CA2263603A1 - Polymeric multilayer heat exchangers containing a barrier layer - Google Patents
Polymeric multilayer heat exchangers containing a barrier layer Download PDFInfo
- Publication number
- CA2263603A1 CA2263603A1 CA002263603A CA2263603A CA2263603A1 CA 2263603 A1 CA2263603 A1 CA 2263603A1 CA 002263603 A CA002263603 A CA 002263603A CA 2263603 A CA2263603 A CA 2263603A CA 2263603 A1 CA2263603 A1 CA 2263603A1
- Authority
- CA
- Canada
- Prior art keywords
- heat exchanger
- polymer
- recited
- liquid
- gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/34—Layered products comprising a layer of synthetic resin comprising polyamides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
- B32B7/04—Interconnection of layers
- B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F21/00—Constructions of heat-exchange apparatus characterised by the selection of particular materials
- F28F21/06—Constructions of heat-exchange apparatus characterised by the selection of particular materials of plastics material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/70—Other properties
- B32B2307/704—Crystalline
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2457/00—Electrical equipment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2605/00—Vehicles
Abstract
Heat exchangers which have heat exchange structures made from at least one layer of an organic polymer and at least one layer of a barrier polymer are particularly useful where light weight is important, such as in automobiles, trucks and aircraft.
Description
POLYMERIC MULTILAYER HEAT EXCHANGERS CONTAINrNG A BARRIER
LAYER
FIELD OF TH~ INVENTION
s This invention concerns a heat e~c~h:~nger wherein the material which comprises the heat exchange surface structure cont~inc at least one polymeric barrier layer and at least one polymeric thermoplastic layer.
TECHNICAL BACKGROUND
Heat exçh~ngers are common pieces of equipment, used in many applications, 0 such as chemical processes, in automotive uses, household uses, and others. Heat exch~ngers are most commonly used to transfer heat between two fluids such as two liquids, a liquid and a gas, or between two gases. Traditionally, the materials used for the heat exchange surfaces are metals, which usually have relatively high thermal conductivities and good strength. However metals have certain drawbacks, such as high forming and assembly costs~ relatively high densities and therefore high weights, and sometlmes poor corroslon reslstance.
To overcome some of these disadv~nt~es, heat exchangers using plastics have been developed. For in~t~n~e, in highly corrosive environments heat exchangers using polytetrafluoroethylene (or perfluorinated tetrafluoroethylene copolymers) have been 20 used. However plastics have some inherent disadvantages, such as poorer heat transfer coefficients, in some cases relatively poor chemical stability, and permeability to the gas(es) or li~uid(s) which contact the heat exchange surfaces. However, they often offer the advantages of lighter weight and easier fabrication than metals. The.crore, improved plastic heat e~r~h~rlgers are sought.
J~r~n~se Patent Application 03/007891 describes a heat exell~nger tube made from a liquid crystalline polymer and a filler having high heat conductivity. No mention is made of a tube having multiple layers of polymers.
French Patent Application 2,566,107 describes heat ~ch~nger panels made from polymers such as polyethylene. No mention is made of layered plastics or barrier layers.
U.S. Patents 4,923,004, 4,955,435,5,275,235 and 5,316,078 describe heat ngers which employ various polyamides for the heat e~ch~n~e surface m~teri~l~
Barrier layers are not mentioned in these patents.
W O 98/10927 PCTICA97100~47 D. A. Reay, Heat Recovery Systems & CHP, vol. 9, p. 209-16 ( 1989), and I. H.
Gross, Procee~ings of Antec '93, p. 964-968 (1993) describe the use of polymers in heat exchangers. No mention is made of using layered polymer structures, nor of using L~Ps.
SUMMARY OF T~E INVENTION
This invention concerns, a multilayer heat ~xch~nger col.tS~ ,g a heat exrh~nge surface m~teri~l, said HESM comprising a polymeric barrier layer and a layer of a second polymer.
This invention also concerns a heat e~ch~nger panel wherein a heat çxch~n~e 0 surface material comprises a layer of a polymeric barrier layer and a layer of a second polymer.
By a heat exchange surface material (HESM) is meant a material which is used as part o~ a heat exçh~n~er or a component thereof, and which is the material through which the ma}or portion of the heat that is exchanged between the two fluids (gas or liquid) is meant to flow. It also performs the function of keeping the two fluids between which heat is being exchanged apart.
BRIEF DESCRIPTION OF THE DRAWINGS
Both figures 1 and 2 depict the al~palaL~Is that used to produce the film as described in Example 6.
Figure I is a sch~m~tic drawing from the side, of an app~lus for carrying out the multilayer film forming process described herein. An extruder, 1, supplies molten first therrnoplastic to slit die 2 from which issues a molten multilayer thermoplastic film 3. A
second extruder, 34, supplies molten second thermoplastic to slit die 2. A third extruder, 35, supplies molten third therrnoplastic to slit die 2. The molten 3-layer film 3 falls 2s vertically until it contacts approximately simlllt:mloously embossed surfaces 7 and 8 of rollers 5 and 6, respectively. Rolling bank 4 of thermoplastic is also present. Rollers 5 and 6 are driven in rotation in the directions shown. Multilayer film 9 exits the gap from bclweeJI rollers 5 and 6, goes between (optional) cooling rollers 9 and 10, and is wound up on windup roll 11.
Figure 2 shows the same rollers 5 and 6 and rolling bank 4 from the top, together with one method of osçill~tin~ the rollers 5 and 6 parallel to the axis (center line) of each of these rollers. Lever 9 is connected to a fixed point by pin 10, and to arms 13 and 14 wO 98/10927 PCT/CA97/00647 by pins 19 and 20 respectively. The arrns 13 and 14 are connPcted to rollers ~ and 6 respectively, through thrust bearings 15 and 16 Ic~ec~ ely, allowing rollers S and 6 to rotate while being oscill~tef1 Lever 9 contains slot 16 into which cam 17 is fitted.
Motor 18 rotates cam 17 thereby causing lever 9 to oscillate ap~uloxilllately s perpendicularly to the rotational axis of rollers ~ and 6. This causes ~ and 6 to oscillate in directions opposite to each other and parallel to their rotational axis.
In other words in this appa dLus the molten multilayer film formed in the slit die 2 is passed through rollers which oscillate along the axis of rotation of the rollers, thereby pal~hlg a transverse (to the direction of movement of the film) .~hç~ling action to the 0 molten polymer of the multilayer film.
DETAILS OF THE INVENTION
Heat exchangers described herein function to exchange heat (energy) between two fluids. These fluids may be gas(es) and/or liquid(s).
One of the materials which is part of the HESM is a polymer layer (PL). By a polymer layer is mean a layer that is made of a natural or synthetic polymer, preferably an organic polymer. It is also preferred that the PL is a thermoplastic. Any polymer may be used so long as it meets certain requirements. It must of course withstand the tempe~dLules to which the HESM is exposed, and should throughout that tel~ aLu range provide sufficient strength (together with the barrier layer) to the HESM to 20 reasonably m~int~in its shape and contain the fluids in the heat exrh~nger, as needed, unless the HESM is deliberately ~lesi~n~d to be flexible. If it is exposed to one or more of the fluids in the heat exch~nger (or any other adventitious materials that may contact it) it preferably should be reasonably chPmic~lly stable to those fluids so as to m~int~in its integrity.
2s Although various types of heat eYrh~n~ers made simply of single layers of polymers have been described, they sometimes have serious drawbacks when they are the only m~t~ri~l~ in HESMs. Somçtimçs the polymer of the HESM may not be chemically stable to one or more of the fluids in the heat çxrh~n~er, for in~t~nce~ many polyesters hydrolyze or otherwise degrade in the presence of water, water-alcohol, or 30 water-glycol l~ es, especi~lly at higher than ambient tenlpelalules. Many polymers are relatively permeable to many liquids and/or gases, and therefore allow losses and/or migration of these materials in or from the heat ~Yrh~nger. Some polymers may be ~ CA 02263603 1999-02-22 swollen by one or more of the fluids used in the heat exchanger thereby ch~nging their dimensions and/or physical properties. All of the above are of course problems in polymeric heat e~cchangers.
It has been found that a polymeric barrier layer (PBL) used in the HESM often 5 alleviates or elimin~tes one or more of the above mentioned problems. By a PBL is meant a layer whose polymer has a relatively low permeability to at least one of the fluids that are e~cch~ngina the heat energy. If a gas phase/liquid phase heat exchanger is being used, the perrneabilities refer to the liquid phase.
The polymer of a PBL should have a permeabili~y to a liquid or a gas which is -- lo l/lO (O. l O) or less, preferably about l/l 00 (O.OlO) or less~ than the permeabilit~ of the most permeable polymer layer in the multilayer structure. Alternatively the PBL should have a permeability to liquids of about 3 l g-mil/m-/day (0.79 g-mmlm~/day) or less~
preferably about 3. l g-millm~/day (0.079 g-mrn/m-/day) or less, or a permeability to gases (for a gas/gas heat exchanger) of about l 00 ml-mil/m~/day (2.5 ml-mm/m-/day) or less, preferably lO ml-mil/m-/dav (0.~5 ml-mm/m~lday) or less. Permeability measurements on liquids to obtain these values should be at 38~C, while measurements on gases should be at 2~~C.
If the PBL is placed between a fluid and any particular PL in the HES~I it oftenprotects that PL from chemical degradation by the fluid, and/or also often protects the PL
~o from being swollen by that fluid. For instance, in automotive heat exchangers which help cool the engine, the commonly used internal coolant is a mixture of a glycol and water, and the e~cternal coolant is air. With many PLs diffusion of water and/or glycol is so rapid that frequent replenishment of the water/glycol mixture is needed. If a PBL (to the water/glycol mixture) is included, the diffusion is greatly decreased.
In order to obtain rapid heat transfer through the HESM, thickness through the material between the heat transfer fluids should be as small as possible. This would be true with any material used for an HESM, but is especially important with plastics since their heat transfer coefficients are usually relatively low when compared to metals. Since the PBL is often the more expensive of the polymers present in the HESM, it is usually economically preferable to limit its use. Therefore, in most constructions it is preferred ~EN~E~ S~
that the PBL is present in relatively thin layer~s) and that layer(s) of the PL be relatively thick so as to carry much of the structural load of the HESM (i.e., pressure of the fluid(s), ;ll structural shape and dim~ lns~ etc.).
The HESM is made up of one or more PBL(s)and one or more PLs. If more than PBL andtor PL is present, more than one type of PBL and/or PL, respectively, can be used. In addition other layers may be present. For example, so called tie layers (TL), also called adhesive layers, may be used to increase the adhesion beLween various PBLs and PLs. or between PLs or between PBLs. The number and p~ eln.ont of the various layers in the HESM will vary depending on the particular polymers chosen, the fluids o used in or by the heat exch~nger, telllp~lalule requirements, enVirnnmpnt~l needs, etc.
