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Publication numberUS3554183 A
Publication typeGrant
Publication dateJan 12, 1971
Filing dateOct 4, 1968
Priority dateOct 4, 1968
Publication numberUS 3554183 A, US 3554183A, US-A-3554183, US3554183 A, US3554183A
InventorsEdward L Coyle, George M Grover
Original AssigneeAcf Ind Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Heat pipe heating system for a railway tank car or the like
US 3554183 A
Abstract  available in
Images(8)
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Claims  available in
Description  (OCR text may contain errors)

O Unrted States Patent [111 3,55

[72] Inventors George M. Grover 3,378,449 4/1968 Roberts et al l65/l05X Los Alamos, N. Mex.; 3,468,300 9/1968 Geyer et al. 165/105X Edward L. Coyle, St. Charles, Mo. FORElGN PATENTS [211 APPLNQ 7651208 771,878 8/1934 France 165/105 [22] 1968 723,857 8/1942 Germany l65/l05 [45] Patented Jan. 12, 1971 OTHER REFERENCES [73] Assignee ACF lndustries,lncorporated I N Y k,N Y l. Deverall, J. E. et al., High Thermal Conductances acorporation of New Jersey geviciegofl 1965, Los Alamos Scientific Laboratory. pp.

an 2. Sandia Laboratories Heat Pipe Conference 1966 [54] HEAT PIPE HEATING SYSTEM FOR A RAILWAY Albuquerque, N .M., pp 12 and 24 (91 pages), SC-M-66-623 Primary Examiner-Albert W. Davis, Jr. g AttorneysSamuel .I. Snyder and Eugene N. Riddle [52] US. Cl. 126/3435,

165/105, 165/134 [51] lnLCl- Bfild /04, ABSTRACT: A heat transfer pipe containing a vaporizable Fzsd /00 fluid and having a porous wick on its inner surface is mounted Field ofSearch 165/105, in h tank of a railway tank and extends into a furnace 134; 126/3435 outside the tank. The outer end of the pipe communicated 56] R f cted with a reservoir for the fluid. The wick has a plurality of e erences I porous metallic layers designed to provide good heat transfer, UNITED STATES PATENTS as well as a high degree of capillary action. Evaporation of the 1,975,868 [0/1934 Schlumbohm l/l05X liquid produced by the furnace and condensation along the 2,581,347 l/ 1952 Backstrom /105X whole length of the pipe in the tank transfer a great amount of 3,305,005 2/ 1967 Grover et al 165/105 heat into the tank at a generally uniform temperature.

"mmtmlzmn I 0554.183

SHEET 1' BF 8- N INVENTORS. 2.3 N GEORGE M. GROVER it EDWARD 1.. COYLE ATTORNEY PATENTED JAN 1 2 I97! SHEET 8 OF 8 HEAT ms HEATING SYSTEM FOR A RAILWAY TANK CAR orrrneu a BACKGROUND OF THE INVENTION Heat transfer pipes commonly known as heat pipes" comprise an outer enclosed shell, a porous wick, and a working fluid for wetting the wick.A portion of the heat pipe referred to as the evaporator section is heated and the working fluid in the evaporator area is vaporized and driven through the pipe. As heat is given off by the heat pipe, the vaporized fluid condenses to a liquid and is re'turned to the boiler areaby the SUMMARY or. THE INVENTION The present invention is directed to a railway tank car having a heat pipe mounted thereon for heating and maintaining the lading at a predetermined temperature during transit and at unloading sites. A generally straight length of the heat pipe is mounted within the tank and has, an outer end portion extending outwardly of the tank into a heat producing furnace.

The heat transfer pipe comprises an outer enclosed shell, a porous wick positioned against the inner surface of the shell, and a vaporizable fluid within the shell, the fluid being vaporized from the'heat generated by the furnace and moving and inner tank 12. A center sill 18 extends the length of railway car 10, with outer jacket I4 being attached to the outer sides of center sill 18. A coupler I9 is mounted within each end of center sill 18. A wheeled truck 20 is provided adjacent each end of railway tank car 10.

