US3181525A - Radiant heaters - Google Patents

Description

1955 H. s. M KANN 3,181,525

RADIANT HEATERS Filed 8, 1962 5 Sheets-Sheet 1 FIG. 2 mvmozz Henry S. McKunn ATTORNEYS H. S. M KANN RADIANT HEATERS May 4, 1965 5 Sheets-Sheet 2 Filed Aug. 28, 1962 INVENTOR Henry S. McKunn BY MQ -k FIGJI.

ATTORNEYS H. s M KANN RADIANT HEATERS May 4, 1965 5 Sheets-Sheet 3 Filed Aug. 28, 1962 INVENTOR ry S McKann ATTORNEYS l Hen M y 1965 H. s. MCKANN 3,181,525

RADIANT HEATERS Filed Aug. 28, 1962 5 Sheets-Sheet 4 FIGJO.

INVENTOR Henry S. McKann FIG.9. Ma k ATTORNEYS y 1965 H. s. MCKANN 3,181,525

RADIANT HEATERS Filed Aug. 28, 1962 5 Sheets-Sheet 5 co 2 E l v F In \0 I l Q l I 1 '2 m w v g 1 8 INVENTOR.

Henry S. McKunn BY M fi-k O" (D ATTOR N E Y8 United States l atent 3,181,525 RADIANT HEATERS Henry S. McKann, Frederieksburg, Va, assignor to General Products Co., Inc., Fredericksburg, Van, a corporation of Virginia Fiied Aug. 28, 1962, Ser. No. 219,941 7 Claims. (Cl. 126-94) This invention relates to heaters which are especially useful in enclosed and semienclosed spaces and, more particularly, to radiant heaters of the over-head type.

Heretofore, heating of interior spaces in buildings, and of semi-enclosed spaces, has usually been accomplished by systems and devices depending upon convection or combined convection and radiation. In recent years, radiant heaters of various types have been adopted to a rather limited extent, usually for special applications where only a particular portion of an enclosed area is involved. In general, radiant heaters of the prior-art have presented a number of difiiculties, including particularly low efficiency, relatively poor heat distribution, relatively short life, and the fact that most such devices have discharged the products of combustion from the burner directly into the space where the heater is used. An additional disadvantage arose because the devices of the prior-art have been limited to gas burners, sothat those desiring to employ oil as the fuel were not able to employ radiant heaters.

Many applications were radiant heaters are feasible require that the heater be suspended a substantial distance above the floor or work area. In such instances, it is frequently desirable to center the heater above the area to be heated. When prior-art radiant heaters have been employed in this manner, it has proved particularly difiicult to obtain even distribution of heat over the floor space involved. In this regard, a particular disadvantage has been that, because of the configuration of the heaters, either little heat is supplied to the area immediately below the heater, or too much heat is concentrated in that area.

A general object of the present invention is to devise an improved radiant heater which is free from the disadvantages encountered with prior-art devices.

Another object is to provide a radiant heater having particularly high efficiency in heat conversion and characterized by improved over-all etiiciency as compared to radiant heaters heretofore employed.

A further object is to provide a radiant heater which can be used with an oil burner.

Yet another object is to provide a radiant heater for installation above an area to be heated, the heater providing good over-all heat distribution and supplying heat to that area which is directly below the heater.

A still further object is to provide a radiant heater which is quiet in operation.

In order that the manner in which these and other objects are attained in accordance with the invention can be understood in detail, reference is bad to the accompanying drawings, which form a part of this specification, and wherein:

FIG. 1 is a side elevational view of a radiant heater constructed and installed in accordance with one embodiment of the invention;

FIG. 2 is a view of the device of FIG. 1, generally in top plan and taken on line 2-2 of FIG. 1;

FIG. 3 is a vertical longitudinal sectional view taken on line 3-3, FIG. 2;

FIG. 4 is a vertical transverse sectional view taken on line 4-4, FIG. 3;

FIG. 5 is a perspective view of the frame means employed in the device of FIG. 1;

FIG. 6 is a perspective view showing certain casings and tubes of the device in assembled relation but apart from the remainder of the structure;

FIG. 7 is a fragmentary enlarged end elevational view of one of the tubes of the device of FIG. 1, including a portion of the casing wall which supports the tube;

FIG. 8 is a sectional view taken on line 8-8, FIG. 7;

