US2722732A - Method of making a heat exchanger - Google Patents

Description

Nov. 8, 1955 R. A. SANDBERG 2,722,732

METHOD OF MAKING A HEAT EXCHANGER Filed April 19. 1949 3 Sheets-Sheet l WK7N "IIMMHNAlwin .1* mulmlmw "hwmlmil'm 000800000808000800000000 1 n hymn wl hnl'ml" M' Y "1mWlunllW'nm""n uw '1mm "www mm W7mmmm-ummwu| .Mwnnw 'mm 0 0 0 0 0 0 0 0 0 0 0000000 Early QH. Sandberg Nov. 8, 1955 R. A. SANDBERG METHOD OFI MAKING A HEAT EXCHANGER 3 Sheets-Sheet 2 Filed April 19. 1949 fmVEnZ'ar' EatycH.5az2db-exg HLLHE Nov. 8, 1955 R. A. sANDBl-:RG

METHOD OF' MAKING A HEAT EXCHANGER 3 Sheets-Sheet 5 Filed April 19. 1949 .ELLES fn VEEL Unite States Patent O METHOD or MAKING A HEAT EXCHANGER Ray A. Sandberg, Waukegan, Ill., assigner to Houdaille- Hershey Corporation, Detroit, Mich., a corporation of Michigan Application April 19, 1949, Serial No. 88,342

1 Claim. (Cl. 29157.3)

The present invention relates to a radiant heat panel and to methods for making the same. More particularly, the present invention relates to a radiant heat panel con struction capable of serving as a plaster base and as a heat exchanger and to methods for making such a radiant heat panel.

The use of metal plaster laths, both in the form of perforated metal sheets and as an expanded metal sheet, is old in the housing art. Also, use of radiant heat panels for heating has also been proposed. Such panels have been employed as base boards or embedded in the walls, floors or ceilings of rooms to replace the more conventional radiator or hot air heating systems.

The present invention now provides an improved radiant heat panel construction capable of serving both as a plaster base to replace conventional sheet metal lath, and as a heat exchanger to replace that type of radiant panel previously embedded in the walls or ceiling of the room.

ln general, the radiant heat panel of the' present invention comprises a backing plate having perforated or eX- panded portions capable of serving as a metal lath. A continuous sinuous tube is secured to the backing plate by suitable means, as by deformation of the plate or the tube, the tube serving to convey a heat transfer fluid closely adjacent the plate so that the backing plate and tube together serve efhciently as a heat exchanger. The improved wall construction thus obtained includes the radiant heat panel and the coating of plaster applied thereto.

To employ the radiant heat panel hereinbefore described, the heat panel is secured to the joists or studding or inner wall or ceiling construction of a room and plaster is applied directly over the entire radiant heat panel. The perforated or expanded backing plate serves to provide an adequate anchoring base for the plaster applied to the panel, and the efficient heat transfer from the plastered wall upon the circulation of heated fluid through the exchanger serves to heat the room.

It is, therefore, an important object of the present invention to provide an improved radiant heat panel.

Another important object of the present invention is to provide an improved wall construction including a radiant heat panel capable of serving as a plaster base and as a heat exchanger, and a layer of plaster applied to the heat panel.

A further important object of the present invention is to provide an improved radiant heat panel including a backing plate capable of serving both as a plaster base and as a heat exchange member, and a sinuous tube secured to the plate for conveying a heat exchange fluid in thermal proximity to the backing plate.

lt is a still further important object of the present invention to provide an improved method for making a radiant heat panel,

On the drawings:

Figure 1 is an elevational view, with parts broken away,

showing the installation of the radiant heat panel of the present invention in a wall or the like;

Figure 2 is an enlarged, broken sectional view further illustrating the installation of Figure l;

Figure 3 is an enlarged, broken elevational View of the radiant heat panel of the present invention;

