US2615687A - Heat exchanger - Google Patents

Description

Oct. 28, 1952 I SIMMONS 2,615,687

HEAT EXCHANGER Filed Jan. 3, 1948 2 SHEETS-SI-iEET l IN VEN TOR.

v ATTORNEY Patented Oct. 28, '1952 2,615,687? H .nmrvnxommcnn r Application anuary 3, 194-8; seriai Noii4'40 Lance. L. SimmonasDetroit;.Mich .assignor to,

American Blower Corporation 'Dearborn, Michi," a corporation Delaware; g

7 3 Claims. (o1. 257F144) This-invention relates to new'anduseful improvementszin heat exchangers".

Qneof theobjectsof this invention is to pro.-

vide a heat exchanger assembly wherein there is a bank of heat exchange tubes which are 1 assembled into .a casing for unitinstallation.

Another object is to provide aheat exchanger assembly' having a means-to permit expansion and contracti-on-of the tubes therein without dis-.

tortionr Another object is to provide .aheat exchanger] assembly wherein the tubes may .be individually insertedfland. removedfor ease.v of repair and.-

maintenance.

Another. object is to provide a heat exchanger. assembly comprising .a bank of tribesahdhaving. a means to prevent bypassing of the air streamv around -theldges or the ends of the tubes.

Another object is to provide a supporting structurefor'jaheat exchange unit which closes offflowaround the unit.

lAnpthler object is to provide. a heat exchanger. assemblyflhaving an outer supporting structure.

and a'n i'nner bank .of heat exchange tubes, the

inner bank of tubes being slidably insertable into. and removable from the outer structure. forfease. of. maintenance and repair without dismantling.

the outer structure. v a

Another object is to provide a newandimproved heat exchanger "assembly which may be simply'and inexpensively manufactured and assembled 'f'oi'jcommeroial installation and use.

Qth'er-objects will become apparent from time toftime" throughout the specification and claims as hereinafter related.

This invention consists of the new and 'im-" in a supporting structure to illustrate more clearly the manner of. installation,"

Fig. 2 is a broken and shortened view in front elevationof this heat exchanger assembly com pletely assembled, 1 I

Fig; 3 is a-vie'w in leftel'evation-of the assembly of'Fig.1:2, :f1 v

Figf l "is a sectional view ofthe'assemblytaken QntheIBHneI-l-of: Fig;

Fig. 5 is a viewin l frontelevation ofthe'sub-M assembly .of the innercasing and heating" tubes whichlis shown'partially installed in Fig.1., I 1 a Fig. 6 ha 'top sectionali view. taken. on .the line -6.6--of ig.-,5 butnsho'wing the.'tube'icdm nections to v the headers fland one .of --the return bend guide slots in section, and

Fig. 7 is a detailsectionalview.of: the heating tubes support and;- ta'ken on. the .section line .5,-=j L Referring Y to the "drawings. by characters of, reference, there. is a heatexchanger. assembly I comprising anzouter casing orsupportingstrum. ture e2. and. a heat I exchanger subeassembly 3. Theroutercasing-2. is constructed .of-. a welded structure of angle andlchannel members; and.is formed in a. rectangulariramework having closed top and .bottom walls A and- 5 and: a closed end walliformed .by the base portion of said..cha n; nel members. JIhe casing 2 has-,tw'o opposite open sides 1 ,and- 8 andan. open end sac msertion of thei {sub-assembly 3. .The.. .various angles and;--channels:-=have a plurality fof. holes I ll through the sides thereof for receiving. bolts or other-securingmeans-for mounting-pr secure ing'the-casing in positionw a:

The heat-exchanger sub-assembly. 3 .c mprises a supporting'structure formed of apairof chan nel members II and I2 forming .-clos ergl top andv bottom walls and '.-.a pair-bf .end. wall .a members 13 land .:l-i.--- -Secured on the-endwwallu area pairfof" headers i5 and 16 having inlet and. outlet.

