Патент USA US2136641код для вставки
Nov. 15, 1938. H. F. SMITH 2,136,641 REFRIGERATING APPARATUS ‘ Filed Dec- 21. 1936 a Sheets-Sheet 2 BY . 1%.“, Mum. [W8 ATTORNEYS. Nov. 15, 1938. ' H. F‘. SMITH 2,136,641 REFRIGERATING APPARATUS Filed Dec. 21, 1936 3 Sheets-Sheet 3 ,H” ML/ m wsX AW 3 ‘3.m” mm nV8 NT/ Patented Nov. 15, 1938 u 2,136,641 . UNITED STATES PATENT OFFICE ' 2,136,641 REFRIGERATING APPARATUS Harry F. Smith, Dayton, Ohio, assignor to General Motors Corporation, Dayton, Ohio, at corpora tion of Delaware Application December 21, 1936, Serial No. 116,944 2 Claims. (Cl. 257-263)‘ ‘ This invention relates to heat transfer de vices and particularly to condenser constructions for'refrigerating systems. ' An object of my invention is to provide a heat 5 exchanger‘ of the type having a closed ?uid con veying passage extending therethrough and which exchanger is of improved construction and increased eiiiciency. ' Another object of my invention is to provide a__ 10 heat exchanger comprising a plurality of ‘parts, adapted to be assembled together and bonded to one another by present-day economical copper hydrogen brazing methods to form a unitary - device of improved structural strength. 15 A further object of my. invention is to provide an improved heat exchanger ‘structure having separate heat transfer ?ns disposed between and contacting closed ?uid conveying ducts thereof and having the ?ns interlocking and contacting one another to provide a continuous fin surface extending entirely across portions of, the struc ' _ture to reduce the temperature gradient between‘ ‘certain portions of the heat exchanger. A still further object of my invention is to in crease the heat transfer efficiency of a heat ex ‘ Fig. 5 is a fragmentary sectional view similar to Fig. 4 and taken on the line 5—5 of Fig. 6 showing a modi?ed end construction of the heat exchanger; ‘ Fig. 6 is a fragmentary sectionaliview of the a modi?ed end construction of the heat exchanger taken on the line 6-6 of Fig. 5; _ Fig. 7 is a plan view of a metal strip adapted to be stamped‘and formed to‘ provide a fin ele ment for the heat exchanger; ' of Fig. 7 through the metal strip after having apertures stamped therein; and Fig. 9 is a fragmentary sectional view through a ?n element formed from the metal strip dis 15 closed in Fig. 8 in accordance with‘the invention. Referring to the drawings, for illustrating my invention, I have shown in Fig. 1 thereof a uni tary heat exchanger generally represented by the reference character I ll, such for example as a condenser for the refrigerating system. The heat exchanger Ill comprises a plurality of su perimposed and horizontally extending parallelly arranged closed refrigerant conveying conduits I l. The conduits ll extend beyond the ex changer to‘thereby obtain greater capacity from changer proper and have pressed sheetgmetal an exchanger of given size or to decrease the overall dimensions of an exchanger of a pre cap members l2 secured to the ends thereof. A plurality of pipes or conduits l3 secured to cer tain of the cap members I2 connect the refrig determined capacity. In carrying out the foregoing objects it is a still further and more speci?c object of the in vention to form certain portions of the ?uid con veying conduits ofmy improved heat exchanger from strips of sheet metal that‘are bent or folded into the desired shape and have certain portions thereof secured together to provide parts of the ?uid conduits with a plurality of closed passages. Further objects and advantages of the present invention will be apparent from the following 40 description, reference being had to the accom panying drawings, wherein a preferred form of the present'invention is clearly shown. erant conveying conduits H ‘in communicative relation to‘provide a series ?ow for refrigerating ?uid through the condenser or exchanger Ill. The condenser l0 may be provided with inlet and outlet pipe connections l4 and I5 respectively at one end thereof. The heat exchanger 10 also comprises a ?n arrangement for augmenting the transfer of heat from ?uid in conduits II to the air or other cooling medium for the ?uid and this - arrangement includesa plurality of ?ns IS. A metal plate I‘! is secured to the fins l6 at the top ‘ and bottom of the exchanger l0 and these plates have flanges l8 extending outwardly therefrom In the drawings: Fig. 1 is‘a front elevational view of a heat ex changer constructed in accordance with my in ‘which serve as mounting means for the ex vention; which is mounted an air circulating fan or ‘ Fig. 2 is an enlarged fragmentary end view of the heat exchanger taken'in the direction of the arrow 2 in Fig. 1 and showing the end portion 50 partly in elevation and partly in section; Fig. 3 is a fragmentary view of the heat ex changer partly in elevation and partly in section‘ and taken on the line 3—3 of Fig. 2; _ ‘Fig. 4 is a- fragmentary horizontal view of the heat exchanger taken on the line 4—4 of ‘Fig. 2; 10 Fig. 8 is a sectional view taken on the line 8-8 changer orfor connecting same in an enclosed path of air such as to a shroud or the like in blower. ‘ Referring now to Fig. 2 of the drawings it will be noted that the ?uid conduits ll extend ing through the heat exchanger III are ?attened as at 2| to provide a relatively ?at elongated passage for the flow of refrigerant therein. After the tubes or conduits I l have been ?attened a strip of metal 22 corrugated ‘as at 23 is in serted in each. of the conduits. The corruga 65 2 2,130,1341 tions is formed in metal strip 22 provide ?at portions 23 which lie against or abut the walls of conduit ll. Metal strip 22 thus serves to d1-v vide the refrigerating ?uid ?owing through con duit ll into a plurality of paths of ?ow to there by awment the transfer of heatbetween the fluid and the conduit walls and consequently to the ?n arrangement Ii of the heat exchanger. The cap members I: of conduits ii have an 10 elongated portion 25 which is ?attened to cor respond to the ?attened conduits II‘ and this portion" ?ts over and is secured to the ends mined size“ is assembled.