FIG. 9 is a fragmentary view, partly in elevation and partly in vertical transverse section, of a portion of the frame and radiating fin assembly of the device of FIG. 1;

FIG. 10 is a fragmentary sectional view, with some parts shown in elevation, taken on line 1016, FIG. 9;

FIG. 11 is a fragmentary vertical sectional view illustrating a portion of the device of FIG. 1 modified for use with a gas burner;

FIG. 12 is a view, partly in side elevation and partly in vertical longitudinal section, of a radiant heater constructed in accordance with another embodiment of the invention;

FIG. 13 is a vertical transverse sectional view taken on line I313, FIG. 12;

FIG. 14 is a vertical transverse sectional view, similar to FIG. 4, illustrating a modified form of the invention; and

FIG. 15 is a fragmentary enlarged view, partly in elevation and partly in vertical transverse section of a portion of the frame and radiating fin assembly of the heater of FIG. 14.

Referring now to the drawings in detail, and first to FIGS. 1-10 thereof, it will be seen that the embodiment of the invention here illustrated comprises a pair of up right casings I and 2, best seen in FIGS. 3 and 6, a frame structure indicated generally at 3, FIG. 5, a plurality of straight, cylindrical tubes 47, and a plurality of reflecting vanes 8.

Casing 1 includes tow fiat, parallel walls 9 and 10, wall 10 being provided with a series of openings equal in number to the tubes 4-7, each of such openings being defined by a circular flange 1.1 which projects inwardly of the casing. Walls 9 and 10 have straight sides and semi-circular ends and are identical in size and shape. Walls 9 and 10 are interconnected by shells 12 and 13 which are of generally U-shape and which are joined to each other along the free edges of the legs of the U, as will be evident from FIG. 6. As best seen in FIG. 3, wall 9 has a peripheral flange 14 which projects inwardly of the casing, while wall 10 has an outwardly projecting eripheral flange 15. The corresponding portions of shells 12 and 13 engage flanges 14 and 15 in face-to-face contact and are welded or otherwise securely fixed thereto. Casing 1 also includes two semi-circular flow-directing partitions I6 and 17 which are formed by bending fiat metal sheets into semi-circular configuration, the shape of the partitions It: and I7 being such that the side edges thereof respectively engage the walls of shells '12 and 13, while the end edges of the partition engage the inner face of wall 10.

Casing 2 includes a pair of flat walls 18 and 19, Wall outwardly relative to the casing. Wall 19 is identical with enemas wall 9 of casing 1, save that wall 19 has an additional opening, at 21, to accommodate the barrel of a conventional oil burner shown at 22, FIGS. 1 and 3. Casing 2 also comprises shells 23 and 24 which bridge the space between walls 18 and 19, the edge portions of shells 23 and 24 being securely attached to flange of wall 18 and flange 25 of wall 19. Immediately above the lowermost opening in wall 13, the interior space defined by casing 2 is bridged by a horizontal partition 26. A semicircular flow-directing partition 27 is secured within casing 2 in such fashion as to jointly embrace the areas in which the next two openings are located in wall 13. In the area of the uppermost opening in wall 18, casing 2 is provided and 6, a vent opening is provided at the top of easing V 2 extending through the upper portion of shell 24 and being defined by an upwardly projecting cylindrical flange 29.

The frame structure 3 comprises two longitudinally extending upper frame members 30 and 31 and two longitudinally extending lower frame members 32 and 33, upper frame members 39 and 31 being interconnected at their ends by cross members 34 and 35, respectively, and lower frame members 32 and 33 being interconnected at their ends by cross members 36 and 37, respectively. The upper and lower longitudinal frame members are interconnected by upright frame members 38, described in detail hereinafter.

Frame members 30-37 are all formed of metal stock having a right angle transverse cross section. Upper cross frame members 34 and 35 are so arranged that one web of each such member depends vertically from the top of the frame structure while, in the case of the lower cross frame members 36 and 37, one web of each such member projects vertically upwardly. The space between the upper and lower cross'frame members is such that casings 1 and 2 are snugly received, casing 1 thus being engaged between cross frame members 34 and 36, while casing 2 is engaged between cross frame members 35 and 37. The vertical webs of cross frame members 34 and 36 engage the outer surface of wall 9 of casing 1, while the vertical webs of cross frame members 35 and 37 engage the outer surface of wall 19 of casing 2. The arcuate end portions of casings 1 and 2 engage the respective horizontai Webs of the cross frame members. The casings are rigidly secured to the frame structure by spot welding,