fittings .11 and I 18 respectively extending through the-wall I3 The header l5 functions as: a fluid inlet.-receiver and-the header 16 functions asa fluid" 0.1.1t16t7q601160t01'; the- :inlet i! being posi-x tioned abovethe-ioutlet 18w Extendingt 10ngi-2 header: l5. and'their outlet ends" orv runs' '2 l -con-.=.

nected'to the header i 6 by. compression fittings or unions 2 2:12 'The tubes "I 9 are: substantially "U shapedfir-andzfarei' formed of "straight sections of tubing joined: together by reverse. bend couplings 23f'at'zthe; end il 4 "of the; sub=assemb1y structure- 3. The fins Ollfthfi tubes l9'a're preferably helical but areshown diagrammaticallyinthe drawings =for l'ease. of illustration? Thetendi wall 1 I4 is substantially*U-shaped or of f'channel form whentaken' in horizontalisection; @The side pore. tions H of the end :wall H cover' the .sides. .or the-.re'ver'se' bend couplings and: .close. the 'end.

of theisub'a'ss'embly 5 structure :3. t The r'sideivvall portions fl 'riaresconnected=rby out-turnediflanges 3 I4 to the offset portions M which are joined to the edge flanges of the top and bottom wall channel members H and I2 for rigidity of assembly. The end wall I4 has flanged portions I4 at top and bottom by which it is bolted or secured to the top and bottom wall members II and I2 to provide a rigid sub-assembly struc ture. The side wall portions I4 of the end wall I4 have a plurality of horizontal slots therein which are open toward the finned portion of the tubes through the out-turned flanges HP. The reverse bend couplings 23 each have a pair of projecting carrier members or ears 24 thereon which extend laterally outward from opposite sides of the reverse bend coupling 23 and which fit slidably into the slots 25 in the end wall I4. The end wall I4 and slots 25 function to support the tubes I9 at their reverse bend portions and to permit expansion and contraction of the tubes without distortion. The side portions of the end wall II also function to prevent air passing over the tubes I9 from bypassing around the reverse bend portions where there are no fins and heat transfer is poor. At the end wall I3 there is a T-shaped baiiie member 26 which extends between the headers I5 and I5 and projects outward to and has its cross arm portion abutting the end of the finned portion of the tubes I9 adjacent their inlet and outlet ends. The baffle 26 functions to prevent air from bypassing around the header end portion of the tubes I9 where there are no fins and heat transfer is poor but at the same time permitting free access to the unions 22 for removal of the tubes I9.

In the central portion of the sub-assembly struc- 1 ture 3 there is a supporting channel member 21 which bears against the fins on the tubes I9 to prevent lateral movement and which acts as a support for the top and bottom wall channel members II and I2. On the outer sides of tubes I9 there are a pair of tube supporting members 28 which are shown in a detail sectional view in Fig. 7. The member 28 comprises a large channel member 29 and a small channel member 30 inverted and secured therewithin with r a corrugated sheet metal member 3| secured to the small channel member 30. The corrugations of the member 3| fit the fins of the tubes I9 and support them.

Positioned longitudinally of the outer casing 2 are angle members 32, 33, 34 and 35 which cooperate with the edges of the top and bottom walls II and I2 of the sub-assembly structure 3 for guiding the same into the casing 2. The members 32, 33, 34 and 35 extend to the top and bottom edges respectively of the fins of the extreme top and bottom runs (see Fig. 4) of the rows of tubes I9 and thereby function to prevent bypassing of air around the top and bottom edges of the bank of tubes I9 and also to close the space between top and bottom walls II and I2 and the top and bottom walls '4 and 5. The end wall I3 of the sub-assembly structure 3 has a plurality of holes 36 around the edge thereof which fit a plurality of studs or other bolts or clamping means 31 in open end of the casing 2 for securing the sub-assembly 3 to the casing 2.

