US2784947A - Heat exchange assembly - Google Patents

Description

March 12, 1957 D. G. PETERSON 784,947

HEAT EXCHANGE ASSEMBLY Filed Sept. 13, 19.54 2 Shee2;s-SheerI l INVENTOR DAVID G. PETERSON ATTORNEY March 12, 1957 Filed Sept. 13, 1954 D. G. PETERSON HEAT EXCHANGE ASSEMBLY 2 Sheets-Sheet 2 FIG. 2

INVENTOR DAVID G PETERSON United States Patent 2,784,947 HEAT EXCHAN ASSEMLY Applicationseptember 13, 1954, Serial No. 455,696

5 Claims. (Cl. 257-445) The present invention is concerned with improvements in plate type exchangers utilized for the` transmission of heat between twQ confined lluids and it relates particularly to an improved method of.Y assembling heat exchanger envelopes having rowsof undulated wires and corrugated channels providing extended` surface fins.

A well known type of apparatusfor the transfer of heat between two confined fluids comprises a plurality of metallic plates spaced` apar-t to form passages through alternate ones of which a relatively hot fluid` such as exhaust gasA flows while air or other fluid to be heated traverses the intermediate passages. Commonly a series of envelope components are provided consisting of parallel plates with the space therebetween closed along one pair of opposite edges to laterally bound opposite sides of the passage for the heating fluid. The envelope components are mounted in spaced parallel relation to form the passages for the fluid to be heated and the interenvelope spaces are similarly closed along one pair of opposite side edges. Such spaced envelopes form a core that is usually enclosed within :a housing with which are associated inlet and outlet manifolds and supply and discharge ducts for the two fluids.

To increase heat transfer elllciency the walls of the tluid passages are frequently provided with ns projecting into the path of the fluids and serving to increase the conduction of heat to and through the Walls that bound Ithe passages. One form for the extended surface iin-S extending between walls comprises sinuously bent wires forming a continuous series of `Ushaped loops whose legs constitute pin like fins projecting from the walls bounding the passage within the envelope. On the outer face of these Walls extended surface may be provided in the form of channel members extending parallel to the direction of fluid flow. To promote efficient heat transfer through pins and passage separating walls good bonds must be provided between the elements and the wall members such as by brazing or welding.

The present invention is directed to an improved arrangement or assembling the plates that form the passage walls and the sinuously looped wires that constitute the extended surface from these walls so as to form an integral heat exchange envelope.

'Ihe invention will be best understood upon consideration of the following detailed description of several illustrative embodiments thereof when read in conjunction with the accompanying drawings in which:

Figure l is a fragmentary perspective view of a heat exchanger envelope component with a wall partially broken away to show double composite channels utilized to hold the sinuous wire iin elements in position.

Figure 2 is a perspective view illustrating the use of a slightly different positioning and retaining channel from that shown in Figure l.

Plate type heat exchangers of the general type herein disclosed are made up from a plurality of separate envelope components, each comprising metallic plates 11 and 12 2,784,947 Patented Mar. 12 1957 spaced apart to form a passageway 13 for one fluid' while spaces outside the walls 11 and 12 which are located between adjacent envelope components of a completed heat exchanger llorm passages for the other fluid, To provide extended surface in the passageway 13 a plurality of fin elements are mounted between the inner surfaces of the walls 11 and 12 in the form of wires 14 sinuously bent to form U-shaped loops extending back and forth so the leg portions thereot` constitute pin like fins 15 extending between the walls. To facilitate bonding these sinuous elements to the passage walls 11` `and 12, channel members 16 are fitted over and along adjacent yoke portions of the sinuously bent elements. These same channel members also serve as stiffeners which increase the loverall strength and rigidity of the assembled envelope thereby greatly enhancing its final utility.

. In bonding the passage wall plates` 11 and 12 together with the sinuous wire members 14 .and the channel' members 16 into an integral unit, a process of furnace brazing has proved most satisfactory, since by such a process the constituent elements yare placed in a mutually good heat transfer relationship and the entire `operation may be speedily performed with a minimum 4of handling. The devices of this invention incorporate the use of permanent wire positioning channels whichposition the sinuous Wire elements andv provide stability to. the constituent elements during the brazing operation.