or otherwise fastening, the casings to the cross framemembers All of tubes 4-7 are of the same dimensions and configuration and only tube 4 will be described in detail. As seen in FIGS. 7 and 8, the tube includes a plain cylindrical body portion 39 and, at each end, an axially short, longitudinally fluted portion 40. At the inner end of each portion 40, there is provided an outwardly projecting, circumferentially extending bead 41 which is interrupted only by the flutes 42. The outer diameter of end portions are such that these portions can be accommodated snugly within the circular flanges 11 provided on casing walls 10 and 18. The flutes 42 extend inwardly of the tube and, therefore, have bottom portions which are spaced inwardly from flanges 11 when the tubes are in place. Thus, as indicated at 43, the flutes combine with flanges 11 to provide air flow spaces through which air can be inducted into the flow system defined by the tubes and casings.

The end portions 40 of the tubes are slip-fitted into the openings defined by flanges 11, during assembly of the rigid structure comprising casings 1 and 2 and frame structrue 3. The axial distance between the two beads 41 of '4 are all coaxial.

each tube is less than the spacing between walls 10 and 18, when the tubes are cool. The beads 41 are effective to maintain the tubes in approximately centered position with respect to casings 1 and 2 and it will be understood that, when one of the beads 41 on one of the tubes engages the corresponding one of walls 19 and 18, the other bead 41 of that tube will be spaced from the other of walls 16) and 18 by a distance less than the axial length of end portions 40. Thus, once the assembly has been completed, the tubes cannot be displaced therefrom.

As seen in FIGS. 3 and 11, a burner shield 44 is secured to the edges of the upright frame members 38 at the bottom of casing 2, so as to extend immediately adjacent to and parallel with the bottom portion of casing wall 19. The shield 44 has a circular opening of the same size as opening 21, this opening in the shield being coaxially aligned with respect to opening 21. Shield 44 is rectangular and bent along line 45 to provide an upper portion which slantsupwardly away from wall 19.

Three mounting bolts 46 are tackwelded to Wall '19 at points spaced about opening 21, the bolts 46 projecting through suitable apertures in wall 19 and burner shield 44 so as to provide means for rigidly mounting the burner 22 on casing 2.

Opening 21, the opening in burner shield 44, and tube Mounting bolts 46 are so disposed that the barrel of burner 22 is coaxial with respect totube 4 when the burner is mounted. Hence, the burner discharges its product of combustion axially into that open end of tube 4 which is associatedwith the lowermost opening in wall 18 of casing 2. The products of combustion so discharged now travel a tortuous path defined by tube 4, partition 16 and the walls of casing 1, tube 5, partition 27 and the Walls of casing 2, tube 6, partition 17 and the walls of casing 1, tube 7, and partition 28 and the wallsof casing 2, the products of combustion ultimately being discharged via the vent defined by upwardly extending flange 29.

Referring now to FIGS. 5, 9 and 10, it will be seen that each upright frame member 38 is made from a single metal piece of right-angle transverse cross section. Thus, each member 38 has a plain web 47 and a wider web 48. Considering the upright 38 in its mounted position, web 48 thereof is provided with a plurality of slots 49 which slant downwardly and outwardly and open away from frame structure 3 Each slot 49 has a main portion 50 which slants downwardly and outwardly, and a short inner portion 51 which extends downwardly at right angles to portion 56. The edges of main portions 59 of the slots are parallel straight lines, the lower edge of each slot being extended beyond the outer edge of the upright 38 by reason of a triangular projection 52. Thus, the upper edge of each projection 52 constitutes an extension of the lower edge of each slot portion 59.

As seen in FIG. 5, there are three of the uprights 38 on each side of the frame structure 3. The uprights are arranged in such fashion that their plain webs 47 engage the vertical faces presented by longitudinal frame members 39-33. Hence, the wider webs 48 of the up rights project outwardlyat right angles from the sides of the frame structure; Thus, for each upright 38, the slots 49 are arranged in a vertically, extending series. Since all of the uprights are identical, and since the slots 49 are identically arranged on all of the uprights, it will be understood that corresponding ones of the slots 49 on all of the uprights on each side of the frame structure lie in a common longitudinally extending plane.