Most commonly, tie layers and PBL(s) will be relatively thin coll.paled to the PI,(s~. Typical constructions are given below, wherein Fluids 1 and 2 represent the fluids involved in the heat transfer:
(a) Fluid I /PBL/PL/Fluid 2 (b) Fluid 11PL-I/PBL/PL-2/Fluid 2 (c) Fluid l/PBL-11PL/PBL-2/Fluid 2 (d) Fluid 1/PL-l/PBL-1/PL-2/PBL-2/Fluid 2 (e) Fluid l/PL-1/PL-2/PBL/Fluid 2 (f) Fluid 1/PBL-I/PL-1/PL-2/PBL-2/Fluid 2 20 In all of the above constructions, tie layers may be present between all, some or none of the various polymer layers.
Some of the above constructions may be particularly useful in certain situations.
If Fluid l but not Fluid 2 chemically ~tt~ckecl the PL, construction (a) may be particularly useful, but (c) and (f) may also be lltili7PIl If both Fluids 1 and 2 ~tt~r~d 25 the PL present construction (c) or (f~ may be particularly useful. If one wanted to minimi7~ diffusion of one fluid to another, a construction having two PBL layers, such as (c), (d) or (f) could be chosen. If a special surface is required to reduce abrasive damage - on the Fluid 1 side, but great stiffnP~s is also required from the PL, a construction such as (e) could be chosen wherein PL- 1 and PL-2 have the requisite properties. These and 30 other combinations of layers having the correct properties for various applications will be ap~ ent to the artisan.
Polymers useful as PBLs will depend on what the fluids that are being heat e~.h~n~ed are. Perrneabilities of various polymers are known or can be measured by known methods, see for instance ASTM E 96-95, ASTM F 1249-90 and ASTM D3985-95. These methods measure gas or vapor permeabilities, but may be readily modified to s measure the permeability of liquids, by using liquids in the measurement and having them contact the polymer whose permeability is being measured. When testing the permeability of a potential barrier polymer, it is preferred that test be carried out on a single layer of the barrier polymer itself. For a list of polymer permeabilities see S.
Pauly in J. Brandrup, et al., Ed., Polymer Handbook, 3rd Edition, John Wiley & Sons, o New York, 1989, p. VI-435 to VI-449. If a polymer acts as a PBL in one particular heat exchanger, it may be only be a PL in another heat exchanger due to differing liquids in the two heat exchangers.
If one of the heat exchange fluids is a gas and the other is a liquid (during actual heat exchanger operation) it is preferred that the barrier layer be relatively impermeable to the liquid. If both heat exchange fluids are liquids the barrier layer must be relatively impermeable to at least one fluid liquid, but is preferably relatively impermeable to both liquids. The same is true of a gaslgas heat ~xrh~nger. It is also preferred that the permeability of the barrier layer be measured under telllpel.lLLIle conditions under which the heat exchanger typically operates.
One preferred heat exchanger herein is an automotive or other heat ~xçh~n~er in which one fluid is water a water/alcohol mixture, or a water/glycol (such as ethylene glycol or 1,2-propylene glycol) mixture, and the other fluid is a gas, most commonly air.
Here it is p~cfelled that the barrier layer have a low permeability to the liquid fluid, the water, water/alcohol, or water/glycol mixture.
Polymers which may be useful in PBLs for liquids include various polyolefins such as polyethylene, polypropylene, ethylene/carbon monoxide copolymers and various polycycloolefins, fluoropolymers such as poly(tetrafluoroethylene), polyesters such as poly(ethylene terephth~l~te), poly(butylene terephth~l~t~), poly(ethylene 2,6-napthoate), other polymers such as poly(vinyl chloride), poly(vinylidene chloride), and 30 polyacrylonitrile. For use in PBLs for gases polymers such as fluoropolymers such as poly(tetrafluoroethylene), polyesters such as poly(ethylene terephth~l~te), poly(butylene terephth~l~t~), poly(ethylene 2,6-napthoate), polyamides such as nylon-6,6, nylon-6, and high te.l-pcldlule nylons; and other polymers such as poly(vinyl chloride), poly(vinylidene chloride), polyacrylonitrile, copolymers of ethylene and vinyl alcohol, and poly(vinyl alcohol).
One preferred class of polymers for PBLs for both gases and liquids are li~uid crystalline polymers (LCP). By an LCP is meant a polymer that is anisotropic when tested in the TOT Test described in U.S. Patent 4,118,372. These polymers tend to have very good barrier properties and are inert to many materials which are used as heat ex~h~n~e fluids.
Useful LCPs include those described in U.S. Patents 3,991,013, 3,991,014 o 4,011,199, 4,048,148, 4,075,262, 4,083,829, 4,118,372, 4,122,070, 4,130,545, 4,153,779, 4,159,365, 4,161,470, 4,169,933, 4,184,996, 4,189,549, 4,219,461, 4,232,143, 4,232,144, 4,245,082, 4,256,624, 4,269,965, 4,272,625, 4,370,466, 4,383,105, 4,447,592, 4,522.974, 4,617,369, 4,664,972, 4,684,712, 4,727,129, 4,727,~31, 4,728,7~4, 4,749,769, 4,762,907, 4,778,927, 4,816,555, 4,849,499, 4,851,496, 4,851,497, 4,857,626, 4,864,013, 4,868,278, 4,882,410, 4,923,947, 4,999,416,5,015,721, 5,015,722, S,025,082, 5,086,158, 5,102,935, 5,110,896, and 5,143,956, and European Patent Application 356,226. Useful thermotropic LCPs include polyesters, poly(ester-amides), poly(ester-imides), and polyazomethines. Especially useful are LCPs that are polyesters or poly(ester-amides).
It is also ~lef~l-cd in these polyesters or poly(ester-amides) that at least about 50 percent, 20 more preferably at least about 75 percent, of the bonds to ester or amide groups, i.e., the free bonds of -C(O)O- and -C(O)NR~- wherein R' is hydrogen or hydrocarbyl, be tocarbon atoms which are part of aromatic rings.
Included within the rlçfinition herein of a PBL is a blend of 2 or more polymershaving the required pçrm~bility.
Useful thermoplastic polymers for PLs (or PBLs in the proper circl~rn~t:ln~e~) are those that have the requisite properties as described above, and include: polyolefins such as polyethylene and polypropylene; polyesters such as poly(ethylene terephth~l~t~, poly(butylene terephth~l~te), poly(ethylene 2,6-napthalate), and a polyester from 2,2-bis(4-hydroxyphenyl)propane and a combination of isophthalic and ~e. plllhalic acids;
30 styrenics such as polystyrene and copolymers of styrene with (meth)acrylic esters;
acrylonitrile-but~lien~-styrene thermoplastics; (meth)acrylic polymers in-.hl-ling homo-and copolymers of the parent acids, and/or their esters and/or arnides; polyacetals such as polymethylene oxide; fully and partially fluoropolymers such as polytetrafluoroethylene, polychlorollinuoroethylene, poly(tetrafluoroethylene/hexafluoroprol)ylene) copolymers, poly[tetrafluoroethylene/perfluoro(propyl vinyl ether)] copolymers, poly(vinyl fluoride), poly(vinylidene fluoride), and poly(vinyl fluoride/ethylene) copolymers; ionomers such as an ionomer of an ethylene-acrylic acid copolymer, polycarbonates; poly(amide-imides); poly(ester-carbonates); poly(imide-ethers); polym~lhyl~ue~ e; linear polyolefins such as polypropylene; poly(ethPrketonek~tone); polyimides; poly(phenylene sulfide); polymers of cyclic olefins; poly(vinylidene chloride); polysulfones; poly(ether-sulfones); and polyamides such as nylon-6,6 nylon-6, nylon-6,12, nylon-6,12, nylon 4,6, o and the polyamides from tel~hl}-alic acid and 1,6-hex~ne~ minP andlor 2-methyl-1,5-pent~nP~ mine Polyamides are preferred PLs and preferred amides are nylon-6,6, nylon-6, and a copolymer of terephth~lic acid with 1,6-hex~n~ mine and 2-methyl-1,5-pent~nP~ min~ wherein 1,6-hex~ne~ minP is about 30 to about 70 mole percent of the total tli~mine used to prepare the polymer. Especially preferred polyarnides are nylon-6,6, nylon-6 and a copolymer of terephthalic acid with 1 ,6-h~n~ mine and 2-methyl-1,5-pent~n~ minP wherein 1,6-hPY~ne~i~minP is about 50 mole percent ofthe total diamine used to prepare the polymer. Included within the definition of the polymer for a PL herein are blends of 2 or more polymers, for instance a polymer tongh~n~-l with a rubber and optionally other ingredients.
Useful th~rrnosetting polymers for PLs (or PBLs in the proper circumstances) arethose that have the requisite properties as described above, and include epoxies, thermoset polyesters, and phenolics. These polymers will be forrned into their final shapes before being cro~slin~Pfl as is normal with thprmosetting polymers.
The polymers may contain other materials conventionally found in polymers, 2s such as fillers, reinforcing agents, antioxidants, antio70n~ntc, dyes, pigment~, etc. An e~peci~lly useful material is a filler with high heat conductivity, which may increase the efficiency of the heat e~c~h~n~er.
The composition of a tie layer will depend on which two polymers are on either side of it. For in~t~nce the tie layer may be the polymer of a PL functionalized or grafted 30 to provide adhesion between the PL and PBL layers, or may be a blend of one or more polymers of the PL and one or more of the polymers of the PRL(s).
Typical thi~n~c~es for PL layers will range from about 0.025 to about 0.25 mm.
Typical thickn~es for PBL layers will be about 0.01 to about 0.1 mrn. Tie }ayers will usually be as thin as possible, consistent with their providing adhesion between polymer layers. This is usually about 0.01 to about 0.1 mm. The total thickness ofthe structure is s preferably less than about 0.7 mm, more preferably about 0.12 to about 0.5 mm, and especially preferably about 0.15 mm to about 0.4 mm.
Heat exch~ngers of many different configurations are, made and used, see for in~t~n-~e R. K. Shah, et al., in W. Gerhartz, et al., Ed., Ullmann's Encyclopedia of Industrial Chemistry, 5th Ed., Vol. B-3, VCH Verlagsgesellschaft mbH, Weinheim, 0 1988, p. 2-l to 2-108. As can be seen from this article, and is well known in the art, probably the two most common heat exchange "elements" are the tube and the plate. In a tube type heat exchanger one of the fluids flow through a usually circular cross sectioned tube, while the other fluid flows on the exterior of the tube. Usually many small tubes are employed to create a large heat exch~nge surface. Som~tim~s the tubes may be finned for more efficient heat transfer. In a plate element, small passageways, akin to small tubes, are fabricated within plate of the heat exchange material. One of the fluids flows on the inside of the passageways while the other fluid flows over the exterior surface of the plates. The passageways are usually small to increase surface area, and multiple plates are often used. All of the ~liscllC~ion about heat exchange surface 20 materials also applies to heat exchange panels.
For tube type heat exchangers cont~ining LCPs, the multilayer material describedherein can be made by multilayer coextrusion of a thermoplastic tube, see for in~t~n~e U.S. Patent ~,288,529. However, LCPs when so extruded tend to be weak in the transverse direction (perpl~nfiic~ r to the long axis of the tube). Such problems can be 2s solved by using a cou"l~,-lul~ling die for the LCP portion of the extruded tube, as described in U.S. Patents 4,963,428 and 4,966,807, and G.W. Farell, et al., Journal of Polymer F.ngin~ering, vol. 6, p. 263-289 ~1986). The tubes can be assembled into a full heat exchanger by inserting them into tanks with proper size holes and sealing the holes with a filler such as epoxy resin, or by heat sealing (e.g., melt welding).
