US3006612A - Heat exchangers - Google Patents

Description

Oct. 31., 1961 R. M. HERBERT 3,006,612

HEAT EXCHANGERS Filed March 17, 1958 2 Sheets-Sheet 1 INV EN TOR. R/cme M /fffer RANK:

ATTOR R. M. HERBERT HEAT EXCHANGERS Oct. 31, 1961 2 Sheets-Sheet 2 Filed March 17, 1958 INVENTOR. R/c/m/eo Mfeafr ATTOR United States Patent Oliice 3,006,612 Patented Oct. 31, 1961 3,006,612 HEAT EXCHANGERS Richard M. lerbert, York, Pa., assignor to Borg-Warner Corporation, Chicago, lll., a corporation of Iliinois Filed Mar. 17, 1958, Ser. No. 721,739 6 Claims. (Cl. 257-241) This invention relates to heat-exchangers of the type adapted for transferring heat between a liquid heatexchange medium, such as water, and an evaporating, or condensing, medium, such as a refrigerant.

The principal object of the invention is to provide a heat-exchanger of the type wherein the evaporating, or condensing, medium ows through the interior of a tube with the liquid heat-exchange medium llowing over the exterior of said tube in a transversely alternating path, thereby promoting eicient heat transfer between the two said mediums.

A further object of the invention is to provide a heatexchanger of the type described, which is compact in form, of high eiciency, inexpensive and easy to fabricate, and having a low pressure drop therethrough. Yet another object of the invention is to provide for efficient heat transfer between an evaporating, or condensing, medium within `a tube and a liquid heat-exchange medium flowing over the tube by causing the liquid heat-exchange medium to turbulently flow in an undulating path across said tube` The invention consists of the novel constructions, arrangements and devices to be hereinafter described and claimed for carrying out the above-stated objects and such other objects as will appear from the following description of a preferred embodiment of the invention described with reference to the accompanying drawings, in which:

FIG. 1 is a vertical view of the hereindisclosed heatexchanger with parts thereof in elevation and parts thereof in section to better show details;

FIG. 2 is a plan of the heat-exchanger with parts thereof broken away in order to better show details, and showing the refrigerant flow in an outwardly spiralling path;

FIG. 3 is a view similar to FIG. 2 but showing the refrigerant flow on its return inwardly spiralling path;

FIG. 4 is a vertical view of a ow directing bathe plate and an associated refrigerant tube before being formed into a spiral convolution;

FIG. 5 is a vertical sectional view, with parts thereof in elevation, taken on line 5-5 of FIG. 6; and l FIG. 6 is a detail showing the undulating flow path of the liquid heat-exchange medium over the refrigerant tube.

Like numerals refer to like parts throughout the several views.

Turning now to the drawings, and particularly FIGS. 1-3 thereof, there is shown a heat-exchanger comprising a casing 10, which casing includes a cylindrical side wall 11, a top wall 12, and a bottom wall 13. It will be apparent that the exact conguration of the casing is unimportant so long as there are at least two opposed walls in spaced apart parallel planes, such as top and bottom walls 12 and 13. A corrugated, spirally wound battle plate 14, comprising a plurality 0f individual corrugations 14', extends between walls 12 and 13. A pair of gaskets 15 and 16 are provided between the baffle plate 14 and walls 12 and -13 in order to provide a perfect seal therebetween.

The convolutions of baffle plate 14 are spaced apart to provide a spiral fluid passageway 17 between adjacent convolutions, the passageway 17 extending between top and bottom wal-ls 12 and 13. An inspection of FIGS. 1 and 6 reveals that the ow through passageway 17 is normal to the corrugations 14. The innermost convolution is so arranged as to define a chamber 18 within casing 10.

As shown, a plurality of spirally wound tube bundles 19 are provided in the passageway `17. Each tube bundle 19 comprises an outwardly spiralling tube pass 20 and an inwardly spiralling tube pass 21. It is apparent that the number of tube bundles provided varies with the application and size of the heat-exchanger. It is further apparent that each tube bundle could comprise but a single tube pass 20 or 21 rather than the double pass, as shown. The invention contemplates all such variations.

Baffie plate 14 is provided with a plurality of longitudinal rows of indentations 22, there being one row for each tube pass. An inspection of FIGS. 2, 5 and 6 shows that an indentation 22 is provided on the crest and trough of each corrugation 14' in baffle plate 14 traversed by a tube pass 20 or 21, the purpose of the indentations being to receive. properly space, and maintain in position the tube bundles 19.