Figure 4 is an enlarged, fragmentary sectional View illustrating one step of the method of making the heat exchanger of the present invention;

Figure 5 is an enlarged sectional view similar to Figure 4 illustrating a further step in the manufacture of the radiant heating panel; l

Figure 6 is a perspective, fragmentary, somewhat schematic View of a room equipped with radiant heat panels of the present invention and illustratingvthe circulation of a heat exchange medium through the panels;

Figure 7 is an enlarged, broken elevational View illustrating a modified form of radiant heating panels of the present invention;

Figure 8 is an enlarged, fragmentary sectional view showing one step of a modified method of making a radiant heat panel of the present invention; and

Figure 9 is an enlarged, fragmentary sectional View similar to Figure 8 and showing another step of the method of Figure 8.

As shown on the drawings:

In Figure 1, reference numeral 10 refers generally to a radiant heat panel of the present invention including a backing plate 11 formed of a metal sheet having desirable heat transfer properties. The backing plate 11 is provided with longitudinal aligned, vertically ofset series of rows of perforations 12 separated by spaced, non-perforated portions 13 extending entirely across the width of the plate 11.

The plate is thus divided into a plurality of apertured sections separated by non-apertured plate sections.

The non-apertured plate sections 13 of the plate 11 are adapted to receive a sinuous tube 14 having straight, substantially parallel portions 14a joined by curved portions 14b. As may be seen from Figure 3, the straight portions 14a of the sinuous tube 14 extend across the entire width of the plate 11 and the curved portions 14b lie outside of the confines of the plate 11. The straight portions 14a of the tube 14 are preferably employed to join the tube to the plate to secure the same thereto against relative movement.

As shown in Figures 4 and 5 of the drawings, the preferred method for securing the tube 14 to the nonapertured portions 13 of plate 11 involves irst the formation of a re-entrant groove 15 in the non-apertured plate portion 13. The formation of the re-entrant groove may be carried out by the employment of a iiexible, resiliently deformable forming die, such as a die made of rubber, or by iirst forming a groove having an arcuate bottom and straight upstanding side walls with the side walls later being deformed outwardly to define the arcuate, re-entrant side walls of the grooves 15. By either method, the re-entrant groove 15 thus formed is provided with a restricted groove inlet 16 defined by arcuate groove side walls 15a and the arcuate groove bottom 15b. The tube 14 is positioned within the groove 1S and is bottomed against the arcuate bottom 15b of the groove. Next, one exposed portion of the tube 14 is deformed or fiattened, as at 17, so that the tube is deformed from its circular cross-section with the walls of the tube being collapsed outwardly against the interior surfaces of the arcuate side walls 15a of the groove 15 with the deformed tube being in greater than semi-peripheral contact with the groove 15.

Alternatively, the tube 14 may be secured to the plate 11 by the method shown in Figures 8 and 9 of the drawings. In the practice of this modified method, the nonapertured portions 13 of the plate 11 are provided with grooves 21 having relatively straight, upstanding side walls 22 and an arcuate, closed bottom wall 23. The grooved plate 11 is next placed on a backing die 24 having an elongated groove 25 formed therein to receive each of the grooves 23. It is to be noted that the groove 23 is bottomed in the groove 25, while the plate portion 13 is spaced from the upper surface of die 24, as at 26. In addition, the side walls 22 of the plate groove 7.1 are spaced inwardly from the side walls 27 of the die groove 25. The tube 14, or more particularly, the straight portions 14a of the tube 14, is bottomed in the groove, the arcuate inner periphery of the groove bottom wall 23 preferably snugly receiving the tube 14a, as shown in Figure 8. Thus, preferably the outside diameter of the tube 14a is approximately the inside diameter of the arcuate bottom groove wall 23.

