US1971842A - Heat transfer device - Google Patents

Description

3 F. M. YOUNG 1,971,342

. HEAT TRANSFER. DEVICE Filed Jan. 15, 1934 ll l n J Y -J l LllLll'lJlllllll. |||1 |||1|||1 1 WA 20 74 I0 13 I [29- E I Inventor.

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' Patented Aug. 28,

ATENT OFFICE 1,971.84: nm'r mansrnannvrca Fred M. Young, Racine, Wia., allignor to Young Radiator Company, Racine, Wis.

Application January 15, 1934, Serial No. 706,619

' 4 Claims. (01. 251-454) My invention relates to improvements inheat transfer devices commonly called radiators wherein a number of tubes, preferably in individual rows, are supplied with a multiplicity of closely spaced strip fins, the tubes terminating preferably in suitable headers having connections whereby a suitable" heating or cooling liquid or gas may be caused to circulate through the tubes and whereby an air current is caused to pass around the tubes and between the finsand is heated or cooled thereby.

The object of my invention is to increase strength, and efiiciency, improve appearance, reduce cost and produce a more desirable product.

I accomplish these objects by means of suitably positfiied and shaped embossments in the fins and novel formations in the front and rear edges of the fins whereby these edges are held in spaced relation and the 'air current is also suitgo ably directed as it enters, passes through and leaves the space between the fins.

An example, embodying the preferred form of my device, has been shown in the accompanying drawing in which: a

Figure 1 is a fractional front elevation of a radiator equipped with my improvements.

Figure 2 is a horizontal section taken on line 2 of Figure 1.

Figure 3 is an enlarged side view of a fraction of a strip fin.

Figure 4 is a fractional end view of the core as shown in Figure 1.

Figure 5 is a fractional elevation of a modification.

My invention is applicable to any size radiator and any form of headers or connections. The' form of core shown is particularly adapted for use in large units, wherein two separate core units are used, each comprising a row of tubes and 40 separate fin strips for each core. I have, however, as a;matter of convenience, shown a radiator having a single row of tubes only and suitably positioned strip fins thereon. In larger units commonly called blast heaters, the cores each may be two or three feet wide and from six to ten feet long. Obviously a single row of tubes having strip fins as shown will have strength and rigidity sufllcient for such larger units, and also provide the desired degree of independent flexibility to accommodate itself to varying degrees.of temperature.

For large units it is the custom to provide two rows of -tubes, ea ch'f row having its own strip fins, similar td-that shown in Figure 2. It will,

. however, be understoodthat my device is adapt of two independent cores.

able to any size radiator, and that it is suitable for use with two or more rows of tubes having fins wide enough to form a single core instead It will further be understood that applicants improved device may be used without headers by supplying suitable connections between certain tube ends whereby the liquid or gas may pass through the tubes in series or series multiple for use in refrigerators and the like.

' In the various figures the tubes are designated by the numeral 10. These tubes are supplied with the usual headers 11-11, having inlet and outlet connections 12-12. The fins 13 are supplied with suitably flanged openings 14 through which the tubes extend and are bonded thereto.

Fins are made from thin copper and are therefore fragile. I provide means for stiffening the .body of the fin in the form of suitably positioned embossments 15. These embossments are closely spaced and positioned to thereby register with the depression formed by the embossments on adjacent fins, thus to maintain an equal space between the fins. I

The embossments are positioned as indicated in Figure 2-, wherein one is directly between the tubes, and a closely spaced row on either side as indicated in alternate position with the center embossment'and the tubes. Thus it will be seen that the larger surface. of the fin is occupied by the tubes and embossments. The swiftly moving' air will be split and deflected by the first row of embossments. This operation will be re peated by the tubes and center embossments and again by the embossments on the discharge side of the core.

The airwill be divided in a way into waves and turned over and over as it impinges the various surfaces at angles which will not greatly impede the air fiow but will produce highly emcient heat transfer. It will be understood that the embossments may be variously shaped, that is, either cone shaped, round knobs or otherwise.

