create and control turbulence. Alternatively, only the exit opening 32 may be made to vibrate to achieve substantially the same effect. For example, the intermediate structure 26, or, alternatively, only the exit opening 32, may be constructed, in whole or in part, of a metal or other material that vibrates at ultrasonic frequencies in response to an applied magnetic field or voltage.
Referring to
For various applications, the system 20 may further include one or more vanes 33 or other devices for manipulating the flow of one or both of the components to create additional turbulation. The vanes 33 may be located upstream of the first opening 22, between the first and second openings, 22,24, or downstream of the second opening 24. The vanes 33 may take the form of ridges machined into the walls of the conduits or manifolds through which the components flow. Referring also to
For various applications, the system 20 may further include one or more sensors 35 located downstream of the second opening 24 and operable to sense one or more properties of the mixed first and second flows and to provide a signal indicative thereof for controlling an upstream activity, such as the flow rates of one or both components, to optimize the sensed properties. For example, in one application, the components are diesel fuel and water, and the downstream sensor 35 is operable to detect the amount of water in the mixed first and second flows and to provide a sensor signal indicative thereof for controlling the flow of water to optimize the detected amount.
For various applications, a plurality of the systems 20, or portions thereof, may be arranged in series to further mix the components. For example, a third opening may be located downstream of the second opening 24 and structurally and functionally related thereto in substantially the same manner as the first opening 22 is related to the second opening 24, including a second intermediate structure extending between the second opening 24 and a point that is adjacent to an upstream side of the third opening.
Referring also to
In operation, the first component flows past the exit openings 232 of the intermediate structures 226 associated with the second portion of the first polygonal openings 222 such that turbulence is created which mixes the first and second components, the second component flows past the exit openings 232 of the intermediate structures 226 associated with the first portion of the first polygonal openings 222 such that turbulence is created which mixes the first and second components, and the mixed first and second components flow out the second polygonal openings 224. After exiting the second openings 224, the components may continue to mix as adjacent streams interact with, e.g., shear against, each other, as seen in
In addition to those expressly included, any one or more of the additional features discussed in association with the first embodiment of the present invention may be incorporated into or otherwise used with this particular implementation of the system 220 for this particular application.
The implementation of
When mixing diesel fuel and water, relatively fine scale mixing is desired. The scale of mixing is, at least in part, a function of the number of vertices among the sets of first and second polygonal openings 222,224. As such, the implementation of
The implementation of
Thus, it will be appreciated that the present invention overcomes many obstacles associated with mixing components. For example, the present invention mixes at the point of application and eliminates the need to store mixtures in a state where components might separate, and it eliminates the need for premixed emulsions and potentially-polluting additives. With regard to mixing diesel fuel and water, for example, the present invention avoids the presence of unconsumed water and thereby minimizes corrosion, avoids mixing the diesel fuel and water until needed, thereby eliminating the growth of microbes and the untimely separation of the mixed components, and minimizes adverse interference with flow rates through the use of turbulence rather than mechanical mixing mechanisms.
Although the invention has been disclosed with reference to various particular embodiments and implementations, it is understood that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims.