The deformable, hollow tube 14a is next contacted with a forming punch or roll 2S urged against the tube 14 to deform the same, as at 29, to the forni shown in Figure 9. The tube 14a, being hollow and deformable, thus serves to transmit force from the punch 28 to the side walls 22 of the groove 21. Since the groove wall 23 is bottomed in the groove 25, and further, since clearance is provided between groove side walls 22 and 27, the groove side walls 22 are deformed outwardly into contact with the side walls 27 of the die 24. The deformation of the tube 14a and the walls 22 increases the width of the groove 21, and this increase in width draws the plate 13 downwardly into extended surface engagement with the upper exposed surface of die 2d. Also, the plate portions 13 of the plate 11 are each deformed to the contour of Figure 9 simultaneously, so no un desired lateral or transverse movement of the plate 11 can occur. The resulting simultaneous deformation of the plate and the tube securely locks the tube to the plate and the finished article is identical with that illustrated in Figure 5.

The tube 14, when made by either of the hereinbefore explained methods, is maintained in position within the groove by the re-entrant contour of the plate groove, the restricted groove inlet 16 and the non-circular contour of the tube. in particular, the tube is maintained in position within the groove by the engagement of the tube with the interior side wall surfaces of the arcuate side walls 15:1 at a point below the restricted groove inlet 16. Thus, it may be seen that the tube is readily secured to the grooved non-apertured plate portions 13.

In the modification of the invention shown in Figure 7 of the drawings, the backing plate takes the form of an expanded metal lath section 18 with the apertured portions 13 of the plate 11 being formed as an expanded metal sheet of conventional type separated by nonexpanded intermediate portions 19 similar to the portions 13 hereinbefore described. A sinuous tube 14 is secured in the manner hereinbefore described within a re-entrant groove extending across the entire width of the backing plate 18. The curved portions 14h of the tube 14- also extend beyond the expanded sections 18 of the plate.

It will, of course, be understood that each of the forms of backing plates may be provided by joining non-apertured portions 13 or non-expanded portions 19 to expanded or apertured metal lath sections. Alternatively, the expanded metal laths or apertured metal lath backing sheets may be formed with integral non-apertured orv non-expanded portions to receive the straight portions 14a of the tube 14. In each case, the tube 14 is secured to the non-apertured or non-expanded portions of the plate by means of the re-entrant groove and distortion of the tube as hereinbefore described.

The employment of the radiant heating panel of the present invention is illustrated in Figures l and 2 of the drawings, in which it may be seen that the radiant heat panel is secured to the wall or ceiling supporting structure, as to the joists or studding, by suitable means, as

by nails or the like (not shown), and that a layer of plaster 20 is later applied directly to the radiant heat panel. The heat panel is preferably installed with the grooves of the panel extending outwardly of the finished wall surface 20h toward the supporting wall structure.

It will be seen in Figure 2 that plaster indicated generally at 20 will iiow through the apertures 12 of the aperture portions of the radiant heat panel 10 and that this plaster will form a substantially continuous layer 20a on each side of the radiant heat panel, inasmuch as that plaster passing through the apertures 12 is separated by only a relatively narrow non-apertured plate portion lying between the apertures 12.

The outer finished plaster surface 20b then may be finished by the conventional practices of the art with the radiant heat panel 10 being completely embedded in the finished wall. It is obvious that upon the passage of heat exchange iiuids through the tube 14 that this heat will be imparted to the backing plate for heating the interior of the room in the walls in which the heat exchanger 10 is embedded.

However, it is preferred that the entire wall or ceiling panel or structure be pre-fabricated as a single structural unit. By Way of example, the metal lath and tube assembly 10 may be molded into plaster in predetermined lengths and widths with the inner plaster wall face iinished smooth to present a desirable, smooth surface. Alternatively, or in addition, the wall structure may be finished with a paper or fibrous sheet or with a fabric covering material. The joints between such prefabricated panels may be joined and sealed by the use of joining tape or moulding. By the use of such prefabricated structures, plastering at the site could be eliminated and only painting would be necessary to provide a nished Wall surface.