Figure l illustrates a type of heat exchanger envelope component comprising `a pair `of plates 11 and 12 separated by parallel rows of sinuously bent wires 1 4 forming a continuous series of U-shlaped loops whose legs comprise pins 15 extending from plate 11 to plate 12. In this arrangement, a series of composite channel members 16 -are used to position -the loops of eac-h wire element adjacent the top and bottom plates. The channel members 16 are rolled as a single unit with one channel portion 16A adapted to hold the sinuous wires in an upright position while the adjacent channel 16B serves as a spacer maintaining adjacent sinuous wires 14 evenly spaced.

In assembling this unit in preparation for the brazing operation, the plate 12 is first supported .in a horizontal plane .and a sheet or quantity of brazing material 17 is placed thereupon before rows of the composite channel members 16 are stationed in juxtaposition along the plate with the open or channel sid-e thereof facing upward. The loops or yokes of sinuously bent wires are press fitted into the alternate channels 16A while the intermediate channels 16B are left unoccupied .and provide a positive spacing means abutting the next channel 16. Similar channels 16, brazing material 17 and an upper plate 11 are superposed over the upper wire loops to provide the assembly of Figure l. Additional brazing material is used as a liner 1S within each channel part 16A containing the wire loops, so that when the entire assembly is heated to a brazing temperature all the brazing material will melt and on cooling will solidify to bond the Wire loops to the channels and the channels to the plates defining the passage walls with an adequate quantity of brazing material at the exact point of usage.

Figure 2 illustrates a variation of the heat exchanger component shown in Figure 1, differing only in the specific form of the wire holding channel. In the device of Figure 2 the wire positioning and retaining channels 20 and 24 are spaced vapart by a web 22 while a spacer flange 26 adjoi'ns channel 24 to provide a positive spacing means to the next adjacent double channel member. Ihe web 22 and the flange 26 produce what is, in effect, base portions of inverted channels alternately placed and in a juxtaposed relation with the upright channels 20 and 24.

In assembly, brazing material is inserted between all rice surfaces to be joined such 4as between the channels and plates, and `also within the channels so when the oomposite unit is raised to a brazing temperature, a plentiful supply of molten brazing material Will be available at the approximate location of its ultimate use.

What l claim is:

1. An envelope for a heat exchanger comprising metallic plates spaced apart to form walls for a iluid passageway; `a plurality of heat exchange elements mounted i'n spaced parallel relation in said passageway as metallic wires sinuously bent to provide a plurality of U-shaped loops with leg portions extending in an upright relation between the plates .and intervening loop` portions lying adjacent `said passage walls; and means positioning each sinuous wire relative to adjacent sinuous wires, said means including channel members bridging adjacent loops of each sinuous wire together with metallic spacers positioned uniformly at one side thereof to extend transversely a distance substantially equal to the width of one of said channel members.

2. An envelope for a heat exchanger as dened in claim 1 wherein the metallic spacer comprises a channel member integral with and similarly disposed to the first namedchannel member.

3. An envelope for a heat exchanger 'as denedin claim 1 wherein alternate spacers comprise web portions of channel members having sides in common with adjacent wire positioning channels.

4. An envelope for a heat exchanger as defined in claim l wherein `the web portion of the metallic spacers lie substantially parallel to and removed from each passage wall.

5. An envelope for a heat exchanger comprising metallic plates spaced apart to form walls for a fluid passageway therebetween; a plurality of heat exchange elements mounted in spaced parallel relation in said passageway comprising metallic wires sinuously bent to provide a series of longitudinally aligned loops whose leg portions extend in an upright relation between plates and whose intervening yoke portions lie adjacent said passage walls; channel elements bridging aligned yokes 'along opposite' sides `of the sinuous wires to impart longitudinal stability thereto; and a metallic spacer channel between adjacent channel elements integral with at least one of said channel elements arranged to impart lateral stability thereto, the transverse dimension of said metallic spacer channel being similar to that of said channel elements to provide a positive spacing means with a minimum resistance to fluid ow.

' References Cited in the file 0f this patent UNITED STATES PATENTS Blackmore July 9, 1918 2,151,206 Hawthorn Mar. 2l, 1939 2,550,512 Woolrich Apr. 24, 1951 2,591,878 Rogers et al. Apr. 8, 1952 2,606,007 Simpelaar Aug. 5, 1952 2,614,517 Peterson Oct. 21, 1952 2,697,588 Jensen Dec. 21, 1954

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