US2611585A - Heat exchanger - Google Patents

Description

Sept. 23, 1952 c. BOLING HEAT EXCHANGER Filed March 30, 1948 INVENTOR Patented Sept. 23, 1952 HEAT EXCHANGER Cecil Boling, Brewster, N. Y., assignor to-The Heat-X-Changer. 00., Inc., Brewster, N. Y., a corporation of New York Application March 30, 1948, Serial No. 17,899

8 Claims. (Cl. 257241) This invention relates to the transfer of heat from one fluid to another, and more in particular to highly efficient heat-exchange units and the method of makingthe same.

An object of this invention is to provide a heat exchange assembly whereby heat is transferred from one material to another in an extremely heat-exchange units of the above character in a.

simple manner which is inexpensive and yet thoroughly practical in every respect. These and other objects will be in part obvious and in part pointed out below.

The invention accordingly consists in the features of construction, combinations of elements, arrangements of parts and in the several steps and relation andorder of each of the same to one or more of the others, all as will be illustratively described herein, and the scope of the application of which will'be indicated in the fol:- lowing claims. y

In the drawing: r Figure 1 is a side plan view with portions broken away of a heat-exchange unit constituting one embodiment of the invention;

Figure 2 is an enlarged sectional view on the line 2-2 of Figure 1'; 1 A

Figure 3 is an enlarged sectional view on the line 3--3 of Figure 1 showing only the central portion of the unit; and,

Figure 4 is a top plan view. of the unit of Fig- 4O urel. v.

Referring to Figure 1 of the drawing, an elongated cylinder or tube 2 has coiled about it a spiral tube 4 which formsfive complete'turns betweenits flareden'ds 6' and 8. .The ends of tube2 are reducedat l and"l2,,and except for these reduced ends, substantially the entire tube 2 and substantially the entire length of tube 4 are embedded in a cast aluminum block-l4; block I4 is cylindrical with two protrusions I6 and 18 at the ends surrounding theportions of tube'4' ad- A further 0b-"" jac'ent ends 6 and B. "As shown best in Figure 2.

tube 4 is somewhat ovalin-*cross-section-,- having been originally circular in cross-section, and; hen having been deformedto the oval shape when wound into aspiral: r

Positioned within tube 2 is a heat-exchange assembly 20 which is formed by a central expanded tube 22 and a fin construction 24. The structure of fin construction 24 is best shown in Figure 3 where it is seen that it is formed from a corrugated sheet of metal bent into cylindrical form. There are 21 flat fin portions or corrugations, and the corrugations originally forming the edges of the sheet are-overlapped to form a single fin portion so that there are ten pairs of fiat fin portions symmetrically positioned in the annular space between tubes 2 and 22. Each of these flat fin portions is positioned substantially radially with respect to tubes 2 and 22, and in this form they extend tangentially with respect to an imaginary cylinder the diameter of which is approximately one-half the diameter of tube 22.

During manufacture, tube 2 originally has its ends of the same diameter as its main body portion and tube 22 is of slightly smaller diameter than here appears; thus, fin construction 24 and tube 22 are readily positioned within tube 2. The two tubes and the fin construction then are held fixed and tube 22 is expanded to the diameter shown. This expanding is performed by drawing through the tube a cylindrical die of greater diameter than the original internal diameter of tube 22. Thus, tube 22 is expanded so that it continually presses outwardly against each fin portion, and expands the fin construction 24 with considerable force against the inner surface of tube 2. In this way an extremely rigid heat transfer assembly is provided within tube 2, and each of the fin portions is in good heat contacting relationship with tube 2 as well as with tube 22.