Heat exchanger plates of the layered material described herein may be made by relatively standard methods. They may be directly coextruded, complete with passages in them. A flat sheet or film may be coextruded, therrnoformed into the correct shape ~ CA 02263603 1999-02-22 ' " ' and joined adhesively or by heat into the plate. Such coextrusions are known processes, see for instance H. Mar, et al., Ed., Encyclopedia of Polymer Science and Engineering, 2nd'Ed., Vol. 6, John Wiley & Sons, New York, 1986, p. 608-613, ibid., Vol. 7, 1987, p.
106- 127, all of which is hereby included by reference. Individual films or sheets of the PL(s) and PBL(s) may be l~min~ted together, then formed into a heat e~cchanger plate.
For fabrication of a plastic heat e~cchanger made with plates see U.S. Patent 4,955,~35.
The beat e~changers described herein are useful for ~utomotive and other vehicleuses, in aircraft, as comfort heat e~changers, and various ventii~ting, heating'~nd air conditioning applications. They are particularly useful as liquid-gas heat e,Ychangers o used to cool automotive gasoline or diesel engines. In that case the liquid is usually water, water and a glycol, or water and an alcohol.
EXAMPLE I
Small diameter tubing (~0.37 cm diameter and 250-310 ,um wall thickness) was made with multilayer construction, nylon 66/LCP/nylon 66, using three e~truders nd a s die to separately feed the different materials as separate layers. The LCP was a polyester of the composition ~,4'-biphenolfhydroquinonelterephthalic acid/2,6-naphthalene dicarboxylic acid/4-hydro~ybenzoic acid/6-hydroxy-2-naphthoic acid (mole ratio 50/50/70130/270/50). The LCP layer was about 51 ~m thick. The tubing was sealed at one end, then filled with a 1: 1 (vol.) miYture of commercial automotive antifreeze and ~o water, subsequently sealed at the other end and then placed in an oven maintained at 100~C. The loss of the fluid with respect to time, was obtained by weighing. The loss was found to be: 7.7 g/m2 (0.5 gm/100 in') tubing surface area/day.
A heat exchanger was constructed from coe~ctruded tubing (OD 0.366 cm~ ID
0.328 cm) of configuration (inside of tube to outside) 64 !lm HTN nylon/ 51 llm LCP (as in E.Yamplel)176 ,um HTN nylon and active surface area of 1.959 m~. The HTN was a blend of a polyamide which is a polymer of 1,6-he~ane~i~mine and 2-methyl- 1.5-pentane~i~mine (1:1 mole ratio) and terephthalic acid, with a synthetic rubber (~'ordel(~) 3681, and EPDM-type rubber, available from E. I. DuPont de Nemours & Co Wilmington, DE, 19898) and a functionalized synthetic rubber (which is a maleic anhydride functionalized EPDM) in an 85/15/5 weight ratio, respectively.
AMENOED S~E~
Wo 98/10927 PCTtCA97/00647 Hot water (81 ~C) was circulated through the exchanger while ambient air was passed across the surface of the tubes. Operation over a total of 24 days resulted in a loss of 201 gm water, equivalent to a water loss rate of 4.3 gmlm2124 h.
~ EXAMPLE 3 A film of the following composition was produced by the blown film coextrusion method:
layer 1 nylon 6/Sclair~) 1 lKl~/Fusabond~
D226bla functionalized synthetic rubbef (72.5113.616.816.8 weight percent) 0.05 mm layer 2 XB603 (function~1i7Pd EMA) 0.01 mm layer 3 LCP 0.01 mm layer 4 XB603 0.01 mrn layer 5 LCP 0.01 rnm layer 6 XB603 0.01 mm layer 7 Same as Layer 1 0.05 mrn aLLDPE available from Nova Chemicals, Calgary, Alberta, Canada hA maleic anhydride grafted LLDPE available from E. I. duPont de Nemours &
Co., Wilmington, DE U.S.A.
CA maleic anhydride functionali~d EPDM.
The LCP used was a polymer of the following monomers in the bracketed molar ratios; 4,4'-biphenol(26.3)/hydroquinone(26.3)/1 ,6-hP~r~n~ nline(47.4)lterephthalic acid(36.8)/2,6-n~phth~lene dicarboxylic acid(63.2)/4-hydro~ybcl~oic acid(89.5)/6-hydroxy-2-napthoic acid(36.8). Melting point (DSC) of this LCP was 265~C.
2s The film was used as a "lid" of an al~ it.~ cup co~ ing ethylene glycol:
water mixture (a used ~1:1 ratio of commercial automotive ~llirl~e~e and water, radiator fluid), secured between metal rings and gaskets to avoid leakage and was placed in the inverted position ( so that the li~uid would contact the film) in an oven at 100 C.
Periodically, the cup was removed from the oven, cooled and weighed and placed back in the oven. The repeated cooling and reh~tin~ made the film concave or convex because of the pressure differences inside the cup as a consequence of the le~ ,e~ c variations.
This induces another repeated fatigue stress which can be qualitatively observed, but was not measured.
Evaluation of this film~ at 60~C, showed a fluid loss of 12.6 g/m~/day (0.~1 gm/100 in~/day). A film (0.19 mrn thick) of nylon-6,6 blended with synthetic rubber (Nordel~ 3681) and functionalized synthetic rubber (which is a maleic anhydride grafted EPDM) in an 80/10/10 weight ratio respectively (an also contains less than 1 weight per-ent of an epoxy resin), showed a lo~s of 159 g/m'lday (10.27 gm/100 in~/day) under the same conditions.
EXAl~IPLE 4 o Tubing was extruded with the following configuration (inside to outside of tube) and outer diameter 3.6 mm;
inside layer LCP 0.05 mm middle layer XB603 0.05 mm outer layer nylon 6.6 0.075 mm The LCP used was a polymer of the following monomers in the bracketed molar ratios; 4,4'-biphenol(35.5)/hydroquinone(35.5)/1,6-hexane~i~mine(29.0)/terephthalic acid(60)12,6-naphthalene dicarboxylic acid(40)/4-hydroxybenzoic acid(l30). The melting point (DSC) of this LCP was 255~C.
~o Evaluation as per Exarnple 1 at 38~C showed a loss of 0.02 gm/100 in'/day; nylon 6,6 tubing of the same dimensions showed a loss of 2.04 gm/100 in~/day.
Example S
For this example a coextruded 3-layer film was used. When coextruded, the melt temperature of the inner layer was 269~C, while the melt temperature of the outer layers was 292~C, and the line speed was 14.5 m/min. The inner layer, which was 0.076 mm thick, was Bynel~) 4006 (this is a maleic anhydride modified high density polyethylene with a melt index of 0.6, available from E. I. DuPont de Nemours & Co., Wilmington, DE, U.S.A.) The two outer layers were the same polymer used for layer 1 of Example 3, and each outer layer was 0.057 mm thick. The film was corona treated on both sides to about 4.8xlO~ N/cm (48 dynes/cm).
The film was formed into heat exchanger panels consisting or 13 rectangularly shaped liquid flow channels with manifolds on each end, and each panel had a primary AIVI~NOED SltE~T
heat exchange surface area about 54 cm long and 5 cm wide. Panels (67) were stacked by joining the manifolds, al~d the primary heat eYch~nge surface of the stack was ex~ AIPd to be 33,626 cm2.
A similar heat exchanger was made from single layer film 0.19 mm thick of the 5 same polymer of the outer layers of the above heat e~rch~nger. This 69 panel heat exçl~ e. had a surface area of about 34,632 cm2.
Both of these heat e~rh~n~ers were tested using 77~C water. The heat exchanger constructed from the 3-layer film had a water loss of 0.17 g/hr, while the heat ex~h~nger constructed from the single layer film had a water loss of 1.1 glhr.
o Example 6 Polymer A was a liquid crystalline polymer which was an aromatic polyester, and was a copolymer of (molar ratios in parenth~ses): 4,4'-biphenol(26.3)/hydroquinone(26.3)/1,6-hexdne~ minP(47.4)/terephthalic acid(36.8)/2,6-n~rhth~1ene dicarboxylic acid(63.2)/4-hydroxybenzoic acid(~9.5)/6-hydroxy-2-napthoic acid(36.8).
Polymer B was a nylon 6/Sclair(~ 1 lKl~/Fusabond~) D226b/a functionalized synthetic rubbef (72.5/13.6/6.816.8 weight percent (3LLDPE available from Nova Chemicals, Calgary, Alberta, Canada, bA maleic anhydride grafted LLDPE availablefrom E. I. duPont de Nemours & Co., Wilmington, DE U.S.A.; CA maleic anhydride 20 function~li7~(~ EPDM.) Polymer C was a blend prepared in a twin screw extruder of 40 percent by weight of Polymer A and 60 percent by weight of Polymer B.
The a~dlus used included a 3/4" (1.91 cm) Brabender (Type 2003, C. W.
Brabender Instruments, H~c~ s~c~ NJ, U.S.A.), a 1" (2.54 cm) Wilmod extruder, and a 25 3.8 cm NRM extruder. Polymer A was extruded from the Wilmod extruder running at 45 rpm and the melt te~ cldlure was 280~C. Polymer B was extruded from the NRM
extruder running at 20 rpm and at a melt lell~y~dlule of 280~C. Polymer C was extruded from the Brabender extruder running at 60 rpm and with a melt ~elll~ldlul~ of 270~C.
The output of each of these extruders was fed to 15.2 cm wide film die which was30 configured to handle three se~Jdld~e feeds. Polymers A and B were the outside layers and Polymer C was the inner layer.
The molten film fell by gravity on the oscill~ting rollers, which were arranged as shown in Fig. 1. The rollers were 8.9 cm in diarneter and 20.3 cm wide, and the surfaces were faced with stainless steel which were embossed with a diamond or knurled pattern, about 50-75 ,um deep, with a 90~ included angle for the sides, with the knurling lines at s an angle of 30~ to the axis of rotation of the roll. The rotational speeds of the rollers were m~nl-~lly controlled using a variable speed drive motor and was set so the surface speed of the rolls was 6m/min. The rate of oscillation was also m~nll~lly controlled by a variable speed drive motor and was 50 Hz, while the amplitude of oscillation could be varied by ch~nging the cam 17, and was 1.3 mm. Each roller was individually heated by 0 Calrod~ electrical heaters, which were in turn ~lltom~tically controlled by digital controllers. It is believed that the roller t~ pcldLuies could be ..~ e~ to about +1~C, and the roller telll~ dlu~cs were 1 77~C. Afte} passing through the oscill~ting rollers the film was passed through a set of cooling rolls and then rolled up on a roll.
In the beginning of the run, the speed of extrusion and rotation of the oscillating S rollers were adjusted so that a rolling bank ofthe polymer built up on the oscill:~ting rollers, and then the speed of the osçill~ting rollers was set as closely as possible to m~int~in a cQmt~nt sized rolling bank. Occasionally some manual adj--ctTnentc were needed.