‘ The cap members I2 I with the conduits l3 secured thereto are then as sembled upon the heat exchanger with the ends 26 of conduits Ii ?tting into the elongated por tion 25 of cap members i2 and the outwardly ?ared parts 21 in abutting relation with the end of the ?n elements 3i employed to provide the fin arrangement for the structure. It will be noted that, during the superimposing assembly operation of the parts, the extending portions 31 of the ?n elements 3| overlap or straddle the conduits II._ This straddling of fin members or 23 of the conduits H (see Figs. 3 and 4). The elements 3| on conduits I i is an essential feature ends of the elongated portions 23 of cap mem , of this invention in order to permit the sub .15 hers I! are ?aredoutwardly as at 21 adjacent the stantially continuous ?at portions formed by legs exclmnger llandthese?angesaresecuredtothe 35 and 36 to abut against the ?attened portions 2| of the conduits. The extending portions 31 on end portions of the fin arrangement It. > The ?n arrangement It of the heat exchanger ?n members 3i are of su?lcient length to interdhclosed comprises a plurality of corrugated or _fere with the extending portions 31 on other sup folded metal strips generaly represented by the erimposed ?n members 3i during the assembly reference character 3i. There is a corrugated operation. The extending portions 31 of mem bers 3| which straddle the conduits ii are there strip 3| interpowd between each of the superim posed-conduits II and it will be noted that each fore telescoped together so as to be disposed in‘ corrmated strip provides a plurality of relatively contacting relation as shown in Fig. 3. The tall thin s through the exchanger Ill for smooth rounded end portions of the extensions the ?ow of air or other cooling ?uid therethrough. 31 permits the telescoping or interlocking thereof to be readily carried out during the operation The blank strip of metal- from which a corru gated ?n element 3i is formed is disclosed at 32 of assembling parts of the structure together. inl"lg.7. Theblank32is?rstpunchedoutas This telescoping or interlocking relation of the 15 . 20 25 Y~ at 33 to provide a plurality of spaced apart elon- , extensions 31 with one another thus provides a 30 continuous contacting ?n surface across the gated apertures or openings. The material ad iacent the lengthwise opposed walls 34 of the openings formed by the punched out portions 33 are then bent in opposite directions to one an otherasshownat? and" inFig. 7 to provide legs or ?anges extending at right angles to the extension of the strip 32. Alternate apertures in the blank strip 32 have the opposed walls thereof bent in opposite directions to the walls of adja cent apertures as disclosed in Fig. 8 of the draw ings for a purpose to be presently described. The punched and preformed thin metal strip 32 shown in Fig. 8 is then folded or bent on lines passing through the center of an extending parallel with the ‘extension of each aperture formed in strip 32 to produce a length of corrugated strip form 3|, a fragmentary portion of which is shown in Fig. 9 of the drawings. By referring to Fig. 9 it will be seen that the folding operation per formed on the preformed ?at strip 32 causes the strip to assume a rig-sag form with the legs or ?anges 3| and 33 thereof extending in the same direction and disposed closely adjacent one an other. It will also be observed that the material between the ends of the apertures in blank‘, 32 and the lengthwise edges of the blank extend be yond the end walls ofthe apertures as at‘31 to provide the corrugated structure II with raised plurality of spaced apart conduits ii on each side of the exchanger. This arrangement pro vides a heat exchanger or condenser structure wherein the temperature gradient between cer 35 tain portions-and relative to other portions there of is greatly reduced to increase the efficiency of the structure. It is obvious that the ?n ele ments 3| afford a maximum amount of heat transfer ?n surface for the exchanger l0 and 40 provide a plurality of narrow air passages through the exchanger to thus cause substantially all air circulated through the exchanger to contact either the ?ns or the closed ?uid conduits there of or both. ‘ After assembling all of the parts of the ex changer structure it in the manner described these plurality of parts may be secured or bonded together in any conventional manner well-known to those skilled in the art and now practiced in the manufacture of such devices. For example, the various assembled parts of the