US 2988033 A
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Description (OCR text may contain errors)
June 13, 1961 w. H. GAPP HEAT EXCHANGERS Filed June 11, 1959 2,988,033 HEAT EXCHANGERS William Henry Gapp, Great Barr, Birmingham, England, assignor to Wilmot-Breeden Limited, Birmingham, England Filed June 11, 1959, Ser. No. 819,735 Claims priority, application Great Britain June 18, 1958 2 Claims. (Cl. 113-118) This invention relates to heat exchanger elements of the kind having a corrugated metal sheet for separating the fluids between which an exchange of heat is to be effected, said sheet being secured at one side to a plate having apertures through which one of the fluids can enter the passages formed between the sheet and the plate.
The object of the invention is to provide a convenient method of manufacturing such an element whereby the ends of the passages between the sheet and the plate can be sealed in such a manner that the flow of the other fluid along the passages at the other side of the sheet will be substantially unrestricted.
According to the invention a method of manufacturing a heat exchanger element of the kind specified comprises first forming the corrugated sheet in such a manner that each corrugation is of V or U cross-section, and each rib formed in the side of the sheet which is to be remote from the plate has opposite end portions which are reversely folded to tapering form, then crushing the end portions of the several ribs, and subsequently welding or otherwise securing the crushed portions of the sheet to the plate at positions beyond the apertures.
In the accompanying drawings:
FIGURE 1 is a sectional view through a part of a heat exchanger incorporating elements manufactured in accordance with the invention.
FIGURE 2 is a perspective view showing one form of corrugated sheet at an intermediate stage in its manufacture.
FIGURE 3 is a fragmentary perspective view of the corrugated sheet shown in FIGURE 2 in its final form, and
FIGURES 4 and 5 are fragmentary perspective and side views respectively of an alternative form of corrugated sheet in the intermediate stage shown in FIGURE 2.
A metal sheet a is first corrugated to a form in which each corrugation is of V or U cross-section. During the corrugating process the end portions of each rib formed at the side of the sheet which is to be remote from the associated plate b are shaped to taper towards the extremities. This tapering of each end portion is effected by reversely folding the corrugation forming the rib so as to form in the rib a V or U-shaped depression a increasing in depth towards the end of the sheet. If desired, as shown in FIGURE 2, in the end edge of each depression is cut a V, or other notch a which allows the sheet to lie flush against a flat surface. Alternatively, as shown in FIGURES 4 and 5, the reversely folded portion of the rib may project from the opposite side of the sheet.
After compressing the sheet in a lateral direction relatively to the corrugations the tapering end portions of the sheet are then crushed flat as shown in FIGURE 3 tats Patet Patented June 13, 1961 to a marginal depth at least equal to the depth of the notches a where such are provided. These crushed portions are then welded or otherwise secured to the plate b at positions beyond the apertures b therein. Also the outer walls of the two outermost corrugations are likewise secured to the plate b so that there are formed between the sheet a and plate b a plurality of passages interconnecting the apertures b Elements as above described are mounted in pairs with the crests of the corrugations of the one element remote from its plate presented to the similar crests of the other element of the pair with a small dividing piece d between them. There is thus formed between the plates b of the pair of elements a duct e which is divided into two series of passages through which one of the fluids can flow as illustrated by the arrows shown in full. At the other sides of the plates of these two elements are defined further ducts through which the other fluid can flow, these ducts incorporating baflles (not shown) whereby said other fluid will be caused to flow through the passages formed between the plates and the sheets as illushated by the arrows shown in broken lines to exchange heat with said one fluid. Moreover, the further ducts may be defined at their opposite sides by the equivalent sides of similar elements forming part of the heat exchanger.
Having thus described my invention what I claim as new and desire to secure by Letters Patent is:
1. A method of manufacturing a heat exchanger element of the kind having a corrugated metal sheet for separating the fluids between which an exchange of heat is to be effected, and a plate to one side of which the corrugated sheet is secured, and which is provided with apertures for permitting one of the fluids to enter and leave the passages formed between the corrugated sheet and the plate, comprising the steps of reversely folding to a tapering form the end portions of the ribs formed by the corrugations in the side of said sheet to be disposed remote from said plate, compressing said sheet laterally with respect to the corrugations therein after reversely folding the end portions of said ribs, subsequently crushing the reversely folded end portions of said ribs, and then securing the crushed portions to said plate at positions beyond the apertures therein so that the latter communicate with the passages formed between said corrugated sheet and said plate.
2. A method according to claim 1, and including the step of forming notches in the reversely folded end portions of said ribs preparatory to the crushing of said end portions.
References Cited in the file of this patent UNITED STATES PATENTS 1,206,717 Kochling Nov. 28, 1916 1,462,475 Atkinson July 24, 1923 1,704,326 Junkers Mar. 5, 1929 1,775,103 Hume Sept. 9, 1930 2,092,835 Edwards Sept. 14, 1937 2,262,086 Barrow Nov. 11, 1941 2,638,958 Norquist May 19, 1953