Heat exchanger system and method
A heat exchanger includes a shell and a sheet assembly disposed within the shell. The sheet assembly may include a number of substantially parallel rectangular sheets configured such that they define first passageways extending generally in a first direction and second passageways extending generally in a second direction perpendicular to the first direction. The sheet assembly may be configured such that communicating a first fluid through the first passageways and communicating a second fluid through the second passageways causes heat transfer between the first and second fluids. For example, the first fluid may comprise high pressure vapor and the second fluid may comprise a liquid solution such that the communicating the high pressure vapor and the liquid solution through the first and second passageways, respectively, causes at least a portion of the high pressure vapor to condense and at least a portion of liquid solution to boil off.
This application claims the benefit of Ser. No. 60/504,138 titled “Jet Ejector System and Method,” filed provisionally on Sep. 19, 2003.
TECHNICAL FIELD OF THE INVENTIONThis invention relates in general to heat exchangers and, more particularly, to a heat exchanger having a sheet assembly disposed within a shell.
BACKGROUND OF THE INVENTIONHeat exchangers generally transfer heat energy from one fluid to another fluid without mixing the two fluids. As used herein, the term “fluid” may refer to liquids, gasses, vapors, or any other fluid substance. Common applications of heat exchangers include automotive radiators, boilers, furnaces, refrigerators and air conditioning systems. Two common types of heat exchangers are (1) shell and tube heat exchangers; and (2) plate and frame heat exchangers.
Shell and tube heat exchangers may be used in applications where high temperature and pressure demands are significant, since a shell may be designed to withstand relatively high pressures. However, shell and tube heat exchangers can be relatively expensive and difficult to manufacture. Plate and frame heat exchangers are often used on low-viscous applications with moderate demands on operating temperatures and pressures, typically below 150° C. Gasket material is chosen to withstand the operating temperature at hand and the properties of the processing fluid. There are several types of plate heat exchangers including gasketed, brazed, welded and semi-weld or hybrid types.
SUMMARY OF THE INVENTIONA heat exchanger includes a shell and a sheet assembly disposed within the shell. The sheet assembly may include a number of substantially parallel rectangular sheets configured such that they define first passageways extending generally in a first direction and second passageways extending generally in a second direction perpendicular to the first direction. The sheet assembly may be configured such that communicating a first fluid through the first passageways and communicating a second fluid through the second passageways causes heat transfer between the first and second fluids. For example, the first fluid may comprise high pressure vapor and the second fluid may comprise a liquid solution such that the communicating the high pressure vapor and the liquid solution through the first and second passageways, respectively, causes at least a portion of the high pressure vapor to condense and at least a portion of liquid solution to boil off.
According to another embodiment of the invention, a jet ejector includes a nozzle having a first stream flowing therethrough and including an upstream portion, a downstream portion, and a throat disposed between the upstream portion and the downstream portion, a plurality of sets of apertures located in a wall of the nozzle in the throat, wherein the plurality of sets are longitudinally spaced along the wall and each set of apertures having its apertures circumferentially located around the wall, and a device operable to inject a motive fluid through the apertures and into the first stream.
Various embodiments of the present invention may benefit from numerous advantages. It should be noted that one or more embodiments may benefit from some, none, or all of the advantages discussed below.
One advantage of the invention is that a heat exchanger is provided that includes sheet assembly disposed within the shell. Thus, the heat exchanger may simultaneously benefit from the advantages of shell and tube heat exchanges and plate and frame heat exchangers. For example, because the sheet assembly is disposed within the shell, the heat exchanger may utilize relative high pressure fluids (such as high pressure steam, for example). In addition, the heat exchanger is relatively inexpensive as compared with prior heat exchangers, such as shell and tube heat exchangers, for example. In some embodiments, polymers may be used to form the sheet assembly, which may provide various benefits, such as decreased costs, increased heat transfer per cost, increased corrosion-resistance, as well as increased ease of manufacturing the heat exchanger (due to the increased pliability of polymers as compared with metals). Another advantage is that in some embodiments, the heat exchanger has a lower pressure drop than traditional heat exchangers.
