US 3537516 A
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United States Patent  Inventor Charles 0. Kunz East Alton, Illinois 2: Appl. No. 741,982
 Filed July 2,1968 [4-5] Patented Nov. 3, 1970  Assignee Olin Corporation a corporation of Virginia  COMPACT HEAT EXCHANGE COMPONENT 6 Claims, 8 Drawing Figs.
 11.8. C1. 165/181, 29/1573  int. Cl; F281 1/14  Field of Search 165/181(MF), 181(1F), 181
v  References Cited UNITED STATES PATENTS 3,206,838 9/1965 Pauls 165/181X hi I, l ll 1 l. I I i 2,868,515 1/1959 Garland 165/150 3,294,162 12/1966 Loeh1einetal.... 165/181 3,343,596 9/1967 Kritzer 165/183X 3,151,670 10/1964 Kritzer 165/181X 3,360,040 12/1967 Kritzer 165/181 3,404,446 10/1968 Kritzer 165/18l-X ABSTRACT: A heat exchange component is provided which is made of at least two sheets of metal joined together at ap propriate portions thereof to define a cavity through which a cooling medium is passed. Edgeportions of the sheets, however, are not joined and are bent apart and twisted in a manner to obtain optimum surface area for a given volume into which such a heat exchanger would be placed.
Patented Nov. 3, 1970 Shut 1 012 Ow MU k mM H m m ATTORNEY Patented Nov. 3, 1970 3,537,516
Sheet 2 M2 1 lA/Hlllllllllllllllllf &1111111111111111111111 ja/ 111111 111/1 1 T 1111111)11111f INVENTOR CHARLES 0 KUNZ ATTOR EY COMPACT HEAT EXCHANGE COMPONENT As described in application Ser. No. 630,376, filed Apr. 12, 1967, now abandoned, assigned to the same assignee as the present invention, heat exchange components and a method of forming heat exchange components are described in which at least two sheets of material are bonded together at appropriate portions thereof, so as to define at least one cavity through which a heat exchange medium is passed. However, the edge portions are not bonded together; rather, the edge portions are bent apart to define heat exchange fin area. For example, a heat exchange medium to be cooled may be passed over the fins and because of the large surface area presented by the fin area, very effective heat exchange is achieved between the fluid passing over the fins and a heat exchange medium passing through the conduit.
While heat exchangers of this type have been found to be very effective for many applications, where the space for a heat exchanger must be kept to a minimum, the problem is presented of how to utilize the fin area resulting from bending the edge portions of the sheet apart so as to obtain the most efficient use of a given volume available for heat exchange.
It is, therefore, an object of the present invention to obtain maximum heat exchange for a given volume available for heat exchange.
It is another object of the present invention to provide the maximum amount of fin surface area for a given volume available for heat exchange.
It is another object of the present invention to provide a heat exchanger in which very effective heat exchange is achieved between a heat exchange medium passing over the fin area and a cooling medium passing through at least one conduit which is integral with said fin area.
Other objects .will appear from the following description and drawings, in which:
FIG. 1 is a top view showing a stop-weld pattern which may be applied to one of the sheets to be used in forming the heat exchanger of the present invention;
FIG. 2 is a top view of a partially completed heat exchanger which shows the edge portion fin area cut to define fin area;
FIG. 3 is a perspective view of a portion of a heat exchanger according to the present invention with the individual fins being bent and twistedso as to minimize the space required for a given amount of heat exchange;
FIG. 3A is a modification of FIG. 3;
FIG. 4 is a perspective view of a helically wound heat exchanger according to the present invention;
FIG. 5 is a top view of a helically wound heat exchanger according to the present invention;
FIG. 6 is a side view of a heat exchanger according to the present invention which has been wound in a serpentine shape and tiered; and
FIG. 7 is a bottom view of a heat exchanger according to the present invention which has been wound in the form of a serpentine and tiered.
The heat exchanger of the present invention is shown most clearly in FIG. 3. A heat exchanger 10 having a conduit portion is provided between bonded areas 30 and 31.
Individual fins 40 are provided. The fins 40 are integral with the bonded areas 30 and 31. The fins 40 comprise an edge portion 41 which is relatively flat and is generally perpendicular to a plane passing through bonded portions 30 and 31. The fins also have a base portion 42 which is integral with either bonded portion 30 or 31. At the base portion, the fins have been bent approximately 90, apart with respect to the plane passing trough bonded portions 30 and 31. Additionally, the fins have been twisted approximately 90. Thus, the fin edge portion 41 is perpendicular to a plane passing through the base portions 30 and 31.
