US2204613A

US2204613A - Heat exchanger

Info

Publication number: US2204613A
Application number: US29008A
Authority: US
Inventors: Rudolph S Nelson; Arnold D Siedle
Original assignee: Hoover Co
Current assignee: Hoover Co
Priority date: 1935-06-29
Filing date: 1935-06-29
Publication date: 1940-06-18
Anticipated expiration: 1957-06-18

Description

June 18, 1940. R. s. NELSON ET AL 2,204,613 7 HEAT EXCHANGEB Filed June 29, 1935 Fal Puaafo/z J/l elwn adj mold D. flleclla.

Patented June 18, 1940 PATENT OFFICE.

HEAT EXCHANGER Rudolph S. Nelson and Arnold D. Siedle, North Canton, Ohio, assignors to The Hoover Company, North Canton, Ohio, a corporation of Ohio Application June 29, 1935, Serial No. 29,008

7 Claims.

This invention relates to refrigerating systems and more particularly to a vessel which may be used as a part of such a system. The method of construction is claimed in our copending application Serial No. 208,278, filed May 16, 1938.

With the advent of air cooling in refrigerating systems, the problem .of fabricating a coil of pipe with a large heat-radiating surface thereon presents itself. A coil of pipe of this kind may be used to advantage as a condenser or an evaporator, and in an absorption systemras an absorber, particularly if effective heat discharging means can be secured thereto.

It is an object of the present invention to provide an a-ircooled coil of pipe with a large amount of heat-radiating surface thereon and with the heat-radiating surface arranged in such a Way as to direct the flow of air over the coil to effectively transfer heat between the coil and the atmosphere.

It is another object of the invention to provide a heat transfer coil which is easy to fabricate and which has large heat-transfer areas secured thereto.

Other objects and advantages reside in certain novel features of the arrangement and construction of parts as will be apparent from the following description taken in connection with the accompanying drawing, in which Figure 1 is a side view of a coil of pipe constructed in accordance with the principles of the invention and illustrating one form thereof;

Figure 2 is an end view of the coil assembly shown in Figure l, the View being taken from. the left of Figure 1;

Figure 3 is a fragmentary plan view of the arrangement of Figures 1 and 2;

Figure! is an end view of a modified form of the invention; and

Figure -5 is a fragmentary perspective view of an assembly of pipes and heat-radiating plates used in thedevice of Figure' l.

7 In describing the structure shown in the drawing, it will be assumed that the device is to be used to dischargeheat from a fluid therein to the atmosphere, as when used as an air-cooled condenser, although the device is capable of other "uses; forexample,'as an evaporator or other de- 'vice for absorbing'hea't. Referring to the drawing in detail and first to the a'rrangement'illustrated in Figures 1, 2 and 3, fitwill be seenthat a coilassembly is shown as constructed of a number of pieces of pipe designated H to l9; inclusive,.together with a number 1 of-heat-radiating plates, the plates of one series being designated 2!, and the plates of another series beingdesignated 22. The pipes II to W inclusive are somewhat similar in shape, each having a long straight portion with a hook or reverse bend at one end thereof. It will be noted however that the bends of certain of the pipes have different lengths than those of others of the pipes. As is best shown in Figures 2 and 3, the bends on the pipes l2 and I6 are of the same length and are the shortest of any of those in the coil assembly. The pipes ll, l3, l5, I1 and i9 have bends of the same length, these bends being slightly longer than those on the pipes 02 and I 6. The pipes M and I8 have bends of the same length, these being still longer than thos on the pipes H, l3, l5, l1 and l9.

The heat-radiating plates 2i and 22 are identical in construction. In the arrangement illustrated each is provided with five holes therein arranged in offset or staggered relation, three of the holes being near the lefthand edge of the plate as viewed in Figure 2, and two holes near the righthand edge thereof. In making up the coil the pipes of the series I l to 59, designated by the odd numerals are passed successively through the openings in the plates 2i, all of the hookshaped portions being on one end, as the left end in Figure 1. Thus the straight portion of the pipe H is passed through the upper holes in the plates 2|, the straight portion of the pipe 53 passed through the next lower holes in the plates 2|, and so on. v

Likewise, pipes of the series III to it designated by the even numerals have their straight portions passed through openings in the plate 22, the bent portions of the pipes being to the'right of the assembly as viewed in Figure 1.

After the pipes have been assembled in the plates 2| and 22 as indicated above, the end of each straight portion of a pipe is welded to the end of the bent portion of the next pipe of the series. as being merely butt welds, but it is obvious that one end of each pipe may be flared slightly to overlap the end of the succeeding pipe with which it is connected so that a lap weld can be made.