Other technical advantages are readily apparent to one skilled in the art from the following figures, descriptions, and claims.
BRIEF DESCRIPTION OF THE DRAWINGSFor a more complete understanding of the invention, and for further features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:
In the illustrated embodiment, multi-effect evaporator 26 includes any suitable number of tanks 27a, 27b, 27c in series each containing a feed 28 having a nonvolatile component, such as salt or sugar. Jet ejector 24 coupled to evaporator tank 22 and receives a vapor from evaporator tank 22. A heat exchanger 29 in evaporator tank 22 receives the vapor from jet ejector 24 where at least some of the vapor condenses therein. The heat of condensation provides the heat of evaporation to evaporator tank 22. At least some of the vapor inside evaporator tank 22 is delivered to a heat exchanger 30a in tank 27a, whereby the condensing, evaporating, and delivering steps continue through each tank until the last tank in the series (in this embodiment, tank 27c) is reached.
System 20 may also include a condenser 32 coupled to tank 27c for removing energy from system 20, and a vacuum pump (not illustrated) for removing noncondensibles from system 20. Any suitable devices may be utilized for removing concentrated feed 33 from tanks 22 and 27a-27c, and a plurality of sensible heat exchangers 34 may be coupled to tanks 22 and 27a-27c for heating the feed 28 before entering the tanks 22, 27a-27c. Sensible heat exchangers 34 may also be utilized for other suitable functions.
The pressure difference between the condensing steam and the boiling feed 28 depends upon the temperature difference between heat exchanger 29 and evaporator tank 22. In addition, salts (or other soluble materials) depress the vapor pressure, which increases the pressure difference even further. Table 1 illustrates the required compression ratio for pure water (i.e., no salt) as a function of the temperature difference.
The required temperature difference depends upon the cost of heat exchangers and the cost of capital. In one embodiment, a temperature difference of 5° C. is considered economical. For a medium-pressure vapor-compression evaporator, such as system 20, the required compression ratio is approximately 1.2.
For optimization purposes, it is desirable to find equations that present the same information.
One reason jet ejectors may be inefficient is because they blend two gas streams with widely different velocities, which may occur when the motive pressure is significantly different from the inlet pressure. Thus, according to the teachings of one embodiment of the invention, the efficiency of jet ejectors may be improved substantially by developing jet ejectors and/or jet ejector systems that accomplish the required compression task by minimizing Pmotive/Pinlet.
In
For various embodiments of the invention utilizing the concept of
Table 7 illustrates the mass yield for various embodiments. The results indicate that the method works best when the per-stage compression ratio is small, which requires more stages. Further, the method works best when the area ratio is small, which also requires more stages. More stages allow the inlet pressures and motive pressures to be closely matched, thereby allowing streams with similar velocities to be blended. In some embodiments, extraordinarily high mass yields (kg water/kg steam) are possible.
An advantage of utilizing a cascaded arrangement of jet ejectors, such as jet ejector system 50, is that it blends gas streams of similar pressures; therefore, the velocity of each gas stream is similar. This leads to high efficiencies, even using traditional jet ejectors. Efficiency may be improved further by improving the design of the jet ejector, as is described in further detail below.
Thus, an advantage of the jet ejector systems described above is that they blend gas streams of similar pressures; therefore, the velocity of each gas stream is similar. This leads to high efficiencies, even using traditional jet ejectors. The efficiency may be improved further by improving the design of the jet ejector, some embodiments of which are described below in conjunction with
In operation, first stream 208, which may be any suitable propelled gas, such as low pressure vapor, enters upstream portion 203 of nozzle 202. Throat 205 then initially accelerates first stream 208 when it enters throat 205. The motive fluid 207 accelerates first stream 208 even further after entering throat 205 via apertures 206. To minimize the velocity difference between motive fluid 207 and first stream 208, it is advantageous to have the upstream most set of apertures 206a accelerate first stream 208 first, then the next set of apertures 206b accelerate first stream 208 second, and then the next set of apertures 206c accelerate first stream 208 last. The size of arrows 212 is meant to illustrate the accelerating of first stream 208 through nozzle 202.