In the resulting film, the Polymer a layer was about 0.051 mm thick, the PolymerB layer was about 0.10 mrn thick and the Polymer C layer was about 0.051 mm thick.
Using the above three-layer film, heat e~ch~n~er panels were made using the procedure of Example 2 of U.S. Patent 5,050,671, as described below.
The sheets were coated on the Polymer B side with a solution of benzyl alcohol and phenol, as described in U.S. Patent 4,935,462. The coated sides were placed in face-25 to-face contact, between female molds co~ ;; ~,g grooves parallel to the long axis of the sheets, with inlet and outlet headers at each end of the sheets. The molds were then heated in a press at 160~C and 241 MPa p-~S~UIc was applied while nitrogen gas was passed b~Lwt;en the sheets so that each sheet conformed to the shape of the grooves, the two sheets were bonded together, and the headers were bonded to the ends of the sheets.
No fractures or tears were evident in the resulting panel in the outer s~ cçs (which were Polymer A). The headers of several of these panels were bonded together to form a heat exchanger.
.. .. .
WO 98/10927 PCTtCA97/00647 An otherwise i~lPntic~l heat e~h~neer was made from 0 2 mm thick sheeting of Polymer B (the ~hçetine didn't go through the oscillating rollers). Water at 70~C was passed through the two heat ex~h~neers, and the rate of water loss by diffusion through the panels ~ d. The rate of water loss for the heat çxl~h~ngPr made with the three-5 polymer layer panels was 0.8 g/hr more than 10 times less than that of the heat çxrh~ngermade from Polymer B alone which lost about 9.1 g~r of water.
LAYER
FIELD OF TH~ INVENTION
s This invention concerns a heat e~c~h:~nger wherein the material which comprises the heat exchange surface structure cont~inc at least one polymeric barrier layer and at least one polymeric thermoplastic layer.
TECHNICAL BACKGROUND
Heat exçh~ngers are common pieces of equipment, used in many applications, 0 such as chemical processes, in automotive uses, household uses, and others. Heat exch~ngers are most commonly used to transfer heat between two fluids such as two liquids, a liquid and a gas, or between two gases. Traditionally, the materials used for the heat exchange surfaces are metals, which usually have relatively high thermal conductivities and good strength. However metals have certain drawbacks, such as high forming and assembly costs~ relatively high densities and therefore high weights, and sometlmes poor corroslon reslstance.
To overcome some of these disadv~nt~es, heat exchangers using plastics have been developed. For in~t~n~e, in highly corrosive environments heat exchangers using polytetrafluoroethylene (or perfluorinated tetrafluoroethylene copolymers) have been 20 used. However plastics have some inherent disadvantages, such as poorer heat transfer coefficients, in some cases relatively poor chemical stability, and permeability to the gas(es) or li~uid(s) which contact the heat exchange surfaces. However, they often offer the advantages of lighter weight and easier fabrication than metals. The.crore, improved plastic heat e~r~h~rlgers are sought.
J~r~n~se Patent Application 03/007891 describes a heat exell~nger tube made from a liquid crystalline polymer and a filler having high heat conductivity. No mention is made of a tube having multiple layers of polymers.
French Patent Application 2,566,107 describes heat ~ch~nger panels made from polymers such as polyethylene. No mention is made of layered plastics or barrier layers.
U.S. Patents 4,923,004, 4,955,435,5,275,235 and 5,316,078 describe heat ngers which employ various polyamides for the heat e~ch~n~e surface m~teri~l~
Barrier layers are not mentioned in these patents.
W O 98/10927 PCTICA97100~47 D. A. Reay, Heat Recovery Systems & CHP, vol. 9, p. 209-16 ( 1989), and I. H.
Gross, Procee~ings of Antec '93, p. 964-968 (1993) describe the use of polymers in heat exchangers. No mention is made of using layered polymer structures, nor of using L~Ps.
SUMMARY OF T~E INVENTION
This invention concerns, a multilayer heat ~xch~nger col.tS~ ,g a heat exrh~nge surface m~teri~l, said HESM comprising a polymeric barrier layer and a layer of a second polymer.
This invention also concerns a heat e~ch~nger panel wherein a heat çxch~n~e 0 surface material comprises a layer of a polymeric barrier layer and a layer of a second polymer.
By a heat exchange surface material (HESM) is meant a material which is used as part o~ a heat exçh~n~er or a component thereof, and which is the material through which the ma}or portion of the heat that is exchanged between the two fluids (gas or liquid) is meant to flow. It also performs the function of keeping the two fluids between which heat is being exchanged apart.
BRIEF DESCRIPTION OF THE DRAWINGS
Both figures 1 and 2 depict the al~palaL~Is that used to produce the film as described in Example 6.
Figure I is a sch~m~tic drawing from the side, of an app~lus for carrying out the multilayer film forming process described herein. An extruder, 1, supplies molten first therrnoplastic to slit die 2 from which issues a molten multilayer thermoplastic film 3. A
second extruder, 34, supplies molten second thermoplastic to slit die 2. A third extruder, 35, supplies molten third therrnoplastic to slit die 2. The molten 3-layer film 3 falls 2s vertically until it contacts approximately simlllt:mloously embossed surfaces 7 and 8 of rollers 5 and 6, respectively. Rolling bank 4 of thermoplastic is also present. Rollers 5 and 6 are driven in rotation in the directions shown. Multilayer film 9 exits the gap from bclweeJI rollers 5 and 6, goes between (optional) cooling rollers 9 and 10, and is wound up on windup roll 11.
Figure 2 shows the same rollers 5 and 6 and rolling bank 4 from the top, together with one method of osçill~tin~ the rollers 5 and 6 parallel to the axis (center line) of each of these rollers. Lever 9 is connected to a fixed point by pin 10, and to arms 13 and 14 wO 98/10927 PCT/CA97/00647 by pins 19 and 20 respectively. The arrns 13 and 14 are connPcted to rollers ~ and 6 respectively, through thrust bearings 15 and 16 Ic~ec~ ely, allowing rollers S and 6 to rotate while being oscill~tef1 Lever 9 contains slot 16 into which cam 17 is fitted.
Motor 18 rotates cam 17 thereby causing lever 9 to oscillate ap~uloxilllately s perpendicularly to the rotational axis of rollers ~ and 6. This causes ~ and 6 to oscillate in directions opposite to each other and parallel to their rotational axis.
In other words in this appa dLus the molten multilayer film formed in the slit die 2 is passed through rollers which oscillate along the axis of rotation of the rollers, thereby pal~hlg a transverse (to the direction of movement of the film) .~hç~ling action to the 0 molten polymer of the multilayer film.
DETAILS OF THE INVENTION
Heat exchangers described herein function to exchange heat (energy) between two fluids. These fluids may be gas(es) and/or liquid(s).
One of the materials which is part of the HESM is a polymer layer (PL). By a polymer layer is mean a layer that is made of a natural or synthetic polymer, preferably an organic polymer. It is also preferred that the PL is a thermoplastic. Any polymer may be used so long as it meets certain requirements. It must of course withstand the tempe~dLules to which the HESM is exposed, and should throughout that tel~ aLu range provide sufficient strength (together with the barrier layer) to the HESM to 20 reasonably m~int~in its shape and contain the fluids in the heat exrh~nger, as needed, unless the HESM is deliberately ~lesi~n~d to be flexible. If it is exposed to one or more of the fluids in the heat exch~nger (or any other adventitious materials that may contact it) it preferably should be reasonably chPmic~lly stable to those fluids so as to m~int~in its integrity.
2s Although various types of heat eYrh~n~ers made simply of single layers of polymers have been described, they sometimes have serious drawbacks when they are the only m~t~ri~l~ in HESMs. Somçtimçs the polymer of the HESM may not be chemically stable to one or more of the fluids in the heat çxrh~n~er, for in~t~nce~ many polyesters hydrolyze or otherwise degrade in the presence of water, water-alcohol, or 30 water-glycol l~ es, especi~lly at higher than ambient tenlpelalules. Many polymers are relatively permeable to many liquids and/or gases, and therefore allow losses and/or migration of these materials in or from the heat ~Yrh~nger. Some polymers may be ~ CA 02263603 1999-02-22 swollen by one or more of the fluids used in the heat exchanger thereby ch~nging their dimensions and/or physical properties. All of the above are of course problems in polymeric heat e~cchangers.
It has been found that a polymeric barrier layer (PBL) used in the HESM often 5 alleviates or elimin~tes one or more of the above mentioned problems. By a PBL is meant a layer whose polymer has a relatively low permeability to at least one of the fluids that are e~cch~ngina the heat energy. If a gas phase/liquid phase heat exchanger is being used, the perrneabilities refer to the liquid phase.
The polymer of a PBL should have a permeabili~y to a liquid or a gas which is -- lo l/lO (O. l O) or less, preferably about l/l 00 (O.OlO) or less~ than the permeabilit~ of the most permeable polymer layer in the multilayer structure. Alternatively the PBL should have a permeability to liquids of about 3 l g-mil/m-/day (0.79 g-mmlm~/day) or less~
preferably about 3. l g-millm~/day (0.079 g-mrn/m-/day) or less, or a permeability to gases (for a gas/gas heat exchanger) of about l 00 ml-mil/m~/day (2.5 ml-mm/m-/day) or less, preferably lO ml-mil/m-/dav (0.~5 ml-mm/m~lday) or less. Permeability measurements on liquids to obtain these values should be at 38~C, while measurements on gases should be at 2~~C.
If the PBL is placed between a fluid and any particular PL in the HES~I it oftenprotects that PL from chemical degradation by the fluid, and/or also often protects the PL
~o from being swollen by that fluid. For instance, in automotive heat exchangers which help cool the engine, the commonly used internal coolant is a mixture of a glycol and water, and the e~cternal coolant is air. With many PLs diffusion of water and/or glycol is so rapid that frequent replenishment of the water/glycol mixture is needed. If a PBL (to the water/glycol mixture) is included, the diffusion is greatly decreased.
In order to obtain rapid heat transfer through the HESM, thickness through the material between the heat transfer fluids should be as small as possible. This would be true with any material used for an HESM, but is especially important with plastics since their heat transfer coefficients are usually relatively low when compared to metals. Since the PBL is often the more expensive of the polymers present in the HESM, it is usually economically preferable to limit its use. Therefore, in most constructions it is preferred ~EN~E~ S~
that the PBL is present in relatively thin layer~s) and that layer(s) of the PL be relatively thick so as to carry much of the structural load of the HESM (i.e., pressure of the fluid(s), ;ll structural shape and dim~ lns~ etc.).
The HESM is made up of one or more PBL(s)and one or more PLs. If more than PBL andtor PL is present, more than one type of PBL and/or PL, respectively, can be used. In addition other layers may be present. For example, so called tie layers (TL), also called adhesive layers, may be used to increase the adhesion beLween various PBLs and PLs. or between PLs or between PBLs. The number and p~ eln.ont of the various layers in the HESM will vary depending on the particular polymers chosen, the fluids o used in or by the heat exch~nger, telllp~lalule requirements, enVirnnmpnt~l needs, etc.