It will thus be apparent that not only are the individual fins 40 each bent in opposite directions from each other approximately 180, but also they are also rotated or twisted 90 so that the faces of edge portions 41 are transverse with respect to the longitudinal axis of the heat exchanger.
The heat exchanger 10, as shown in FIG. 3, contains two parallel portions 50 and 60 joined to each other and integral 5 with a bend portion 70. In the bend portion 70, it will be apparent that fin members 71 and 72 on the outside of the bend section are at a greater distance from each other than are the fins 42 and 43 in the parallel portion. Additionally, the angle between the fin members 71 and 72, as defined by a plane passing through each of them in a vertical direction, is acute whereas planes passing through the fins 42 and 43 would appear to never meet, i.e., fins 42 and 43 are approximately parallel.
Furthermore, on the inside of the bend section 70, the fins, for example, 73 and 74, appear to be bent towards each other and would have an acute angle approximately defined by a plane passing through each of the fins 73 and 74. The planes would appear to approximately meet at a center point 75, located approximately halfway between portions 50 and 60.
In another embodiment of the present invention, shown in FIG. 3A, a heat exchanger 100 is shown. As was the case in FIG. 3, a center conduit 200 is provided, together with bonded portions 300 and 310. Furthermore, fins 400 are provided. As was the case in FIG. 3, the edge portion 410 of the fins are transverse to the longitudinal axis of the heat exchanger. The embodiment in FIG. 3A differs from that in FIG. 3 in that the fins 400 are bent more than 180 apart. Thus, there is an angle of greater than between a plane passing through the bonded portions 300 and 310 and the fins 400. As was the case in FIG. 3, the fins are twisted at the base portion 420 so that the edge portions 410 are transverse to the longitudinal axis of the heat exchanger. This embodiment utilizes even less space than the embodiment in FIG. 3. By careful assembly, even more fin area can be obtained for a given volume with the embodiment in FIG. 3A than can be attained in the embodiment in FIG. 3.
One exemplary method of making a heat exchanger according to the present invention is to apply to one sheet of material 100, a pattern of stop-weld material 101. This stop-weld pattern may comprise a center portion 103 throughout the entire length of the strip. If desired, the end portions of the center strip 104 and 105 may be somewhat wider than the remainder of the strip so that a somewhat larger opening is provided at the ends for inflation and attachment of equipment used to circulate a heat exchanger through the center passageway.
The pattern may also comprise edge portions 106 and 107. These portions operate to avoid bonding so that the fins 40 can be provided. It will thus be apparent that two bonding strips 108 and 109 remain which contain no stop-weld pattern.
The pattern of stop-weld material may be provided by numerous methods known to those skilled in the art. For example, the well-known silk screen process may be utilized. Likewise, the process covered in Keith application, Ser. No. 723,055 may be utilized in which a stop-weld pattern is applied over the entire first sheet and then a portion is removed, for example, by milling, to define those portions where bonding is to take place.
Thus, when the second sheet is placed upon the sheet and the sheets are bonded together by appropriate steps, bonding will take place only in the portions 108 and 109. This bonding may be either cold bonding or hot bonding as described in Ser. No. 630,376 now abandoned and in Ser. No. 723,055.
After the bonding operation, the strip 1 is cut into a plurality of sections 2, 3, 4, 5, etc. The inward length of the cut in FIG. 2 is made to include the nonbonded edge portions. It will be apparent from FIG. 3 that for each of the cut elements, 2 and 3 in FIG. 2, two opposite fins from each result, or a total of four.
The strip may be inflated either before or'after the fins are bent and twisted. In any case, a center passageway 6 is provided which may have enlarged openings 7 and 8 at the ends thereof, provided by way of a stop-weld pattern and after inflation, inlet and outlet conduit passageways will result.
After the cutting operation, the sections 2 and 3 are bent. As mentioned previously, this bending involves separating the two sheets and bending them approximately 180 with respect to each other and approximately 90 with respect to a plane passing through the bonded portions. The sheets are also twisted 90. While separate operations may be provided for the bending and twisting, in the preferred embodiment of the present invention, the bending and twisting is done simultaneously.
If the heat exchanger has not yet been inflated, the next step of the process is to inflate it to define the passageway 20. An inflation needle and fluid pressure is all that is necessary for the inflation operation, as is now well known in the art.
The heat exchanger can then be bent into various appropriate shapes.