Mounted on an end of railway tank car I0 is furnace 22 of the open flame type. To supply fuel, such as propane gas, to furnace 22, a fuel container 24 is mounted on each side of railway tank car 10 and has a fuel line 26 leading to furnace 22. Mounted within inner tank 12 for heating liquid lading therein to temperatures of 500 F. or greater is a heat pipe 28 for transferring heat from 'fumace 22 to the lading within inner tank 12. Heat pipe 28 includes an inner portion mounted within tank 12 and an outer end portion 32 which extends through the adjacent end of inner tank 12 and outer jacket 14 within furnace 22. As shown in FIG. 2, brackets generally indicated 3 4, have sleeves 36 receiving inner heat pipe portion 30 and lower legs secured to the inner surface of tank 12 to support heat pipe section 30 within the tank at a height above the bottom of the tank. As shown in FIG. 1, heat pipe 28 slopes downwardly to outer end portion 32 within furnace 22. As it is desirable for pipe 28 to have such a downwardly slope under all operating conditions, the slope may preferably be between 2 percent and 4 percent, which is normally the maximum railway grade encountered. Thus, the slope of pipe 28 outwardly away from the furnace to condense along the length of the pipe upon the transfer of heat to the lading within the tank car. Upon condensing, the fluid is returned by the capillary action of the wick to the outerv end portion of the pipe. Sufficient working fluid is put intojthe heat pipe to wet the entire wick and the wick is held tightly and uniformly against the inside wall of the heat pipe; The. outer end of the heat pipe is connected to a reservoir adapted to contain all of the vaporizable fluid when the heat pipe is not operating. To obtain efi'rcient heat transfer and capillary action by the wick, it is formed of a number of layers of wire mesh and permeable metal.

BRIEF DESCRIPTION or THE DRAWING The invention is illustrated in the accompanying drawing, in

which:

FIG. 1, is a side elevation of a railway tank car having a heat pipe in the tank and extending out of the tank into a furnace.

FIG. 2 is a schematic view of a baffle arrangement to provide circulation beneath the heat pipe to the bottom of the tank.

FIG. 3 is a top plan view of the heat pipe, with a portion of the tank broken away. v

FIG. 4 is a front elevation oftheheat' pipe and its reservoir. FIG. 5 is a sectional view taken along line 5-5 of FIG. 4. FIG. 6 is a partial sectional view along line 15- 6 of FIG. 5. FIGS. 7 and 8 are sectional views of portions of another em bodiment of the heat pipe.

FIGS. 9 and I0 are enlarged sectional views of the evaporator and condenser portions of the heat pipe shown in FIG. 5.

FIGS. I1 and 12 are partial sectional views of another variation of the heat pipe.

FIGS. 13 and 14 show another modification of the condenser section of the heat pipe.

FIGS. 15 and 16 are partial views of the furnace and evaporator section of the heat pipe.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an insulated railway tank car is generally indicated 10 in FIG. I and comprises an inner tank 12, and outer jacket 14 extending about the circumference of tank 12, and a layer of insulating material 16, stich as a polyurethane foam material or fiber glass, between outer jacket 14 under operating conditions may vary from around 0 to an 8 percent slope depending on the grade of the railway track.

Referring now to furnace 22 and more particularly to FIGS. 15 and 16, an outer housing 38 extends downwardly to a horizontal section 42 beneath center sill I8 as shown in FIG. 15. Fuel lines 26 from fuel containers or tanks 24 lead to burner nozzles 44 suitably mounted within furnace 22. Positioned above nozzles 44 are a plurality of vanes or tins 46 secured about outer end portion 32of heat pipe 28. A bearing 48 supports outer end portion 32 and is secured between tank 12 and furnace 22.

Extending upwardly from horizontal section 42 is an inner housing generally indicated 54 and forming an air outlet conduit. An upper cap or cover generallyindicated 62 is positioned over the upper end of housing 54 to prevent foreign matter and rain from entering outlet conduit or duct formed by inner housing 54. The air and gas mixture burns below fins 46, and the heat passes upwardly through the spaced fins 46 to heat pipe section 32. Fins 46 are at a temperature of around 700 800 F. The construction of the furnace and the portion of the heat pipe therein are more fully shown and described in application 663,342, mentioned above.