Thus, an advantage of the jet ejectors described in
Thus, advantages of the liquid jet ejectors of
A heat exchanger 314 is coupled inside vessel 302 and is operable to receive the vapor from knock-out tank 312, at least some of the vapor condensing within heat exchanger 314, thereby forming a distilled liquid such as distilled water if the feed is, for example, salt water. The heat of condensation provides the heat of evaporation to vessel 302 to evaporate feed 304. Concentrated product 315 is removed from vessel 302 via any suitable method. Energy that is added to system 300 may be removed using a condenser 318. Alternatively, if condenser 318 were eliminated, the energy added to system 300 will increase the temperature of concentrated product 315. This is acceptable if the product is not temperature sensitive. To remove noncondensibles from system 300, a small stream is pulled from vessel 302 and passed through a condenser 320, and then sent to a vacuum pump (not explicitly illustrated).
In system 300, motive liquid 309 may be a nonvolatile, immiscible, nontoxic, low-viscosity liquid (e.g., silicone oil) or it may be water. If it is water, the water will be in near equilibrium with the vapors discharged from jet ejector 306. When this water is pumped, it may easily cavitate in pump 308. In one embodiment, to overcome this problem, knock-out tank 312 is elevated relative to pump 308 so there is no cavitation. Ideally, if the system were perfect, the liquid water could be recycled indefinitely. However, in reality, energy is input into the circulating water (e.g., pump losses, pipe friction). This energy input causes the circulating water to evaporate, so make-up water should be added. In one embodiment, the make-up water is feed water, which has the following benefits: (1) the nonvolatile components increase the fluid density, which improves the efficiency of the jet ejector and (2) the waste thermal energy generated within the circulating fluid causes water to evaporate, which forms more product.
-
- Temperature difference in main heat exchanger=5° C.
- Compression ratio=1.2
- Number of multi-effect evaporators=8 (three shown in
FIG. 49 ) - Steam jet ejector per-stage compression ratio=1.03
- Steam jet ejector number of stages=6
- Steam jet ejector number of cascade levels=3
- Steam jet ejector area ratio=5
- Liquid jet ejector efficiency=0.75
- Pump efficiency=0.85 (appropriate for large industrial pumps)
- Steam turbine efficiency=0.8 (relative to isentropic turbine)
The mass ratios shown for the cascade steam jet ejector are based upon the analysis presented above.
The mass flow through the liquid jet ejector is calculated as follows:
where Ĥcond is the specific enthalpy of the condensing steam (1.2 atm), Ĥevap is the specific enthalpy of the evaporating steam (1.0 atm), ηpump is the pump efficiency, ηejector is the liquid jet ejector efficiency, and Wshaft is the shaft work. The shaft work is calculated as follows:
Wshaft=ηturbine(Ĥhigh−Ĥlow)msteam
where mstream is the mass of high-pressure steam, ηturbine is the turbine efficiency (compared to isentropic), Ĥhigh is the specific enthalpy of the high-pressure steam from the boiler, and Ĥlow is the specific enthalpy of the low-pressure steam exiting the turbine. (Note: The conditions at the exit of the turbine correspond to an isentropic expansion.)
The following table compares various options:
*Effect = Energy of single-effect evapor/Energy of the option
This table illustrates that a simple liquid jet ejector combined with a high-efficiency engine (
An advantage is it uses a high-efficiency liquid jet ejector in a cost-effective dewatering system. When combined with steam jet ejectors and multi-effect evaporators, any energy inefficiencies of the liquid jet system (liquid jet itself, pump, turbine) produce heat that usefully distills liquid. This liquid jet ejector may be used in water-based air conditioning.
In
In system 400, motive liquid 410 may be a nonvolatile, immiscible, nontoxic, low-viscosity liquid (e.g., silicone oil) or it may be water. If it is water, the water will be in near equilibrium with the vapors discharged from jet ejector 406. When this water is pumped, it may easily cavitate in pump 408. In one embodiment, to overcome this problem, knock-out tank 412 is elevated relative to pump 408 so there is no cavitation. Ideally, if the system were perfect, the liquid water could be recycled indefinitely. However, in reality, energy is input into the circulating water (e.g., pump losses, pipe friction). This energy input causes the circulating water to evaporate, so make-up water should be added. In one embodiment, the make-up water is feed water, which has the following benefits: (1) the nonvolatile components increase the fluid density, which improves the efficiency of the jet ejector and (2) the waste thermal energy generated within the circulating fluid causes water to evaporate, which forms more product.