According to one embodiment of the present invention, the 7 heat exchanger may be bent into a helix, as shown in FIGS. 4 and 5. Thus, the heat exchanger shown in FIG. 4 has a center conduit 220 through which a heat exchange medium is passed. Bonded areas 230 and 231 are provided. Integral therewith, bent and twisted fins 241, 242, 243 and 244 (indicated schematically) are provided, as described in regard to FIG. 3. The top of the helix is shown in FIG. 5, and an end portion 270 is provided similar to that in FIG. 3. However, it is apparent that at one point thereof, 250, the heat exchanger moves downwardly and another bend portion 280 is encountered. Another bend portion 290 would be found at the opposite end and so forth. It will be apparent that a heat exchanger of this type will occupy very little space as far as the vertical dimension is concerned. Each layer will occupy no more height than the combined height of the passageway 220 and bonded portions 230 and 231. Thus, no additional volume is occupied by fins. Connections of an appropriate nature are provided at either end of the heat exchanger for the passage of a fluid, generally a liquid cooling medium, through conduit portion 220.
Another embodiment of the present invention is shown in FIGS. 6 and 7. In this case, the heat exchanger having a center conduit 320 is wound into a serpentine shape having legs 301, 302 and 303. This results in end portions 370. As indicated schematically, there is provided, as described previously, fins 341, 342, 343 and 344. If desired, a second row may be provided. Ifa second row is provided, as shown in FIG. 7, the leg 304 moves downwardly and then the heat exchanger is wound again in a serpentine manner. Thus, end 37E, shown in FIG. 6 is the end portion of the second tier. Likewise, end portion 372 is from the second tier. This two-tiered serpentine structure again is effective in keeping the volume required to house the heat exchanger at a minimum. Furthermore, by using two tiers, there is a high concentration of fins, so that'effective heat exchange is obtained between a fluid passing through the fins and a cooling medium passing through passageway 320.
Other geometrical shapes which take advantage of the dimensional reduction provided by the present invention will be apparent to those skilled in the art. For example, the additional shapes shown in FIG. 9-l3 of Ser. No. 630,376 now abandoned, may be utilized, as well as many others.
It is to be understood that the invention is not limited to-the illustrations described and shown herein which are deemed to be merely illustrative of the best modes of carrying out the invention, and which are susceptible of modifications of form, size, arrangement of parts, and detail of operation, but rather is intended to encompass all such modifications which are within the spirit and scope of the invention as set forth in the appended claims.
1. A heat exchanger comprising: two sheets of metal, each of which cooperate to completely define at least one tubular passageway; edge portions defined by the same two sheets of metal which define said tubular passageway, said edge portions being on opposite sides of said tubular passageway and being separated from said tubular passageway by a bonded portion extending coextensively with said edge portions and said tubular assageway in which said sheets of metalare bonded toget er; said sheets in each of said edge portions being bent apart greater than with respect to each other to provide efficient heat exchange surface; said bent apart sheets in said edge portion being formed into fins, said fins being transverse to the longitudinal axis of said heat exchanger, said fins being twisted approximately 90 and being parallel throughout at least a substantial portion of said heat exchanger; whereby said fins are in heat exchange relationship with said tubular passageway, the heat exchange between said tubular passageway and said fins taking place substantially through the said two sheets of metal which define said tubular passageway.
2. A heat exchanger according to claim l in which planes passing through said fins define acute angles at outer bend portions of said heat exchanger.
3. A heat exchanger according to claim l in which at the inner edge bend portions, said fins point toward each other.
4. A heat exchanger according to claim 1 which is wound into a helix.
5. A heat exchanger according to claim 1 which is wound into a serpentine.
6. A heat exchanger comprising two sheets of metal, each of which cooperate to completely define at least one tubular passageway; edge portions defined by the same two sheets of metal which define said tubular passageway, said edge portions being on opposite sides of said tubular passageway and being separated from said tubular passageway by a bonded portion extending coextensively with said edge portions and said tubular passageway in which said sheets of metal are bonded together; said sheets in each of said edge portions being bent apart at least about with respect to each other to provide efficient hcat exchange surface; said bent apart sheets in said edge portions .being formed into fins, said fins being transverse to the longitudinal axis of said heat exchanger; said fins being twisted approximately 90 and said fins being parallel throughout at least a substantial portion of said heat exchanger; said heat exchanger being wound into a serpentine structure comprising a first row having a serpentine configuration and at least an adjacent second row having a serpentine configuration, wherein said first and said at least second row are integrally connected, whereby the fins are in heat exchange relation with said tubular passageway, the heat exchange between said tubular passageway andsaid fins taking place substantially through the said two sheets of metal which define said tubular passageway.