Referring to FIGS. 3 to 6, 9 and 10, heat pipe 28 may have an inside diameter of about 3 inches, and it is welded to a reservoir 70 in the form of a transverse stainless steel pipe located beyond the furnace and extending across one end of the car. The heat pipe is closed by an entl'cap 72. Reservoir 70 has a nipple 73 through which it is charged with liquid and an inert gas, such as argon, and has a safety head 74, including a rupture disc, for relieving excessive pressure. The far end of the heat pipe has a welded end cap 76 provided with a stainless steel fiber plug 78, for providing capillary action and insulation at the end. As shown in FIG. 10, pipe section 32 is joined to reservoir 70, and the construction in the area marked 10 on FIG. 5 includes a ring 80 of nickel coated copper, sintered fiber porous material, or other felted porous metal, held by a snap ring 82, and two layers of rolled or pressed tine mesh stainless steel wire screen 84 folded along the wall of the reservoir as indicated at 86. Beneath screens 84 there are a pair of layers of similar screen 88, and between screens 88 and the wall of pipe section 32 are eight layers of screen 90 of coarser mesh, forming a layer about a quarter of an inch thick. These several screens constitute the wick at the evaporator and of the heat pipe.

FIG. 9 shows the construction of the wick in the region marked 9 in FIG. 5. Wire screens 88 form the two top layers of the wick. The eight coarse layers of screen 90 are reduced to four layers, which are feathered out as shown, leaving eventually two layers of screen 88, 92 separated from the wall of pipe 30 by a corrugated screen 94, best shown in FIG. 6. This wick structure extends out to the end of the pipe. The wick is held in place by coil spring 96, which is anchored to pin 98 on ring 100 at one end, and anchored to spring clip 102 at the other end. Corrugated screen 94 provides large pores for longitudinal flow, while at the same time maintaining some wicking action, which is primarily provided by surface layers 88, 92.

FIGS. 7 and 8 show a variation of the wick structure. At the evaporator end, as shown in FIG. 8, the construction is similar to that of FIG. 10, except that beneath the four layers of screen 110, which may have a 50 by 250 mesh, there is a layer 112 of felted metal about one-tenth inch thick, extending throughout the evaporator section of the heat pipe. In the condenser section the layer 112 is replaced by a corrugated screen 114, which may be similar to that shown in FIG. 6, holding several layers of fine mesh screen 116 spaced from the wall of the heat pipe. The coil spring 96 for holding the wick against the wall of the pipe may be the same as coil spring 96 of FIG. 5. Adjacent screens are overlapped as indicated at 115. To prevent shifting of corrugated screen 114 relative to the porous metal sheet 112, they are both welded to wire screen 1 17.

FIGS. 11 and 12 show a wick which, in the evaporator portion, may be the same as that of FIGS. and 10, including coarse screens 90 and fine mesh screens 88. Along the condenser portion, however, the corrugated screen shown in FIG. 6 is replaced by wide rings 118, 119 of felted metal. The rings 118, 119 are held in place by welding to wire screen rings 120, 121. A thin layer of felted metal, including rings 122, 123, are placed on layer 118, 119 and held in place by coil spring 96. The layers 118, 119, 122 and 123 are more easily fabricated than wire mesh layers and may be obtained in cylindrical form. Layer 122, 123 is of fine porosity to provide wicking action primarily, and layer 118, 119 is of large porosity to provide longitudinal flow paths for the liquid.

Another construction of the wick which may be employed in either the condenser section 30 or the outer end heat section 32 of the heat pipe is shown in FIGS. 13 and 14. Corrugated sheet metal strips 126 are placed contiguously to one another, or connected together at their edges. Matted steel fibers 128 are packed within the corrugations on both sides of strips 126, and the structure, formed intoa cylindrical section, is sintered. The sintered fibers provide a highly desirable wicking characteristic when placed on the wall of the condenser section 30 of the heat pipe, as shown in FIG. 13, while the metal strips 126 provide a very effective heat transfer across the wick. As seen in FIG. 14, strips 126 are offset or staggered from one another to provide a tortuous flow passage in a longitudinal direction, as well as an annular direction about the circumference of the pipe. Thus the liquid will be nicked from the bottom of the pipe to the upper portion thereof through the sintered fiber material having sheet metal corrugations therein.