Thus, advantages of the vapor-compression evaporator systems of
Referring now to
In general, heat exchanger assembly 500 is configured to allow at least two fluids to be communicated into shell 510, through passageways defined by sheet assembly 512 (such passageways are illustrated and discussed below with reference to
Due to the transfer of heat between first fluid 530 and second fluid 532, at least a portion of first fluid 530 and/or second fluid 532 may change state within shell 510 and thus exit shell 510 in a different state than such fluids 530 and/or 532 entered shell 510. For example, in a particular embodiment, relatively high-pressure steam 534 enters shell 510 through first inlet 520, enters one or more first passageways within sheet assembly 512, becomes cooled by a liquid 540 flowing through one or more second passageways adjacent to the one or more first passageways within sheet assembly 512, which causes at least a portion of the steam 534 to condense to form steam condensate 536. The steam condensate 536 flows toward and through first outlet 522. Concurrently, liquid 540 (saltwater, seawater, concentrated fermentation broth, or concentrated brine, for example) enters shell 510 through second inlet 524, enters one or more second passageways within sheet assembly 512, becomes heated by steam 534 flowing through the one or more first passageways adjacent to the one or more second passageways within sheet assembly 512, which causes at least a portion of the liquid 540 to boil to form relatively low pressure steam 542. The low pressure steam 542 escapes from shell 510 through second outlet 526, while the unboiled remainder of liquid 540 flows toward and through third outlet 528.
In some embodiments, heat exchanger assembly 500 includes one or more pumps 550 operable to pump liquid 540 that has exited shell 510 through third outlet 528 back into shell 510 through second inlet 524, as indicated by arrows 552. Pump 550 may comprise any suitable device or devices for pumping a fluid through one or more fluid passageways. As shown in
Heat exchanger assembly 500 may also include a plurality of mounting devices 560 coupled to shell 510 and operable to mount sheet assembly 512 within shell 510. Each mounting device 560 may be associated with a particular corner of sheet assembly 512. Each mounting device 560 may be coupled to shell 510 in any suitable manner, such as by welding or using fasteners, for example. In the embodiment shown in
Since first volume 564 is separated from second volume 566 by the configuration of sheet assembly 512 and mounting devices 560, first fluid 530 is kept separate from second fluid 532 within shell 510. In addition, one or more gaskets 562 may be disposed between each Y-shaped bracket 560 and its corresponding corner of sheet assembly 512 to provide a seal between first volume 564 and second volume 566 at each corner of sheet assembly 512. Gaskets 562 may comprise any suitable type of seal or gasket, may have any suitable shape (such as having a square, rectangular or round cross-section, for example) and may be formed from any material suitable for forming a seal or gasket.
Heat exchanger assembly 500 may also include one or more devices for sliding, rolling, or otherwise positioning sheet assembly 512 within shell 510. Such devices may be particularly useful in embodiments in which sheet assembly 512 is relatively heavy or massive, such as where sheet assembly 512 is formed from metal. In the embodiment shown in
As discussed above with reference to
In the embodiments shown in
Sheets 580 may be coupled to each other at edges 590 in any suitable manner, as discussed in greater detail below with reference to
Sheets 580 may also include one or more protrusions for preventing passageways 582 or 586 between adjacent sheets 580 from being cut off, such as due to the distortion of sheets 580 during operation of heat exchanger apparatus 500 (such as due to the presence of high-pressure fluids, for example) and/or to provide additional strength or stiffening to sheets 580. In the embodiment shown in
As discussed above, in forming sheet assembly 512, second flange portion 596a of flange 592a of sheet 580a may be coupled to second flange portion 596b of flange 592b of sheet 580b in any suitable manner.