After the expanding of tube 22 the ends of tube 2 are reduced and tube 4, which has-been wound into a spiral in a mandril, is slippedinto place. The tube assembly thus formed is then positioned within amold and the block of aluminumis cast around it. The aluminumbonds to the entire embedded surfaces of tubes 2 and 4 and provides excellent heat transfer relationship between the aluminum and each of these tubes. As shown best in Figure 3, tube 4 is in intimate contact a with tube 2 and the aluminum fills into the cracks at the edges of tube 4 sufficiently to avoid any cavity. Block [4 not only provides for the even distribution and transfer of heat between tube '2 and tube'4, but the blockalso provides; a heat carry-over so that fluid is cooled evenly in one tube and heated evenly in another. tube without minor fluctuations in temperature in the one is a tendency for the entirewall of tube 2 tube maintained at substantially the same tempera-- ture.

The gas passing through tube 2 is-carried in assembly within said annular chamber and comprising sheet metal corrugations each of which is substantially straight and is non-distortable and extends longitudinally of said chamber bridging the space between said rigid members and is connected to the next adjacent corrugation by a trough-like connecting portion-whichpresents a straight portion-in contact with a surface of one of said members, the distance between said rigid cylindrical members being such that each of said trough-like connecting portions is distorted and each of said trough-like connecting portions is subjected-to substantial compressive forces which I tare applied at the inner and outer peripheries of the passageways between the fins of fin construe tion 24 as well as through tube 22, and'there'is" a minimum resistance to flow. Some of the heat from tube 2 is picked up directly by the refrigerant gas, but the major portion of the heat passes by conduction from tube 2 to the various fin portionswith this heat transfer being facilitated'by the excellent contact which is provided betweenttube' 2 and the corrugation ridgesor fin edges. An additional amount of heat passes from the fin portionsto the gas while the remainder-of: theyheat is transferred from the fin to tube22 and thence to the gas around and mainly withinthistube. I n

In this embodiment-tubes}, 4- and 22 and fin construction 24 are, of copper and the passageways for the refrigerant arefree of other materials such as solder andpthe like. to be. of: advantage in the adaptation of this invention to certain "uses. 7 r

As many possible embodiments may bemade of the mechanical features of the above invention This has proved and as the art" hereindescribed might be varied in variousparts; allwithoutdeparting from the scope of the invention; itzis'to be understood that all matter hereina-bove set forth, or shown in the accompanying drawings is to be interpreted as illustrative and not ina limiting sense.

Iclaim: 1

V 1". In: heat exchange: apparatus of: the type whereina fiuid'i's subjected'to a heatv transfer operation, the combina tion of, a pair of concentrically positioned rig-idmembers; defining a substantially annular chamber for the flow-of the fluid to be subjectedfto a heat'transfer operation, and anannular'rnetallic fin assembly within said chamber and comprising sheet metal corrugations each of which issubstantially straight and .tion which presentsastraight portion incontact V wima surface of one-of said membera the distance between said rigid members :b 'eing. such that each ofsaid trough-like: connecting portions is distorted and-each of saidtroughelike connecting portions issubj'ectedcto substantial compressive forces which are applied at the inner and: outer peripheries of said fin assembly by said. rigid members. 7

H -2. In heat exchangelapparatus of the; type wherein" a fluid, is subjected to aheat transfer operation, the'zcombination of, a .pair of hollow concentrically positioned rigid cylindrical .mem-

bers defininga; cylindrical central chamber; and

an annular chamber. both of which chambers are transfer operation, and an annular metallic fin for the flowof :flu-id-to. be" subjected to ,a hea-t said fin assembly by said rigid members.

wherein 'a' fl'uidis subjected to a heat transfer operation, the combination of, a pair of concentrically positioned rigid cylindrical members defining-a substantially annular chamber between the-cuter surface ofthe smaller of said members and the inner surface of the larger of said members, saidmembers providing for the flow through saidannular chamber of thefluid to be subjected to a heat transfer. operation, an annular metallic finassembly within said chamber and comprising sheet metal corrugations each of which is substantially rectangular and straight and is not distorted and extends longitudinally of said chamber bridging the space between said rigid members andis connected to the next adjacent oorrugation by a trough-like connecting portion Which3presents a straight portion'in contact with atsurface of one of said cylindrical members,

being such thatreach .of said trough-like connecting portions is, distortedand each of said trough-like connecting portions 'is subjected ,to substantial compressive'forces-which are applied at-the inner and outer peripheries of said fin assembly by said cylindrical members, and means exteriorly of the larger of sai'dcylindrical .members and providing a' passageway-fora second fluid and providing for the transfer of heat between fluid fl'oWing-through' said cylindrical members and said secondfluid. 1