One of the desired conditions in radiators of this type isthat the air pass through the entire surface at the same speed. This requires an even distribution of air and that it travels at right angle to the rows of tubes, the fins restricting this travel in the other direction. I provide means whereby the air will be caused to travel at right angle to the rows of tubes which means is also adapted to act as spacers to the fin edges in the following manner:

The fins are necessarilyvery thin and fragile and therefore will not normally remain in spaced frelationat their edges. My improved spacers are designated intheir entirety, in Figures 1 to 4, by reference character A. These spacers are formed by means of a slit of the proper length and 5 distance from th'e edge of the fin. The freed strip thus'released is pressed preferably in the form clearly indicated in Figures .1 and 3, providing converging ends 2020 whichterminate at the apexes into a short fiat section, 21 whose l distance from the fin is equal to one-half'the distance between fins as illustrated in Figures 1 and 4. I

The fins are exactly alike except that these spacers A, are formed alternately on opposite l sides of the fin edges and project preferably alternately on opposite sides of the fin, and the fins are assembled on the tubes'whereby the apexes register with the apexes on adjacent fins, alternately as clearly illustrated in Figure 1.

Thus the edges will be held'in spaced relation.

The spacers A, do not materially reduce the area between the fins but the side walls positioned as they are will straighten the air' flow as it approaches the fins and direct it toward 25 the embossments. The spacers on the discharge side will materially assist in maintaining this desired distribution of air as it passes through the core. I,

The efiiciency of the device will be increased 3 in that the air will impinge the'diverging and alternating surfaces and a beneficial turbulence will result. The spacers A cooperating with the embossments will split the air into narrow strata which impinge the various surfaces thus to reduce materially the difference in temperature between the discharged air and the fins.

Obviously the spacing members may be formed into a height equal to the distance between fins as indicated in Figure 5, and designated by reference character B. These spacers B are, as illustrated, in staggered relation in regard to the assembly, but in this instance they all project in the same direction. Thus the fins are held in spaced relation and the spacers B act to direct the air flow similar to spacers A. Oh-

viously the apexes of spacers B may be pointed or round. In either event the surface which they'contact is fiat. However in the case of spacers A the contacting surfaces must be either 0 fiat or one fiat or convexed and the other any surface which will rest securely thereon.

. Thus the fins are stiffened by the embossments and the edges held in spaced alignment. The air will travel therebetween at equal speed 5,; and a highly eflicient condition of turbulence prevail.

Obviously many. minor'changes in the shape of the embossments and spacers and positions the spirit of my invention.

Having thus shown and described my invention I claim.

1. A heat transfer device comprising, a row of tubes; and means whereby a liquid or gas may circulate therethrough, a multiplicity of closely spaced strip fins through which said tubes extend, a plurality of embossments on said fins, one embossment positioned between. each tube and a row on each side thereof positioned alternately with said tubes and said center embossments, a plurality of spaced apart slits cut along the front and rear edges of said fins leav- 'ing narrow strips which are formed into converging ends terminating at the apex into a short fiat surface forming projections, said projectionspositioned alternately on opposite sides of said fins, and located whereby projections on adjacent fins register, forming alternately positioned spacers. 2. A'heat transfer device comprising, a plurality of tubes, means whereby a liquid or gas may circulate therethrough, 'a multiplicity of closely spaced fins through which said tubes extend, a plurality of spaced apart slits out along the front and rear edges of said fins leaving narrow strips which are formed into converging ends terminating at the apex into a short fiat surface forming projections, said projections positioned alternately on opposite sides of said fins, and located whereby projections on adjacent fins register, forming alternately positioned spacers. 3. A heat transfer device comprising a row of tubes and means whereby a liquid or gas may pass therethrough, a multiplicity of closely spaced strip fins through which said tubes extend, suitably positioned spacers between the edges of said fins having spaced apart means on the front and rear edges to-direct the air current transversely between said fins, a plurality of embossments in said fins one positioned between each tube, and a row of embossments on each" side thereof spaced alternately with said tubes and center embossments.

4. An air directing means for a heat transfer device having upper and lower headers and a rowof tubes the ends of which are attached thereto, whereby a liquid or gas may pass from one header to the other, a multiplicity of closely spaced strip fins through which said tubesextend, comprising, a plurality of embossments on said fins, one center embossment positioned be- .tween each tube, a row of embossments on each side row of tubes and positioned alternately with said tubes and said center embossments, the projection formed by each 'embossmentregistering with thedepression formed by the adjacent embossment. FRED M. YOUNG.

CERTIFICATE or common.

Patent No. 1,971,842. augusrzs, 1934.

FRED u. YOUNG.

It is hereby certified that error appears in the printed specification of the above numbered patent. requiring correction as follows: Page 2, line 129, claim 4, after "side" insert the words of said; and that the said Letters Patent should he read with this correction therein that the-same may conform to the record .of

the case in the Patent Office.

Signed and sealed this 30th day of October, A. D. 1934.

liealie Frazer (Seal) I v I Acting Commissioner of.Patenta.

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