The operation of this assembly should be clear from the foregoing description but will be restated for clarity. The open sides of the-casing v 2 and the sub-assembly structure 3 are in registry when the apparatus is assembled and an air stream is directed through the bank of tubes I9 for heating or cooling. Heat transfer fluid is circulated through the tubes I9 entering through c .at

the header I5 and leaving through the header I6. As was heretofore described the baffle 26 and the end wall I4 function to prevent bypassing of air around the respective ends of the tubes I9 where there are no fins and heat transfer is poor. Similarly the guide rails or angles 32, 33, 34 and 35 prevent air from bypassing around the edges ofthe bank of tubes. The slots 25 in the end wall I4 serve the dual purpose of supporting the reverse bend portion of the tubes I9 and permit expansion and contraction of the tubes without distortion. It should also be noted that this assembly has the additional advantage of permitting removal and insertion of individual tubes in the bank of tubes I9 so that for maintenance and repair the entire assembly need not be dismantled for the removal of a single tube.

Having thus described the invention, what is claimed and is desired to be secured by Letters Patent of the United States is: p

l. A heat exchanger assembly comprising an outer casing adaptable to be secured in a predetermined position, said casing comprising a rectangular framework having closed top and bottom walls and a closed end wall and having an open end and open sides, an inner casing slid'ably fitting said outer casing and adapted for insertion or removal through said outer casing open end-for ease of assembly and maintenance, said inner casing comprising a rigid rectangular structure having closed top and bottom and opposite end walls and having open sides registering with said outer casing open sides, said outer and inner casing top and bottom walls having cooperable side flanges forming guide rails, said outer casing flanges also closing the spaces, be tween said top walls and said bottom walls, a pair of headers secured within said structure and spaced from one of said inner casing closed end walls, one of said headers having an inlet connection and the other having an outlet connection, said connections extending through apertures in said one end wall, a plurality of substantially U shaped finned heat transfer tubes positioned longitudinally of said inner casing and having their inlet ends connected to said one header and their outlet ends connected to said other header, a baffle member of T shaped crosssection, having a stem portion and a cross portion, positioned between said headers and carried by said one wall, said stem portion being secured to said one wall and extending substantially the length of said headers, said cross portion extending substantially the length of said headers and laterally into overlapping relation to the tube fins, and means for supporting said tubes by their reverse bend portions at the other of said inner casing closed end walls.

2. A heat exchanger assembly comprising a casing having closed top and bottom end walls and open sides for passage of air therethrough, a pair of headers at one of said closed end walls, one of said .headers having an inlet connection and the other having an outlet connection, a plurality of substantially U-shaped finned heat transfer tubes positioned longitudinally of said casing and having their inlet ends connected to said one header and their outlet ends to said other header, the other of said closed end walls being formed to have an end wall portion and side wall portions, said side wall portions being positioned to shield the reverse bend portionsof said tubes to pr ve ypa in of air around the finned portions thereof. each of the reverse'bend"portlonsof said tubes having at leasttwo oppositely directed projectingimembers;l said side wall portions .havinga plurality" of longitudinal lslotsin which .saidz projectingimemibersiarelpositioned, and said slots performingfthe dualifurictiorr-of supporting. the reverse bendaportions ,of .said .tubeswandnpermitting individual thermal: expansion and contraction of said-ltubes. 312A heatil exchanger. assembly comprising 1. a casing ihavinglclosedtopand bottom. and end. walls and Fop'en .sides. for passagerof sg'as therethrou h.

a pairsof headerslat ongofsaid closed endwalls,

one of said headers having an inlet connection sitioned at the other of said closed end walls for supporting said tubes at their reverse bend p'ortions, a T-shaped baffle having a stem portion and a cross portion, the stem portion being positioned between said headers and extending substantially the entire vertical height of said casing and extending outward between the inlet and outlet ends of said tubes to a line beyond said coupling members at the beginning of the finned portion of said tubes, said cross portion also extending substantially the entire height of said casing and into overlapping relation to the tube fins, and said baflie blocking the flow of gas over said coupling members thereby causing the gas flow at the header ends of said tubes to be directed across the finned portion of said tubes.

