US 3519070 A
Description (OCR text may contain errors)
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HEAT EXCHANGE UNIT Filed June 14, 1968 .Z J iVENTOR Char/es TBapp/er ymagw ATTORNEY United States Patent 3,519,070 HEAT EXCHANGE UNIT Charles T. Bappler, Menlo Park, Edison, N.J., assignor to Coolenheat, Inc., Linden, N.J., a corporation of New Jersey Filed June 14, 1968, Ser. No. 746,720 Int. Cl. F28f l /36 U.S. Cl. 165-184 2 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a heat exchange unit comprising a tube for carrying fluid therethrough with a helical fin strip wrapped therearound with the inner edge or circumference of the thin strip being provided with undulations so as to contact the outer surface of the tube upon which it is disposed over its entire length to provide a maximum path of heat transfer into or out of the fin strip. The unit further is provided with its helical circumferential portion disposed away from the tube provided with a plurality of means to spread the distribution of the fluid carried in the tube to adjacent surfaces or other tubes having fin strips thereon.
The present invention relates to a heat exchanger unit and more particularly to a unit in which a fluid is passed through a tube and another fluid is passed around the exterior of the tube so that a heat exchange transfer takes place. The tubes may have a cooler fluid passed therethrough, such as a gas or a liquid, and another gas may be passed in heat exchange relationship around the exterior of the tube so that the gas flowing around the outside of the tubes is cool. On the other hand, the heat transfer may be in reverse wherein the hot gas or a hot liquid flows through the interior of the tube and the gas or air being passed around the exterior of the tubes is heated thereby.
In such an arrangement, in order to increase the efliciency of the heat transfer from the fluid passing through the tube and the air or the fluid passing around the exterior of the tube, the tube, or the entire heat exchanger, which generally comprises a plurality of rows of tubes, is provided with extended surface area. The extended surface area may comprise a form of helical fin or continuous strip of material that can be wound around the tube.
It is an object of the present invention to provide a heat exchange unit in which the tubing is provided with an extended surface wrapped therearound and in contact with the outer surface of the tube so as to provide a maximum amount of contact area between the tube and the fin provides a maximum path of heat transfer into or out of the fin.
It is an object of the present invention to further provide a continuous strip of fin that is wrapped around a heat transfer tube having an inner circumferential portion comprising a continuous zig-zag edge in contact with the outer surface of the tube to form a path of heat transfer into or out of the fin.
It is yet another object of the present invention to provide a helical fin tube in which the inner surface of the fin tube is crimped or deformed to provide a serrated configuration that is in contact along its entire edge with the outer surface of the tube.
It is yet another object of the present invention to provide a helical fin for a tube in which the outer circumferential portion of the helical fin is provided with means for dividing or separating the outer circumferential portion into a plurality of segments or individual portions so that the individual segments can spread the distribution of the fluid across the outer edge of the fin and so carry 3,519,070 Patented July 7, 1970 the fluid more evenly to the next adjacent row of finned tubes directly adjacent the first tube or first row of tubes.
It is yet another object of the present invention to provide a helical fin strip for winding around a tube in which the outer circumferential portion of the fin is in segmented form that permits the fin strip to be easily wound around the tube.
It is yet another object of the present invention to provide a helical finned tube in which a helical continuous fin strip having crimped alternating undulations adjacent the inner circumferential portion thereof provide a maximum path of heat transfer from the tube to the fin and which tube is further provided with means adjacent the outer circumferential portion of the fin strip for a more uniform and wider distribution of the fluid across the bottom edge of the fin strip so as to carry the fluid more evenly down to a row of fin tubes disposed directly below a first row of fin tubes.
It is yet another object of the present invention to provide a fin tube with a continuous helical fin wrapped therearound and having a crimped inner circumferential portion so as to supply more total surface with the same number of fins per inch and more fin edge in contact with the tube for better total heat transfer which will permit, for example, the use of four rows of finned tubes per unit, instead of the conventional requirement of six rows per unit.
It is still another object of the present invention to provide a novel fin tube which has a more exposed surface totally per lineal foot, all dimensions of tube and fin and fin spacing being equal, and more cross-sectional area of fin in contact with the tube for greater heat transfer.
It is yet another object of the present invention to provide a fin tube having an extended surface thereon which provides approximately forty percent more total exposed surface per lineal foot of finned tube, without the disadvantage of having less spread-out distribution of the fluids from one row to the row below, as in a conventional crimped fin.
Varius other objects and advantages of the present invention will be readily apparent from the following detailed description when considered in connection with the accompanying drawing forming a part thereof and in which:
FIG. 1 is a perspective view illustrating the fin tube embodied in the present invention;
FIG. 2. is a cross-section taken along the lines 22 of FIG. 1;
FIG. 3 is an enlarged section taken along the lines 33 of FIG. 2;
FIG. 4 is a view illustrating the distribution of fluids fro mone row to the row below when utilizing the finned configuration of the present invention; and
FIG. 5 illustrates the fluid distribution of a conventional fin tube not having the configuration of the present invention.
Referring to the drawing, the reference numeral 10 generally designates a tubular member or tube through which is passed a fluid such as liquid or gas so as to cause a heat transfer or heat exchange relationship to occur between the fiuid passing through the tube and fluid passing around the exterior of the tube. The tubes are generally disposed in rows and spaced one above the other so as to form a heat exchange unit.
Each tube is provided with a winding or continuous coil of extended surface material generally designated 12 there around. The extended surface material comprises a helical winding so as to form a helical fin or strip consisting of a series of individual turns 14 spaced closely adjacent each other to provide a heat transfer surface. The inner periphery or circumference of the turns are 3 crimped together so as to form a series of undulations or alternate substantially U-shaped configurations 18, as best seen in FIG. 3. The helical fin 12 has generally parallel outer and inner edges and 22, respectively. The inner circumferential portion of the helical fin strip is pressed against the outer surface of the tube so that the entire edge of the continuous strip is in contact with the tube. Thus, the cross-sectional area of the fin edge 22 in contact with the tube is the thickness of the fin times the outside circumference of the fin, not the tube, and the path of heat transfer into or out of the fin is substantially more than with a plurality of individual extended surface fins disposed on a tube.
It will be noted that the helical fin consists of a flat or coplanar middle and outer circumferential portions 24 the latter having a plurality of individual spaced apart sections 26. These sections or segments 26, as illustrated in the drawing, are provided by V-shaped slots 28 made in the outer portion of the fin strip.
If desired, a bonding material may :be applied between the inner edge 22 of the fin strip and the outer surface of the tube surface, by any well known means, so that there is substantially one hundred percent contact between the edge of the helical fin strip and the surface of the tube, should there be any high or low spots in the outer surface of the tube or the inner edge of the helical strip. If desired, the V-shaped slots 28 can be substantially radially cut so as to divide the outer circumferential portion 24 of the fin strip into spaced individual sections in order have a spread-out distribution of the fluids from one row to a next adjacent row of finned tubes.
Referring to FIG. 4, it will be seen that there are a series of dotted lines indicating the advantage of the individual plurality of segments or sections adjacent the outer circumferential portion of the continuous helical fin strip with the dotted lines illustrating the spread-out distribution of the fluids from one row to the row below Referring to FIG. 5, the dotted rows of lines therein indicate the converging distribution of the fluids from one row to another row of fin tubes where the spaced or individual outer circumferential sections are not provided in a finned tube.
Thus, from the foregoing description, it is apparent that the finned tube configuration or construction of the present invention provides a helically wound fin strip of extended surface area around a tube for use in a heat exchanger or heat transfer relationship in which the inner circumferential portion of the helical strip is provided with a plurality of undulations that are disposed to have substantially complete contact with the outer surface of a tube so as to provide a maximum path of heat transfer into or out of the fin, while the outer circumferential portion of the helically wound fin strip is provided with means therein dividing the outer circumferential portion into a plurality of individual sections so as to provide a maximum spread-out distribution of the fluids from one fin tube or row of fin tubes to another row of fin tubes below it.
Inasmuch as various changes may be made in the form, location and relative arrangement of the several parts without departing from the essential characteristics of the invention, and it is to be understood that this invention is not to be limited, except by the scope of the appended claims.
What is claimed is:
l. A heat transfer unit comprising a tubular member having a continuous extended surface member helically wound thereon, said extended surface member comprising parallel outer and inner circumferential portions and a middle portion, said inner circumferential portion having its entire inner edge formed of alternate U-shaped crimped undulations, bonding material disposed on said inner circumferential portion and the outer surface of said tubular member to provide substantially one hundred percent contact between said surfaces to compensate for high and low spots in said tubular member, said middle portion extending substantially perpendicular to said tubular member and its entire area being disposed in the same plane, said outer circumferential portion being coplanar with said middle portion and having circumferentially spaced cutout portion in its outer edge dividing it into individual segments to provide spread out distribution of fluid heat transfer from one tubular member to another.
2. The unit of claim 1 wherein said slots are of V-shape.
References Cited UNITED STATES PATENTS 1,689,568 10/1928 Wade 29-157.3
2,117,445 5/ 1938 Niemchek -184 2,529,545 11/1950 Edwards 165184 FOREIGN PATENTS 1,006,374 9/1965 Great Britain.
ROBERT A. OLEARY, Primary Examiner T. W. STREULE, Assistant Examiner US. Cl. X.R. 2 9-157.3