US2795114A - Heat exchange devices - Google Patents

Description

June 11, 1957 I Filed Dec. 3, 1953 H. W. KLEIST HEAT EXCHANGE DEVICES 2 Sheets-Sheet l 2 Sheets-Sheet 2 June 11, 1957 w,

HEAT EXCHANGE DEVICES Filed Dec. 3, 1953 .In wen Zar y 6 Jlrman nrjaezzsz by .300???" X arzer' flflorneys Patented June 1 l 1 957 HEAT EXCHANGE DEVICES Herman W. Kleist, Hollywood, Ill., assignor to Dole Refrigerating Company, Chicago, 111., a corporation of Illinois Application December 3, 1953, Serial No. 395,866

2 Claims. (Cl. 62-4) This invention relates to an improvement in heat exchange devices, and has for one purpose to provide an improved eutectic heat exchange element in which a body of eutectic serves as a storage means for, in effect, storing cold.

Another purpose is to provide such a unit which can be used singly, or in multiple, in ducts or passages in which air or some other fluid is cooled.

Another purpose is to provide an improved, simple and efficient finned structure or plate in which a body of eutectic, or its surrounding housing or casing, is in heat exchange relation with a duct through which a refrigerant fluid can be cycled or circulated.

Another purpose is to provide a cooling or heat exchange system in which a refrigerant is cycled or circulated through one or more heat exchange units, each such unit having an eutectic which can be cooled or frozen by the intermittent or periodic circulation or cycling of a refrigerant.

Another purpose is to provide such a unit which is well adapted for use in systems in which a volatile refrigerant is cycled.

Another purpose is to provide improved control means for such a system.

Other purposes will appear from time to time in the course of the specification and claims.

I illustrate my invention more or less diagrammatically in the accompanying drawings, wherein:

Figure l is a side elevation of a finned eutectic unit, with parts broken away and parts in vertical section;

Figure 2 is a section on the line 2-2 of Figure 1;

Figure 3 is a perspective view of a variant form of unit;

Figure 4 is a section, on an enlarged scale, on the line 44 of Figure 3;

Figure 5 is a vertical section, on a reduced scale, illustrating a duct with a plurality of units therein; and

Figure 6 is a schematic or diagrammatic showing of the system of Figure 5.

Like parts are indicated by like symbols throughout the specification and drawings.

Considering, first, the form of Figure 1, 1 illustrates the inlet end, and 2 the outlet end, of a duct 3, which is adapted to be connected to any suitable means for circulating a fluid refrigerant, for example, a volatile refrigerant. 4 generally indicates a housing, preferably of Sheet metal, surrounding the duct 3. It may be of any suitable shape, but I illustrate it as generally square in cross-section and having connecting side walls 5, 6, 7 and 8, with end walls 9 and 10. In the particular form herein shown, the ends 1 and 2 of the duct 3 pass through the end walls. Within the housing thus formed I position a body of a suitable eutectic, indicated at 11, which somewhat incompletely fills the space within the housing 4. I find it advantageous to leave sufficient space so that when the eutectic is frozen by the passage of a suitable refrigerant through the duct 3 its bulk is not so far increased as to rupture or deform the housing or container 4. I also find it preferable to have the duct 3 in a lower part of the interior of the container or housing 4, as clearly shown in Figure 2, and to have it at all times completelyimrnersed'in or surrounded by the body of eutectic. The tube may abut the bottom wall 5 of the container or housing, or, if desired, it may be positioned somewhat above the bottom, to increase to a maximum the. area of its heat exchange with the eutectic body. On'the other hand, under some circumstances, it may be advantageous to have the duct 3 contact one Wall of the container 4, thereby to cool the outer sheet metal housing and to subject the eutectic to a freezing temperature from a maximum heat exchange surface.

Surrounding the housing or container 4, I illustrate a plurality of fins 12. These fins may be of any convenient size and shape, but I illustrate them as rectangular, and, in Figure 2, as generally square, and apertured generally centrally toreceive the exterior of the housing 4. The central apertures may be punched, if desired, and it may be advantageous to have ears 12a in contact with the exterior surfaces of the housing or container 4. I find it advantageous to have the fins 12 lie in parallel planes. It is a convenience in manufacture andin use, but not a necessity, to have the planes of the fins generally at right angles to the walls of the eutectic container 4.

In Figures 3 and 4, I illustrate a variant form in which a separate lower housing 13 is partly filled with an eutectic mass 14, and engages an exterior wall of a duct 15, having an inlet connection 15a and a suitable outlet connection to permit it to be connected in any suitable system for circulating a suitable refrigerant. Fins 16 are shown with contacting ears 16a, the fins being in heat exchange relation both with the bottom container 13 and with the duct 15. In other words, the duct through which the refrigerant passes, instead of being immersed in the eutectic, as in the form of Figures 1 and 2, abuts a side or face of a separate container in which the eutectic is contained.

I illustrate, in Figure 5, a convenient and efficient application of my unit to cooling fluids, for example, air or other gases. In Figure 5, I illustrate a duct 20 having an inlet end 21and an outlet end 22. Air or any other gas may be suitably passed therethrough, by natural draft or by any suitable forced circulation, the details of which do not form part of the present invention. Within the duct 20 I illustrate, as an example, three of my units, as shown in Figures 1 and 2. The units are shown with their fins 12 arranged in parallelism with the axis of the duct, and in contact with opposite walls 20a and 20b of the duct. Thus, each adjacent pair-of fins 12 defines a passage through which the air or gas being cooled can easily flow. The gas or air flows about the Walls of the container 4. Assuming that the eutectic has been frozen by suitable passage of a refrigerant therethrough, the eutectic serves as a stand-by or storage body, effective to continue the cooling operation through intervals of nonoperation of whatever cycling structure is employed. In other words, the frozen eutectic provides a stand-by and maintains an even cooling effect, and the refrigerant need be cycled or circulated only with suficient frequency to maintain an adequate freezing of the eutectic.

Whereas I do not wish to be limited to any specific means for freezing the eutectic, I illustrate diagrammatically, in Figure 6, a compressor 30, driven by any suitable motor 31. An inlet duct 32 delivers evaporated refrigerant to the compressor, and the compressed refrigerant is delivered along a suitable duct 33 to any suitable condenser 34, where the compressed refrigerant is reduced to liquid form. The liquid may be received in a suitable collector 35 for delivery in liquid form along the duct 36. I illustrate my three units in Figure 5 as arranged in series, and the same units are indicated diagrammatically parallel. Since the details may vary from installation .to i

installation, I do not illustrate them further herein.

I may employ any suitable control means, and I illustrate, for example, a thermostatic element .40 responsive to the temperature of the air or gas adjacent the outlet 22, said element being suitably connected .to the motor 31 which drives the compressor. Thus the compressor may be caused to stop or start its cycling of the volatile refrigerant in response to variationsin temperature to which the thermostatic element 40 is subjected. It willbe understood, of course,.that individual control may be employed for individual elements, or.any other suitable control system may be employed; However, I find it.

practical to control the compressor, and to cut it on and off, in response to the temperature of the air passing from beyond the last unit. It will be understood, of course, that having the bodies of eutectic in the individual elements greatly simplifies the control problem, and makes it much less critical.

It will be realized that, whereas, I have described and illustrated a practical and operative device, nevertheless many changes may be made in the size, shape, number and disposition of parts without departing from the spirit of my invention. I therefore wish mydescription and drawings to be taken as, in a broad sense illustrative or diagrammatic, rather than as limiting me to my precise showing. I also wish it understood that, :whereas I have talked in terms of refrigeration, my units may be applied to any heat exchange problem, and, under some circumstances, maybe used in heating.

It should also be kept in mind that the arrangement of fins may be widely varied. However, it is desirable that the fins lie in parallel planes perpendicular ttotheaxis of the refrigerating duct 3, when a multiple arrangement is employed, as in Figure 5. The fins 12 then may substantially abut and divide the duct 20 into a group .of parallel inter-fin ducts through which a plurality of parallel streams of air pass from the inlet 21 to the outlet 22 of the duct 20. It is a matter of choice whether natural draft is employed, or forced draft. It has been thought unnecessary to show any particular means formoving air, since a variety of fans, blowers, or air-driving means ,may be employed. Itwill also be understood that I may rather widely varythe form or cross-section of the housings or containers 4. However, I find itadvantageous to employ square or rectangular containers, to increase the linear length of the heat transfer contact between the walls of such containers and the opposed edges or flanges of the fins 12. It is important that the container be so shaped that it will not readily be ruptured by the expansion of the eutectic caused by the freezing of the eutectic. I find that a square or rectangular form is practical in this respect, when partially but not completely filled with the eutectic.

It will be understood that any suitable means may be employed for positioning the eutectic within the plate. I

illustrate, for example, filler apertures 25 and screwthreaded removable filler plugs 26.

I claim:

1. In a heat exchange structure for cooling air and the like, an air duct, a plurality of finned eutectic heat exchange structures arranged in said duct, each such heat exchange structure having a longitudinally extending housing having walls providing an elongated gas-tight container, a refrigerant duct extending longitudinally through said container having an inlet and an outlet adapted for connection in a system for circulating a fluid refrigerant, and a plurality of parallel free-edged fins lying in planes transverse to the longitudinal extension of the housing and in heat transfer relation with the walls of the housing, whereby the fins are positioned in eifective heat exchange relation with the eutectic within the housing, the fins of adjacent heat exchange structures being generally aligned to provide communicating spaces extending along the axis of the air duct, means for cycling a volatile refrigerant through refrigerant ducts of the heat exchange structures, said .means including a compressor and a condenser, and means responsive to the temperature of air flowing through the air duct and beyond said eutectic heat exchange structures, for controlling the operation of the compressor.

2. The structure of claim 1 characterized in that the gas-tight container is rectangular in transverse cross-see tion, the free edged fins having rectangular apertures through which said rectangular container extends, said fins lying in generally parallel planes.

References Cited in the file of this patent UNITED STATES PATENTS 1,701,617 Hyde Feb. 12, 1929 1,855,989 Rowledge Apr. 26, 1932 1,926,719 Gibbs et al Sept. 12, 1933 2,063,646 Whitesel Dec. 8, 1936 2,137,555 Young Nov. 22, 1938 2,163,599 Houdry June 27, 1939 2,227,686 Wittrnann Jan. 7, 1941 2,241,411 McGuifey May 13, 1941 2,400,334 Berry May 14, 1946 2,499,736 Kleen Mar. 7, 1950 2,607,201 Kleist Aug. 19, 1952 2,632,315 Coblentz Mar. 24, 1953 2,644,317 Haywood July 7, 1953

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