Each vane 8 extends completely around the heater and, as will be clear from FIG. 2, is made in four sections each extending from the middle of one side of the heater. around one corner thereof to the middle of one end of the heater. The sections are secured together in end-to-end relation, the ends of adjacent sections being overlapped and the section-to-section attachment being accomplished by sheet metal screws as indicated at 53,

FIG. 2. As will be clear from FIGS. 9 and 10, each vane section is made from initially flat sheet metal. Along one edge, each section includes a continuous dependent portion 54 and a terminal flange 55 which projects parallel to the main body of the vane section. Portions 54 and 55 combine to form a hook structure capable of seating in the offset inner slot portions 51. The width of main slot portions is markedly greater than the thickness of the sheet metal from which the vane sections are made, the v idth of slot portions 5% being only slightly less than the depth of the inner slot portions 51. Along a line spaced from dependent portion 54 by a distance materially less than the length of the main slot portions 59, the vane sections are provided with a lon itudinally extending rib 56 which, in this embodiment, is in the nature of a continuous V-shaped bend.

The vane sections are made of sheet metal having a material amount of resiliency so as to be capable of some deformation during assembly. Assembly is accomplished simply by forcing the vanes into slots 49, with portions entering the slots first. Thus, as the vane sections reach their final positions, portions 54 and 55 snap into the inner slot portions 51. The longitudinally extending ribs 56 are of such height as to completely fill the main slot portions 5i Hence, portions 54- and 55 of the vane sections coact with the inner slot portions to retain the vane sections against removal, while the longitudinally extending ribs 56 coact with the upper edge of main slot portions 56 to hold the bodies of the vane sections against the upper edges of supporting projections 52. Assembly of the vanes is completed simply by applying the sheet metal screws at the point indicated at 53.

Except in the area occupied by burner 22, the vanes 3 extend completely around the frame structure 3. The lowermost vanes terminate at burner shield 44, as will be evident from FIG. 1. From FIG. 3, it will be seen that the upper, outwardly projecting portion of the burner shield terminates at the lower edge of the next adjacent one of the vanes 8.

The vanes 8 are spaced apart by equal distances and all slant downwardly and outwardly at the same angle. The angle at which the vanes are disposed, and the spacing between the vanes, are so chosen that the heat radiated laterally from tubes 4-7 is reflected downwardly and therefore distributed throughout the area to be heated by the device. In this connection, it will be understood that the heat refiected by vanes 8 is directed to areas surrounding that area located immediately below the heater.Refcrring to FIGS. 3-6, it will be seen that the construction of the frame structure and the disposition of the lowermost tube 4 is such that the entire area beneath tube 4 is free and unimpeded, so that heat can be radiated directly downwardly from this tube. Thus, there are no vanes Whatever below tube 4 and the lower longitudinal frame members 32 and 33 are spaced outwardly from that tube, assuring that free radiation of heat downwardly from tube 4 can occur.

Since the vanes 8 extend completely around the heater, they embrace the end casings 1 and 2 and are therefore effective to reflect that heat which is radiated from the walls of the casings.

Frame structure 3 is of open configuration and, laterally of the heater, only the reflecting vanes 8 are present. At the top of the device, there is provided a closure 57 of sheet metal which presents a rectangular top wall and short dependent peripheral flanges 58. The main body of the top closure 57 is secured directly to the upper frame members, as by means of sheet metal screws engaged in cross frame members 34 and 35. At the ends of the heater, peripheral flanges 58 engage the dependent webs of cross frame members 34 and 35 while, at the sides of the heater, the dependent flanges 58 engage over the outer edges of webs 43 of uprights 38 above the uppermost one of vanes 8. Top closure 57 is provided with a circular opening which surrounds the vent-defining flange 2 and accommodates the lower end of a vent pipe 59 which engages over the flange 29. A pair of mounting rods 60, FIGS. 1-3, secured at their upper ends to any suitable portion of the building structure or the like, extend through closure 57 and are fixed, as by welding, to the tops of casings 1 and 2 immediately adjacent to walls 10 and 18, respectively. Thus, as seen in FIG. 1, the heater is vertically suspended by rods 60 and the vent pipe 59 is positioned to carry the products of combustion away from the heater and out of the area being heated.