structure Ill may bevbrazed together with the aid of copper brazing material in a hydrogen furnace by insert ing the structure therein or by passing same therethrough. This brazing of the structure will seal the plurality of ?uid conduit connections and will provide a metal-to-m'etal contact of the fin portions on each side of a ?at substantially con elements 3i with one another and with the con tinuom surface formed by the legs or ?anges 35 and 33. The ?at substantially continuous sur faces formed by the legs 35 and 3t inwardly of the extensions 31 are adapted to be placed in abutting relation with and secured to the ?at duits, II. The brazing of the structure will also 60 bond the leg portions 35 and 38 of the fin elements 3i to the ?at lengthwise extending portion of the plate l1 to thereby provide a unitary heat ex changer of increased structural strength. Referring now to Figs. 5 and 6 of the drawings 65 it will be noted that I have disclosed a modi?ed closed conduit structure for the heat exchanger iii. In this modi?ed structure a pair of metal strips II and 42 having their edges bent over to provide legs are placed together in opposed rela tion upon a corrugated strip 45. This strip 45 tenedsurface II of conduits ll. ' In assembling the parts of the exchanger de scribed a corrugated ?n strip element 3| is placed upon a plate l1 and a conduit II is. then placed upon the fin element 3| with the ?attened wall 10 3i thereof in intimate contact with the substan tially continuous ?at surface of the fin formed by the legs 33 and 3'. Another ?n element or is constructed or formed in a fashion similar to structure 3| is then placed over the conduit ll - the corrugated strip 22 to provide, when brazed and the superimposing operations described are within strips ti and 42, a closed ?uid conduit 36. Since the edges 43 and 44 of metal strips 75 contimied until a heat exchanger of a predeter 2,186,641 3. II and 42 are bent or disposed at right angles What is claimed is as follows: ' to the ?at longitudinally extending portions 1. A unitary heat exchanger comprising in com thereof a~plug or the like element 41 must be bination, a closed ?uid conveying conduit having placed between the elongated portion 25 of the a plurality of spaced apart portions, an element cap members l2 at the point where the conduit ‘ interposed between each of the spaced apart por-l 46 is secured to the cap members. This plug 41 . tions of said conduit, each of said elements com closes the space between the straight sided con prising a single strip 01’ metal bent or folded in . duit 4B and the semi-cylindrical inner ‘surface of zig-zag form to provide a plurality of fins ex the portion 25 of cap members I2. tending between said spaced apart portions of 10 From the foregoing it will be seen that I have said conduit and disposed in intimate thermal 10 provided an improved heat exchanger such as a condenser for a refrigerating system and that the contact therewith,v each of said elements being ‘ apertured inwardly of an edge portion thereof at improved construction materially increases the the point of said bends or folds to position an ve'tllciency of such devices and provides a device of ‘end portion of said ?ns in straddling‘relation to is increased structural strength. By increasing the said conduit portions, and the straddling end por 15 e?lciency of a heat exchanger by incorporating tions of said ?ns of one element being telescoped therein the maximum amount of ?n surface such a substantial distance into the straddling end por structures can be made small and compact and a ' tions of another of said elements to provide an‘ structure of predetermined size will have greater 20 capacity than heretofore obtainable. '1‘he_tele- scoping or interlocking of the separate ?n ele extended contacting surface. between the ?ns along at least one side of said heat exchanger. 20 2. A heat exchanger including a closed fluid conveying conduit having a pair of elements asso ments with one another in my improved heat ex changer construction provides or forms a con ciated therewith, each of said elements compris tinuous contacting ?n surface extending entirely ' ing a strip of metal folded back and forth to pro across both sides of the exchanger and thereby vide a plurality of ?ns extending laterally from 25 decreases the temperature gradient between por tions of the exchanger. It is thus seen that the increased eillciency of my ‘improved heat ex changer'is due partly to the placing of a maxi mum amount of ?n surface extending across the sides of the structure. The improved heat ex changer is simple in construction and the meth ods of assembling and manufacturing the same can be carried out at low cost. of said elements to provide an extended contact While the form of embodiment of- the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow. said conduit and disposed in intimate thermal contact therewith, each of said elements being apertured inwardly of an edge portion thereof at the point of said folds to position an end portion of said ?ns in straddling relation to said conduit, 80 and the straddling end portions of \said ?ns of one element being telescoped a substantial dis tance into the straddling end portions of the other " ing surface between the ?ns along a side of said 35 conduit. - HARRY 1". SMITH.