US 2814470 A
Description (OCR text may contain errors)
Nov. 26, 1957 D. e. PETERSON HEAT EXCHANGER Filed Feb. 12, 1952 COMPLL'TZD WIRE STE/P IVFTW AK mwwqq wzimok SPA C lNG COMB WIRE S UPPL Y HEELS A TTORNEY United States Patent U HEAT EXCHANGER David G. Peterson, Wellsville, N. Y., assignmto The Air Preheater Corporation, New York, N. Y.
Application February 12, 1952, Serial No. 271,192 3 Claims. (Cl. 257262.14)
The present invention relates to heat exchangers and particularly to an improved matrix or core for use in heat exchange passages.
In the earlier application of Sven Holm, filed under Serial No. 752,008 on June 3, 1947, now Patent No. 2,595,457, dated May 6, 1952, there is disclosed a form of extended surface for the walls of the flow passages of heat exchangers comprising wire elements bent sinusoidally to provide a plurality of U-shaped loops that extend back and fourth between the walls of the passage and constitute pin-like fins serving to extend their surfaces. The present invention contemplates simplification of the construction of such heat exchanger cores by assembling a number of the aforesaid sinusoidally looped elements into a matrix which may be inserted between metallic plates that form the walls of the heat transfer passage with provision for bonding the elements to the walls in good heat transfer relationship thereto. Briefly described, the matrix is formed by disposing the plurality of the looped wire elements upright and in parallel relation and tying them together by means of strips that extend transversely of a group of these elements.
The invention will be best understood upon reference to the following detailed description of illustrative embodiment of the invention when read in conjunction with the accompanying drawings in which:
Figure 1 is a schematic view of a series of machines and work stations utilized in carrying out the improved method embodied in the invention.
Figure 2 is a fragmentary perspective view of a matrix as formed on the apparatus of Figure 1 and Figure 3 is a transverse sectional view thereof.
Figure 4 is a side elevational view of a heat exchanger envelope comprising plates spaced to form a fluid passage and having the matrix of the invention applied to the passage walls and Figure 5 is a corresponding transverse sectional view.
Figure 6 is a fragmentary perspective view of a portion of another matrix embodying the invention and Figures 7 and 8 are corresponding plane and end views thereof.
In Figure 1 the numeral 10 designates a series of wire reels from each of which a strand of metallic wire is drawn with the wires being fed in parallelism to a forming press 14 in which each of the individual wires is sinusoidally bent to form a looped wire element as appears in Figure 2 having a plurality of generally U-shaped loops whose upright leg portions 17 are joined together by yoke portions 18 extending in alignment along the axis of the wire element. The wire elements next advance in parallelism to a welding station being maintained in proper parallel relation by a spacing comb 20 so that at the welding station 21 the wire elements 16 are in parallelism and are properly spaced so that the yokes 18 of any one element are in transverse alignment with the similar yokes 18, of the wire elements at either side thereof. Narrow metallic strips 22 and 23 are fed into the welding machine so as to extend transversely of the wire elements 16 therein with the strips 22 and 23 in contact with the outer faces of the yokes 18, 25 so that each strip 22 and 23 may be welded at a plurality of points along its length to a number of adjacently positioned looped wire elements 16 with the strips holding the wire elements together at what may be termed crests 24 and their dwells 26 on the outer faces of the yoke portions 18, 25 located at these positions. Thus, there is formed a matrix which is designated as a whole by the numeral 30 that consists of parallel looped wire elements 16 tied together by the transversely extending strips 22 and 23. As the matrix 30 leaves the welding station 21 it passes to a cut-off die 31 where a suitable length of the matrix is cut off to fit in a fluid passage of the heat exchanger which is to be constructed. The cut-oif and completed matrix 31A. as shown in Figure 1 is then placed between a pair of metallic plates 32 and 33 that form opposite walls of a heat exchange envelope with the space therebetween constituting a passage for the flow of one of the fluids between which heat is to be exchanged. The transverse strip members 22 and 23 of the matrix contact the passage walls 32 and 33 and are bonded thereto in good heat transfer relationship as by brazing, for example. The outer walls of the envelope may also have extended surface which in the form shown in Figures 4 and 5 is constituted by U-shaped channels 35 bonded to the outer walls of the passage.
The matrix shown in Figures 6 to 8 is in general formed in the same manner as that described above in Figures 2 and 3 and is used between the walls of a heat exchange passage in similar manner to that illustrated in Figures 4 and 5. Here, however, the matrix itself is constituted by the parallelly disposed looped wire elements 16 which are tied together by the narrow metallic strips 38 which rest on the inner surfaces of the yokes 26 located only at the dwell or valley portion of the sinusoidal looped element 16.
In both forms of the invention, it will be apparent that the looped wire elements 16 whose upright leg portions 17 constitute pin fins disposed in a heat exchange passage may be readily assembled and more efiiciently handled during the construction of a heat exchanger because the looped elements 16 are maintained in upright relation between transverse strips 22 and 23 of the matrix. In addition to uniting the looped wire elements into the form of a matrix the transverse strips 22 and 23 provide ample area for maintaining a good heat transfer bond between the passage walls of the heat exchanger and the pin-like fins which constitute extensions of the wall surface.
When the weld is made between the transverse strips 22, 23 of the wire elements 16 practically no distortion of the sinusoidally bent wire takes place. This enables the wire elements to be brazed between the plates that form walls of a heat exchanger envelope without using special mounting channels on the edges of the wire elements as has been proposed heretofore.
The transverse strip element 38 of the matrix shown in Figures 6 to 8 are illustrated as being provided at their ends with annularly bent portions 40 which serve as stops to properly space on a series of matrixes mounted in side by side relation in a fluid passage.
What I claim is:
l. A heat exchanger core comprising metallic plate members mounted in spaced relation to form a fluid passage; a plurality of sinusoidal fin elements in said passage each comprising a metallic wire bent to sinusoidal form to provide a plurality of substantially U-shaped loops disposed in alignment along the axis of said wire with the leg portions extending back and forth between the walls of said passage, the yoke portions of adjacent fin members being in alignment transversely of said passage;
3 and metallic strips spaced along top and bottom yoke References Cited in the file of this patent portions of said elements to extend transversely in contact with each of said yoke portions of each of the plu- UNITED STATES PATENTS rality of said sinusoidal members; bonds between the con- 5761069 Perry 1 tacting faces of said strips and the yokes of said elements 5 2,014,912 Taro? P 1935 to form said sinusoidal elements into a rigid matrix; and 2,082,899 Noms J 1937 bonds between the opposite faces of said bars and said 21112743 P0916 Mall 1938 plate members for attaching said sinusoidal elements to 2,140,610 Wlllard 1933 said members as extended surface therefor. 2,277,462 Spofiord 24, 1942 2. A matrix as recited in claim 1 wherein laterally adja- 10 2,384,157 Burke p 4, 1945 cent strips contact oppositely extending yoke portions that 21500501 Trumplel' Mall 1950 join the leg parts of said sinusoidal elements. 2,591,873 Rogers et P 9 2 3. A matrix as recited in claim 1 wherein said strips 2,595,457 P et y 1952 2,678,808 Gler May 18, 1954 are mounted on the outer surfaces of the yoke portions that join the leg parts of said sinusoidal elements at the 15 crests of the sinusoidal loops.