4. A heat exchanger assembly comprising a casing having closed top and bottom and end walls and open sides for passage of air therethrough, a pair of headers at one of said closed end walls, one of said headers having an inlet connection and the other having an outlet connection, a plurality of substantially U-shaped finned heat transfer tubes positioned longitudinally of said casing and having their inlet ends connected to said one header and their outlet ends to said other header, the other of said closed end walls being formed to have an end wall portion and side wall portions, said side wall portions being positioned to shield the reverse bend portions of said tubes to prevent bypassing of air around the finned portions thereof,

each of the reverse bend portions of said tubes having a pair of oppositely alined projections; said side wall portions having a plurality of longitudinal slots in which are positioned said alined projections, said slots performing the dual function of supporting the reverse bend portions of said tubes and permitting individual thermal expansion and contraction of said tubes, a T- shaped baffie positioned between said headers and extending substantially the entire vertical height of said casing and extending outward between the inlet and outlet ends of said tubes to the beginning of the finned portion of said tubes, and

said baffle being operable to prevent flow of air 5. A heat exchanger assembly comprising a casing having closed top and bottom and opposite end walls and open sidesfor passage of air therethrough, a pair of headers at one of said closed end walls, one of said headers having an inlet connection and the other having an outlet connection, a plurality of heat transfer tubes positioned longitudinally of said casing, each of side portions of s'aid channel member'- having parallel slots -opening---" toward said headers through said. out-turned flanges, and carrier members projecting oppositelyfrom the outer side'srof each :ofsaid coupling members andpextending into said slots, said carrierimembe'rs' sup- .porting said tubes on the side edges of said slots.

header and their outlet ends to said other header,

said tubes being individually connected to said headers by union type fittings to permit individual insertion and removal of tubes for ease of maintenance, the other of said closed end walls being formed to havean end wall portion and side wall portions, said side wall portions being positioned to shield the reverse bend portions of said tubes to prevent bypassing of air around the finned portions thereof, each of the reverse bend portions of said tubes having a pair of oppositely alined projections, said side wall portions having a plurality of longitudinal slots in which are positioned said alined projections, said slots performing the dual function of supporting the reverse bend portions of said tubes and permitting individual thermal expansion and contraction of said tubes, a T-shaped baffle positioned between said headers and extending substantially the entire vertical height of said casing and extend ing outward between the inlet and outlet ends of said tubes to the beginning of the finned portion of said tubes, and said baflle being operable to prevent flow of air over the end portions of said tubes connected to said headers and thereby causing the air flow to be directed across the finned portion of said tubes. I

7. In a heat exchanger, a plurailty of heat transfer tubes adapted to be positioned in and transverse to the path of flow of a fluid medium,

said tubes each having a return bend portion comprising a generally U-shaped coupling memher having supporting ears extending laterally outward therefrom, an end wall member of generally U-shaped section on the planes of said tubes and having out-turned. flanges, the side walls of said wall member having oppositely positioned guide slots each opening through one of said flanges, each of said coupling members being positioned between said side walls and having its supporting ears extending respectively into opposite ones of said slots and supported by the slot side edges for free guided expansion and contraction of said tubes.

8. In a heat exchanger, an inlet header having an inlet pipe, an outlet header extending parallel to said inlet header and having an outlet pipe, a wall member having an aperture receiving said inlet pip and having an aperture receiving said outlet pipe, a plurality of indivdually finned heat transfer tubes, coupling members detachably connecting the tube inlet and outlet ends to said inlet and outlet headers, respectively, and a T- shaped bafile member having a stem portion and a cross portion, said stem portion extending substantially the length of said headers and from said wall member through the space between said headers and projecting beyond said coupling members, said cross portion extending substantially the length of said headers and laterally into overlapping relation to the tube fins.

- LANCE L. SIMMONS.

REFERENCES CITED The following references are of record in the file of this patent:

Number 8 UNITED STATES PATENTS Name Date Price July 13, 1926 French Jan. 6, 1931 Holton et al Jan. 6, 1931 Smith Aug. 11, 1931 Soule Nov. 17, 1931 Bulkeley Jan. 19, 1932 Potter Oct. 25, 1932 Young et al Oct. 9, 1934 Anderson Apr. 26, 1938 Lea Mar; 31, 1942

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