US2339284A - Heat transfer element - Google Patents

Description

Jan. 18, 1944. A. B. MODINE HEAT TRANSFER ELEMENT Filed July 14, 1941 2 Sheets$heet 1 java/21 87 A. B. MODINE HEAT TRANSFER ELEIENT Filed July 14, 1941 2 Sheets-Sheet 2 I ari9iwf-s-mdi7 w wiz s,

' metal is complemented by the desirable thermo in Fig. 9 after bonding.

. or units of the core are of such material and so relatively high melting point in combination with 1 various units together, tively high heat conductivity. In actual practice collected at certain points thereof to increase the sary to melt the copper during the bonding operaclosure herein given. that a surplus of the melted copper will flow dur- .line 22 of Fig. l; i outlet. The core I comprises a plurality of indiupper and lower headers broken away; 45- are positioned adjacent one another, spacer strips showing the assembly prior to the bonding opa fin portion ll having side walls l2 extending "core as m y. wi h the upper l m li n r n provided adjacent their free longitudinal edges away;

Patented Jan. 18, 1944 2,339,284

UNITED STATES. PATENT OFFICE HEAT 'rmmsraa mmmn'r 'Arthur B. Modine. St. Petersburg, Fla. Application July 14, .1941, Serial No. 402,265 5 Claims. (01.251-128') The invention relates generallyto heat transfer- .01 applyin the bonding material prior to the elements or cores, and more particularly-to a bonding operation; novel method and means of constructing and as- Fig. 8 is a similar view of the same after the sembling the same. bonding operation;

The invention has among its objects the pro- 6 Fig. 9 is a view similar to Fig. 7, illustrating anduction of a heat transfer element or core of steel other manner of initially securing the bonding and copper or other suitable materials, wherein material to thecore units; and the desirable tensile characteristicsv of the one Fig. 10 is a. view of the construction illustrated characteristics of the other metal. 10 The present invention contemplates a cor Another object of the invention is the producstructure built up of a series of elements or units tion of such a core in which the various elements which are constructed of a material having a shaped that a bonding material of relatively high a bonding metal having a relatively lower meltheat conductivity may be employed to bond the ing point. where the bonding m t has a- A further object of the invention is the producone combination of metals used could be that of tion of such a core in which the elements or units steel and copper, the latter being used for the thereof are so shaped that a surplus of molten bonding material and the steel for the core strucbonding material which is very fluent and will ture, The characteristics of the steel are such readily flow from one point to another may be that it would withstand the temperatures necesheat transfer capacity of the device. tion and yet have sufllcient tensile strength to A further object of the invention is the promeet the requirements of the device. Likewise, duction of a novel method for constructing such the same metal might be employed for both the devices which is relatively simple and very efllstructure and the bonding material, with one or cient, whereby a single bonding operation is reboth being alloyed with other metals to achieve quired in'the construction of the device. the desired results, the heat conductivity of the Many other objects and advantages of the conbonding material, however, being substantially struction herein shown and described will be not less than that of the structure material. The obvious to those skilled in'the art from' the discore elements or units are preferably so shaped To this end my invention consists in the novel ing the bonding operation and collect at certain construction, arrangement and combination of points, where it will be most eflicient in the parts herein shown and described, and more paras transfer of heat.

ticularly pointed out in the claims. Refen'ing to the drawings, Fig. 1 illustrates In the drawings, wherein like reference charthe application of the invention to a radiator acters indicate like or corresponding parts: core or the like, I designating generally a core Fig. 1 is a perspective view of a radiator core having upper and lower headers 2 and 3, the or the like embodying the present invention; 40 upper header 2 being provided with a fluid inlet Fig. 2 is a sectional view taken substantially on 4 and the lower header with a corresponding Fig. 3 is a sectional view taken approximately vidual fin units or elements 5 which are vertically on the line 3-3 of Fig. 1, with portions of the arranged or stacked in banks 6. These banks Fig. 4 isa perspective view of a portion of the I being interposed intermediate each pair of assembly, illustrating the construction thereof; banks at opposite ends of the units or elements Fig. -5 is a perspective view similar to Fig. 4 5. The fin units or elements 5 each comprise eration; I v transversely therefrom adjacent the longitudinal Fig. 6 is a perspective view of a portion of the edges of the fln portion. The side walls I2 are with opposed inwardly extending flanges Hi, the a Fig. 7 is aperspective view illustrating a slightlatter being spaced-from one another as clearly ly diflerent construction and showing one means illustrated in Figs. 3, 4 and 5. The units or elements are constructed from relatively thin sheet material having a relatively high-melting point, such as steel, the units being vertically stacked in banks 6, as shown in Fig. 3, with the flanges I! of each unit positioned adjacent to the fin portion ll of the adjoining unit and bonded thereto, as shown at M in Fig. 3. The banks 6 are positioned adjacent one another and are connected with the spacing bars or strips 1 as shown in Fig. 6, the latter strips likewise being bonded to the adjacent banks to form passages II therebetween, thev side walls of the passages being formed by the side walls I! of the respective fln units or elements with the spacers I forming the end walls of said passage.