Most commonly, tie layers and PBL(s) will be relatively thin coll.paled to the PI,(s~. Typical constructions are given below, wherein Fluids 1 and 2 represent the fluids involved in the heat transfer:
(a) Fluid I /PBL/PL/Fluid 2 (b) Fluid 11PL-I/PBL/PL-2/Fluid 2 (c) Fluid l/PBL-11PL/PBL-2/Fluid 2 (d) Fluid 1/PL-l/PBL-1/PL-2/PBL-2/Fluid 2 (e) Fluid l/PL-1/PL-2/PBL/Fluid 2 (f) Fluid 1/PBL-I/PL-1/PL-2/PBL-2/Fluid 2 20 In all of the above constructions, tie layers may be present between all, some or none of the various polymer layers.
Some of the above constructions may be particularly useful in certain situations.
If Fluid l but not Fluid 2 chemically ~tt~ckecl the PL, construction (a) may be particularly useful, but (c) and (f) may also be lltili7PIl If both Fluids 1 and 2 ~tt~r~d 25 the PL present construction (c) or (f~ may be particularly useful. If one wanted to minimi7~ diffusion of one fluid to another, a construction having two PBL layers, such as (c), (d) or (f) could be chosen. If a special surface is required to reduce abrasive damage - on the Fluid 1 side, but great stiffnP~s is also required from the PL, a construction such as (e) could be chosen wherein PL- 1 and PL-2 have the requisite properties. These and 30 other combinations of layers having the correct properties for various applications will be ap~ ent to the artisan.
Polymers useful as PBLs will depend on what the fluids that are being heat e~.h~n~ed are. Perrneabilities of various polymers are known or can be measured by known methods, see for instance ASTM E 96-95, ASTM F 1249-90 and ASTM D3985-95. These methods measure gas or vapor permeabilities, but may be readily modified to s measure the permeability of liquids, by using liquids in the measurement and having them contact the polymer whose permeability is being measured. When testing the permeability of a potential barrier polymer, it is preferred that test be carried out on a single layer of the barrier polymer itself. For a list of polymer permeabilities see S.
Pauly in J. Brandrup, et al., Ed., Polymer Handbook, 3rd Edition, John Wiley & Sons, o New York, 1989, p. VI-435 to VI-449. If a polymer acts as a PBL in one particular heat exchanger, it may be only be a PL in another heat exchanger due to differing liquids in the two heat exchangers.
If one of the heat exchange fluids is a gas and the other is a liquid (during actual heat exchanger operation) it is preferred that the barrier layer be relatively impermeable to the liquid. If both heat exchange fluids are liquids the barrier layer must be relatively impermeable to at least one fluid liquid, but is preferably relatively impermeable to both liquids. The same is true of a gaslgas heat ~xrh~nger. It is also preferred that the permeability of the barrier layer be measured under telllpel.lLLIle conditions under which the heat exchanger typically operates.
One preferred heat exchanger herein is an automotive or other heat ~xçh~n~er in which one fluid is water a water/alcohol mixture, or a water/glycol (such as ethylene glycol or 1,2-propylene glycol) mixture, and the other fluid is a gas, most commonly air.
Here it is p~cfelled that the barrier layer have a low permeability to the liquid fluid, the water, water/alcohol, or water/glycol mixture.
Polymers which may be useful in PBLs for liquids include various polyolefins such as polyethylene, polypropylene, ethylene/carbon monoxide copolymers and various polycycloolefins, fluoropolymers such as poly(tetrafluoroethylene), polyesters such as poly(ethylene terephth~l~te), poly(butylene terephth~l~t~), poly(ethylene 2,6-napthoate), other polymers such as poly(vinyl chloride), poly(vinylidene chloride), and 30 polyacrylonitrile. For use in PBLs for gases polymers such as fluoropolymers such as poly(tetrafluoroethylene), polyesters such as poly(ethylene terephth~l~te), poly(butylene terephth~l~t~), poly(ethylene 2,6-napthoate), polyamides such as nylon-6,6, nylon-6, and high te.l-pcldlule nylons; and other polymers such as poly(vinyl chloride), poly(vinylidene chloride), polyacrylonitrile, copolymers of ethylene and vinyl alcohol, and poly(vinyl alcohol).
One preferred class of polymers for PBLs for both gases and liquids are li~uid crystalline polymers (LCP). By an LCP is meant a polymer that is anisotropic when tested in the TOT Test described in U.S. Patent 4,118,372. These polymers tend to have very good barrier properties and are inert to many materials which are used as heat ex~h~n~e fluids.
Useful LCPs include those described in U.S. Patents 3,991,013, 3,991,014 o 4,011,199, 4,048,148, 4,075,262, 4,083,829, 4,118,372, 4,122,070, 4,130,545, 4,153,779, 4,159,365, 4,161,470, 4,169,933, 4,184,996, 4,189,549, 4,219,461, 4,232,143, 4,232,144, 4,245,082, 4,256,624, 4,269,965, 4,272,625, 4,370,466, 4,383,105, 4,447,592, 4,522.974, 4,617,369, 4,664,972, 4,684,712, 4,727,129, 4,727,~31, 4,728,7~4, 4,749,769, 4,762,907, 4,778,927, 4,816,555, 4,849,499, 4,851,496, 4,851,497, 4,857,626, 4,864,013, 4,868,278, 4,882,410, 4,923,947, 4,999,416,5,015,721, 5,015,722, S,025,082, 5,086,158, 5,102,935, 5,110,896, and 5,143,956, and European Patent Application 356,226. Useful thermotropic LCPs include polyesters, poly(ester-amides), poly(ester-imides), and polyazomethines. Especially useful are LCPs that are polyesters or poly(ester-amides).
It is also ~lef~l-cd in these polyesters or poly(ester-amides) that at least about 50 percent, 20 more preferably at least about 75 percent, of the bonds to ester or amide groups, i.e., the free bonds of -C(O)O- and -C(O)NR~- wherein R' is hydrogen or hydrocarbyl, be tocarbon atoms which are part of aromatic rings.
Included within the rlçfinition herein of a PBL is a blend of 2 or more polymershaving the required pçrm~bility.
Useful thermoplastic polymers for PLs (or PBLs in the proper circl~rn~t:ln~e~) are those that have the requisite properties as described above, and include: polyolefins such as polyethylene and polypropylene; polyesters such as poly(ethylene terephth~l~t~, poly(butylene terephth~l~te), poly(ethylene 2,6-napthalate), and a polyester from 2,2-bis(4-hydroxyphenyl)propane and a combination of isophthalic and ~e. plllhalic acids;
30 styrenics such as polystyrene and copolymers of styrene with (meth)acrylic esters;
acrylonitrile-but~lien~-styrene thermoplastics; (meth)acrylic polymers in-.hl-ling homo-and copolymers of the parent acids, and/or their esters and/or arnides; polyacetals such as polymethylene oxide; fully and partially fluoropolymers such as polytetrafluoroethylene, polychlorollinuoroethylene, poly(tetrafluoroethylene/hexafluoroprol)ylene) copolymers, poly[tetrafluoroethylene/perfluoro(propyl vinyl ether)] copolymers, poly(vinyl fluoride), poly(vinylidene fluoride), and poly(vinyl fluoride/ethylene) copolymers; ionomers such as an ionomer of an ethylene-acrylic acid copolymer, polycarbonates; poly(amide-imides); poly(ester-carbonates); poly(imide-ethers); polym~lhyl~ue~ e; linear polyolefins such as polypropylene; poly(ethPrketonek~tone); polyimides; poly(phenylene sulfide); polymers of cyclic olefins; poly(vinylidene chloride); polysulfones; poly(ether-sulfones); and polyamides such as nylon-6,6 nylon-6, nylon-6,12, nylon-6,12, nylon 4,6, o and the polyamides from tel~hl}-alic acid and 1,6-hex~ne~ minP andlor 2-methyl-1,5-pent~nP~ mine Polyamides are preferred PLs and preferred amides are nylon-6,6, nylon-6, and a copolymer of terephth~lic acid with 1,6-hex~n~ mine and 2-methyl-1,5-pent~nP~ min~ wherein 1,6-hex~ne~ minP is about 30 to about 70 mole percent of the total tli~mine used to prepare the polymer. Especially preferred polyarnides are nylon-6,6, nylon-6 and a copolymer of terephthalic acid with 1 ,6-h~n~ mine and 2-methyl-1,5-pent~n~ minP wherein 1,6-hPY~ne~i~minP is about 50 mole percent ofthe total diamine used to prepare the polymer. Included within the definition of the polymer for a PL herein are blends of 2 or more polymers, for instance a polymer tongh~n~-l with a rubber and optionally other ingredients.
Useful th~rrnosetting polymers for PLs (or PBLs in the proper circumstances) arethose that have the requisite properties as described above, and include epoxies, thermoset polyesters, and phenolics. These polymers will be forrned into their final shapes before being cro~slin~Pfl as is normal with thprmosetting polymers.
The polymers may contain other materials conventionally found in polymers, 2s such as fillers, reinforcing agents, antioxidants, antio70n~ntc, dyes, pigment~, etc. An e~peci~lly useful material is a filler with high heat conductivity, which may increase the efficiency of the heat e~c~h~n~er.
The composition of a tie layer will depend on which two polymers are on either side of it. For in~t~nce the tie layer may be the polymer of a PL functionalized or grafted 30 to provide adhesion between the PL and PBL layers, or may be a blend of one or more polymers of the PL and one or more of the polymers of the PRL(s).
Typical thi~n~c~es for PL layers will range from about 0.025 to about 0.25 mm.
Typical thickn~es for PBL layers will be about 0.01 to about 0.1 mrn. Tie }ayers will usually be as thin as possible, consistent with their providing adhesion between polymer layers. This is usually about 0.01 to about 0.1 mm. The total thickness ofthe structure is s preferably less than about 0.7 mm, more preferably about 0.12 to about 0.5 mm, and especially preferably about 0.15 mm to about 0.4 mm.
Heat exch~ngers of many different configurations are, made and used, see for in~t~n-~e R. K. Shah, et al., in W. Gerhartz, et al., Ed., Ullmann's Encyclopedia of Industrial Chemistry, 5th Ed., Vol. B-3, VCH Verlagsgesellschaft mbH, Weinheim, 0 1988, p. 2-l to 2-108. As can be seen from this article, and is well known in the art, probably the two most common heat exchange "elements" are the tube and the plate. In a tube type heat exchanger one of the fluids flow through a usually circular cross sectioned tube, while the other fluid flows on the exterior of the tube. Usually many small tubes are employed to create a large heat exch~nge surface. Som~tim~s the tubes may be finned for more efficient heat transfer. In a plate element, small passageways, akin to small tubes, are fabricated within plate of the heat exchange material. One of the fluids flows on the inside of the passageways while the other fluid flows over the exterior surface of the plates. The passageways are usually small to increase surface area, and multiple plates are often used. All of the ~liscllC~ion about heat exchange surface 20 materials also applies to heat exchange panels.
