Plate Fin Fluid Processing Device
A device for processing fluids includes a number of fin layers with a number of plates separating the fin layers so that a fluid flow passage is defined through each fin layer. A first fluid inlet is in communication with a first end portion of the fluid flow passage, a first fluid outlet is in communication with a second end portion of the fluid flow passage, a second fluid inlet is in communication with the second end portion of the fluid flow passage and a second fluid outlet in communication with the first end portion of the fluid flow passage. The fluid flowing through the second inlet is subjected to a shearing action by the fin layers so that mass transfer to the fluid flowing through the first inlet occurs. The device may be used for both liquid-liquid processes, such as extraction, or gas-liquid processes, such as adsorption, absorption or desorption and reactions.
This application claims priority from U.S. Provisional Patent Application Ser. No. 60/958,776, filed Jul. 9, 2007.
FIELD OF THE INVENTIONThe invention relates generally to fluid processing equipment and, more particularly, to a device for performing fluid processes that employs plate fin technology.
BACKGROUNDSeveral important processes in chemical or food production, waste treatment and recovery or purification operations involve the combination of two or more fluids so that separation, mixing and/or a reaction occurs. Such processes include gas-liquid processes, such as adsorption, absorption, desorption and two-phase reactions, and liquid-liquid processes, such as extraction and reactions. While acceptable equipment exists for performing such processes, deficiencies exist which detract from the efficiency of such devices.
The process of liquid-liquid extraction is well-known in the art, as are extractor devices for performing extraction. In liquid-liquid extraction, one or more components are removed from a liquid solution or mixture feed by intimate contact with a second liquid. The second liquid is immiscible with the liquid mixture, but functions as a solvent for removing the component(s) from the mixture as the second liquid exhibits a preferential affinity or selectivity towards one or more of the components in the mixture feed. Liquid-liquid extraction is therefore a mass transfer operation.
A conventional device widely used for performing liquid-liquid extractions is a sieve tray column, also sometimes referred to as a perforated plate column. Examples of such devices are presented in U.S. Pat. No. 3,988,116 to Robbins and U.S. Pat. No. 4,424,131 to Baird.
The liquid-liquid extraction process that occurs in a conventional sieve tray column 10 is illustrated in
As illustrated in
When bubbles reach the underside of the upper tray 12, their movement is impeded and they will rejoin to form a new layer of solution (Liquid 1) with a uniform concentration of component A. The layer is called a rejoining layer and is illustrated at 22 in
The mass transfer of component A to the solvent outside of the bubble 16 occurs by diffusion due to the gradient of concentration of component A at a boundary of the bubble. With reference to
CAb=concentration of component A at the inner edge of the boundary
CA=concentration of component A at the outer edge of the boundary (which is the concentration of component A in the solvent)
b=the thickness of the boundary
If the transfer through the boundary area is faster, then CAb and CA can reach equilibrium sooner. The transfer from inside of the bubble to the inner edge of the boundary, that is, the transition from concentration CA0 to concentration CAb (where CA0 is the concentration of A at the center of the bubble), is typically the rate control (limiting) step because it is slower than the transfer through the boundary area. The mass transfer from CA0 to CAb highly depends on diffusion which has a high mass transfer resistance. As a result, CAb increases slowly giving a low mass transfer efficiency due to the lower gradient in the boundary area of the bubbles (per the above equation).
Turning to an example involving a gas-liquid process, absorption or desorption is typically performed using a packed bed tower filled with high surface area or high efficiency packing materials. The efficiency from current packed bed devices, as described above with regard to the liquid-liquid extraction column, is also restricted by the limitation of mass transfer within the bubbles or droplets formed in the tower.
The formation of smaller bubbles or droplets in either the liquid-liquid or gas-liquid devices described above would help to provide more surface area per volume of material and a reduction of the diffusion distance in the bubbles or droplets. A need therefore exists for a fluid processing device that can provide a large surface area via the formation of smaller bubbles or droplets for mass transfer, and also provide convection mass transfer via mixing within bubbles or droplets through frequently separating and rejoining the bubbles or droplets.