The operation of the apparatus will be understood by those skilled in the art, for the principles of the heat pipe have been described in the literature and patents. Briefly, in the evapora tor or boiler section 32 of heat pipe 28, furnace 22 supplies heat to vaporize the liquid, which may be water. The vapor moves through the central part of the heat pipe. The lading in the tank car 10 removes heat from the wall of heat pipe 28 and causes some of the vapor to condense along the portion 30 of the pipe. The condensate flows back through the heat pipe to evaporator section 32, aided by the capillary action of the wick. The great amount of heat energy in the vapor maintains the heat pipe temperature along the pipe with a very small gradient. When the heat pipe is not in operation, the water drains into the reservoir, where no damage is caused if the water freezes since the reservoir is never full of water. Other features and operational characteristics have been referred to above and will be understood by those skilled in the art.

I claim: l. A railway tank car comprising a tank shell having ends to form an enclosure for carrying lading, a heat transfer pipe mounted on the tank car having an inner end portion extending within the tank shell and an outer end portion extending outwardly of an end of said tank shell, and heat producing means mounted on said railway tank car outwardly of said shell to heat said outer end portion for the transfer of heat therefrom to the portion of the pipe within the shell and a subsequent transfer of heat to the lading within the shell, said heat transfer pipe comprising an outer enclosed casing extending axially generally in the direction of the longitudinal axis of the car at a slope of at least 2 percent with respect to the longitudinal axis of the railway car, a porous wick positioned against the inner circumferential surface of the casing at least within the outer end portion, a vaporizable fluid within the casing, said fluid being vaporized by the heat generated by said heat producing means and moving away from said heat producing means to said inner end portion, said vaporized fluid condensing along the length of the heat transfer pipe within the tank shell and returning to the outer end portion by a capillary action of said wick, and a closed sump reservoir of a large cross-sectional area relative to said casing being outside the tank shell and connected to the bottom of said outer end por' tion of said pipe for draining off and storing the vaporizable fluid when said heat producing means is not in operation, said wick extending along a wall of the reservoir immediately sub jacent the heat pipe to the bottom of the reservoir whereby the vaporizable fluid may be drained from said reservoir into said pipe by a capillary action, said reservoir having a sufficient capacity to prevent damage to said heat pipe due to freezing of the vaporizable fluid.

2. Apparatus according to claim 1, wherein said reservoir includes an elongated chamber intersecting said heat transfer rpe.