For tube type heat exchangers cont~ining LCPs, the multilayer material describedherein can be made by multilayer coextrusion of a thermoplastic tube, see for in~t~n~e U.S. Patent ~,288,529. However, LCPs when so extruded tend to be weak in the transverse direction (perpl~nfiic~ r to the long axis of the tube). Such problems can be 2s solved by using a cou"l~,-lul~ling die for the LCP portion of the extruded tube, as described in U.S. Patents 4,963,428 and 4,966,807, and G.W. Farell, et al., Journal of Polymer F.ngin~ering, vol. 6, p. 263-289 ~1986). The tubes can be assembled into a full heat exchanger by inserting them into tanks with proper size holes and sealing the holes with a filler such as epoxy resin, or by heat sealing (e.g., melt welding).
Heat exchanger plates of the layered material described herein may be made by relatively standard methods. They may be directly coextruded, complete with passages in them. A flat sheet or film may be coextruded, therrnoformed into the correct shape ~ CA 02263603 1999-02-22 ' " ' and joined adhesively or by heat into the plate. Such coextrusions are known processes, see for instance H. Mar, et al., Ed., Encyclopedia of Polymer Science and Engineering, 2nd'Ed., Vol. 6, John Wiley & Sons, New York, 1986, p. 608-613, ibid., Vol. 7, 1987, p.
106- 127, all of which is hereby included by reference. Individual films or sheets of the PL(s) and PBL(s) may be l~min~ted together, then formed into a heat e~cchanger plate.
For fabrication of a plastic heat e~cchanger made with plates see U.S. Patent 4,955,~35.
The beat e~changers described herein are useful for ~utomotive and other vehicleuses, in aircraft, as comfort heat e~changers, and various ventii~ting, heating'~nd air conditioning applications. They are particularly useful as liquid-gas heat e,Ychangers o used to cool automotive gasoline or diesel engines. In that case the liquid is usually water, water and a glycol, or water and an alcohol.
EXAMPLE I
Small diameter tubing (~0.37 cm diameter and 250-310 ,um wall thickness) was made with multilayer construction, nylon 66/LCP/nylon 66, using three e~truders nd a s die to separately feed the different materials as separate layers. The LCP was a polyester of the composition ~,4'-biphenolfhydroquinonelterephthalic acid/2,6-naphthalene dicarboxylic acid/4-hydro~ybenzoic acid/6-hydroxy-2-naphthoic acid (mole ratio 50/50/70130/270/50). The LCP layer was about 51 ~m thick. The tubing was sealed at one end, then filled with a 1: 1 (vol.) miYture of commercial automotive antifreeze and ~o water, subsequently sealed at the other end and then placed in an oven maintained at 100~C. The loss of the fluid with respect to time, was obtained by weighing. The loss was found to be: 7.7 g/m2 (0.5 gm/100 in') tubing surface area/day.
A heat exchanger was constructed from coe~ctruded tubing (OD 0.366 cm~ ID
0.328 cm) of configuration (inside of tube to outside) 64 !lm HTN nylon/ 51 llm LCP (as in E.Yamplel)176 ,um HTN nylon and active surface area of 1.959 m~. The HTN was a blend of a polyamide which is a polymer of 1,6-he~ane~i~mine and 2-methyl- 1.5-pentane~i~mine (1:1 mole ratio) and terephthalic acid, with a synthetic rubber (~'ordel(~) 3681, and EPDM-type rubber, available from E. I. DuPont de Nemours & Co Wilmington, DE, 19898) and a functionalized synthetic rubber (which is a maleic anhydride functionalized EPDM) in an 85/15/5 weight ratio, respectively.
AMENOED S~E~
Wo 98/10927 PCTtCA97/00647 Hot water (81 ~C) was circulated through the exchanger while ambient air was passed across the surface of the tubes. Operation over a total of 24 days resulted in a loss of 201 gm water, equivalent to a water loss rate of 4.3 gmlm2124 h.
~ EXAMPLE 3 A film of the following composition was produced by the blown film coextrusion method:
layer 1 nylon 6/Sclair~) 1 lKl~/Fusabond~
D226bla functionalized synthetic rubbef (72.5113.616.816.8 weight percent) 0.05 mm layer 2 XB603 (function~1i7Pd EMA) 0.01 mm layer 3 LCP 0.01 mm layer 4 XB603 0.01 mrn layer 5 LCP 0.01 rnm layer 6 XB603 0.01 mm layer 7 Same as Layer 1 0.05 mrn aLLDPE available from Nova Chemicals, Calgary, Alberta, Canada hA maleic anhydride grafted LLDPE available from E. I. duPont de Nemours &
Co., Wilmington, DE U.S.A.
CA maleic anhydride functionali~d EPDM.
The LCP used was a polymer of the following monomers in the bracketed molar ratios; 4,4'-biphenol(26.3)/hydroquinone(26.3)/1 ,6-hP~r~n~ nline(47.4)lterephthalic acid(36.8)/2,6-n~phth~lene dicarboxylic acid(63.2)/4-hydro~ybcl~oic acid(89.5)/6-hydroxy-2-napthoic acid(36.8). Melting point (DSC) of this LCP was 265~C.
2s The film was used as a "lid" of an al~ it.~ cup co~ ing ethylene glycol:
water mixture (a used ~1:1 ratio of commercial automotive ~llirl~e~e and water, radiator fluid), secured between metal rings and gaskets to avoid leakage and was placed in the inverted position ( so that the li~uid would contact the film) in an oven at 100 C.
Periodically, the cup was removed from the oven, cooled and weighed and placed back in the oven. The repeated cooling and reh~tin~ made the film concave or convex because of the pressure differences inside the cup as a consequence of the le~ ,e~ c variations.
This induces another repeated fatigue stress which can be qualitatively observed, but was not measured.
Evaluation of this film~ at 60~C, showed a fluid loss of 12.6 g/m~/day (0.~1 gm/100 in~/day). A film (0.19 mrn thick) of nylon-6,6 blended with synthetic rubber (Nordel~ 3681) and functionalized synthetic rubber (which is a maleic anhydride grafted EPDM) in an 80/10/10 weight ratio respectively (an also contains less than 1 weight per-ent of an epoxy resin), showed a lo~s of 159 g/m'lday (10.27 gm/100 in~/day) under the same conditions.
EXAl~IPLE 4 o Tubing was extruded with the following configuration (inside to outside of tube) and outer diameter 3.6 mm;
inside layer LCP 0.05 mm middle layer XB603 0.05 mm outer layer nylon 6.6 0.075 mm The LCP used was a polymer of the following monomers in the bracketed molar ratios; 4,4'-biphenol(35.5)/hydroquinone(35.5)/1,6-hexane~i~mine(29.0)/terephthalic acid(60)12,6-naphthalene dicarboxylic acid(40)/4-hydroxybenzoic acid(l30). The melting point (DSC) of this LCP was 255~C.
~o Evaluation as per Exarnple 1 at 38~C showed a loss of 0.02 gm/100 in'/day; nylon 6,6 tubing of the same dimensions showed a loss of 2.04 gm/100 in~/day.
Example S
For this example a coextruded 3-layer film was used. When coextruded, the melt temperature of the inner layer was 269~C, while the melt temperature of the outer layers was 292~C, and the line speed was 14.5 m/min. The inner layer, which was 0.076 mm thick, was Bynel~) 4006 (this is a maleic anhydride modified high density polyethylene with a melt index of 0.6, available from E. I. DuPont de Nemours & Co., Wilmington, DE, U.S.A.) The two outer layers were the same polymer used for layer 1 of Example 3, and each outer layer was 0.057 mm thick. The film was corona treated on both sides to about 4.8xlO~ N/cm (48 dynes/cm).
The film was formed into heat exchanger panels consisting or 13 rectangularly shaped liquid flow channels with manifolds on each end, and each panel had a primary AIVI~NOED SltE~T
heat exchange surface area about 54 cm long and 5 cm wide. Panels (67) were stacked by joining the manifolds, al~d the primary heat eYch~nge surface of the stack was ex~ AIPd to be 33,626 cm2.
A similar heat exchanger was made from single layer film 0.19 mm thick of the 5 same polymer of the outer layers of the above heat e~rch~nger. This 69 panel heat exçl~ e. had a surface area of about 34,632 cm2.
Both of these heat e~rh~n~ers were tested using 77~C water. The heat exchanger constructed from the 3-layer film had a water loss of 0.17 g/hr, while the heat ex~h~nger constructed from the single layer film had a water loss of 1.1 glhr.
o Example 6 Polymer A was a liquid crystalline polymer which was an aromatic polyester, and was a copolymer of (molar ratios in parenth~ses): 4,4'-biphenol(26.3)/hydroquinone(26.3)/1,6-hexdne~ minP(47.4)/terephthalic acid(36.8)/2,6-n~rhth~1ene dicarboxylic acid(63.2)/4-hydroxybenzoic acid(~9.5)/6-hydroxy-2-napthoic acid(36.8).
Polymer B was a nylon 6/Sclair(~ 1 lKl~/Fusabond~) D226b/a functionalized synthetic rubbef (72.5/13.6/6.816.8 weight percent (3LLDPE available from Nova Chemicals, Calgary, Alberta, Canada, bA maleic anhydride grafted LLDPE availablefrom E. I. duPont de Nemours & Co., Wilmington, DE U.S.A.; CA maleic anhydride 20 function~li7~(~ EPDM.) Polymer C was a blend prepared in a twin screw extruder of 40 percent by weight of Polymer A and 60 percent by weight of Polymer B.
The a~dlus used included a 3/4" (1.91 cm) Brabender (Type 2003, C. W.
Brabender Instruments, H~c~ s~c~ NJ, U.S.A.), a 1" (2.54 cm) Wilmod extruder, and a 25 3.8 cm NRM extruder. Polymer A was extruded from the Wilmod extruder running at 45 rpm and the melt te~ cldlure was 280~C. Polymer B was extruded from the NRM
extruder running at 20 rpm and at a melt lell~y~dlule of 280~C. Polymer C was extruded from the Brabender extruder running at 60 rpm and with a melt ~elll~ldlul~ of 270~C.
The output of each of these extruders was fed to 15.2 cm wide film die which was30 configured to handle three se~Jdld~e feeds. Polymers A and B were the outside layers and Polymer C was the inner layer.
The molten film fell by gravity on the oscill~ting rollers, which were arranged as shown in Fig. 1. The rollers were 8.9 cm in diarneter and 20.3 cm wide, and the surfaces were faced with stainless steel which were embossed with a diamond or knurled pattern, about 50-75 ,um deep, with a 90~ included angle for the sides, with the knurling lines at s an angle of 30~ to the axis of rotation of the roll. The rotational speeds of the rollers were m~nl-~lly controlled using a variable speed drive motor and was set so the surface speed of the rolls was 6m/min. The rate of oscillation was also m~nll~lly controlled by a variable speed drive motor and was 50 Hz, while the amplitude of oscillation could be varied by ch~nging the cam 17, and was 1.3 mm. Each roller was individually heated by 0 Calrod~ electrical heaters, which were in turn ~lltom~tically controlled by digital controllers. It is believed that the roller t~ pcldLuies could be ..~ e~ to about +1~C, and the roller telll~ dlu~cs were 1 77~C. Afte} passing through the oscill~ting rollers the film was passed through a set of cooling rolls and then rolled up on a roll.
