US2143873A - Heat exchanging system - Google Patents

Description

Jan. 11, 1939. I J. GAUDl l I ,143,873

HEAT EXCHANGING SYSTEM Filed Dec. 31, 1935 lrrn ' INVENTOR. John B. GdUd/Ifi.

ATTO By Patented Jan. 17, 1939 PATENT v OFFICE HEAT nxonsnenvo sys'rm We John B. Gaudin, New York, N. Y. Application December 31, 1935, Serial No. 50,945

4 Claims. retest-.141 v This invention relates to heat-exchanging systems, especially to radiator devices for use in such systems, and more particularly to a known type of radiator characterized by so-called fins usually comprising thin sheets of metal associated in heat-conducting relation with more compact heated conduits or bodies, and so disposed as to transfer the heat therefrom to the surrounding atmosphere or other fluid environment.

The efficiency secured in systems including fin-type radiators so constructed leaves much to be desired, and the problem of increasing this efficiency, while retaining the desirable structural features characteristic of the fin-type ra-V diator unit, has been the subjectof prolonged research and experimentation by heatingengineers, with results not entirely satisfactory.

As the outcome of my own investigation of this problem, I have discovered that a prime obstacle to economical transfer of the heat available under such conditions is to be attributed to inefilcient provision for rapid heat conduction in the vicinity of the central conduit for the heating medium, this being due to the small mass of the metallic body at the region of the connection between the fins and the conduit, so that the heat hasbeen so sluggish in its emergence to the space to be heated that the advantage of the fin-type members has been practically lost.

The general object of the present invention is to provide, in a heating or heat-exchanging sys-' tem of the class described, and in which fin-type radiators are employed for the sake'of their characteristic advantages, various improvements in structural form of the component elements of the typical fin-type radiator unit, and also improvements in the co-ordination of such fin-type units as co-operating instrumentalities for the transferof heat to the space to be heated, which improvements will obviate to a great extent, if

not entirely, the aforesaid disadvantages, and I will advance the performance of the fin-type radiators toward their optimum degree of emciency and economy.

In pursuance of this general'obiect, an object of the invention is to provide a laminated, tubular, heat-conducting body, along the entire longitudinal axis of the radiator, adapted to yield rapidly to the fins a maximum amount of the,

heat carried by its fluid heating medium, and another object of the invention is to avoid entrapment of heat centrally within the fins; also, as a means to this end, to provide for the better circulation of air in the interstit al spaces of the assembly of fins, and for the freer flow of'said air therefrom after it shall have been heated, with more rapid, more uniform, and more complete, transfer of the heat so communicated to this circulating air, such heat transfer being greatly improved by my novel arangements herein disclosed, inasmuch as the air is caused thereby to flow rapidly between the-heated fins, and to flow therefrom into the circumambient atmosphere of the space to be heated, to which the heated air in transit acts to transfer its heat by the known and rel able operation of convection and diffusion.

A cognate object of the invention, in pursuance of the aforesaid general object, is to effect such a change in the physical structure of the fin components as to provide a novel, shorter path for transfer of heat from the center of the fin structure to the periphery thereof by direct,

metallic conduction, this path being provided in the form of sheet-metal complemental fins lying in planes substantially parallel with, and contiguous to, other, fluted fins which are disposed in a series the members of which extend radially from the ,axial conduit of the conduit, 1. e., at right angles thereto, the flutings of the lastnamed series co-operating with the flat surfaces of the fins in the complemental series to form of such contour or cross-section as to reduce the discrepancies in the lengths of the paths by which heat is conducted metallically from the centers'to themargina of the fins. Such an improved conduit may take desirably the form of a rather flat elliptical or oblong tube, i. e., one

that is sensibly oblong in cross-section.

Among other obiectsof the invention are the provision of improved means by which the novel f fin-type radiator structure embodying the sevi eral features already disclosed briefly, and to be described more at length hereinafter, may be supported in use, and co-ordinated with themice conduits of existing heating, or heat-exchanging. systems, to which it is desirable that my improvements shall be applicable without essential disturbance of those systems, and among such adapter means are included header and coupling devices to be described.

Other objects and advantages will appear as the description of the particular physical embodiment selected to illustrate the inyention progresses, and the novel features'of 'the 'invention will be particularly pointed out in the appended claims.

In describing the invention in detail and the particular physical embodiment selected to illustrate the invention, reference will be had to the accompanying drawing, and the several views thereof, wherein like characters of reference designate corresponding parts, and in which:

Figure 1 is a view in plan, partly in horizontal section, of a fin-type radiator in the construction of which the present invention has been em a ed;

Fig. 2 is a plan view of a modification;

Fig. 3 is a view in vertical section on the line 33 of Fig. 1;

Fig. 4 is a view in elevation of one of the planiform fin elements taken separately;

Fig. 5 is a fragmentary, detail view of the header parts and central conduit, in assembled relation, and taken separately from the fin components; V

Fig. 6 is a. detail view in front elevation of one of the header parts, taken separately; and

Fig. '7 is a similar detail view of the complemen tal header part, also taken separately.

In a now-preferred embodiment of the invention selected for illustrative disclosure herein, the part designated'by the reference character Ii is a conduit, preferably made of copper, or of an alloy of copper, on account of the superior heat-' conductivity, resistance to corrosion, and other desirable properties which qualify that metal for use in systems intended to circulate fluids for household heating, for refrigeration, and for heat-interchange in many of its other applications; and in pursuance of an important feature of the present invention, to which a brief reference has been already made, this conduit'ispreferably characterized by having an oblong crosssection, or one that is generally elliptical. in contour, the primary object of such formation of the conduit beingto permit the assembly therewith of fins having a rectangular, or other, noncircular contour which facilitates optimum occupation usefully of a given cubical space, while preserving the advantages of uniform radius of direct metallic heat-conduction which has been heretofore characteristic onlyof fiat circular fins associated with a central conduit of circular cross-section.

In' the structure illustrated herein, merely by way of example, I have provided two series of fins,

preferably made of the same material, .1. e., of copper, or a copper alloy of suitable composition,

having due regard to the necessarythinness of the sheet 'metal of which the fins are composed, the several members of these series respectively being designated by the reference characters i2 and II, the latter numeral being applied to each of a series of fin members or components characterized by having the form of fiat plates, or having a general planiform conformation; the components of the other series being characterized by a fluted conformation; and thecoinponents of both series having a common, rectangular form, substantially oblong, inthe instance illustrated, this not being intended, however, to exclude the use of other non-circular shapes.

The flutings c of the fin components ll may be desirably made in a zig-zag conformation, as shown clearly in Figs. 1 and 3, and this fiuting resembles conventional fiuting of suchfins in general contour,- but difiers preferably thereas shown in Figs. 1 and 3. The latter figure shows from substantially in various features which I have discovered to yield improved efllciency of a very high order in the transmission of heat between the contiguous walls of the fins and the fluid medium. such as air, circulated thereover.

One of these differences resides in the sharper pitch of the walls 0, as compared with earlier types of fluted fins, and I secure thereby an increase in the area available for heat-exchange within a given cubical space, as compared with the known types of fluted fins. Another difieronce-emerges in the shape of the walls, as clearly seen in Figs. 1 and 3. The walls 0 run from end to end of the fluted fin of my novel type, and a series of long, parallel, vertical channels or flues F is thus provided, in which the circulated air or other fluid may flow with uninterrupted continuity, promoting optimum heat-exchanging efficiency.

These flues, in fact, are of ideal form to co-operate in imparting to the ascending air the kinetic energy derived from the heated conduit ii, and so hastening its speed of circulation, for no space whatever is wasted, and there are no regions where the upward draft is materially, checked. The channels of narrowest cross-section are those at the lateral margins, and those near the middle, and all of the other fiues may be of approximately double the cross-section of the outermost lateral fiues, as is clearly shown.

The innermost are only constricted at the region of greatest heat, namely,.along the straight sides of the tube H, and it is desirable that the swiftest flow of air shall occur at this region,

which is in fact the case, so that in this respect my novel disposition of the walls with their fluelike contour is more correct theoretically than the disposition provided for by known types of fin radiators. I

In pursuance of what may be regarded as the underlying object of the present invention, i. e., the creation and maintenance of direct metallic conduction of heat from the tube II, which is its prime source within the radiator, in the instance illustrated, and in order to efiect equalized transfer of this heat to the circumambient atmosphere of the space to be heated, I have provided, in the series of fin elements ii. a heat-conductive instrumentality which is novel, both in' the idea of means which it embodies,'and in its combinative relationship with the better known fluted-type fins l2.

The fins it are formed separately from the fins l2, and each fin i3 comprises a plate or planiform body part, which is preferably of rectangular or other non-circular form, and desirablyof approximately the oblong shape shown in Fig. 4, and it is illustrated as having marginal flanges ll suitably spaced apart to receive between them. and to fit over, the outer marginal edges l2 of the fluted fin components l2, as shown in Figs 1 and 3.

The fin components of each series are severally provided with body orifices respectively, so that theycan be assembled in tandem relation upon the conduit ll. As illustrated, these orifices are surrounded by hollow bosses l2." and I8" respectively, of which the bosses I!" are the smaller, being adapted to ,fit snugly upon the conduit ll,

70 also how the bosses i2" fit snugly upon the bosses l3", and preferably each of the bosses is slightly coved, as indicated at c', in Fig. 4, so that they may be more readily assembled with a force fit upon the conduit.

In so assembling them, it is convenient, first, to force a planiiorm fin component of the series I3 upon a conduit ll of. suitable size, and then to force a fluted fin component of the series I! into the position shown near the left-hand end of Fig. 1, its boss l2" being forced upon the underlying boss I3"; so that there is at that region a triple-laminated, heat-conductive wall or body in which the concentric bosses re-inforce the underlying parallel conduit walls, and act as.

mental planiform'fin-component l3 may be considered to constitute a compound fin; and each successive compound fin so constituted may be conveniently installed by forcing its members into place seriatim; although this suggestion is not intended to exclude the adoption of any other convenient procedure in fabricating-an assembly of the type illustrated.

Again, the closely set relationship of adjacent compound fins, as illustrated in Fig. 1, has the desirable effect that the body part of each succeeding planiform fin component serves in a complemental fashion to complete the structure of the triangular channels or flues F whose other two walls are formed by flutings of the fluted fin component.

Furthermore, the planiform body portions. it, which derive heat by metallic conduction directly from the relatively long, parallel, mutually contiguous areas of contact between their bosses It" and the underlying conduit M, are, by virtue of the radially extending, unbroken body portion it, of each such component, endowed with a novel characteristic capacity to transfer heat by metallic conduction over the shortest possible route toward the periphery of the radiator.

As the distances radially, from the axially disposed oblong tube ll are substantially equal for each point on the periphery, which equality clearly appears from the showing in Fig. 4, it is evident that I have provided for a more uniform distribution of conducted heat than has heretofore been possible-with the use of such fin-type radiators as have utilized round ,conduits and square fins, even when the fins were corrugated.

The disposition of these compound fins in contiguous relation with each other according to my invention, serves an extremely. important further purpose, moreover, in that the heat in course of transfer from the core to the periphery of the radiator structure, is tapped oil from the planiform fins by the fluted complements] fin components at all such regions of contact therebetween as are designated by the reference characters c.

Without elaborating the description of this service, which is readily understandable from the disclosure in the drawings, it will sufllce to say that, not only does heat travel laterally from the fiat wall portion of conduit H along the tortuous path afforded for metallic conduction by the zigzag walls of the fiutings, but at each linear contact, as c, the fin component 12 receives from the fin component I! an increment of heat by direct- I metallic conduction. This heat-increment has only travelled over one-half of the distance from its source that must be travelled by heat conducted over the tortuous path, and is thus adapted to reinforce the heat available for the member l2 to carry to its further reaches, and so a'desirable and novel transfer and equalization of heat is eifected until, by the time the periphery of the radiator is reached, substantially all of the heat units which were available for transfer to the currents of air circulated upwards through the flues F between the fin components has been so transferred, and the transfer has been accomplished in the most efilcient manner because none of the available heat has been entrapped or lost.

Again, it will be noticed that each flue is formed by two walls of fiuting and one, relatively fiat, wall formed by the fiat fin, so that the combined heat made available by each type of conduction is efiectively distributed throughout the radiator.

It is evident that the size of the radiators can be extended to an indefinite length, within practical limits, according to the requirements of individualinstallations, and that no separately formed boundary wall members have to be prosion and contraction oi. the system is self-compensating throughout, and does not set up deleterious internal tension, so that no undue strain is imposed upon the conduit, nor is there undue compressionof the fin components. If extreme conditions of heat should supervene, conceivably the expansion of the fluted members l2 might force the flanges i3 outwardly and cause a telescopic readjustment to take place as between adjacent compound fins, but without harm to the system. Such telescopic arrangements are within the scope of the underlying idea of means, and in general the particular physical embodiment disclosed is to be regarded as illustrative rather than, limitative.

Wide range is possible in the selection of fittings and as a convenient and now-preferred form of fittings I have shown at each end of the conduit l l a fitting which is desirably simple, but efllcient for the intended use, as it afiords a practical means for connecting such a radiator with the domestic heating pipes of a dwelling, or in any other heat-exchanging system for which the system of fin-type radiator embodying my improvements may be available.

Each fitting includes a female part 2! and a male part 22, these parts having complemental surfaces adapted to be fastened together by bolts 23, leaving, as at 28, a slight clearance conform ing in general contour to the end of conduit H,

- which is desirably flared, as at I l x, to be clamped in the manner shown in Figs. 1 and 5. The

member 22 has a nozzle 25 suitably threaded forin Fig. 2, where the compound fin elements F may each be considered to embody a fluted fin, as l2, and a fiat fin, as l3, combined and cooperating as already described with respect to 5 the parts so designated in the structure disclosed in Figs. 1 to 4.

Each compound fin in this modification is, however, of greater dimension transversely of the radiator assembly, than are those shown in Fig. 1, and the modified assembly is arranged to be heated by two stretches of conduits HA and HE, which are assembled with the fins in a manner like that already described at length, except that each fin component has two oblong bosses, arranged in parallelism, as will be readily understood from the disposition of the dot-dash lines designated by the reference characters HA and MB in Fig. 2, without further illustration.

Each fitting for this modification comprises a female part 2| with two openings each registering with an end of one of the tubes HA. and B respectively; also a male part 22 is provided, having portions similar to those of the male member 22 of Fig. 1, adapted to hold the ends of the 25 tubes HA and HE, as the case may be, in a clearance like that indicated at M in Fig. 5.

The parts 25' may be formed as manifolds of conventional form, and it will be understood that the irregular lines in Fig. 2 are intended to indicate indefinite extension horizontally of the units,

which will be governed by considerations of convenience, economy and economy in operation, just as in the Fig. 1 form of the invention.

There may be as many of the central tubes,

like those indicated at IA and l lB as may prove to be desirable in accordance with the requirements of any given installation.

Instead of a tubularconduit for heat-conduct ing fluids, the member Il may be substituted by an elongated heat-conductive'body of any suitable character, as, for example, an electrically energized resistor element of any suitable character and contour.

I claim:

1. A heat-exchanging appliance for a heat-exchanging system of the class described; said appliance having the features claimed in claim 4, and in which the heat-conductive member is made as a thin, sheet-metal conduit for fluid, and said fins are respectively polygonal in shape, the flutings and contiguous radial body portions forming parallel vertical flues between the fins and open from end to end of the fins, whereby a heat-transferring fluid may be circulated in 5 said flues in such a manner as to be discharged forcibly therefrom to a circumambient body of fluid.

2- An assembly of fin elements in a heat-exchanging appliance of the fin-type; said assembly comprising a set of complements! fin elements, one having a fluted body portion and another having a planiform body portion with which said flutings co-operate to constitute furrows; and each of said elements having a hollow boss serving to support said elements in complemental relative position and in heat-exchanging fitment upon an elongated heat-conductive member common to both of said elements, said bosses overlapping each other throughout the inter-fin spaces and constituting, with the underlying portions of said heat-conductive member, a triple-laminated structure.

An assembly of fin elements in a heat-exchanging appliance of the fin-type; said assembly including an elongated heat-conductive member of substantially oblong cross-section extending to an indefinite extent along the major axis of the appliance; and a plural series of fin elements, the members of the two series being arranged in alternating disposition, the members of one series respectively having planiform bodies, and the members of the other series respectively having fluted bodies, whereby said elements cooperate to form fiues therebetween, and the respective fin elements each having a boss surrounding said elongated member, said bosses over-lapping each other throughout the inter-fin spaces and constituting, with the underlying portions of said heat-conductive member, a triplelaminated structure.

4. A heat-exchanging appliance for a heat-exchanging system of the class described; said appliance having an elongated heat-conductive member, and pairs of radiating fins with complemental bosses arranged in contiguous, abutting series along said member, one fin-component of each pair comprising one of said bosses fitted closely upon said member, extending along the same for the entire width of the pair, with a radially disposed, integral body portion of sheet metal, and another, complemental fin component having a boss fitted closely upon said first-named boss with an integral body portion of sheet metal having zig-zag flutings disposed between, and contacting with, the radially disposed body fin of the same pair and the radially disposed body fin of an adjoining pair, whereby said elongated member constitutes, with said superimposed bosses and the integral portions angularly connecting the bosses with their respective fin body portions a unitary, triple-laminated heat-conduc tive central metallic structure which may be extended to any desired extent lengthwise by the addition of similar complemental pair components in alternating order.

JOHN B. GAUDIN.

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