The plate fin device basically uses the technology of the FINTEC line of heat exchangers and reactors of Chart Energy & Chemicals, Inc. of The Woodlands, Texas. More specifically, as illustrated in
While three fin layers are illustrated in
As illustrated by arrows 36 and 38 in
As illustrated in
An alternative and preferred embodiment of a fin layer and separating plates of the plate fin device is illustrated in
Multiple fin layers and separating plates with the configuration illustrated in
The operation of the embodiment of the fluid processing device illustrated in
As illustrated in
As an alternative to the linear fin shape illustrated in
With reference to
In the device, the fins provide highly effective mixing within the bubbles of solution, which greatly improves mass transfer in extraction processes. More specifically, as illustrated in
By the dispersing and rejoining process, as illustrated in
To apply the above example to specific processes, amine absorption is a commonly used carbon dioxide (CO2) separation process. In such a gas-liquid process, an amine solution enters the inlet nozzle 48 at the top of the column, as illustrated by arrows 66 and 68 (
An example illustrating a gas-liquid reaction process involves the reaction of ethylene oxide (EO) with CO2 to form ethylene carbonate (EC). EC is an intermediate substance used to form ethylene glycol (EG), which is largely used in the polymers industry. In such a process, EO solution enters the inlet nozzle 48 at the top of the column, as illustrated by arrows 66 and 68 (
During the reaction of the above paragraph, a large amount of heat generated from the reaction can be removed by adding a cooling layer fluid passage adjacent to the reaction layer fluid passages in the column or device so that the reaction temperature can be controlled. An example of the block of a device including such an arrangement is indicated in general at 134 in
It should be noted that injections into the fluid passages may optionally be included in the device of the present invention based on reaction requirements. As an example,
As the above illustrates, the plate fin device not only provides a large surface area for mass transfer due to its unique structure, but also provide convection mass transfer within bubbles or droplets caused by the shearing force of the fin structure and frequent separating and rejoining. During this process, not only is the surface area refreshed, but also convection mass transfer is enhanced. Consequently, the efficiency for mass transfer is greatly improved. In addition, prompt heat removal occurs, which is particularly beneficial for the example of the above paragraph, which is highly exothermic.
Advantages of various embodiments of the plate fin device of the present invention include a low pressure drop across the device, equivalent process performance within a smaller device size and improved process efficiency due to shorter processing time and higher production per volume of device.
While embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made therein without departing from the spirit of the invention.
Claims
1. A device for processing fluids comprising:
- a) a plurality of fin layers;
- b) a plurality of plates separating the plurality of fin layers so that a fluid flow passage is defined through each fin layer;
- c) a first fluid inlet in communication with a first end portion of the fluid flow passages and adapted to receive a first fluid stream;
- d) a first fluid outlet in communication with a second end portion of the fluid flow passages;
- e) a second fluid inlet in communication with the second end portion of the fluid flow passages and adapted to receive a second fluid stream;
- f) a second fluid outlet in communication with the first end portion of the fluid flow passages; and
- g) said plurality of fin layers providing a shearing action on the second fluid stream as it flows through the fluid flow passages to provide mass transfer to the first fluid stream as it flows through the fluid flow passages.
2-28. (canceled)
29. A fluid processing device comprising:
- a) a first plate;
- b) a second plate;
- c) a fin layer positioned between the first and second plates so that a fluid flow passage is defined through the fin layer;
- d) a first fluid inlet in communication with a first end portion of the fluid flow passage and adapted to receive a first fluid stream;
- e) a first fluid outlet in communication with a second end portion of the fluid flow passage;
- f) a second fluid inlet in communication with the second end portion of the fluid flow passage and adapted to receive a second fluid stream;
- g) a second fluid outlet in communication with the first end portion of the fluid flow passage; and
- h) said fin layer providing a shearing action on the second fluid stream as it flows through the fluid flow passage to provide mass transfer to the first fluid stream as it flows through the fluid flow passage.
30-55. (canceled)
56. A method of performing a fluid process comprising the steps of:
- a) providing a device including a fluid flow passage including a plurality of fins;
- b) providing a first fluid inlet stream into a first end portion of the fluid flow passage;
- c) providing a second fluid inlet stream into a second end portion of the fluid flow passage;
- d) performing a shearing action on the second fluid inlet stream using the plurality of fins so that a mass transfer to the first fluid inlet stream occurs;
- e) directing a first fluid outlet stream out of the second end portion of the fluid flow passage; and
- f) directing a second fluid outlet stream out of the first inlet portion of the fluid flow passage.
57. The method of claim 56 wherein the plurality of fins of the fluid flow passage are arranged in a serrated configuration including alternating rows of offset fins.
58. The method of claim 56 wherein the process is extraction and the first fluid inlet stream is a solvent, the second fluid inlet stream is a solution, the first fluid outlet stream is the solvent containing a component extracted from the solution and the second fluid outlet stream is the solution without the extracted component,
59. The method of claim 56 wherein the first fluid inlet stream features liquid.
60. The method of claim 59 wherein the second fluid inlet stream includes liquid.
61. The method of claim 59 wherein the second fluid inlet stream includes gas.
62. The method of claim 56 wherein the process includes a reaction.
63. The method of claim 56 wherein the process includes mixing.
Type: Application
Filed: Jul 11, 2011
Publication Date: Jan 19, 2012
Inventors: Zhijun JIA (La Crosse, WI), Lawrence Andrew Stryker (La Crescent, MN), Douglas Eugene Decker (La Crosse, WI)
Application Number: 13/179,792
International Classification: C07D 317/38 (20060101); B01J 19/00 (20060101);