In the beginning of the run, the speed of extrusion and rotation of the oscillating S rollers were adjusted so that a rolling bank ofthe polymer built up on the oscill:~ting rollers, and then the speed of the osçill~ting rollers was set as closely as possible to m~int~in a cQmt~nt sized rolling bank. Occasionally some manual adj--ctTnentc were needed.
In the resulting film, the Polymer a layer was about 0.051 mm thick, the PolymerB layer was about 0.10 mrn thick and the Polymer C layer was about 0.051 mm thick.
Using the above three-layer film, heat e~ch~n~er panels were made using the procedure of Example 2 of U.S. Patent 5,050,671, as described below.
The sheets were coated on the Polymer B side with a solution of benzyl alcohol and phenol, as described in U.S. Patent 4,935,462. The coated sides were placed in face-25 to-face contact, between female molds co~ ;; ~,g grooves parallel to the long axis of the sheets, with inlet and outlet headers at each end of the sheets. The molds were then heated in a press at 160~C and 241 MPa p-~S~UIc was applied while nitrogen gas was passed b~Lwt;en the sheets so that each sheet conformed to the shape of the grooves, the two sheets were bonded together, and the headers were bonded to the ends of the sheets.
No fractures or tears were evident in the resulting panel in the outer s~ cçs (which were Polymer A). The headers of several of these panels were bonded together to form a heat exchanger.
.. .. .
WO 98/10927 PCTtCA97/00647 An otherwise i~lPntic~l heat e~h~neer was made from 0 2 mm thick sheeting of Polymer B (the ~hçetine didn't go through the oscillating rollers). Water at 70~C was passed through the two heat ex~h~neers, and the rate of water loss by diffusion through the panels ~ d. The rate of water loss for the heat çxl~h~ngPr made with the three-5 polymer layer panels was 0.8 g/hr more than 10 times less than that of the heat çxrh~ngermade from Polymer B alone which lost about 9.1 g~r of water.
Claims (16)
1. A multilayer heat exchanger for gas-gas, gas-liquid or liquid-liquid heat exchange, comprising a heat exchange surface material, characterized in that said heat exchange surface material comprises:
(a) a first polymer which is a polymeric barrier layer; and (b) a layer of a second polymer;
and provided that:
(1 ) if said heat exchanger is a liquid-liquid or liquid-gas heat exchanger saidfirst polymer has a permeability to one of said liquids of 0.79 g-mm/m2/day or less at 38°C, or if said heat exchanger is a gas-gas heat exchanger said first polymer has a permeability to one of said gases of 2.5 ml-mm/m2/day or less at 23°C; and (2) said first polymer and said second polymer are different.
(a) a first polymer which is a polymeric barrier layer; and (b) a layer of a second polymer;
and provided that:
(1 ) if said heat exchanger is a liquid-liquid or liquid-gas heat exchanger saidfirst polymer has a permeability to one of said liquids of 0.79 g-mm/m2/day or less at 38°C, or if said heat exchanger is a gas-gas heat exchanger said first polymer has a permeability to one of said gases of 2.5 ml-mm/m2/day or less at 23°C; and (2) said first polymer and said second polymer are different.
2. The heat exchanger as recited in claim 1 which is a liquid-liquid heat exchanger.
3. The heat exchanger as recited in claim 1 which is a liquid-gas heat exchanger.
4. The heat exchanger as recited in claim 1 which is a gas-gas heat exchanger.
5. The heat exchanger as recited in claim 1 which is part of an automotive vehicle, an aircraft, a heat exchanger for comfort purposes, a heater, an air conditioner, or a ventilator.
6. The heat exchanger as recited in claim 3 which cools an automotive gasoline or diesel engine.
7. The heat exchanger as recited in claim 6 wherein said liquid is water, water and a glycol, or water and an alcohol, and said gas is air.
8. The heat exchanger as recited in claim 1 which is a tube heat exchanger.
9. The heat exchanger as recited in claim 1 which is a plate heat exchanger.
l0. The heat exchanger as recited in claim 1 wherein said first polymer is a thermotropic liquid crystalline polymer.
11. The heat exchanger as recited in claim 10 wherein said thermotropic liquid crystalline polymer is a polyether, or poly(ester-amide).
12. The heat exchanger as recited in claim 1, 6, 7 or 10 wherein said second polymer is a polyamide.
13. The heat exchanger as recited in claim 12 wherein said polyamide is nylon-6,nylon-6,6, or a copolymer of terephthalic acid, 1,6-diaminohexane and 2-methyl-1,5-diaminopentane wherein said 1,6-diaminohexane is about 30 to about 70 mole percent of total diamine present.
14. The heat exchanger as recited in claim 1 wherein one or more tie layers are also present in said heat exchange surface material.
15. The heat exchanger as recited in claim 1 wherein two or more layers of said first polymer are present, or two or more layers of said second polymer are present, or two or more layers of said first polymer are present and two or more layers of said second polymer are present.
16. The heat exchanger as recited in claim 1 wherein if said heat exchanger is aliquid-liquid or liquid-gas heat exchanger said first polymer has a permeability to one of said liquids of 0.079 g-mm/m2/day or less at 38°C, or if said heat exchanger is a gas-gas heat exchanger said first polymer has a permeability to one of said gases of 0.25 ml-mm/m2/day or less at 23°C.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US2593296P | 1996-09-11 | 1996-09-11 | |
| US90638597A | 1997-08-05 | 1997-08-05 | |
| US08/906,385 | 1997-08-05 | ||
| US60/025,932 | 1997-08-05 | ||
| PCT/CA1997/000647 WO1998010927A1 (en) | 1996-09-11 | 1997-09-09 | Polymeric multilayer heat exchangers containing a barrier layer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2263603A1 true CA2263603A1 (en) | 1998-03-19 |
Family
ID=26700482
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002263603A Abandoned CA2263603A1 (en) | 1996-09-11 | 1997-09-09 | Polymeric multilayer heat exchangers containing a barrier layer |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0925182A1 (en) |
| JP (1) | JP2001500242A (en) |
| CA (1) | CA2263603A1 (en) |
| WO (1) | WO1998010927A1 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1342045B1 (en) * | 2000-10-06 | 2004-08-11 | E.I.Du pont de nemours and company | Heat exchanger made from bendable plastic tubing |
| ITMI20020012A1 (en) * | 2002-01-08 | 2003-07-08 | Ausimont Spa | USE OF FLUORINATED LIQUIDS |
| US7122255B2 (en) | 2002-12-10 | 2006-10-17 | E. I. Du Pont Canada Company | Multilayered composite polyamide articles and processes for their preparation |
| JP2005213418A (en) * | 2004-01-30 | 2005-08-11 | Sumitomo Chemical Co Ltd | Liquid crystal polyester resin composition |
| WO2008045968A2 (en) * | 2006-10-10 | 2008-04-17 | Adco Products, Inc. | Radiation curable sealant composition |
| US8211517B2 (en) * | 2009-06-08 | 2012-07-03 | Ei Du Pont De Nemours And Company | Multi-layered coextruded tube |
| US20210139693A1 (en) | 2016-04-05 | 2021-05-13 | Hitachi Chemical Company, Ltd. | Resin composition, hydrogen gas barrier material, cured product, composite material, and structure |
Family Cites Families (72)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3734139A (en) * | 1965-09-20 | 1973-05-22 | Du Pont | Composite thermoplastic structure |
| PH15509A (en) | 1974-05-10 | 1983-02-03 | Du Pont | Improvements in an relating to synthetic polyesters |
| US3991014A (en) | 1974-05-10 | 1976-11-09 | E. I. Du Pont De Nemours And Company | Polyesters of derivatives of hydroquinone and bis(carboxyphenyl)ether |
| US3991013A (en) | 1974-05-10 | 1976-11-09 | E. I. Du Pont De Nemours And Company | Copolyesters of derivatives of hydroquinone |
| US4048148A (en) | 1975-05-09 | 1977-09-13 | E. I. Du Pont De Nemours And Company | Polyazomethine fibers and films |
| US4075262A (en) | 1975-08-12 | 1978-02-21 | E. I. Du Pont De Nemours And Company | Copolyesters capable of forming an anisotropic melt |
| US4011199A (en) | 1975-11-28 | 1977-03-08 | Eastman Kodak Company | Acidolysis process |
| US4122070A (en) | 1976-03-19 | 1978-10-24 | E. I. Du Pont De Nemours And Company | Fibers and anisotropic melts of polyazomethines |
| US4083829A (en) | 1976-05-13 | 1978-04-11 | Celanese Corporation | Melt processable thermotropic wholly aromatic polyester |
| GB1538632A (en) | 1976-06-30 | 1979-01-24 | Sumitomo Chemical Co | Polyester resin composition |
| US4159365A (en) | 1976-11-19 | 1979-06-26 | E. I. Du Pont De Nemours And Company | Polyphenyl-1,4-phenylene terephthalates and fibers therefrom |
| US4169933A (en) | 1977-08-08 | 1979-10-02 | Eastman Kodak Company | Liquid crystal copolyesters containing terephthalic acid and 2,6-naphthalenedicarboxylic acid |
| US4184996A (en) | 1977-09-12 | 1980-01-22 | Celanese Corporation | Melt processable thermotropic wholly aromatic polyester |
| US4130545A (en) | 1977-09-12 | 1978-12-19 | Celanese Corporation | Melt processable thermotropic wholly aromatic polyester comprising both para-oxybenzoyl and meta-oxybenzoyl moieties |
| US4161470A (en) | 1977-10-20 | 1979-07-17 | Celanese Corporation | Polyester of 6-hydroxy-2-naphthoic acid and para-hydroxy benzoic acid capable of readily undergoing melt processing |
| US4153779A (en) | 1978-06-26 | 1979-05-08 | Eastman Kodak Company | Liquid crystal copolyester containing a substituted phenylhydroquinone |
| EP0007715B1 (en) | 1978-07-24 | 1984-02-29 | Imperial Chemical Industries Plc | Thermotropic polyesteramides |