4. Inheat exchange apparatus of the type wherein a fluid is subjected to a heat transfer operation, the combination of, a pair ofconcentrically positioned hollow rigid cylindrical members defining a substantially annular chamber between the outersurface of the smaller of said members and the inner surface of the larger of said members and a cylindrical passageway within the smaller of said memberssaid members providing for the flow through said annular chamber and said" cylindrical passageway of fluid to be subjected to'a heat transferoperation, an annular metallic fin assembly within said chamber and comprising sheet metal corruga= tio'ns. each of which isfsubstantially rectangular and straight and is j bt j distorted and extends longitudinally ofsaid'charfiber bridging the space between 'said rigid'inember's and is connected toji the nextadjacentcorrugation :bya trough like;v connecting portion which resents a straight portion in contactwith a surface ofone of said cylindrical iifeirlbers, the distance between said cylindrical members being such that each of said trough dike connecting: portions is distorted and each of said tro'ugh like connecting portions, is subjected =tosubstantial compressive forces which are applied atf the inner" anapu er peripheries of said fin assemblyby s ai d'cylind'ri cal members, and heat transfer means" in intimate contact with the outer surface of the larger of said cylindrical members and providing a. passageway for a second fluid and providing for the transfer of heat between fluid flowing through said cylindrical members and said second fluid.

5. In heat exchange apparatus of the type wherein a fluid is subjected to a heat transfer operation, the combination of, a pair of concentrically positioned rigid members defining a substantially annular chamber for the fiow of the fluid to be subjected to a. heat transfer operation, an annular metallic fin assembly within said chamber and comprising sheet metal corrugations each of which is substantially straight and is non-distortable and extends longitudinally of said chamber bridging the space between said rigid members and is connected to the next adjacent corrugation by a trough-like connecting portion which presents a straight portion in contact with a surface of one of said members, the distance between said rigid members being such that each of said trough-like connecting portions is distorted and each of said troughlike connecting portions is subjected to substantial compressive forces which are applied at the inner and outer peripheries of said fin assembly by said rigid members, a tube formed into a spiral and closely hugging the outer surface of the larger of said rigid members, and a block of aluminum substantially enclosing said larger rigid member and said tube.

6. Apparatus as described in claim 5 wherein said spiral tube is substantially oval in crosssection, and wherein said fin assembly is formed by a single sheet of corrugated metal.

7. Apparatus as described in claim 6 wherein said rigid members are sheet metal cylinders and the larger of said cylinders has its ends reduced in diameter and projecting from said block of a uminium.-

8. In heat exchange apparatus of the type wherein a fluid is subjected to a heat transfer operation, the combination of, a pair of concentrically positioned rigid members defining a substantially annular chamber for the flow of the fluid to be subjected to a heat transfer operation, and an annular metallic fin assembly within said chamber and comprising a sheet of metal formed into corrugations each of which is substantially rectangular and straight and is non-distortable and extends longitudinally of said chamber bridging the space between said rigid members, each of said corrugations being connected to the next adjacent corrugation by a trough-like connecting portion which presents a straight portion in contact with a surface of one of said members, the distance between said rigid members being such that each of said troughlike connecting portions is distorted from its original shape and each of said trough-like connecting portions is subjected to substantial compressive forces which are applied at the inner and outer peripheries of said fin assembly by said rigid members.

CECIL BOLING.

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

UNITED STATES PATENTS Number Name Date 660,292 Durr Oct. 23, 1900 1,270,198 Parkhurst June 18, 1918 1,584,772 Hyde May. 18, 1926 2,004,389 Jones June 11, 1935 2,206,826 Hopper July 2, 1940 2,324,395 Hoop July 13, 1943

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