The tubes 4-7 are of relatively inexpensive seam-welded construction, the lowermost two tubes which are subjected to higher temperatures advantageously being of stainless steel while the upper tubes can be of any suitable alloy. The tube assembly, combining with casings i and 2, provides an elongated path of travel for the products of combustion discharged by the burner, the gases being completely confined throughout their travel and the structure being such that good heat transfer from the gases to the radiating metal parts is accomplished. Under normal circumstances, temperature differentials between tube 4 and tube 7 are about 1000 F. and higher. It will be noted that this construction has the distinct advantage of providing the hottest section of the system at the bottom of the heater and providing for maximum radiation of heat from that section to the area of use. By employing the combination of tubes 4-7 and casings 1 and 2, the invention provides the distinct advantage of confining all of the products of combustion, first to accomplish highly eflicient utilization of the heat and, second, to completely isolate the products of combustion from the space in which heating is desired.

A particular advantage of the construction just described lies in the fact that all parts of the structure can he made by conventional, inexpensive procedures, most of the parts being adapted for production by practices which are common in the usual sheet metalworking shop. It will be noted that no cast parts are involved and that assembly procedures are unusually simple and easy.

The provision of tubes 4-7, with their end portions slip-fitted into the openings provided by flanges 11, accomplishes another distinct advantage in addition to economy and ease of assembly. When a burner, such as the oil burner 22, discharges its products of combustion into a tortuous passageway such as that here employed, there is a marked tendency toward establishment of a pulsating gas flow which causes the device to be objectionably noisy in operation. .In the present construetion, the flow of hot gases causes a relatively small amount of air to be inducted into the tortuous passage via openings 43 and this eliminates the tendency toward pulsation. The same results can be accomplished by providing plain ends on the tubes 4-7, and making the outer diameter of the ends of the tubes slightly smaller than the inner diameter of the circular flanges 11.

The embodiment of the invention illustrated in FIGS. 1-10 can be modified for use with a gas burner, rather than the oil burner illustrated in those figures. Thus, as seen in FIG. 11, a-ll of the structure remains as hereinbefore described save that partition 28 is eliminated in favor of a downwardly slanting deflecting baffle 61, and a safety opening 62 is provided in Wall 19 of easing 2., below the location of the upper-most one of the tubes, to relieve the system when down drafts occur.

While the embodiment of the invention shown in FIGS. 1-10 employs four tubes arranged in vertical series, a smaller number of tubes can be used when there is less vertical space available for installation of the heater. Thus, as seen in FIGS. 12 and 13, the device can cornprise two upright end casings, indicated generally at 65 and 66, and two elongated, parallel tubes 67 and 6-8 supported by the casings. The construction of the two casings remains substantially as hereinbefore described with reference to the embodiment of FIGS. 1-10, and the anenese two casings are rigidly secured to a frame structure of the same configuration as was described with reference to that embodiment. The reflecting vanes 69, and their manner of support, remain as hereinbefore described.

The burner is mounted on casing 66 and this casing also provides the vent for passing the products of combustion of reflector 71 can be provided with dependent flanges secured to the casing walls by sheet metal screws or other suitable fastening means. verted V-shape transverse cross section and functions to intercept and reflect the heat which is radiated upwardly from tube 67. Save that the reflector 71 serves to reflect such heat both laterally and downwardly, the general operation of the device of FIGS. 12 and 13 is the same as hereinbefore described with reference to the embodiment of FIGS. 1-10.

FIG. 14 illustrates a modified form of the invention applied, for example, to the embodiment hereinbefore described with reference to FIGS. 1-10. In this modified form, the arrangement of the reflecting vanes is specially designed to concentrate the radiated heat in a relatively smaller area below the heater. In FIG. 14, it will be seen that the arrangement of the tubes which conduct the hot gases from the burner, the casings, and the general frame structure remains as illustrated in FIGS. 1-10. However, the reflecting vanes 108 slant downward at a sharper angle and are disposed more closely together so that there is less opportunity for heat radiation laterally of the device. The vertical spacing between the vanes 198, and the angle at which these vanes slant downwardly, are made such that, as viewed horizontally, the vanes have a marked overlap. Thus, it will be noted that the outer, lower edges of the vanes are materially nearer to the outer, lower edge of the next lower vane than to the upper edge thereof.