Secured to the top and bottom or the core are upper and lower headers and 3. header construction may be employed. In the embodiment of the invention illustrated plate it of approximately the same length and width as each of the fin portions ll of the respective units I are positioned adjacent the flanges ii of the bottom units to close the same. The headers are provided with internal fiang'es ll secured to the cores illustrated in.Figs. 2 and 3 by suitable bonding means. Thus fluid enters the inlet 4 in theupper header 2 and passes into the lower header and through the outlet therein. 7 As the fluid the fin portion ll of the respective units is provided with a series of cavities or indentations IS, the latter, in the present instance, being triangular in shape and tapering in depth from the side wall I 2 to the central portion of the fin. so that the portion of greatest depth is adjacent the side walls II. The cavities l9 provide means for Any suitable to the shape of the fin portion.

operation the stacks or banks of units are'preferably placed under compression to prevent all of the molten copper from flowing down the sides or the units, the molten copper being very fluent, readily flowing from one point to another. The copper bonding material may be applied to the spacers I in any suitable manner, as for example, by copper plating before being assembled with the units. The sheet of copper II is of sufficient thickness to provide an excess of metal to insure the filling of the cavities l9, and during the bonding operation will flow down along the side walls I! of the units to provide a thin coating of copper which may form a protective coating over the side walls, protecting the same from the action of fluids that may pass through the device.

Illustrated in Figs. '7 through 10 is a slightly difi'erent form of construction utilizing a slightly different method of assembly. In the construction illustrated in Fig. 7 before bonding and Fig.

8 after bonding the fin-portions 3| are elevated slightly at the central portion thereof as shown at 32, whereby the fin portion slopes downwardly from the central portion to the side walls forming an inverted V-shaped fin. The flanges 33 also conform to the slope of the adjoining fin portions.

. The copper strip 2| is positioned adjacent its respective fin portion, the strip likewise conforming When the assembled core is placed in the furnace or oven for bonding, upon melting of the copper the latter will flow outwardly towardthe side walls and the surplus molten copper will collect adjacent the latter, thereby forming a bi-metal fin tapering toward the central portion thereof with the heaviest portions of the fin being adjacent the side walls.

Illustrated in Figs. 9 and 10 is a similar con-' struction illustrating a slightly different method of assembling the same, wherein Fig. 9 shows the unit prior to bonding and Fig. 10 after bonding.

collecting the molten copper bonding material,

which is very fluent, adjacent the side walls 12 of the units. the preponderance of the copper being closely adjacent to the side wall and diminishing in amount toward the center of the fln portion. Thus the fin portion in its final form is of bi-metal construction in effect tapering in thick-' ,ness from adjacent the side walls I! to the center of the fin portion. Dueto'the high efliciency of the copper as a heat conductor, the heat transfer capacity of a core embodying the present construction is considerably increased.