To complete the assembly a piece of straight pipe 23, which may be part of a refrigerating system and which has no bend therein, may be passed through the lower holes in the plates 22 and be secured as by a weld to the lower bent portion of the pipe l9. Likewise a conduit, which may be part of the refrigerating system maybe welded to the upperstraight portion of the pipe l l,

In the drawing the welds are indicated throughout its entire length, the bent portions of the pipes being also inclined downward slightly. Because of the inclination of the pipes the heat radiating plates 2| and 22, which are disposed at right angles to the pipes passing through the holes therein are also disposed in an inclined position, the inclination of plates 2| being in opposite direction from the vertical, from the inclination of plates 22. Thus when heat is discharged to the atmosphere from the coil and from the plates, air is caused to flow upwardly through the coil, coming in contact with the inclined plates.

A modified form of the invention is shown in Figures 4 and 5. In these figures the heat-radiating plates, only two of which are shown for simplicity in illustration, are formed by cutting a rectangular plate into two pieces so as to form complementary plates designated 25 and 26, the plate 25 having a V-shaped or triangular shaped righthand edge as viewed in Figure 4, while the plate 26 has a complementary depressed or recessed V-shaped lefthand edge.

As in the, arrangement of Figures 1 to 3, the coil assembly of Figures 4 and is made up from pieces of pipe, designated 3| to 4| inclusive, which are straight for the major portion of their length and provided with hooks or bent portions on one of their ends.

The pipes 3| to 4| inclusive may be divided into two groups, those which have long bends or hooks and those which have short ones. The pipes may be assembled from two different stocks, the pipes 3|, 33, 35, 38 and 4|] each having long ,bends of the same length, while the

pipes

32, 34, 36, 31, 39 and 4| each have bends of the same length and shorter than those of the first mentioned group. As in the arrangement previously described the pipes designated by the odd numerals of the series 3| to 4| are assembled with a number of plates 25 by passing the straight portions through holes in these plates. At the same time the pipes designated by the even numerals 32. to 40 are passed through holes in a number of plates 26. It will be noted a that the holes in the

plates

25 and 26 are disposed along the inner V-shaped edges thereof and at equal distances from these edges. The assembly of the pipes and two of the plates is illustrated by the arrangement in Figure 5, it being understood that in this figure, while only one of each of the

plates

25 and 26 is shown, a

number would be employed in the complete assembly. As shown in Figure 5 the pipes designated by the odd numerals 3| to 4| have their bent portions below the plate 25 while the pipes designated by the even numerals 32 to 46 have their bent portions above the plate 26.

After the pipes have been assembled with the heat-radiating plates, they are welded together -to form a cell, the bent portion of one pipe being welded to the end of the straight portion of the next suceeding pipe in the series, as in the arrangement of Figures 1 to 3..

Thus the bent portion of pipe 3| has its end i welded to the straight portion of pipe 312; the

bent portion of the pipe 32 has its end welded to the straight portion of pipe 33 and so on throughout the series until the lower end of the bent portion 4| is reached, a straight pipe 42 which has no bend, being connected thereto and passed through the lower holes in the plates 26.

Since each straight portion of the pipes of the series 3| to 4| is inclined downwardly slightly the

plates

25 and 26 take up positions in which they are inclined slightly with respect to each other.

This relationship is shown exaggerated in Figure 5 for purpose of illustration, the true inclination of the

plates

25 and 26 in the'coinpleted assembly being somewhat similar to the inclination of the plates 2| and 22 in Figure 1. Because of the peculiar shape of the inner edges of the

plates

25 and 26, the arrangement of Figures 4 and 5 has a particular advantage in that as heat is dis charged from the coil and from the

plates

25 and 26 to the atmosphere, air is caused to pass upwardly through the coil and in so doing, is deflected from one heat-radiating plate to the other, especially along the inner edges thereof, so as to cause air to come in heat transfer relation with these plates and with the coil.

From the above description it will be clear that two forms of the invention have been illustrated in which a. coil is assembled and constructed in anovel manner and in which a large heat-radiating surface has been provided. Such a coil could be used to particular advantage as a condenser in a refrigerating system. When so used the gas to be condensed might be supplied to the upper end of the coil and as it condenses be drained away as a liquid through the lower connection thereto. The coil might be used as an absorber or other vessel of a refrigerating system also, or in any place where a transfer of heat to or from a fluid in the coil is desirable.