In addition to the downwardly and outwardly slanting reflecting vanes 108, this form of the invention embodies two dependent vanes each extending longitudinally along one of the lower longitudinal frame members 32 and 33. Thus, each vane 19? includes a vertically depending main body portion of substantial height and a short horizontal inwardly directed flange spot welded or otherwise attached to the'lower face of the horizontal web of the corresponding frame member 32, 33. It will be noted that the vertical main body portions of the dependent vanes 199 are aligned respectively with the outer faces of the vertical webs of frame members 32,

33 and, therefore, are spaced a short distance lateral-1y from the lower one of the gasaeondu-cting tubes. Thus, the vanes 109 define an open space below the entire lower tube, yet depend far enough to constrain to a relatively small area that heat which is radiated downwardly from the lower tube. It is also to be noted that the lowermost vane 10% of the downwardly and outwardly slantting vanes has its upper, inner edge located well above the top of the dependent vanes 109 and extends downwardly to a position near the plane of the bottom edges of the two dependent vanes 109. This relationship between the lowermost vane, indicated at 108', and the two dependent vanes 1G9 serves to further concentrate a large portion of the radiated heat in a relatively small area below the heater. This feature is of particular importance because it is the lower-most tube of the heater which is at the Reflector 7-1 is of in-.

high temperature, since it is nearer to the burner, and 7 therefore presents the greatest source of heat in the system.

As seen in FIG. 15, the vanes 16% are of concavoconvex configuration, with the concave surface opening downwardly. The upright frame members 138 are similar to members 38, FIG. 9, and have downwardly and outwardly slanting main slot portions with straight parallel edges, the lower edge of each slot being extended by a projection 152. The slots also each include an inner portion 151 which extends downwardly from slot portion 156 to accommodate retaining portions 154 and 155 at the inner edge of each vane 19%.

The tips of projections 152 are trimmed, as indicated at 152., to provide an edge portion which extends at a more acute angle relative to the vertical than does the slot 156, the edge portion at 152. being disposed to engage the lower face of the corresponding vane 108. Though the thickness of the sheet metal from which vanes 11% are made is small as compared to the width of slot portions 159, the transverse curvature of the vanes is such that, with portions 15 and 155 engaged in slot portion 151, and with the vane resting on edge portion 152', the upper surface of the vane engages the upper edge of slot portion 154), as indicated at 15th. The vanes 108 are thus restrained against displacement relative to the upright frame members 138. In addition to providing for more positive restraint of the vanes, the concavo-convex form of the vanes 168 aids in concentration of the radiated heat in the selected area below the heater.

It will be understood that the embodiments of the invention illustrated and described are particularly intended for overhead use. In this connection, it is not necessary that the heater be mounted by suspending the same, as via the supporting rods 66, FIG. 1. Thus, for example, the unit can be supported in an elevated position above the floor space to be heated by mounting the unit on a mobile frame comprising a pair of spaced posts or up rights each having its top portion secured to the lower portion of a different one of the casings 1 and 2, FIG. 1, for example. Such an arrangement has the advantage of allowing the unit to be moved from place to place with in a large building such as a factory or warehouse.

While particularly advantageous embodiments of the invention have been chosen for illustration, it will be understood that various changes and modifications can be made therein without departing from the scope of the a invention defined in the appended claims.

What is claimed is:

1. In a radiant heater adapted to be supported in an elevated position above an area over which radiant heat is to be distributed, the combination of two upright hollow metal casings each having an at least generally upright Wall provided with a plurality of circular openings,

said casings being spaced apart with said upright walls facing each other, said openings of each of said upright walls being spaced in an upwardly extending series, the openings in one of said upright walls being aligned horizontally with corresponding ones of the openings in the other of said upright Walls;

frame means rigidly connected to said casings and comprising a plurality of horizontal elongated frame members extending between said casings,

said frame members being rigid and said frame means and casings constituting a rigid assembly in which said casings are supported in their spaced apart relation by said frame members, said rigid assembly including vane supporting means comprising a plurality of laterally extending vane supporting projections arranged in vertically spaced, horizontally aligned series; a plurality of sheet metal tubes of circular transverse cross section,

each of said tubes having one end engaged in an opening in one of said upright walls and the other end engaged in an opening in the other of said walls, said tubes extending horizontally between said casings in parallel, side-by-side relation and forming a vertically extending series which commences with a first, lower tube and ends with a last, upper tube, said tubes being supported on said rigid assembly by the engagement of the ends of said tubes in the openings in said upright walls; one of said casings having an additional opening to accommodate a burner in a position to discharge products of combustion into said first tube; flow directing means in said casings operatively arranged to direct products of combustion successively from tube to tube in said series of tubes; vent means carried by one of said casings in position to receive products of combustion from said last tube, said vent means including means connectable to a vent pipe for conveying products of combustion away from the area over which radiant heat is to be distributed; a plurality of elongated heat reflecting vanes extending horizontally on both sides of said series of tubes,

