US3165150A

US3165150A - Heat-exchanger having selectively spaced heat-exchange shelving integrally formed therein

Info

Publication number: US3165150A
Application number: US833785A
Authority: US
Inventors: Arnold U Hurst; Grant V Mack
Original assignee: Reynolds Metals Co
Current assignee: Reynolds Metals Co
Priority date: 1959-08-14
Filing date: 1959-08-14
Publication date: 1965-01-12
Anticipated expiration: 1982-01-12

Description

Jan. 12, 1965 A. u. HURST ETAL 3,165,150

HEAT-EXCHANGER HAVING SELECTIVELY SPACED HEAT-EXCHANGE SHELVING INTEGRALLY FORMED THEREIN Filed Aug. 14, 1959 4 Sheets-Sheet 1 r INVENTORS AQNOLD u. HURST GRANT v. MACK ww La 9W4 w Jan. 12, 1965 A. u. HURST ETAL 3,165,150

HEAT-EXCHANGER HAVING SELECTIVELY SPACED HEAT-EXCHANGE SHELVING INTEGRALLY FORMED THEREIN Filed Aug. 14, 1959 4 Sheets-Sheet 2 36 r fr" {3:7

INVENTORS ARNOLD U. HURST GRANT V. MAC K ATTORNEY Jan. 12, 1965 u, HURsT ETAL 3,165,150

HEAT-EXCHANGER HAVING SELECTIVELY SPACED HEAT-EXCHANGE SHELVING INTEGRALLY FORMED THEREIN Filed Aug. 14, 1959 4 Sheets-Sheet 3 AQNOLD U. HURST GRANT V. MACK BY w WZM ATTORNEY INVENTORS 1965 A u. HURST ETAL 3,165,150

HEAT-EXCHANGER HAViNG SELECTIVELY SPACED HEAT-EXCHANGE SHELVING INTEGRALLY FORMED THEREIN Filed Aug. 14, 1959 4 Sheets-Sheet 4 INVENTORS ARNOLD U. HURST GRANT V. MACK gywzm ATTORNEYS structure.

United States Patent 3,165,150 HEAT-EXCHANGER HAVING SELECTIVELY SPACED HEAT-EXQHANGE SHELVING IN- TEGRALLY FORMED 'IHEREIN Arnold U. Hurst, Henrico County, Va, and Grant V. Mack, Valley Station, Ky., assignors to Reynolds Metals Company, Richmond, Va, a corporation of Delaware Filed Aug. 14, 1959, Ser. No. 833,785 10 Claims. (Cl. 165-75) This invention relates to an improved heat exchanger and to an improved enclosure structure equipped with the heat exchanger and into which heat may be introduced or from which heat may be removed. More particularly, it relates to a structure of this type wherein the heat exchanger includes non-detachable shelves integrally formed thereon and with the capability of being selectively spaced from each other while being fabricated from a standard sized heat exchanger sheet.

As set forth in the common assignees copending application of Grant V. Mack, Serial No. 741,277, filed June 11, 1958 and now abandoned, an improved heat exchanger useful in refrigerators, heaters or the like and having cantilever-mounted shelving, may be formed from a sheet of metal in which a continuous conduit is incorporated for flow therethrough of the heat exchange medium. While that invention makes possible an eflicient heat exchange, it nevertheless requires the spacing between shelves to be predetermined by the location of the lanced portions of the sheet of metal. A manufacturing requirement, however, exists for a heat exchanger of the Mack type, but which will give the assembler of the heat exchanger into the enclosure structure, a flexible range of shelf spacing while employing a single stock sheet of metal. In this way a marked reduction in inventory and commensurately lower costs may be achieved.

An object of this invention is to provide an improved shelf-type heat exchanger in which the shelves are integrally formed from a standard sized sheet of metal, but also may be installed with a selective spacing between shelves.

Another object is to provide an improved self-type heat exchanger integrally formed from a standard sized sheet of metal and having flanges on at least a portion of the shelf peripheries for mounting purposes, for strengthening purposes or for ornamental purposesyor for a combinationof these purposes.

A further object is to provide an improved shelf-type heat exchanger integrally formed from a standard size sheet of metal and having a connecting portion of the sheet between adjacent shelves and which portion may be mounted optionally adjacent a selected wall surface of the structure housing the heat exchanger.