While only two embodiments of the invention have been shown and described herein, it is obvious that various changes may be made without departing from the spirit of the invention or the scope of the claims.

We claim:

1. A heat transfer device adapted for use in a refrigerating system, said device consisting of a conduit formed into a coil with heat transfer means thereon, said coil including a series of pipes, each pipe having a straight portion with a hook on one end thereof, the end of each straight portion being welded to the end of a hook on the next succeeding pipe of the series and said heat transfer means including plates having holes therein through which the straight portions of the pipes pass, the pipes on one side of the coil passing through one set of plates and the pipes on an opposite side of the coil passing through another set of plates, one set of plates having a V-shaped projection along one edge thereof and the other set of plates having a V-shaped depression along theedge thereof, the arrangement being such that the V-shaped edges of the respective sets of plates are disposed adjacent one another.

2. A heat transfer device adapted for use in a refrigerating system, said device consisting of a conduit formed into a coil with heat'transfer means thereon, said coil including a series of connected pipes, and said heat transfer means including plates having holes therein through which the pipes pass, the pipes on one side of the coil passing through one set of plates and the pipes on an opposite side of the coil passing through another set of plates, one set of plates 75 aeoaeie having a V-shaped extension projecting along one edge thereof, and the other set of plates having a V-shaped depression along the edge thereof, the arrangement being such that the V-shaped edges on the respective sets of plates" are disposed adjacent one another. v

3. A continuous coil heat exchanger comprising two separately assembled banks each of which includes a plurality of separate conduits having an unbent end and a bent end, said conduits being arranged parallel to one another and having the bent ends opposite one another and the unbent ends opposite one another, fins extendingtransversely of and common to a plurality of said conduits and bonding the same together into a unitary assembly, the ends of said conduits being so shaped and positioned that the bent ends of the conduits in one bank can be joined to the unbent ends in the other bank, andmeans joining the bent and unbent ends to form a heat exchanger having a single fluid passage from one end of the exchanger to the other which is slightly inclined downwardly substantially throughout its length.

4. A heat exchanger of the finned tube type having two separately assembled banks each of which comprises a plurality of conduits arranged parallel to one another and inclined to the horizontal, said conduits extending through a plurality of similarly formed, spaced apart fins of heat conducting material, said fins being inclined to the vertical whereby a risingfluid flowing thereover wipes the surface of one fin and is deflected by said one fin to an adjacent fin, one end of certain of the conduits being bent and so shaped that the conduits in one bank can be joined to the conduits in the other bank, and means joining said bent and unbent ends to form a heat exchanger having a continuous fluid passageway from one end of the exchanger to the other which passageway is inclined downwardly substantially throughout its length and in which the heat conducting fins are inclined to the vertical.

5. A heat exchange device of the finned tube type having a continuous coiled pipe inclined to the horizontal substantially throughout its length which coiled pipe pierces a plurality of similar heat conducting fins, said coil comprising a plurality of separately assembled sections each of which has a plurality of similarly formed conduits spaced apart by a plurality of spaced apart,

conduits and a plurality of similar fins.

6. A finned heat transfer" device comprising a serpentine coil formed of a plurality of pipe sections, each section consisting of a straight portion and a return bend portion, said sections being arranged with the straight portion extending in opposite directions, a joint between the return bend portion of one section and the 15 straight portion of the next succeeding section, said transfer device being so constructed and arranged that each succeeding section is incline in an opposite direction, heat conducting fin?! arranged about the straight portions of said 20 sections, said fins being substantially identical inf form, and being positioned at right angles to the straight portions of said sections and common to all those sections inclined in the same direction 7 whereby the fins areinclined to the vertical to provide a flat surface for contact with the upwardly flowing air.

7. A finned heat exchange device comprising a plurality of similarly formed sections of tubing each of which includes a bent end and an unbent end, certain of said sections having a plurality of similarly formed, spaced fins of heat conducting material secured thereto to provide a first unitary sub-assembly, certain other of said sections having a plurality of similarly formed, spaced fins of heat conducting material secured thereto toprovide a second unitary subassembly, a plurality of said fins being common to a plurality of tubing sections in a sub-assembly, the unbent end and the bent ends of the 40 tubing in said. sub-assemblies being shaped and positioned so that the unbent ends may be joined to the bent ends, and means joining the bent and unbent ends to provide a heat exchanger having a continuous fluid passage through the sections of tubing, and in which the tubing sections and fins in one sub-assembly are inclined with respect to the tubing sections and fins in said other sub-assembly.

RUDOLPH s. NELSON. ARNOLD D. SIEDLE.