said vanes extending over and respectively engaging said vane supporting projections, said vanes being spaced apart vertically and each slanting downwardly and outwardly to reflect to said area heat radiated from said tubes; and support means secured to said rigid assembly. 2. A radiant heater in accordance with claim 1 and wherein the ends of said tubes are engaged in the respective ones of said openings in said upright walls in a slip tit, and the edges of said respective openings and the corresponding ends of said tubes coast to define air induction openings for admission of air to said tubes to damp pulsations tending to develop when products of combustion are directed into said first tube. 3. A radiant heater in accordance with claim 1 and wherein said vane supporting means comprises a plurality of upright, rigid frame members, and two of said horizontal frame members are located at the tops of said casings and two of said horizontal frame members are located at the bottoms of said casings,

said upright frame members being rigidly secured to said horizontal frame members, said vane supporting projections being integral with respective ones of said upright frame members. 4. A radiant heater in accordance with claim 1 and wherein two of said horizontal frame members are located at the bottom of said series of tubes and each at a difrent side thereof, the heater further comprising two dependent heat reflecting vanes extending parallel to each other and to said tubes, each of said dependent vanes being mounted on a different one of said two horizontal frame members, said frame means being open between said two horizontal frame members, whereby radiated heat from the lower surface of said first tube can pass downwardly between said two dependent vanes. 5. A radiant heater in accordance with claim 1 and wherein the inclination and width of said heat reflecting vanes is such that the lower, outer edge of each higher vane is nearer the lower, outer edge of the next lower vane than to the inner, higher edge thereof. 6. In a radiant heater adapted to be supported in an elevated position above an area over which radiant heat is to be distributed, the combination of ltl a rigid, open frame structure comprising I I a plurality of horizontally spaced upright frame members each having an elongated flat portion projecting outwardly from the frame structure, each of said flat portions having a series of vertically spaced downwardly and outwardly opening vane accommodating slots, and

a plurality of horizontally extending frame members interconnecting said upright frame members;

two plates each provided with a series of spaced openings,

said plates being rigidly mounted on said frame structure each at a difierent end thereof,

said plates being upright with the openings of one of said plates horizontally aligned respectively with the openings of the other of said plates;

a plurality of metal tubes extending horizontally between said plates and supported thereby,

each of said tubes having one end engaged in one of said openings of one of said plates and the other end engaged in the corresponding opening in the other of said plates,

said tubes extending in parallel, side-by-side relation and forming a vertically aligned series with a first tube at the bottom of the series and a last tube at the top of the series;

duct means operatively associated with said plates and connecting the ends of adjacent ones of said tubes to complete a path via which products of combustion discharged into said first tube are conveyed successively through all of said tubes to a discharge point at the end of said last tube;

means carried by said frame structure for mounting a burner in a position to discharge products of combustion into said first tube; and

a plurality of heat reflecting vanes extending beside said frame structure and parallel to said tubes, said vanes being engaged in said slots and carried by said upright frame members.

7. In a radiant heater adapted to be supported in an elevated position above an area over which radiant heat is to be distributed, the combination of a rigid, open frame structure comprising horizontally spaced upright frame members, and

horizontal frame members secured to and interconnecting said upright frame members;

two upright wall members each rigidly mounted on said frame structure at a different end thereof and each having a plurality of vertically spaced circular openings,

the openings in one of said wall members being horizontally aligned respectively with the openings in the other of said Wall members;

a plurality of metal tubes of circular transverse cross section extending horizontally between said wall members and supported thereby,

each of said tubes having one end engaged in an opening in one of said wall members and the other end engaged in the corresponding opening in the other of said wall members,

said tubes being arranged in parallel side-by-side relation and forming a vertical series with a first tube at the bottom of the series and a last tube at the top;

flow-directing and confining means interconnecting adjacent ends of said tubes to define a tortuous flow path for products of combustion, said first tube constituting the beginning of said flow path;

means carriedby said frame structure for mounting a burner to discharge products of combustion into said first tube;

an elongated heat reflector disposed horizontally between said first tube and the next higher one of said tubes,

1i 1 said reflector having its ends attached respectively to said wall members; and a plurality of vertically spaced heat reflecting vanes carried by said upright frame members and extending parallel to said tubes,

said vanes slanting downwardly and outwardly from said tubes and bridging the space between said Wall members.