Other objects and advantages will become more apparent as the description proceeds and when considered in conjunction with the accompanying drawings in which FIG. 1 is a perspective view of one form of structure, shown as a refrigerator, and with one form of heat-exchanger represented by the invention in place within that FIG. 2 is a plan view of a blank from which a heat exchanger of the type shown in FIG. 1 may be fabricated.

FIG. 3 is a view to a larger scale, taken along line 33 of FIG. 2. I

FIG. 4 is a sectional view toa larger scale taken along line 44 of FIG. 2.

formed from the blank shown in FIG. 2 and during an ice.

' 7 FIG. 8 is a perspective view similar to FIG. 7 and showing one optional arrangement of mounting the heatexchanger, a portion of the conduit pattern being shown.

FIG. 9 is a perspective view similar to FIG. 7 and showing another optional arrangement of mounting the heat-exchanger, a'portion of the conduit pattern of FIG. 7 being seen from the opposite side of that pattern.

FIG. 10 is a perspective view of a heat-exchanger formed in accordance with the invention and indicating a first spacing between shelves.

FIG. 10A is a View of the same heat exchanger shown in FIG. 10 and to the same scale, but indicating a second spacing between shelves.

FIG. 11 is a detail indicating one means for employing a shelf flange in the mounting of the heat-exchanger in an enclosure structure, and a FIG. 12 is a diagrammatic plan view of a typical blank similar to FIG. 5, but showing a modified arrangement of lancing lines.

In accordance with our invention, we make use of an elongated, preferably rectangular sheet of metal of the type shown in the aforementoned Mack application and having a continuous conduit formed therein for flow therethrough of a heat-exchange medium. The conduit has its two ends located at convenient places on the sheet for attachment of suitable couplings serving to connect the heat-exchanger to the supply and return lines for the medium after installation of the, heat-exchanger body in the enclosure .structure. The conduit is arranged in a pattern which may vary widely depending upon the particular usage of the heat-exchanger and the sheet is formed of a heat-conductive metal such as aluminum.

Such a sheet, or panel, may be formed by any of the metal are bonded together to form an integral sheet except at a predetermined location where a passage is to be formed by subsequent internal application of a pressure fiuidwhich bulges out one or both of those confronting sheet portions to form'the passage space. If desired, the sheet may also comprise an embossed sheet containing a space defining the conduit and attached in fluid-sealed relation to a fiat'slie'et or to another embossed sheet. Regardless, however, of the precise manner in which the sheet forming the blank, is made, slits in the form of a T are provided'therein and along which adjoining portions of the sheet maybe'bent outwardly to form generally flat, shelf-like portions integral with the sheet. These shelf-like portions, depending upon the conduit pattern, contain more or less ofthe conduit path and with that conduit being bent at the junction of that shelf with the remainder of the heat-exchanger body, but, however, retaining its open communication with'the remainder of that conduit. As a result of the use of the T-shaped slits, certain advantageous capabilities of the heat-exchanger, not found in the prior art of which we are aware, are now made possible.

" Referring first to FIG. 2, an elongated rectangular metal sheet of thetype above described, serves as a fiat blank 10 from which a heat-exchanger may be shaped in x This blank includes a continuous conduit. having ports 11 and 12, either of which may serve as an inlet or an outlet for the heat-exchange medium depending upon the flow desired. Between these two ports the conduit may have straight run portions such as 13, loop portions such as 14, or other portionssuch as enlarged spaces serving as an accumulator space 15,

the stem portions of two such Ts.

:3 as seen in FIG. 8. When the circuitry entails the ports being at extreme shelves on the heat-exchanger, one straight run portion will sufiice to join the conduits on adjacent shelves as seen in FIG. 2, but when the circuitry requires those ports to be on other than extreme shelves, two of those straight run portions are needed to join certain of the adjacent shelves.

Referring now to FIG. 5 and FIG. 12, there is shown diagrammatically two arrangements of lancing of the blank to provide the shelves for the heat-exchanger. FIG. 2 illustrating an arrangement similar to that of FIG. 5. InFIG. 5 a blank 16 is lanced along a' series of parallel lines here shown at 17, 18, and 19 in order to provide a series of four shelves and with each of those lines extending at one end to a common edge of the blank. At their other ends, each such line is intersected, preferably, but not necessarily, at right angles, by lines 20, 21 and 22 which lie inboard of and generally parallel to the opposite edge of the blank. The extremities of these intersecting lines are preferably at equal distances from the point of intersection of the respective lines. Thus the intersecting lines form the general shape of a T in which the stem portion terminates at one edge of the blank and the cross portion lies inboard of the opposite edge of that same blank. It will be understood that as applied to a blank having a conduit therein, none of these lines will touch or puncture the conduit itself.