As discussed above, sheets 580 may be formed from any suitable material, such as sheet metal or one or more polymers, for example. Table 1 compares various polymers that could be used for the sheet-polymer assemblies. The underlined value in Table 1 is used to calculate the overall heat transfer coefficient, U, which is determined as follows:
The overall heat transfer coefficient U is reported in the fifth column of Table 1. The cost of each polymer per square foot, C, is shown in the fourth column of Table 1. The ratio U/C is reported in the sixth column of Table 1, which is the overall heat transfer coefficient on a dollar basis, rather than an area basis. The ratio U/C may be referred to as the “figure of merit.” The polymers are listed in order, with the highest U/C appearing at the top and the lowest U/C appearing at the bottom. In the last column of Table 1, the U/C for each polymer is compared to that of stainless steel (SS) and titanium (Ti). Stainless steel resists corrosion for many solutions (e.g., sugar, calcium acetate), but titanium may be used for particularly corrosive solutions, such as seawater, for example.
The polymer with the highest U/C is HDPE (high-density polyethylene). Polypropylene is also very good, and it may perform well at slightly higher temperatures. Other polymers (polystyrene, PVC) may also be considered, but their U/C performance may not be quite as good as polyethylene or polypropylene. As a general rule, the thermal conductivity of the polymers is much lower than metals, but their U/C performance may be superior because of their low material cost relative to metals. In addition, polymers are typically less expensive to form into the final shape of sheets 580 and sheet assembly 512 than metals. Further, polymer structures may be easier to seal, providing an additional benefit over metals.
HDPE has a thermal conductivity comparable to stainless steel if the polymer molecules are aligned in the direction of heat flow (see third column, first row, Table 1).
In some situations, the desired size of sheets 580 for a sheet assembly 512 may be larger than the molecularly-oriented polymer (e.g., HDPE) block 654 that may be produced due to available manufacturing equipment, equipment limitations, cost or some other reason.
In addition to providing increased heat transfer per cost as compared with metal, polymers may be more corrosion-resistant, more pliable, and more easily formed into sheets 580 and sheet assembly 512.
aK-mac Plastics (www.k-mac-plastics.net)
bhi = 3000 BtU/(h · ft2 · ° F.) ho = 15,000 BtU/(h · ft2 · ° F.) (dropwise condensation for plastic) ho = 2,000 BtU/(h · ft2 · ° F.) (filmwise condensation for metal) hm = k/x x = 0.01 in = 0.00083 ft
cHubert Interactive
dMcMaster-Carr
ePerry's Handbook of Chemical Engineering (Table 23-22)
fK-mac Plastics
gwww.metalsdepot.com
hwww.halpemtitanium.com
iR. M. Ogorkiewicz, Thermoplastics: Properties and Design, Wiley, London (1974) p. 133-135
jR. M. Ogorkiewicz, Engineering Properties of Thermoplastics, Wiley, London (1970)
kP. e. Powell, Engineering with Polymers, Chapman and Hall, London (1983), p. 242
lBuilding Research Institute, Plastics in Building, National Academy of Sciences, 1955.
mIn the direction of molecular orientation, draw direction ratio of 25 www.electronics-cooling.com/html/2001_august_techdata.html Choy C. L., Luk W. H., and Chen, F. C., 1978, Thermal Conductivity of Highly Oriented Polyethylene, Polymer, Vol. 19, pp. 155-162.
nRickard Metals, rickardmetals.com ($3.50/lb)
oAstro Cosmos, 888-402-7876 ($14/lb, Grade 2)
p3d-cam.com
qboedeker.com
rbayplastics.co.uk
ssdplastics.com
ttstar.com
uplasticsusa.com
vzae-bayern.de
wtoray.fr
xefunda.com
yPerry's Handbook of Chemical Engineering (Table 3-322)
Although embodiments of the invention and their advantages are described in detail, a person skilled in the art could make various alterations, additions, and omissions without departing from the spirit and scope of the present invention.
Claims
1. A heat exchanger apparatus, comprising:
- a shell; and
- a sheet assembly disposed within the shell, the sheet assembly comprising a plurality of sheets arranged such that the plurality of sheets define a plurality of passageways operable to communicate at least two fluids within the shell such that heat is transferred between the at least two fluids.