p 3, Apparatus according to claim 1, wherein said wick tapers as it extends from the portion of the pipe in which the fluid evaporates into the portion of the pipe in which the fluid condenses.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1975868 *Feb 9, 1931Oct 9, 1934American Thermos Bottle CoMethod of cooling indirectly
US2581347 *Aug 5, 1944Jan 8, 1952Electrolux AbAbsorption refrigeration apparatus and heating arrangement therefor
US3305005 *Dec 3, 1965Feb 21, 1967Busse Claus ACapillary insert for heat tubes and process for manufacturing such inserts
US3378449 *Jul 27, 1967Apr 16, 1968Atomic Energy Commission UsaNuclear reactor adapted for use in space
US3468300 *Nov 13, 1968Sep 23, 1969Acf Ind IncHeat transfer means for a railway tank car
*DE723857A Title not available
FR771878A * Title not available
Non-Patent Citations
Reference
1 *1. Deverall, JE etal High Thermal Conductances Devices 4/1965, Los Alamos Scientific Laboratory, pp.29 and 30, LA-3211 2. Sandia Laboratories Heat Pipe Conference 10/1966 Albuquerque, N.M., pp 12 and 24 (91 pages), SC-M-66-623
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3777811 *Jun 1, 1970Dec 11, 1973Trw IncHeat pipe with dual working fluids
US3789920 *May 21, 1970Feb 5, 1974NasaHeat transfer device
US3811496 *Nov 2, 1972May 21, 1974Philips CorpHeat transfer device
US3823769 *Nov 2, 1972Jul 16, 1974Mc Donnell Douglas CorpSeparable heat pipe assembly
US3834457 *Jan 17, 1973Sep 10, 1974Bendix CorpLaminated heat pipe and method of manufacture
US3857441 *Mar 6, 1970Dec 31, 1974Westinghouse Electric CorpHeat pipe wick restrainer
US3913665 *Oct 1, 1973Oct 21, 1975Boeing CoExternal tube artery flexible heat pipe
US3968787 *Mar 16, 1973Jul 13, 1976Hughes Aircraft CompanyControlled vapor chamber cooking device
US4108239 *Mar 22, 1976Aug 22, 1978Siemens AktiengesellschaftHeat pipe
US4129181 *Feb 16, 1977Dec 12, 1978Uop Inc.Heat transfer surface
US4254821 *Aug 10, 1979Mar 10, 1981Thermo Electron CorporationHeat pipe deicing apparatus
US4448043 *Feb 11, 1982May 15, 1984Yvan AragouHeat exchanger with a capillary structure for refrigeration equipment and/or heat pumps and method of making the same
US4586561 *Feb 27, 1984May 6, 1986Exxon Research And Engineering Co.Low temperature heat pipe employing a hydrogen getter
US5947111 *Apr 30, 1998Sep 7, 1999Hudson Products CorporationApparatus for the controlled heating of process fluids
US7841305Jul 1, 2005Nov 30, 2010Grit Industries, Inc.Heat exchange apparatus
US8671570 *Oct 25, 2010Mar 18, 2014Pegatron CorporationVapor chamber and method for manufacturing the same
US20060162906 *Nov 10, 2005Jul 27, 2006Chu-Wan HongHeat pipe with screen mesh wick structure
US20060169439 *Nov 10, 2005Aug 3, 2006Chu-Wan HongHeat pipe with wick structure of screen mesh
US20070000453 *Jul 1, 2005Jan 4, 2007Grit Industries Inc.Heat exchange apparatus
US20100108297 *Apr 28, 2007May 6, 2010Jen-Shyan ChenHeat Pipe and Making Method Thereof
US20110174474 *Oct 25, 2010Jul 21, 2011Juei-Khai LiuVapor chamber and method for manufacturing the same
US20120247067 *Mar 30, 2011Oct 4, 2012Podd Stephen DSteam dispersion system for cargo containers
EP0058628A2 *Feb 12, 1982Aug 25, 1982Yvan AragouHeat exchanger with capillary structure for refrigerating machines and/or heat pumps
EP0058628A3 *Feb 12, 1982Apr 13, 1983Yvan AragouHeat exchanger with capillary structure for refrigeration machines and/or heat pumps, and method for obtaining the same
Classifications
U.S. Classification126/343.50A, 165/104.26, 165/134.1
International ClassificationB65D88/74, F28D15/04
Cooperative ClassificationF28D15/04, B65D88/74
European ClassificationF28D15/04
Legal Events
DateCodeEventDescription
Jan 25, 1985ASAssignment
Owner name: ACF INDUSTRIES, INCORPORATED, 750 THIRD AVENUE, NE
Free format text: RECONVEYS ALL LETTERS PATENTS BACK TO BORROWER RECITED IN REEL 4307FRAMES 396 AND 397 RECORED OCT. 2, 1984 (LOAN HAS BEEN PAID IN FULL);ASSIGNOR:NATIONAL WESTMINSTER BANK USA, AS AGENT;REEL/FRAME:004365/0266
Effective date: 19841220
Oct 2, 1984ASAssignment
Owner name: NATIONAL WESTMINSTER BANK USA, A NATIONAL BANKING
Free format text: SECURITY INTEREST;ASSIGNOR:ACF INDUSTRIES, INCORPORATED;REEL/FRAME:004307/0396