The device may be assembled and bonded in the following manner, illustrated in Figs. 4 and 5 wherein Fig. 4 shows the bonded structure and Fig. 5 the condition prior to bonding: The fin units or elements I are vertically stacked in proper relationship to one another to form a bank 6. a strip of copper 2| of substantially the same width as the fin portions H being inserted intermediate the respective units. If: desired the strips 2| may be spot-welded or otherwise suitably attached to its respective unit to insure proper positioning of the strip relative the unit. The spacers I are then positioned intermediate the banks at the respective ends of the units and the whole placed in a hydrogen furnace. The

latter is brought up to a temperature sufflcient In this modification the fin portion ll is provided with a thin coating 35 of copper on the upper face thereof, a thin sheet 38 of copperv is positioned within the unit, the sheet resting on the flanges 33, the latter in this instance being bent outwardly away fromthe fin portion, as clearly illustrated in Fig. 9. As the bonding copper melts it will likewise flow toward the side walls 34, the stacks or banks of fin units being compressed to bend trated in Fig. 10, is substantially the same as that illustrated in Fig. 8. While I have shown several different ways in which the bonding material may be initially positioned or assembled with respect to the units or elements, obviously the bonding material may be applied in any suitable manner, as for example,

by plating, spraying, the use oi flat sheetsas illustrated, or by the use of granules. It will be apparent from the above description that I have provided a heat transfer core or unit in which the desirable characteristics of the steel structure are combined with the desirable characteristics of the copper to provide a core of great durability having a relatively high heat transfer capacity. likewise. Ihave produced a novel Y 2,339,254 unit may be entirely bonded in a single operation, and have produceda novel fin construction wherein excess or surplus molten bonding material is collected at desired points to produce highly beneficial results. While I have described the core as being constructed of steel and copper, obviously theinvention is not limited to the use of these two metals, but may be utilized with other combinations of metals having suitable tensile and thermo characteristics.

Having thus described my invention, it is obvious that various immaterial modifications may be made in the same without departing from the spirit of my invention; hence, I do not wish to be understood as limiting myself to the exact form, construction, arrangement and combination of parts herein .shown and described, or uses mentioned. 1

What I claim as new and desire to secure by Letters Patent is:

3. In a device of the kind described comprising a plurality of elements arranged in banks to provide fluid passages therebetween, each of said elements comprising a fin member, downwardly extending side walls-carried by each of said members, said side walls being formed with inwardly extending flanges engageable with the fin memand said fln members each having a plurality of troughs oflset from the surface thereof for directing the bonding material in steadily increasing 1 depth toward said side walls and beneath the 1. In a radiator of the kind described, a plurality of channel-shaped units stacked one upon the other and each having leg members connected by a fiat wall, said wall being adapted to-form a divider and heat exchange member in the air passageways of the radiator, bonding material to join each unit to an adjacent unit to provide a bank of units, means for securing a plurality of said banks together in spaced relation to provide a fluid passage between the banks, said bonding material being of equalor greater heat conductivity than that of said units, and said flat wall of each unit having transverse depressions formed therein to direct and conduct a preponderance of bonding material toward the leg ends of the flat wall of each unit to join the legs of the adjacent unit therewith.

of substantially equal or greater heat conductlvity than the material of said units, and said fins flanges of the adjacent fin members-to increase the total metallic thickness of the respective fin members adjacent said side walls during the bonding process,

4. A heat transfer core comprising a plurality of 'units joined together to form fluid and air passages, said units providing a plurality of fins extending across said air passages, bonding material for joining said units, said bonding material being of each unit having independent rows of transverse depressions formed therein with each depression beginning intermediate the breadth of 2. In a device of the kind described, comprising a plurality of elements'arranged in banks, spacers at opposite ends of each bank separating adjacent banks to provide fluid passages therebetween, each of said elements comprising a fin of depressions in the top face thereof terminat ing at points beneath the adjacent faces of said inwardly extending flanges that contact the adjacent fin member, said depressions increasing in depth toward the aforesaid points to direct a preponderance of bonding material thereto.

the fin and extending insteadily increasing depth and width toward the longitudinal sides thereof to collect a preponderance of bonding material adjacent the juncture of said fins and side walls of said passages to increase the heat transfe characteristics of said device. I i

5. In a device of the kind described comprising a plurality of elements arranged in banks to pro vide fluid passages therebetween, each of said elements comprising a fin member, downwardly extending side walls carried by each of said members, said side walls being formed with inwardly extending flanges engageable with the finmem ber of the adjacent element, bonding material for joining said flanges to said adjacent element, and' said fin members each having troughs formed in the face thereof, said troughs each beginning intermediate the sides of the fins and extending

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