2. The heat exchanger apparatus of claim 1, wherein:
- the shell comprises a substantially cylindrical portion extending in a first direction;
- each of the plurality of sheets extending in a second direction substantially perpendicular to the first direction; and
- each of the plurality of passageways defined by a pair of adjacent and substantially parallel sheets.
3. The heat exchanger apparatus of claim 1, wherein each of the plurality of sheets comprises a rectangular shape.
4. The heat exchanger apparatus of claim 1, wherein:
- each of the plurality of passageways is defined by a pair of adjacent and substantially parallel sheets; and
- a first one of the pair of sheets comprises one or more protrusions operable to contact an adjacent second one of the pair of sheets in order to maintain the passageway between the first and second sheets.
5. The heat exchanger apparatus of claim 4, wherein the one or more protrusions associated with the first sheet comprise one or more stiffening ribs.
6. The heat exchanger apparatus of claim 4, wherein:
- the first sheet comprises one or more first corrugations extending in a first direction;
- the second sheet comprises one or more second corrugations extending in a second direction different from the first direction; and
- wherein the one or more first corrugations in the first sheet are configured to contact the one or more second corrugations in the second sheet in order to maintain the passageway between the first and second sheets.
7. The heat exchanger apparatus of claim 1, wherein:
- the plurality of sheets are arranged substantially parallel to each other;
- each of the plurality of passageways is defined by a pair of adjacent and substantially parallel sheets; and
- the plurality of passageways comprise one or more first passageways extending generally in a first direction and one or more second passageways extending generally in a second direction perpendicular to the first direction.
8. The heat exchanger apparatus of claim 7, wherein the plurality of passageways comprise the one or more first passageways alternating with the one or more second passageways.
9. The heat exchanger apparatus of claim 7, wherein;
- the one or more first passageways are configured to communicate a first fluid;
- the one or more second passageways are configured to communicate a second fluid; and
- wherein the one or more first passageways are disposed in relation to the one or more second passageways such that communication of the first fluid and second fluids through the first and second passageways, respectively, causes heat transfer between the first and second fluids.
10. The heat exchanger apparatus of claim 9, wherein;
- the first fluid comprises vapor; and
- the second fluid is selected from the group consisting of saltwater, seawater, fermentation broth, and brine.
11. The heat exchanger apparatus of claim 10, wherein the vapor comprises steam.
12. The heat exchanger apparatus of claim 9, wherein the one or more first passageways are separated from the one or more second passageways such that the first fluid is kept separate from the second fluid.
13. The heat exchanger apparatus of claim 9, further comprising one or more gaskets disposed in contact with each of the plurality of sheets, the one or more gaskets operable to substantially prevent the first fluid from contacting the second fluid.
14. The heat exchanger apparatus of claim 1, wherein:
- each of the plurality of sheets comprises a rectangular shape having four edges;
- the plurality of sheets are arranged substantially parallel to each other such that a first one of the plurality of sheets is located between a second one of the plurality of sheets and a third one of the plurality of sheets;
- the first sheet is coupled to the second sheet at both a first and second edge of the first sheet, the first and second edges of the first sheet being opposite each other and generally parallel; and
- the first sheet is coupled to the third sheet at both a third and fourth edge of the first sheet, the third and fourth edges of the first sheet being opposite each other and generally parallel.
15. The heat exchanger apparatus of claim 14, wherein:
- the first sheet comprises a first flange at the first edge of the first sheet, a second flange at the second edge of the first sheet, a third flange at the third edge of the first sheet, and a fourth flange at the fourth edge of the first sheet;
- the second sheet comprises a first flange at a first edge of the second sheet and a second flange at a second edge of the second sheet, the first and second flanges of the second sheet being coupled to the first and second flanges, respectively, of the first sheet; and
- the third sheet comprises a first flange at a first edge of the third sheet and a second flange at a second edge of the third sheet, the first and second flanges of the third sheet being coupled to the third and fourth flanges, respectively, of the first sheet.
16. The heat exchanger apparatus of claim 14, wherein the first sheet is coupled to the second sheet at both the first and second edges of the first sheet by at least one weld, brazed joint, crimp clamp, crimped joint or fastener.
17. The heat exchanger apparatus of claim 1, further comprising one or more wheels coupled to the sheet assembly and operable to position the sheet assembly within the shell.
18. The heat exchanger apparatus of claim 1, further comprising:
- a plurality of mounting devices coupled to the shell and operable to mount the sheet assembly, each of the plurality of mounting devices associated with a respective corner of the sheet assembly; and
- one or more gaskets, each gasket disposed between one of the mounting devices and the respective corner of the sheet assembly and operable to substantially seal the plurality of passageways at the respective corner of the sheet assembly.
19. The heat exchanger apparatus of claim 1, wherein the shell comprises:
- a first inlet operable to communicate vapor into the shell; and
- a first outlet operable to communicate vapor condensate formed from the vapor out of the shell.
20. The heat exchanger apparatus of claim 19, wherein the shell further comprises:
- a second inlet operable to communicate a solution into the shell; and
- a second outlet operable to communicate at least a portion of the solution out of the shell.
21. The heat exchanger apparatus of claim 20, further comprising a pump operable to pump at least a portion of the solution communicated out of the shell through the second outlet back into the shell through the second inlet.
22. The heat exchanger apparatus of claim 20, wherein the shell further comprises a third outlet operable to allow vapor generated from the solution boiling within the shell to escape the shell.
23. The heat exchanger apparatus of claim 1, wherein at least one of the plurality of sheets is formed from sheet metal.
24. The heat exchanger apparatus of claim 1, wherein at least one of the plurality of sheets is formed from one or more polymer materials.
25. The heat exchanger apparatus of claim 1, wherein at least one of the plurality of sheets is formed from a polymer selected from the group consisting of high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polypropylene.
26. The heat exchanger apparatus of claim 1, wherein at least one of the plurality of sheets is formed from a polymer selected from the group consisting of high-impact polystyrene (HIPS), ultra-high MW polyethylene, polyvinyl chloride (PVC), and acrylic.
27. The heat exchanger apparatus of claim 1, wherein at least one of the plurality of sheets is formed from high-density polyethylene (HDPE) that has been drawn through a die to align the HDPE molecules in a direction perpendicular to a surface of the sheet in order to increase the thermal conductivity of the sheet.
28. A method of providing heat exchange, comprising:
- communicating a first fluid through a heat exchanger comprising a shell and a sheet assembly disposed within the shell, the sheet assembly comprising a plurality of sheets arranged such that the plurality of sheets define one or more first passageways and one or more second passageways, wherein communicating the first fluid through the heat exchanger comprises communicating the first fluid through the one or more first passageways defined by the sheet assembly;
- communicating a second fluid through the heat exchanger, wherein communicating the second fluid through the heat exchanger comprises communicating the second fluid through the one or more second passageways defined by the sheet assembly; and
- wherein communicating the first fluid through the one or more first passageways defined by the sheet assembly and communicating the second fluid through the one or more second passageways defined by the sheet assembly causes heat transfer between the first and second fluids.
29. The method of claim 28, wherein the first fluid comprises vapor and the second fluid comprises a liquid.
30. The method of claim 28, wherein:
- the first fluid comprises vapor; and
- communicating the vapor through the one or more first passageways defined by the sheet assembly comprises at least a portion of the vapor condensing within the one or more first passageways.
31. The method of claim 30, wherein:
- the second fluid comprises a liquid; and
- communicating the liquid through the one or more second passageways defined by the sheet assembly comprises at least a portion of the liquid boiling and creating vapor.
32. The method of claim 31, wherein the second fluid is selected from the group consisting of saltwater, seawater, fermentation broth, and brine.
33. The method of claim 28, wherein:
- communicating the first fluid through the heat exchanger comprises communicating the first fluid into the shell through one or more first inlets formed in the shell, through the one or more first passageways defined by the sheet assembly, and out of the shell through one or more first outlets formed in the shell; and
- communicating the second fluid through the heat exchanger comprises communicating the second fluid into the shell through one or more second inlets formed in the shell, through the one or more second passageways defined by the sheet assembly, and out of the shell through one or more second outlets formed in the shell.