Each tube bundle 19 has an inlet 23 and an outlet 24. A plurality of individual headers 25 are provided and are connected to the individual inlets 23 by fittings 25". Obviously a single header could be provided for feeding all inlets. A uid container 26 is positioned within chamber 18 and is connected to the outlet 24 of the various tube bundles 19 by a plurality of lines 27 connected to respective outlets 24 by fittings 27'. Refrigerant exits container 26 by way of a line 28 provided for that purpose. A liquid heat-exchange medium inlet line 29 is provided leading into chamber 18. A liquid heatexchange medium outlet line 30 leads through the cylindrical wall 11 of casing 10.

The inward terminal edge 31 of bafe plate 14 defines an inlet 32 to the passageway 17 formed by spirallv wound bafe plate 14. The outward terminal edge 33 of baille plate 14 defines an outlet 34 for passageway 17.

The distance between the various tube convolutions may be varied as desired either by varying the depth of the indentations 22. or by varying the size of the individual corrugation 14' in bathe plate 14. It is apparent that both the heat transfer rate and the pressure drop varies according to the spacing between the individual convolutons of the tube bundles 19. Further, the passageway 17 may be widened or narrowed according to how tightly the baffle-plate 14 is wound, which also varies the heat-transfer rate and pressure drop.

In use, the heat-exchanger can function eitheras a refrigerant evaporator, or as a refrigerant condenser. The only dierence would be in the functioning of container 26. When the heat-exchanger is to be used as `a refrigerant evaporator, container 26 then functions as a refrigerant accumulator in order to prevent the passage of any unvaporized refrigerant from the heat-exchanger.

When the heat-exchanger is in use as a refrigerant condenser, then container 26 functions as a refrigerant receiver with the added advantage of being located in heatexchange relation with the heat-exchange medium in 3 chamber 18, thereby providing additional lheat-exchange surface.

In operation, the refrigerant ilows into .the various tube bundles 19 through headers 25 and thence ilows in an outwardly spiralling path through tube passes 20 and, at the outermost point, reverses direction and ilows on an inwardly spiralling path through tube passes 21, discharging into container 26 from whence it exists by way of discharge `line 28. As was pointed out above, whether a single pass be Iused, or a multiple p-ass be used, is purely a matter of expediency, and both are contemplated.

VThe heat-exchange medium tobe heated or cooled, dependent on the function of the heat-exchanger, ilows into Vehamber 18 byvway of inlet line 29. From cham- Yberm18 the heat-exchange medium ilows into the inlet 32 to passageway 17. The heat-exchange medium ilows in an undulating path across tube bundles 19, as can clearly be seen in FIG. 6, this being the effect of the corrugrations `14' in baille plate 14. The continual back and forth passageofutheheat-exchange medium across tube bundles 19 provides forhighly'eilicient heat-exchange between refrigerant and the heat-exchange medium.

Itrwill be noted that the liquid heat-exchange medium makes a single, spirally directed pass through the heatexchanger before exiting through outlet line 30. It would makeno difference to the functioning of the heat-exchanger if the direction of ilow of the liquid heat-exchange medium were reversed with line 30 then functioning as an inlet and line 29 then functioning as an outlet. K l

While the primary purpose of baille plate 14 is to cause the heatexchange medium ilowing through passageway 17 to undulate in its path across tube bundles 19, thereby promoting better heat-exchange, ancillary thereto is a heat-exchanging function of the baille. An inspection of FIG. clearly reveals that there is a direct exchange of heat between the various tube passes 20 and 21 and baille plate 14 at the points of contact therebetween (indentations '22). v

Dependent on the use ofthe heat-exchanger as an evaporator or condenser, heat ilows from the liquid heatexchange medium to the baille plate 14 and thence to the various Vtube passes '20 and 21; or, reversely, from the various tube passes 20 and 21 to the baille plate 14 and thence to the liquid heat-exchange medium,

It will be readily obvious that where it is not desired that baille plate 14 perform a heat-exchanging function, the same may then be fashioned from a plastic material, in which case its only function would be that of causing the heat-exchange medium to ilow in an undulatory path. In forming the baille plate 14 .of a plastic material, it is evident that'gaskets 15 may be dispensed with and the plastic baille plate 14 be ailixed directly to walls 12 and 13 to provide Va iluid tight seal therebetween.A

Further, while I have set out the heat-exchanger as a unitary structure, it is apparent that wall 11 might be dispensed with and top and bottom walls 12 and 13 then function merely as sealing plates, providing a self-contained core. In such an instance, the self-contained core c ould be installed in an open tank in any multiple desired providing, in effect, an open circuit system. The invention contemplates all such modifications.

