US 2948515 A
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Description (OCR text may contain errors)
Aug. 9, 1960 Filed April 1, 1957 J. R. MEHALICK EI'AL HEAT TRANSFER DEVICE 2 Sheets-Sheet 1 INVEN J. RIC RD ME CK. EDWA R. IZ
Aug. 9, 1960 -R HALl cK EI'AL 2,948,515 I HEATPTRANSFER DEVICE Filed April 1, 1957- 2 Sheets-Sheet 2 INVENTOR. J. RICHARD MEHALICK. BY EDWARD R. IZZO.
' to flow over a coil in two different directions.
HEAT TRANSFER DEVICE John Richard Mehalick, Fayetteville, and Edward R. Izzo,
De Witt, N.Y., assignors to Carrier Corporation, Syracuse, N.Y., a corporation .of Delaware Filed Apr. 1, 1957, Ser. No. 650,042
1 Claim. (Cl. 257-137) This invention relates to heat transfer devices. More specifically this invention relates to a heat transfer device including tubular means having an extended surface construction such as a plurality of fins assembled thereabout.
Heat transfer devices or assemblies of the type described are widely used in fields where a transfer of heat between a first medium flowing in the confined path within the tube or coil and a second medium flowing over the surface of the assembly is desired. This invention contemplates a heat transfer device wherein the extended surface is in the form of a series of spaced platesfa'ssembled. about the surface of the tube. Assemblies of this type are known generally as plate fin coils. 'Under'some circumstances it is desirable that two separate paths of air flowing over the coil be provided. Likewise it is often desirable to cause one path ofTiali r 1s invention involves a plate fin coil construction wherein the plate fins are formed so that when assembled about the coil, a barrier or partition is formed to define two separate and distinct portions of the coils so that either of the air flow paths mentioned above may be obtained.
A chief object of this invention is the provision of a heat transfer device of the type under consideration that may be employed under circumstances where it is desired that there be two or more separate paths across the face of the device for the flow of a medium such as air, or that there be flow paths for several media over the same heat transfer device.
Another object is the provision of an improved heat transfer device wherein more efficient transfer of heat between a medium flowing within the device and a medium flowing over the surface of the device may be obtained.
Other objects and advantages of the invention will be apparent from a consideration of the invention as described in the ensuing specifications and drawings, in which Figure l is'a front view of a heat transfer coil forming the subject of this invention;
Figure 2 is a side view of one of the plate fins illustrated in Figure 1;
Figure 3 is a front view of another of the fins illustrated in Figure 2;
Figure 4 is a side view of the fin illustrated in Figure 3;
Figure 5 is a front view of another of the fins illustrated in Figure 1; and
Figure 6 is a partial perspective view of an air conditioning unit of the room cooler type having assembled therein a heat transfer coil forming the subject of this invention.
In utilizing heat transfer coils of the kind described in air conditioning units of the room cooler type it is often desirable that the flow of air to be conditioned by the unit enters through the lower portion of the heat transfer coil functioning as the evaporator, and is discharged through the upper portion of the coil. In the 2 interest of obtaining eificient operation of the unit, it is necessary that the-two air streams described above be segregated by a wall or partition member. Heretofore it has been proposed that the coil be provided with a separate member serving as the wall. This entails cutting the plate fins intermediate their ends.
' This invention contemplates a heat transfer coil of the type described wherein the extended surface normally associated with such coil is formed so that portions thereof cooperate to provide the wall or barrier member for separating two parts or portions of the air stream.
Referring to Figure 1 it will be noted that there is disclosed a heat transfer device or coil 10 of a conventional type 'includinghorizontal sections of tubing 11, having a plurality ofreturn bends 11a connecting them to form a continuous tubular member, having an inlet end 12, and an outlet end 13, arranged to form a serpentine configurations In a refrigeration system of the type employed in conventional-room coolers, refrigerant in one phase is supplied to the device 10 through the inlet 12 of the tubular construction. 1 The refrigerant changes phase in the device as air at a; temperature different from the temperature of the refrigerant flows over the member and flows therefrom through outlet 13.