34. The method of claim 33, wherein:
- the first fluid comprises vapor;
- communicating the vapor through the heat exchanger comprises at least a portion of the vapor condensing within the one or more first passageways defined by the sheet assembly;
- the second fluid comprises a liquid; and
- communicating the liquid through the heat exchanger comprises at least a portion of the liquid boiling within the one or more second passageways defined by the sheet assembly.
35. The method of claim 33, wherein:
- the second fluid comprises a liquid; and
- communicating the second fluid through the heat exchanger comprises communicating the liquid into the shell through one or more first inlets formed in the shell, communicating the liquid through the one or more second passageways defined by the sheet assembly such that at least a portion of the liquid boils and forms vapor, allowing the vapor to escape the shell through one or more first outlets formed in the shell, and communicating at least a portion of the unboiled liquid out of the shell through one or more second outlets formed in the shell;
36. The method of claim 28, wherein the heat exchanger is configured such that the first fluid communicated through the heat exchanger is prevented from mixing with the second fluid communicated through the heat exchanger.
37. An apparatus for use in a heat exchanger, the apparatus being disposed within a shell and comprising:
- a plurality of sheets arranged such that the plurality of sheets define a plurality of passageways operable to communicate at least two fluids within the shell such that heat is transferred between the at least two fluids.
38. The apparatus of claim 37, wherein each of the plurality of sheets comprises a rectangular shape.
39. The apparatus of claim 37, wherein:
- each of the plurality of passageways is defined by a pair of adjacent and substantially parallel sheets; and
- a first one of plurality of sheets comprises one or more protrusions operable to contact an adjacent second one of plurality of sheets in order to maintain the passageway between the first and second sheets.
40. The apparatus of claim 37, wherein:
- the plurality of sheets are arranged substantially parallel to each other;
- each of the plurality of passageways is defined by a pair of adjacent and substantially parallel sheets; and
- the plurality of passageways comprise one or more first passageways extending generally in a first direction and one or more second passageways extending generally in a second direction perpendicular to the first direction.
41. The apparatus of claim 40, wherein the plurality of passageways comprise the one or more first passageways alternating with the one or more second passageways.
42. The apparatus of claim 40, wherein;
- the one or more first passageways are configured to communicate a first fluid; and
- the one or more second passageways are configured to communicate a second fluid.
43. The apparatus of claim 1, wherein:
- each of the plurality of sheets comprises a rectangular shape having four edges;
- the plurality of sheets are arranged substantially parallel to each other such that a first one of the plurality of sheets is located between a second one of the plurality of sheets and a third one of the plurality of sheets;
- the first sheet is coupled to the second sheet at both a first and second edge of the first sheet, the first and second edges of the first sheet being opposite each other and generally parallel; and
- the first sheet is coupled to the third sheet at both a third and fourth edge of the first sheet, the third and fourth edges of the first sheet being opposite each other and generally parallel.
44. The heat exchanger apparatus of claim 43, wherein:
- the first sheet comprises a first flange at the first edge of the first sheet, a second flange at the second edge of the first sheet, a third flange at the third edge of the first sheet, and a fourth flange at the fourth edge of the first sheet;
- the second sheet comprises a first flange at a first edge of the second sheet and a second flange at a second edge of the second sheet, the first and second flanges of the second sheet being coupled to the first and second flanges, respectively, of the first sheet; and
- the third sheet comprises a first flange at a first edge of the third sheet and a second flange at a second edge of the third sheet, the first and second flanges of the third sheet being coupled to the third and fourth flanges, respectively, of the first sheet.
45. The apparatus of claim 37, wherein at least one of the plurality of sheets is formed from sheet metal.
46. The apparatus of claim 37, wherein at least one of the plurality of sheets is formed from one or more polymer materials.
47. The apparatus of claim 37, wherein at least one of the plurality of sheets is formed from high-density polyethylene (HDPE) that has been drawn through a die to align the HDPE molecules in a direction perpendicular to a surface of the sheet in order to increase the thermal conductivity of the sheet.
Type: Application
Filed: Sep 17, 2004
Publication Date: Mar 24, 2005
Inventor: Mark Holtzapple (College Station, TX)
Application Number: 10/944,374