In the version shown in FIG. 12, a blank 23 may be formed with a line 24 extending to one edge and another line'25 extending to the opposite edge, these lines forming Intersecting these lines inboard of the edges of the blank are two lines 26 and 27 spaced from each other and serving as the cross portions of the respective Ts. Lines of the type shown may be formed in the metal blanks by any suitable lancing means known in the art and result in a sharp slit extending completely through the blank. It will be understood, of course, that in all examples, the spacing between the stems of the T slits need not be uniform, nor need the length of the cross lines of those Ts be uniform. Thus shelves of ditferent sizes may be fashioned in accordance with the invention.

, Passing now to FIG. 2, the same general arrangement of slitting is provided with the stems 30, 31 and 32 of the 'Ts terminating at a common edge of the blank 10. The

cross portions 33, 34 and 35 of the Ts lie inboard of the opposite edge of that blank and leave the intermediate portions or connecting

tabs

36, 37, and 38 of that blank available for providing a mounting of the conduit portions between the respective shelves.

One important advantage of the present invention will now be apparent, namely that at least three sides of each of the

shelf portions

39, 40, 41 and 42 of the blank may be used for supporting the heat exchanger within the enclosure structure in which it is to be used. At best shown in FIG. 3 the

shelf portions

39 and 40 have

solid metal areas

41 and 42 lying between the stems 30 of the T and the nearest edges of the conduit so that these areas may be bent to form flanges which may serve not only as a mounting means, but also as a reinforcing means and as an ornamentation. Moreover, they serve to remove the sharp edges of the blank from contact with the walls of the enclosure or from the opening in such an enclosure, such as a refrigerator door space.

Similarly, these shelf portions have solid metal areas 43 and 44 lying between an outer edge of the blank and the nearest edges of the conduits so that these areas too may be bent to form flanges for the same purposes. The same arrangement may be used at the non-adjacent edges of these shelves to provide

flanges

45 and 46 and each of the several shelves may be formed with flanges of the type thus described. In general, we prefer to blend flanges on adjacent shelves in dilferent directions as noted in FIG. 3, although this is not necessary since they may all be bent in the same direction.

Considering now FIG. 4, a typical cross section of a straight run portion of the conduit is shown wherein the bonded together portions 47 of the blank 10 defines the boundary of two separated portions 48 and 49 of that blank within which a passage space 50 is provided for the heat-exchange fluid. As is well known, the blank 10 may be bent transversely of the connecting

tabs

36, 37 and 33 of the panel without rupturing the passage space 56 and without closing off communication through that space. Accordingly, with a slitted blank 10 available and of the type as described with respect to FIG. 2, the blank is inserted in a suitable bending apparatus and the first step of shaping is conducted thereon.

As seen in FIG. 6, during this shaping operation the

adjacent shelves

39 and 40 are separated along the stem 3% of their common T and the connecting tab or intermediate portion 36 of the sheet is bent along the cross line 33 of that T. This tab forms the sole connection between the adjacent shelves. For reasons later to appear, the relative dimensions of width and length of the shelves in FIGS. 2 and 6 are modified in order to illustrate a further capability of the invention and without requiring an undue number of drawings. However, as will be seen in all modifications of the invention, the length of each shelf corresponds to the width of the original sheet and, with the exception of the aperture left at one corner of the shelf by reason of the bending of the connecting tab, each of the shelves is substantially rectangular. A maximum use of the original sheet for shelving purposes thus is achieved.

Similarly, the

adjacent shelves

40 and 41 are bent along the stem 31 of their common T and the tab 37 is bent along the cross line 34 of that T; the

adjacent shelves

41 and 42 being bent along the stem 32 of their common T and the tab 38 being bent along the cross line 35 of that T.

An important distinction between the bending actions thus occuring will however be apparent. Whereas the adjacent shelves are bent outwardly along the entire length of the stem of the T; the bending of the tabs need not occur along the entire length of the cross line of that T nor need it occur at equal distances between the point of intersection of the stem and cross lines and the extremities of that cross line. Thus a wide range of flexibility as to spacing of the shelves from each other and of overhang of the parallel edges of those shelves from the junction of the shelves with their tabs is available, all while starting with a standard sized blank for the passageway panel.

When it is desired to have the shelves of the heatexchanger parallel to each other, the bending action shown in FIG. 6 is continued as seen in FIG. 7 until the

several shelves

39, 40, 41 and 42 lie in parallel planes. It will be understood that, if desired, the heat-exchanger may be mounted so that the section 39 may serve as the top surface of an enclosure rather than as a shelf suspended in that enclosure, and that the section 42 may serve as a floor of such enclosure rather than as a shelf suspended therein. It will be further understood that the invention is not limited to four shelves as shown, but may include any number of shelves greater than two, consistent with production facilities for passageway panels.

The overhang of the edges of the shelves may be widely varied depending upon the use to which the heatexchanger is to be put. In some cases it may be desirable to include apertures in the shelf adjacent one extreme edge for the purpose of leading in a separate conducit for connection to the inlet or outlet 11 and 12 of the described conduit. In some cases it may be desirable to provide an accumulator space in the conduit, as seen at 15 in FIG. 8, adjacent an overhang edge 51 of a shelf. Such an edge may be bent upwardly as seen in FIG. 8 so as to rest against a wall of an enclosure. Alternatively, such an overhang edge may be bent downwardly as seen in FIG. 9.

Referring now to FIGS. 10 and 10A, the blank of FIG. 2 is shown with the several shelves in parallel relation, but with the

shelves

41 and 39 mounted in inverted position to illustrate the flexibility of the bending process. In this illustration, each of the shelves shown in FIG. 10 are equally spaced from each other and are bent as close as practicable to the extreme ends of the cross slit of the T. In this arrangement the heat-exchanger has its maximum overall height. 7

By contrast in FIG. 10A the same blank is bent with the bending of the tabs occuring at points between the extreme ends of the cross slit of the T and the point of intersection of that cross slit with the stem slit of the T. Accordingly, a much closer spacing of the shelves results, but each shelf itself still has the same width and length as in FIG. 10. As will be apparent, the assembler of the heat-exchanger into an enclosure thus may use the same standard passageway panel and employ it in either an enclosure having a large height or a small height.

Referring now to FIG. 1 a heat-exchanger such as shown in FIG. 7 may conveniently be mounted in an enclosure 55 such as a domestic-type refrigerator. In this illustration, the several shelf connecting tabs are disposed along the left hand wall 56 of the enclosure lying in planes which are normal to that wall. The same heatexchanger could be reversed to have those tabs adjacent the right wall 57, or the original blank could be slitted, as seen in FIG. to accomplish the same purpose. Alternatively, the transverse dimension of each shelf portion of the original sheet could be made larger than the longitudinal dimension of that shelf, and the resulting heat-exchanger could be mounted with the tabs normal to the rear wall 58. Moreover, the tear or forward overhang, or both, of the edges of any shelf may be varied by selection the points on the cross lines of the Ts at which the tabs are bent. In this way, the position of the edges of the shelves confonting the open side of enclosure 55 may be varied.

Reverting now to FIGS. 2 and 3, the

flanges

41, 43, and 45 on shelf 39 will thus be seen to be disposed in suitable relation to the interior wall surfaces 56, 5'7 and 58 for use in mounting of the heat-exchanger in the enclosure and for purposes of ornamentation. Any suitable means for mounting of the heat-exchanger on the enclosure structure may be employed. As seen in FIG. 11 a simple pin 59 disposed in a wall 60 of the enclosure and projecting inwardly of the wall surface may be used as one example. However, the means for mounting the heat-exchanger may comprise nothing more than having a frictional engagement of the edges of one or more of the several shelves with the wall surfaces, or having the lowermost shelf resting upon the floor of the enclosure space. The purpose to which the assembly is to be put, will in large measure, determine the precise mounting to be employed and the invention is not limited to any particular mounting.

Having thus described our invention in accordance with the Patent Statutes, it will be obvious that various changes and modifications may be made therein without departing from the true spirit and scope thereof and we therefore aim to cover, in the appended claims all such equivalent variations and modifications.

What is claimed is:

1. In combination, an enclosure having an interior wall surface, a heat-exchanger comprising a one-piece metal sheet having a conduit therein to receive a heat-exchange fluid, said sheet having a plurality of generally vertically superposed flat portions provided with opposed ends and.

bent outwardly from the plane of said sheet and with each of said flat portions having a maximum length corresponding to the width of said sheet, and an intermediate portion of said sheet joining adjacent flat portions and having therein a portion of said conduit integrally connected to the remainder of said conduit and bent near the junction of said intermediate portion with said 6 adjacent flat portions, said intermediate portion serving as the sole connection between said adjacent flat portions, each intermediate portion being disposed adjacent one of said ends of the pair of adjacent flat portions interconnected thereby while the adjacent intermediate portion is disposed adjacent the opposite ends of its respective pair of adjacent flat portions whereby the facing surfaces of each pair of adjacent fiat portions are formed from the same side of said sheet; and means for mounting said heat-exchanger upon said wall surface.

2. In combination, an enclosure, a heat-exchanger comprising a one-piece metal sheet having a conduit therein to receive a heat-exchange fluid, said sheet having at least three generally vertically superposed flat portions povided with opposed ends and bent outwardly from the plane of said sheet and mounted within said enclosure and with each of said flat portions having a maximum length corresponding to the width of said sheet, intermediate portions of said sheet joining adjacent fiat portions and having therein a portion of said conduit integrally connected to the remainder of said conduit and bent near the junction of said intermediate portions with said adjacent flat portions, each of said intermediate portions serving as the sole connection between its adjacent flat portions and being adapted to be bent at selected locations thereby to determine the spacing between said adjacent flat portions each intermediate portion being disposed adjacent one of said ends of the pair of adjacent flat portions interconnected thereby while the adjacent intermediate portion is disposed adjacent the opposite ends of its respective pair of adjacent fiat portions whereby the facing surfaces of each pair of adjacent flat portions are formed from the same side of said sheet.

3. Apparatus as defined in claim 2 wherein the spacing between an intermediate flat portion and its adjacent flat portions is non-uniform.

4. Apparatus as defined in claim 2 wherein the spacing between an intermediate flat portion and its adjacent flat portions is uniform.

5. In combination, an enclosure having an interior wall surface, a heat-exchanger comprising a one-piece metal sheet having a conduit therein to receive a heatexchange fluid, said sheet having a plurality of generally vertically superposed flat portions provided with opposed ends and bent outwardly from the plane of said sheet and with each of said flatportions having a maximum length corresponding to the width of said sheet, at least one of said portions having a flange integrally formed thereon along at least one edge confronting said wall sur face, an intermediate portion of said sheet joining adjacent fiat portions and having therein a portion of said conduit integrally connected to the remainder of said conduit and bent near the junction of said intermediate portion with said adjacent flat portion, said intermediate portion serving as the sole connection between said adjacent flat portions, each intermediate portion being disposed adjacent one of said ends of the pair of adjacent flat portions interconnected thereby while the adjacent intermediate portion is disposed adjacent the opposite ends of its respective pair of adjacent flat portions whereby the facing surfaces of each pair of adjacent flat portions are formed from the same side of said sheet; and means for supporting said heat-exchanger in said enclosure including a connection between said flange and said wall surface.

6. A heat-exchanger comprising a one-piece normally substantially flat metal sheet having a conduit therein to receive a heat-exchange fluid, said sheet having a plurality of slits therein each in the form of a T, the stem of each said T terminating at one side edge of said sheet and the cross of each said T being spaced inboard from an opposite side edge of said sheet, said sheet being shaped with substantially vertically superposed shelf portions bent outwardly of the plane of said sheet along bend lines generally parallel to the stem of each said T, said adjacent pairs of shelf portion-s being spaced from one another by the sheet material adjacent the cross of arespective T whereby each adjacent pair of shelf portions is integrally interconnected by said sheet material adjacent the cross of the respective T and oppositely disposed relative to the adjacent sheet material adjacent the cross of an adjacent T and whereby each adjacent pair of shelf adjacent the cross of the respective T;

1 7." heat-exbhanger'a's defined in claim G'Wherein said jbend line's a efer ed near the extremities of the cross of p r v i v 8. A heat-exchanger asdefined'in claim 6 wherein said jb ericl linesfareform'e'd betweenthe stem of each T and the extremities ot' the cros's'of that T.