Assembled about the outer surface of the device 10 is a series of substantially rectangular shaped plates or fins having a relatively small dimension inadirection longitudinal-of thetube. :In the illustrated: embodiment ofthe inventiondhese plates are indicatedat 14. and 15. Openings 16 are provided in the plates to'accom modate successive runs of the tubing 11. To complete the coil assembly, tube sheets 19 and 20 are provided at the opposed sides of the device as shown in Figure 1. In accordance with one feature of this invention the plates or fins 14 are provided with a protuberance 17 formed by upsetting a portion of the fin from its plane. The protuberance 17 extends substantially transversely of the fin as indicated in Figure 2, extending from a first notch 60 in one edge of the plate to a second notch 61 in the opposed edge. The plates 15 are likewise provided with a protuberance 18 of the type described above in conjunction with the description of fin 14 as well as with notches 60 and 61. It will be noted, however, that the protuberance 18 extends a slightly greater distance from the top edge of the plate 15 than the pro-v ly introduced over the surface of the coil or tube 11 so that an arrangement of the type shown in Figure 1 is obtained. Under these circumstances it will be observed that the protuberances 17 and 18 are each vertically offset from the next adjacent protuberance to form a barrier or wall sufficient to maintain segregation of an air stream flowing over the top of the assembly in a manner to be later described.
Figure 5 illustrates an air conditioning unit of the room cooler type equipped with a heat transfer device forming the subject of this invention. A casing 26 includes opposite side walls 27 and 28 connected by a bottom wall 29. A cover 30 and a central partition 31 define, in conjunction with the casing, a chamber having an open end which may be either the conventional high side or low side compartment of the unit. In addition to the structure described there is included an intermediate or horizontally disposed wall 34 having an opening 35 accommodating a fan 36 driven by a motor, not shown. Across the front or open end of the chamber is disposed the coil or heat transfer device 10. An outer facade 50 is arranged over the outer face of the coil and is prolatented Aug. 9, 1960 vided with openings .51 having louvers 52 assembled therein. The inner surface of the facade so has a ledge or shelf 53 adapted to engage in the recess formed by the individual notches 60 in one edge of the fin. The wall 34 is arranged to engage with the recess formed by notches 61 in the opposed edge of the, fins. The parts are so arranged that the barrier formed by the protuberances 17 and 18 cooperates with the wall 34- and ledge 53 to define a path for a first portion of an air stream moving into the chamber under the influence of the fan 36 across the lower portion of the coil, and a path for a second portion of an air stream being discharged from the chamber over the upper or top portion of the coil.
Thus it will be obvious that through a novel fabrication of the fins in the heat transfer device, a coil is arranged so that two separate air streams may flow across the face thereof without providing a separate wall or barrier member. This arrangement is accomplished without necessity of employing expensive tooling. In addition to the advantages described above, it Will be observed that the protuberances 17 and 18 also furnish to space the fins along the surface of .the tube.
The heat transfer device may also be formed of a section of continuous tubing if desired. The fins in this case would be provided with an additional opening to accommodate the return bend portion upon assembly.
While we have described a preferred embodiment of the invention it will be understood that the invention is not limited thereto since it may be otherwise embodied within the scope of the following claim.
In an air conditioning unit including a housing having opposed side walls, an end wall and a cover forming a chamber having an open end; a fan mounted within said chamber; means dividing the chamber into a fan inlet section and a fan discharge section, said means including a coil engaging edge; a 'heat transfer coil mounted in the open end of said housing; a first group of extended surface elements angularly arranged with respect to the coil, having a portion, extending transversely of the element, upset from the plane thereof at a predetermined distance from one edge thereof, and a second group of extended surface elements angularly arranged with respect to the coil, having a portion extending transversely of the element upset from the plane thereof at a predetermined distance from the edge corresponding to the edge used to measure .the distance in the first group, the distance measured in the second group being different than the distance measured in the first group, the extended surface elements of each group being alternated with and parallel to the other group so that the upset portion of each engages the confronting surface on the adjoining element to space the elements to form a continuous barrier; said coil engaging the chamber dividing means so that air induced through a portion of the coil into the inlet portion of the chamber by the fan may be discharged through the coil from the discharge portion of the chamber without intermixing of the air stream within the coil.
References Cited in the file of this patent UNITED STATES PATENTS 1,711,702 Spreen May 7, 1929 2,224,221 Galson Dec. 10, 1940 2,331,691 Hubbard Oct. 12, 1943 2,359,051 Roper Sept. 26, 1944