In Figure 6 is illustrated a residential heating system, shown somewhat diagrammatically as employed in a room 30, heated by radiant heat panels 10 of the present invention. The room 30 may be heated by any desirable form of conventional boiler or furnace 31 capable of heating a heat transfer medium to a relatively elevated temperature. The heat transfer medium is circulated through an upwardly extending pipe or line 31 into a header pipe or line 32 adjacent the ceiling of the room. The header pipe 32 is connected, as at 33, to the free end of a tube 14 of a radiant heat panel 10 as hereinbefore described, The heat transfer uid is thus introduced from the header pipe 32 into the line 14 of the heat panel 10 and following its passage through the heat panel is next introduced into a return line 35 connected as at 34 to the other free extremity of the tube 14 of the radiant panel 10. The return line 35 extends downwardly along one wall of the room and parallel to line 31 into communication with a suitable pump 36 for maintaining operating pressures in the line throughout the system as hereinbcfore described. Fluid from the pump 36 is returned to the boiler 31 through return line 37.

It will be noted that a number of heat panels 10 are illustrated as disposed within the ceiling of the room 30, the number of heat panels 10 depending upon the size and heating characteristics of the room. It is to be noted that those panels 10 which are transversely aligned are in direct abutment while those panels in longitudinal alignment have disposed therebetween a strip 39 of perfo rated or expanded metal lath containing no tubes 14. In this manner, any installation diiculties due to the size and contour of the panels 10 are avoided.

The number of heating installation variations which are possible will be appreciated and the wide applicability of the radiant heat panels of the present invention will be evident. In addition to those panels 10 disposed in the ceiling of the room 30, an additional panel 10 is provided within one wall directly under a window 38. It has been found that, although a ceiling installation such as that herein described is generally sufficient to heat a toorn', it might be desirable to provide an additional panel adjacent windows, doors or other structural components of the room through which serious heat loss might occur. The panel 10 disposed beneath the window 38 is disposed in series with the panels 10 of the ceiling with the window panel being connected to the uid lines 31 and 35 hereinbefore described.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention, and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claim.

I claim as my invention:

'I'he method of forming a heat exchanger which includes the steps of forming a groove in a sheet metal backing plate having a semi-cylindrical bottom wall and straight upstanding side walls, positioning a continuous circular cross-section tube of external diameter substantially equal to the internal diameter of said semi-cylindrical wall in said plate groove, placing the backing plate on a die structure having a groove for receiving the backing plate groove, said die groove being slightly Wider than the overall width of the plate groove and slightly shallower than the overall projection of the plate groove from the plate, and applying a reshaping force through the mouth of said groove against said tube to press the side walls of the tube against the side walls of said plate groove, and continuing to exert a reshaping pressure against said tube to force the side walls of the tube to press the side walls of the plate groove outwardly from straight upstanding relation while leaving a re-entrant configuration with the side walls of the plate groove overlying lthe top part of the tube and locking the tube in the plate groove.

References Cited in the file of this patent UNITED STATES PATENTS 1,971,723 ODell Aug. 28, 1934 1,982,075 Smith Nov. 27, 1934 2,050,993 Bush Aug. 11, 1936 2,091,584 Brown Aug. 31, 1937 2,092,170 Kritzer et al Sept. 7, 1937 2,268,885 McCullough Ian. 6, 1942 2,281,299 Steenstrup Apr. 28, 1942 2,338,090 Bradiield Ian. 4, 1944 2,441,463 Achs May 11, 1948 2,548,036 Milborn Apr. 10, 1951 2,585,043 Sandberg Feb. 12, 1952 2,666,981 Sandberg Jan. 26, 1954 FOREIGN PATENTS 260,414 Great Britain Nov. 4, 1926 307,219 Great Britain Mar. 7, 1929 879,224 France Nov. 10, 1942 891,592 France Mar. 10, 1944

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