9."'Apheat' -exchanger comprising a one-piece normally substantially flatmetal 'sheet,having'a'conduit therein to receive -aheafleirchange fluid, 'saids'heet having a plurality ot'slits therein each in the form of a 'T; the stem of'each Jsaid TY terminating 'at 'onefside'edg'e of said sheet and the t cross offeachi T being spaced inboard from an oppositely side edge of said sheet, said sheet being shaped i with substantially vertically superposed shelf portions bent outwardly of;-theplane oft-said sheet along bend lines generally parallel to the stem of, each said T, at least one offsaid v shelf; portions having a flange, integrally formed 'thereon' along. at least one edge thereof, said adjacent pairs of shelf portions being spaced from one another by the sheet material adjacent the cross of arespective T 3 Whereby each'adjacent pair of shelf portions is integrally interconnected by said sheetmaterial adjacent the cross of the respective T and oppositely disposed relative to the adjacent sheet material adjacent the cross of an adjacent T and whereby each adjacent pair of shelf portions has the facing surfaces thereof formed from the same side of said sheet, at least a portion of said conduit being disposed upon each of said shelf portions and upon said 5 ieet material adjacent the cross of each said T and with each of said conduit portions in communication with each other.

10. A heat-exchanger shelf construction comprising a plurality of vertically superposed substantially flat shelf portions, each pair of adjacent shelf portions being integrally joined together and spaced from each other by an intermediate portion, said shelf construction being formed from a one-piece substantially rectangular blank having opposed side edges, said blank being ivided into said sheif portions by a plurality of substantially T-shaped slits having the stems thereof extending to one of said opposed side edges of said blank and the cross members thereof disposed inboard of the other side edge of said blank to define said intermediate portions respectively between said other side edge and said cross members of said slits whereby each adjacent pair of shelf portions is integrally interconnected by an intermediate portion oppositely disposed relative to an adjacent intermediate portion and has the facing sides thereof formed from the same side of said blank.

References (Zited in the file of this patent UNITED STATES PATENTS 2,439,690 Lippenoerger Apr. 13, 1948 2,509,011 Moore May 23, 1950 2,894,731 Wurtz July 14, 1959 2,966,781 Schaefer et a1. Ian. 3, 1961 2,979,922 De Witte et a1 Apr. 18, 1961

Claims

1. IN COMBINATION, AN ENCLOSURE HAVING AN INTERIOR WALL SURFACE, A HEAT-EXCHANGER COMPRISING A ONE-PIECE METAL SHEET HAVING A CONDUIT THEREIN TO RECEIVE A HEAT-EXCHANGE FLUID, SAID SHEET HAVING A PLURALITY OF GENERALLY VERTICALLY SUPERPOSED FLAT PORTIONS PROVIDED WITH OPPOSED ENDS AND BENT OUTWARDLY FROM THE PLANE OF SAID SHEET AND WITH EACH OF SAID FLAT PORTIONS HAVING A MAXIMUM LENGTH CORRESPONDING TO THE WIDTH OF SAID SHEET, AND AN INTERMEDIATE PORTION OF SAID SHEET JOINING ADJACENT FLAT PORTIONS AND HAVING THEREIN A PORTION OF SAID CONDUIT AND BENT CONNECTED TO THE REMAINDER OF SAID CONDUIT INTEGRALLY NEAR THE JUNCTION OF SAID INTERMEDIATE PORTION WITH SAID ADJACENT FLAT PORTIONS, SAID INTERMEDIATE PORTION SERVING AS THE SOLE CONNECTION BETWEEN SAID ADJACENT FLAT PORTIONS, EACH INTERMEDIATE PORTION BEING DISPOSED ADJACENT ONE OF SAID ENDS OF THE PAIR OF ADJACENT FLAT PORTIONS INTERCONNECTED THEREBY WHILE THE ADJACENT INTERMEDIATE PORTION IS DISPOSED ADJACENT THE OPPOSITE ENDS OF ITS RESPECTIVE PAIR OF ADJACENT FLAT PORTIONS WHEREBY THE FACING SURFACES OF EACH PAIR OF ADJACENT FLAT PORTIONS ARE FORMED FROM THE SAME SIDE OF SAID SHEET; AND MEANS FOR MOUNTING SAID HEAT-EXCHANGER UPON SAID WALL SURFACE.