| US4245082A (en) | 1979-07-09 | 1981-01-13 | E. I. Du Pont De Nemours And Company | Polyesters derived from 3,4'-dihydroxy-benzophenones or 3-hydroxy-4'-(4-hydroxyphenyl-)benzophenone and certain aromatic dicarboxylic acids and filaments thereof |
| US4219461A (en) | 1979-04-23 | 1980-08-26 | Celanese Corporation | Polyester of 6-hydroxy-2-naphthoic acid, para-hydroxy benzoic acid, aromatic diol, and aromatic diacid capable of readily undergoing melt processing |
| US4256624A (en) | 1979-07-02 | 1981-03-17 | Celanese Corporation | Polyester of 6-hydroxy-2-naphthoic acid, aromatic diol, and aromatic diacid capable of undergoing melt processing |
| US4232143A (en) | 1979-09-17 | 1980-11-04 | E. I. Du Pont De Nemours And Company | Polyester which exhibits anisotropy in the melt containing p-oxybenzoyl units and 4,4'-dioxybenzophenone units or methyl and chloro derivatives thereof |
| US4269965A (en) | 1979-09-17 | 1981-05-26 | E. I. Du Pont De Nemours And Company | Aromatic polyester which forms optically anisotropic melts and filaments thereof |
| US4232144A (en) | 1979-09-17 | 1980-11-04 | E. I. Du Pont De Nemours And Company | Polyester which exhibits anisotropy in the melt containing p-oxybenzoyl units and 4-oxy-3'-carbonylbenzophenone units or methyl and chloro derivatives of said units |
| DE3103071A1 (en) * | 1981-01-30 | 1982-08-05 | Daimler-Benz Ag, 7000 Stuttgart | Flexible, two-dimensional heat exchanger element and its use for vehicle air conditioning |
| US4370466A (en) | 1981-09-28 | 1983-01-25 | E. I. Du Pont De Nemours And Company | Optically anisotropic melt forming polyesters |
| US4383105A (en) | 1981-12-28 | 1983-05-10 | E. I. Du Pont De Nemours And Company | Polyimide-esters and filaments |
| US4522974A (en) | 1982-07-26 | 1985-06-11 | Celanese Corporation | Melt processable polyester capable of forming an anisotropic melt comprising a relatively low concentration of 6-oxy-2-naphthoyl moiety-4-benzoyl moiety, 1,4-dioxyphenylene moiety, isophthaloyl moiety and terephthaloyl moiety |
| JPS5943021A (en) | 1982-09-02 | 1984-03-09 | Ueno Seiyaku Oyo Kenkyusho:Kk | Production of aromatic (co)polyester |
| US4447592A (en) | 1983-06-13 | 1984-05-08 | E. I. Du Pont De Nemours And Company | Anisotropic melt polyesters of 6-hydroxy-2-naphthoic acid |
| JPS60240956A (en) * | 1984-05-15 | 1985-11-29 | Matsushita Electric Ind Co Ltd | Heat exchanger |
| FR2566107B1 (en) | 1984-06-15 | 1988-12-09 | Rossignol Sa | PANEL FOR HEAT EXCHANGER, RESULTING EXCHANGER AND APPLICATIONS, ESPECIALLY FOR HEAT PUMPS |
| US4617369A (en) | 1985-09-04 | 1986-10-14 | E. I. Du Pont De Nemours And Company | Polyester polymers of 3-hydroxy-4'-(4-hydroxyphenyl)benzophenone or 3,4'-dihydroxybenzophenone and dicarboxylic acids |
| US4973442A (en) | 1985-09-26 | 1990-11-27 | Foster Miller Inc. | Forming biaxially oriented ordered polymer films |
| DE3542797A1 (en) | 1985-12-04 | 1987-06-11 | Basf Ag | FULLY FLAVORED MESOMORPHIC POLYESTERIMIDES, THEIR PRODUCTION AND USE |
| DE3542814A1 (en) | 1985-12-04 | 1987-06-11 | Basf Ag | FULLY FLAVORED MESOMORPHIC POLYESTER, THEIR PRODUCTION AND USE |
| DE3542777A1 (en) | 1985-12-04 | 1987-06-11 | Basf Ag | FULLY FLAVORED POLYESTER CARBAMIDES, THEIR PRODUCTION AND USE |
| DE3542779A1 (en) | 1985-12-04 | 1987-06-11 | Basf Ag | FULLY FLAVORED MESOMORPHIC POLYESTERAMIDES, THEIR PRODUCTION AND USE |
| DE3542798A1 (en) | 1985-12-04 | 1987-06-11 | Basf Ag | FULLY FLAVORED MESOMORPHIC POLYESTERAMIDIMIDES, THEIR PRODUCTION AND USE |
| DE3542855A1 (en) | 1985-12-04 | 1987-06-11 | Basf Ag | FULLY FLAVORED MESOMORPHIC POLYESTERAMIDES, THEIR PRODUCTION AND USE |
| US4664972A (en) | 1986-04-23 | 1987-05-12 | E. I. Du Pont De Nemours And Company | Optically anisotropic melt forming aromatic copolyesters based on t-butylhydroquinone |
| DE3621519A1 (en) | 1986-06-27 | 1988-01-07 | Basf Ag | FULLY FLAVORED MESOMORPHIC POLYESTER, THEIR PRODUCTION AND USE |
| JPH0717748B2 (en) | 1986-12-19 | 1995-03-01 | 川崎製鉄株式会社 | Aromatic polyester amide |
| EP0272676A3 (en) | 1986-12-23 | 1989-03-29 | Mitsubishi Chemical Corporation | Wholly aromatic polyester and process for its production |
| GB8700923D0 (en) | 1987-01-16 | 1987-02-18 | Ici Plc | Aromatic copolyesters |
| GB8708386D0 (en) | 1987-04-08 | 1987-05-13 | Cesaroni A J | Heat sealing of polyamides |
| US4955435A (en) | 1987-04-08 | 1990-09-11 | Du Pont Canada, Inc. | Heat exchanger fabricated from polymer compositions |
| GB8711428D0 (en) | 1987-05-14 | 1987-06-17 | Du Pont Canada | Comfort heat exchanger |
| EP0311287B1 (en) | 1987-10-05 | 1993-03-03 | Polyplastics Co. Ltd. | Resin having excellent heat resistance and exhibiting anisotropy in molten state |
| IT1223401B (en) | 1987-12-02 | 1990-09-19 | Montedison Spa | THERMOTROPIC CRYSTALLINE LIQUID AROMATIC POLYESTERS |
| DE3742205A1 (en) | 1987-12-12 | 1989-06-22 | Huels Chemische Werke Ag | MOLDING COMPOSITION MADE OF A THERMOTROPEN, AROMATIC POLYESTER |
| IT1215682B (en) | 1988-01-12 | 1990-02-22 | Montedison Spa | AROMATIC POLYESTERS THERMOTROPIC CRYSTALLINE LIQUID. |
| DE3802511A1 (en) | 1988-01-28 | 1989-08-10 | Huels Chemische Werke Ag | MOLDING COMPOSITIONS MADE FROM A THERMOPLASTICALLY PROCESSABLE, AROMATIC POLYESTERIMIDE |
| ATE83116T1 (en) * | 1988-05-05 | 1992-12-15 | Siemens Nixdorf Inf Syst | ARRANGEMENT FOR CONVECTIVE COOLING OF ELECTRONIC COMPONENTS, PARTICULARLY OF INTEGRATED SEMICONDUCTOR CIRCUITS. |
| US4966807A (en) | 1988-06-13 | 1990-10-30 | Foster Miller, Inc. | Multiaxially oriented thermotropic polymer films and method of preparation |
| US4849499A (en) | 1988-08-01 | 1989-07-18 | Eastman Kodak Company | Melt processable, liquid crystalline polyesters |
| US5025082A (en) | 1988-08-24 | 1991-06-18 | Mitsubishi Kasei Corporation | Aromatic polyester, aromatic polyester-amide and processes for producing the same |
| DE3914048A1 (en) | 1988-09-13 | 1990-03-22 | Bayer Ag | EASY-FLOWING POLYAMIDE MOLDS AND ALLOYS |
| JPH02196819A (en) | 1989-01-25 | 1990-08-03 | Nippon Oil Co Ltd | Wholly aromatic polyester |
| GB8910966D0 (en) | 1989-05-12 | 1989-06-28 | Du Pont Canada | Panel heat exchangers formed from thermoplastic polymers |
| JPH037891A (en) | 1989-06-02 | 1991-01-16 | Bando Chem Ind Ltd | Plastic heat exchanging pipe |
| WO1990015706A1 (en) | 1989-06-16 | 1990-12-27 | Foster-Miller, Inc. | Liquid crystal polymer film |
| GB8917241D0 (en) * | 1989-07-28 | 1989-09-13 | Cesaroni Anthony Joseph | Corrugated thermoplastic sheet having fluid flow passages |
| US5275235A (en) | 1989-07-28 | 1994-01-04 | Cesaroni Anthony Joseph | Panel heat exchanger |
| JP3086231B2 (en) | 1989-11-01 | 2000-09-11 | ポリプラスチックス株式会社 | Polyester resin and resin composition showing anisotropy when melted |
| DE4006404A1 (en) | 1990-03-01 | 1991-09-05 | Bayer Ag | Phenolic hydroxy-contg. liq. crystalline ester or ether-amide cpds. |
| US5015722A (en) | 1990-04-04 | 1991-05-14 | Hoechst Celanese Corporation | Melt-processable polyester capable of forming an anisotropic melt which exhibits a highly attractive balance between its molding and heat deflection temperatures |
| JPH0496988A (en) * | 1990-08-15 | 1992-03-30 | Showa Highpolymer Co Ltd | Heat-exchanging medium |
| US5110896A (en) | 1990-12-10 | 1992-05-05 | E. I. Du Pont De Nemours And Company | Thermotropic liquid crystalline polyester compositions |
| CA2090998C (en) | 1992-05-21 | 2000-11-28 | Anthony Joseph Cesaroni | Panel heat exchanger with integral thermoelectric device |
| US6004662A (en) * | 1992-07-14 | 1999-12-21 | Buckley; Theresa M. | Flexible composite material with phase change thermal storage |
| US5485671A (en) * | 1993-09-10 | 1996-01-23 | Aavid Laboratories, Inc. | Method of making a two-phase thermal bag component cooler |
| US5576106A (en) * | 1994-07-28 | 1996-11-19 | E. I. Du Pont De Nemours And Company | Grafted fluoropolymer powders |
-
1997
- 1997-09-09 EP EP97939901A patent/EP0925182A1/en not_active Withdrawn
- 1997-09-09 JP JP10513081A patent/JP2001500242A/en active Pending
- 1997-09-09 CA CA002263603A patent/CA2263603A1/en not_active Abandoned
- 1997-09-09 WO PCT/CA1997/000647 patent/WO1998010927A1/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| EP0925182A1 (en) | 1999-06-30 |
| WO1998010927A1 (en) | 1998-03-19 |
| JP2001500242A (en) | 2001-01-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2016391C (en) | Panel heat exchangers formed from thermoplastic polymers | |
| AU600117B2 (en) | Heat exchanger fabricated from polymer compositions | |
| CA1302219C (en) | Cushioning material | |
| CA1294859C (en) | Process for the manufacture of heat exchangers from polymers | |
| US5195240A (en) | Method for the manufacture of thermoplastic panel heat exchangers | |
| JP2005504951A (en) | Barrier ribbon for heat exchangers including polymer tubes | |
| US20160138817A1 (en) | Flexible liquid desiccant heat and mass transfer panels | |
| CA2263603A1 (en) | Polymeric multilayer heat exchangers containing a barrier layer | |
| JP2005504255A (en) | Method for manufacturing a barrier ribbon for fluid handling having a polymer tube | |
| EP0925181B1 (en) | Heat exchangers containing liquid crystalline polymer layers | |
| KR0177796B1 (en) | Method for the manufacture of thermoplastic panel heat exchangers | |
| US5275235A (en) | Panel heat exchanger | |
| JP2005504233A (en) | Method for producing polymer barrier tube for fluid treatment | |
| WO2000079206A1 (en) | Heat exchanger formed from tubes joined by simultaneous extrusion thermal bonding | |
| AU632842B2 (en) | Panel heat exchanger | |
| WO2000079199A1 (en) | Heat exchanger formed from tubes joined by thermal bonding | |
| WO2000079198A1 (en) | Heat exchanger formed from tubes joined by solvent bonding |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |