US2399487A - Unit heater - Google Patents

Description

w. J. HARTWIG April 30, 1946.

' UNIT HEATER Filed June 19, 1945 v 0 0 0 0 9 Q Q Q 1L9 941E999 INVENTOR.

HTTOZNEVS.

Patented Apr. 30, 1946 UNIT HEATER Walter J. Hartwig, Wausau, Wis, assignor to D. J. v, Murray Manufacturing 00., Wausau, Wis., a

corporation of Wisconsin Application June 19, 1943, Serial No. 491,455 4 2 Claims.

My invention relates in general to improvements in the art of heat transfer, and relates more specifically to various improvements inthe construction and operationof unit heaters or coolers especially of the type wherein one or more fluid confining and circulating coils for the heating or coollng'medium are disposed about a central axis while air or gas which is to be heated or cooled is caused to flow either inwardly or outwardly across the coils with the aid-of a fan or the like arranged concentrically of the central axis of the A primaryobject of this invention is to provide a new and useful heat transfer assemblage which is both simple and compact in construction,

and which is also flexible in its adaptations and extremely efiicient in use.

It has heretofore been proposed as shown in the co-pending application of Newe'nham A, Gray, Serial No. 489,905, filed June '7, 1943, to provide a highly efiicientheat transfer section formed of a single casting with uniform elliptical cross-section at its elongated medial hollow portion and with transverse cylindrical chambers at its opposite ends each provided with a plurality of radially disposed bosses for effecting varied connections between adjoining sections. These improved heat transfer sections may be provided with external radiation pins in order to increase their efliciencyyand may also be grouped both laterally and longitudinally for various heat transfer purposes; and in order'to provide a fluid-tight connection between the adjoining sections it is preferable to utilize connectingnipples having right and left hand external threads at their opposite ends coactingwith similar internal screw threads formed in the adjoining bosses Or cylindrical chamberedend: portions of the adjacent sections. While such oppositelythreaded nipples have heretofore-been utilized for similar purposes, these prior connecting nipples wereordinarily provided with internal projections or other internal means for effecting manipulation thereof; and since the nipples ordinarily serve as fluid conduits or conductors for connecting the interiorsof adjoining sections, such internal projections or manipulating means were very objectionable as being obstructive to the fluid flow and also being debris and dirt accumulators.

It is therefore a mor specific object of my present invention to providean improved oppositely threaded connecting nipple for heat transfersections, which has a smooth and unobstructed' interior "while also being readily manipulable from within its' normal enclosure.

Another specific object of this invention is to provide a simplified right and left hand threaded nipple for quickly connecting various types of heat transfer sections, which is conveniently manipulable from either end with the aid of a flat bar or spanner wrench, and the interior of which is smoothly cylindrical, thus permitting the improved nipple to be formed from sections of ordinary pipe and at minimum cost.

A further specific object of the present invention is to provide an improved unit heater assemblage utilizing heat transfer sections of the above described prior type, either in single or multiple coil formation, and which is extremely simple in construction and highly efficient in operation.

Still another specific object of the invention is to provide a compact and durable unit heater comprising a central fan or blower and one or more concentric heat transfer coils, which can be readily manufactured in various sizes and at minimum cost, by utilizing interchangeably similar cast metal radiator sections.

These and other specific-objects and advantages of the improvement will be apparent from the following detailed description.

A clear understanding of the several features constituting my present invention, and of the mode of constructing, assembling, and operating unit heaters embodying these features, may be had by referring to the drawing accompanying and forming a part of this specification in which like reference characters designate the same or similar parts in the various views.

Fig. l is a part sectional top or plan view of one of my improved unit heaters, portions having been broken away so as to reveal normally concealed structure; i

Fig. 2. is a part sectional side elevation of the unit heater, the section, having been taken along aradial plane; i v

Fig. 3 is a perspective view of one of the improved comer brackets for spacing the housing plates of the unit; 7

Fig. 4 is an enlarged part-sectional side elevation of one of the improved connecting nipples for the heat transfer units; and

Fig.- 5 is a fragment of the adjoining ends of several of the improved heat transfer units, showing the method of stacking two or more of the coils upon each other so as to increasethe capacity of the unit heater.

While the invention has been shown and described herein as' being embodied in an electric motor driven down-blow unit heater utilizing heat transfer sections of the improved Gray type, it is not my desire or intent to thereby unnecessarily restrict the scope or utility of the improved features some of which are more generally applicable to other types of unit heater assemblages.

Referring specifically to Figs. 1 to 4 inclusive of the drawing, the improved unit heater shown therein comprises in general an endless series of interchangeably similar elongated hollow heat transfer units or sections 1 each having as shown in Fig. 1 a screw threaded central end opening 8 I at one of its extreme ends and a lateral screw through and prevent accumulation of debris threaded side opening 9 near its opposite end; a series of externally threaded connecting nipples IIJ each connecting the end opening 8 of one section I with the side opening 9 Man adjoining section I so as to provide an approximately square coil or continuous fluid conducting conduit ex tending around a central upright axis; a series of resilient corner brackets I I sprung into clamping engagement with the ends of the successive sections I; an upper housing plate'l2 having a downwardly directed peripheral flange I3 engagin the upper edges of all of the brackets II, and being providedwith a central frusto-conical pocket or deflecting element I4; a lower housing plate I5 having an upwardly directed peripheral flange I6 engaging the lower edges of all of the brackets I I, and being provided with a central tubular portion I1 disposed concentric with respect to the element I4 and the central upright coil axis; an air circulating fan rotor I8 disposed within the tubular casing portion I1 and having its supporting shaft I9 direct connected to an electric driving motor which is mounted within the pocket element l4; and a series of casing or housing clamping and suspension bolts 2I firmly uniting the plates I2, I5 adjacent to the corner bracket I I.

Each of the hollow heat transfer sections 7 comprises an elongated; body portion having elliptical transverse cross-section as shown in Fig. 2 and being provided with a multiplicity of upwardly and downwardly projecting radiation pins 22, and a transverse approximately cylindrical hollow end chamber 23 formed integral with each end of the body and having several bosses 24 radiating therefrom. The threaded opening 8 of each section I is formed in one of these radiating bosses 24, while the threaded opening, 9 is formed inan end of one of the chambers23; and the casing plates I2, I5 coact with the flat outer faces of the upwardly and downwardly extending bosses 24. Pipe plugs 25 may be utilized to close the unused openings in the bosses 24, but one of these openings at one corner of the coil may be utilized for connection with an inlet pipe 26 while a diagonally opposite opening at another corner may be utilized for attachment to an exhaust pipe 21. Heating or cooling. fluid may thus be passed through the coil from the pipe 26 to the pipe 21, and the radiation pins 22 project into the spaces between the body portions of the sections 1 and the housing plates I2, I5. The heat radiating units or sections 1 are preferably formed by casting and-areinterchangeably similar, and any desired number of the bosses 24 may be provided with tapped or threaded openings. v, I

The connecting nipples ID for uniting the several sections I into groups or coil formation, are of improved construction as shown in detail in Fig. 4. Each of these nipples IIl'is, of tubular shape having a smooth cylindrical internal central bore 28 and. external right and left hand threads 29 at the opposite ends thereof. Each of the extreme ends of each nipple III is provided with one or more sets of diametrically opposite notches 30 adapted for the application of a flat plate or spanner wrench, and when these nipples are rotated in alined properly threaded openings 8, 9, they will draw the adjacent sections 1 firmly and snugly toward each other against an intervening gasket 3|. The nipples I0, may be quickly produced from lengths of standard piping or tubing, and the smooth cylindrical interiors thereof avoid obstruction to flow of fluid theretherein.

The main casing or housing plates I2, I5 and the central flow deflecting element I4 and corner brackets II, may all be formed of sheet metal with the aid of punches and dies, and the brackets II are preferably constructed of resilient material and are of improved formation as shown in Fig. 3. Each of these corner brackets II has a set of semi-circular notches 32 disposed approximately at right angles to each other and adapted to be sprung into clamping engagement with a boss 24 and a cylindrical chamber portion 23 at the adjacent corner of the rectangular coil, as clearly shown in Fig. 1; and when properly applied, no other fastening means for the brackets II is required. The brackets II are of such height, that they will cooperate with the upwardly and downwardly extending bosses 24 so as to prop y space the plates I2, l5 apart; and the flanges I3, I6 of these housing plates I2, I5 snugly engage the upper and lower edge portions of the brackets II so as to prevent displacement of the housing relative to the central vertical axis of the unit heater. The suspension bolts 2| which clamp the plates I2, I5 against the brackets I I and bosses 24, may also be provided with loops or eyes as shown, in order to facilitate suspension or the assemblage from overhead structure.

The central frustro-conical pocket element I4 within which the fan propelling motor 20 is seated and detachably mounted, also serves as a deflector for changing the direction of flow of the air or other gas which is drawn inwardly over the heat transfer coil, from radial to axial, so 7 that this air will flow past the fan rotor I8 and through the tubular discharge portion I! in an axial direction. In some instances, it may be desirable to also provide an inlet grille 33 laterally adjacent to each heat transfer section I between the housing plates I2, I5, and these grilles 33 may be held in place between the successive corner brackets II by means of the flanges I3, I6 of the casing plates and by the clamping bolts 2 I. The outlet end of the tubular portion I! of the lower casing plate I5, may also be provided with a whirl breaker 34 comprising a series of radial vanes, and if so desired the fan rotor I8 may be steadied by contact with the central hub of the breaker 34. l 1

While one of the improved coil assemblages may be suflicient for most unit heaters, it may in some instances be desirable to double or triple the capacity of the unit, and this can readily be accomplished by utilizing two or more of the coils in series as shown in Fig. 5. Each coil assemblage is then composed of four of the heat transfer sections 1 as in Figs. 1 and 2, but several of the coils are stacked or positioned concentrically with respect to their common central axis, and are interconnected by nipples I0 uniting the adjacent bosses'24 thereof. When such a group of coils is assembled in a unit heater,- it is only neces;

sary to lengthen the fan shaft is and to double or triple the vertical length or height of the brackets ii and grilles 33, depending upon the number of coils actually provided. In this manner, any desired number of the interchangeably similar heat transfer units 1 may be utilized to produce unit heater assemblages of any desired capacity, and the housing plates I2, IE will remain the same regardless of the capacity of the heater assemblage.

During normal manufacture and use of the improved unit heaters, the coil assemblages and the corner brackets II and grilles 33 are firmly clamped between the upper and lower housing plates l2, IS with the aid of the corner bolts 2|, and the assemblages may be suspended from overhead structure by utilizing the eyes of these bolts, or they may be otherwise supported in any suitable manner and in any desired position. If the unit is to be utilized as a heater, heating fluid should be passed through the coils from the inlet pipe 26 to the outlet pipe 21; and if the assemblage is to be employed for cooling purposes, cooling medium will be likewise passed through the coils. The motor 20 may then be placed in operation so as to rotate the fan l8, thus causing the fan rotor to draw air or other ambient gas inwardly through the grilles 33 and across the sections 1 between the pins 22 toward the central axis of the unit, thereby either heating or cooling the air or other gas. After having its temperature thus changed, the stream of entering air or gas has its direction of flow converted from radial to axial by the frustro-conical deflector element 14, whereupon the finally conditioned stream is delivered axially through the tubular casing portion I! by the rapidly revolving fan rotor [8. If it is desired to prevent swirling of the blast delivered from the unit, a Whirl-breaker 34 having fiat radial vanes may be utilized, but this breaker may either be omitted entirely, or it may be replaced by a flow regulator having pivotally adjustable vanes. It will thus be noted that the change in temperature of the air or other gas flowing through the unit is effected both automatically and efliciently by the coil sections 1 which have extremely extensive radiating surface by virtue of their transverse elliptical cross-section and the provision of the pins 22, and that the unit for effecting such operation is exceedingly simple, durable, and compact.

From the foregoing detailed description it will be apparent that my present invention provides an improved unit heater or cooler assemblage which may be constructed and assembled at moderate cost by utilizing the interchangeably similar heat transfer sections 1 and the improved nipples Ill, together with the improved corner brackets I I, so as to provide an extremely eflicient and sturdy structure. The improved nipples l not only facilitate firm and leak-proof assembly or the structure, but also insure open and unobstructed passages between the interconnected hollow sections 1; and the formation of the brackets H and casing plates l2, I provides a durable housing which can be quickly and conveniently assembled or dismantled without the aid of an excessive number of bolts, screws or other fastening devices. The grilles 33 and whirl-breakers 34 may or may not be used, and

the fluid supply and exhaust pipes 26, 2! may be connected to the coils in any desired manner which will insure most efiicient distribution of the 6 heat transfer fluid. While the improved unit heater has been shown in vertical position, it may obviously be disposed either vertically, horizontally, or in any other desired position, and the assemblage may also be utilized for cooling as well as heating purposes. The units may also be readily produced in various sizes having any desired heat transfer capacity, and the assemblages are obviously of extremely neat appearance and of exceedingly compact construction.

It should be understood that it is not desired to limit the invention to the exact details of construction, or to the precise mode of use, herein shown and described, for various modifications within the scope of the appended claims may occur to persons skilled in the art.

Iclaim:

1. A heating assemblage comprising, an endless series of elongated similar heat transfer sections each having a set of bosses at each of its opposite ends, each set of said bosses consisting of one boss the central axis of which is disposed longitudinally of the section and a pair of other bosses the common axis of which is dis- 3 posed transversely of the section, conduit means connecting one longitudinal boss of each section with a transverse boss of an adjoining section, a

corner bracket having notches resiliently frictionally engaging two of the bosses at one end 35 of each section, an elongated grille extending along each section and spanning the space between the adjacent brackets, enclosing plates coacting with the opposite sides of all of said grilles and brackets to provide a confining casing for the series having an outlet extending transversely of the latter, and means for circulating air through said grilles and over said heat transfer sections and out of said outlet.

2. A heating assemblage comprising, an endless series of elongated similar heat transfer sections each having a set of bosses at each of its opposite ends, each set of said bosses consisting of one boss the central axis of which is disposed longitudinally of the section and a pair 59 of other bosses the common axis of which is disposed transversely of the section, conduit means connecting one longitudinal boss of each section with a transverse boss of an adjoining section, a

corner bracket having notches resiliently frictionally engaging two of the bosses at one end of each section, an elongated grille extending along each section and spanning the space between th adjacent brackets, enclosing plates coacting with the opposite sides of all of said grilles and 0 brackets to provide a confining casing for the series having an outlet extending transversely of the latter, said plates having peripheral flanges externally engaging said brackets and said grilles to prevent displacement of the plates and of the grilles, and means for circulating air through said grilles and over said heat transfer sections and out of said outlet.

WALTER J. HARTWIG.

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