I wish it to be understood that my invention is not to be limited to lthe specific constructions and arrangements shownand described, except only insofar as the claims may be so limited,`as it will be apparent to those skilled in the art that changes maybe made without departing from the principles of the invention.

I claim:

1. A heat-exchanger comprising, a pair of opposed walls in spaced parallel planes; a corrugated, spirally wound baille plate extending between and enclosed by said walls, the corrugations being normal to the plane of said walls, the convolutions of said baille plate being spaced apart to provide a spiral iluid passageway between the convolutions normal to said corrugations and having an inlet and an outlet; and a tube bundle having an inlet and an outlet, said tube bundle being spirally wound in said iluid passageway in a plane normal to said corrugations forming a second iluid passageway.

2. The heat-exchanger of claim l, and a chamber defined by the innermost convolution of said baille plate and said opposed walls, and a iluid container in said chamber connected in a fluid ilow path with said tube bundle.

3. A heat-exchanger comprising, a housing including, opposed walls in spaced parallel planes; a corrugated, spirally wound baille plate extending between and enclosed by said walls, the corrugations being normal to the plane of said walls, the convolutions of said baille plate being spaced apart to provide a spiral iluid passageway between the convolutions normal to said corrugations and having an inlet and an outlet; and a tube bundle spirally wound in said iluid passageway in a plane normal to said corrugations forming a second iluid passageway and having an inlet and an outlet, the convolutions of said tube handle bearing on opposite sides thereof on the adjacent crests and troughs of said corrugated baille plate.

4. A heat-exchanger comprising, a housing including, opposed walls in spaced parallel planes; a corrugated, spirally wound bafile plate extending between and enclosed by said walls, the corrugations being normal to the plane of said walls, the convolutions of said baille plate being spaced apart to provide a spiral iluid passageway between the convolutions normal to said corrugations and having an inlet and an outlet, the innermost convolutions defining a chamber within said housing in iluid communication with said iluid passageway inlet; a tube bundle spirally wound in said iluid passageway in a plane normal to said corrugations forming a second iluid passageway and having an inlet and an outlet, the convolutions of said tube bundle bearing on opposite sides thereof on the adjacent crests and troughs of said corrugated baille plate; and a iluid container in said chamber, the outlet of said tube bundle discharging within said container.

5. A heat-exchanger comprising, a pair of opposed walls in spaced parallel planes; a corrugated, spirally wound baille plate extending between and enclosed by said walls, the convolutions of said baille plate being spaced Aapart to provide a spiral iluid passageway between the convolutions normal to said corrugations and having an inlet and an outlet; and a tube bundle having an inlet and an outlet, said tube bundle being spirally wound in said iluid passageway in a plane normal to Said corrugations forming a second iluid passageway, the convolutions ofV said tube bundle bearing on opposite sides thereof on said corrugated baille plate, whereby a heat-exchange Vmedium flowing through said spiral iluid passageway ilows over the exterior of said tube bundle in a transversely alternating path.

6. A heat-exchanger comprising, a housing including, opposed walls in spaced parallel planes; a corrugated, spirally wound baille plate extending between and enclosed by said walls, the corrugations being normal to the plane of said walls, the convolutions of said baille plate being spaced apart to provide a spiral iluid passageway between the convolutions normal to said corrugations and having an inlet and an outlet, the innermost convolution defining a chamber within said housing in iluid communication with said iluid passageway inlet; a tube bundle spirally wound in said iluid passageway in a plane normal to said corrugations forming a second iluid passageway and having an inlet and an outlet, a iluid container in said chamber communicating with said tube bundle; said tube bundle and said spiral iluid passageway defining ilow paths for iirst and second heat-exchange iluids respectively, said corrugations connng said second heat-exchange fluid to an undulating path across the convolutions of said tube bundle.

References Cited in the le of this patent UNITED STATES PATENTS 6 Jones July 21, 1931 Mallory Apr. 18, 1933 Askn May 2, 1933 Levin Dec. 1, 1936 Wentworth June 7, 1938 Ramsaur Mar. 26, 1940 Kopp Nov. 12, 1946 Guala Nov. 9, 1954 Allen Feb. 28, 1956 UNITED lSTATES. PATENT OFFICE CERTIFICATE 0F CORRECTION Eaten; No.: 3,006,612 October :3.1Y 1961 Richard M, Herbert mtl'aterror appears in ,the above numbered pat- It is hereby certified Y r entrequiring corretion and that; the said Letters Patent should read as "c orreoted below IColumn 3u line 8 for "existsu read exits V@:i'gma'eand Sealed this rdday of AprIIIQQ.,

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Commissioner of Patents Attesting Officer

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