References Cited by the Examiner UNITED STATES PATENTS 521,139 6/94 Dangler et a1. 12691 Knoernschild 126-91 Kallsen a 126312 Mitchell 98-121 X Brelle, Sr.

Cartter Cartter et a1. Q. 126-91 Cartier a 126-91 Kohnen 98-94 10 JAMES W. WESTHAVER, Piilildi) Examiner.

FREDERICK L. KETTERER', Examiner,

Claims (1)

1. IN A RADIANT HEATER ADAPTED TO BE SUPPORTED IN AN ELEVATED POSITION ABOVE AN AREA OVER WHICH RADIANT HEAT IS TO BE DISTRIBUTED, THE COMBINATION OF TWO UPRIGHT HOLLOW METAL CASINGS EACH HAVING AN AT LEAST GENERALLY UPRIGHT WALL PROVIDED WITH A PLURALITY OF CIRCULAR OPENINGS, SAID CASINGS BEING SPACED APART WITH SAID UPRIGHT WALLS FACING EACH OTHER, SAID OPENINGS OF EACH OF SAID UPRIGHT WALLS BEING SPACED IN AN UPWARDLY EXTENDING SERIES, THE OPENINGS IN ONE OF SAID UPRIGHT WALLS BEING ALIGNED HORIZONTALLY WITH CORRESPONDING ONES OF THE OPENINGS IN THE OTHER OF SAID UPRIGHT WALLS; FRAME MEANS RIGIDLY CONNECTED TO SAID CASINGS AND COMPRISING A PLURALITY OF HORIZONTAL ELONGATED FRAME MEMBERS EXTENDING BETWEEN SAID CASINGS, SAID FRAME MEMBERS BEING RIGID AND SAID FRAME MEANS AND CASINGS CONSTITUTING A RIGID ASSEMBLY IN WHICH SAID CASINGS ARE SUPPORTED IN THEIR SPACED APART RELATION BY SAID FRAME MEMBERS, SAID RIGID ASSEMBLY INCLUDING VANE SUPPORTING MEANS COMPRISING A PLURALITY OF LATERALLY EXTENDING VANE SUPPORTING PROJECTIONS ARRANGED IN VERTICALLY SPACED, HORIZONTALLY ALIGNED SERIES; A PLURALITY OF SHEET METAL TUBES OF CIRCULAR TRANSVERSE CROSS SECTION, EACH OF SAID TUBES HAVING ONE END ENGAGED IN AN OPENING IN ONE OF SAID UPRIGHT WALLS AND THE OTHER AND ENGAGED IN AN OPENING IN THE OTHER OF SAID WALLS, SAID TUBES EXTENDING HORIZONTALLY BETWEEN SAID CASINGS IN PARALLEL, SIDE-BY-SIDE RELATION AND FORMING A VERTICALLY EXTENDING SERIES WHICH COMMENCES WITH A FIRST, LOWER TUBE AND ENDS WITH A LAST, UPPER TUBE, SAID TUBES BEING SUPPORTED ON SAID RIGID ASSEMBLY BY THE ENGAGEMENT OF THE ENDS OF SAID TUBES IN THE OPENINGS IN SAID UPRIGHT WALLS; ONE OF SAID CASINGS HAVING AN ADDITIONAL OPENING TO ACCOMMODATE A BURNER IN A POSITION TO DISCHARGE PRODUCTS OF COMBUSTION INTO SAID FIRST TUBE; FLOW DIRECTING MEANS IN SAID CASINGS OPERATIVELY ARRANGED TO DIRECT PRODUCTS OF COMBUSTION SUCCESSIVELY FROM TUBE TO TUBE IN SAID SERIES OF TUBES; VENT MEANS CARRIED BY ONE OF SAID CASINGS IN POSITION TO RECEIVE PRODUCTS OF COMBUSTION FROM SAID LAST TUBE, SAID VENT MEANS INCLUDING MEANS CONNECTABLE TO A VENT PIPE FOR CONVEYING PRODUCTS OF COMBUSTION AWAY FROM THE AREA OVER WHICH RADIANT HEAT IS TO BE DISTRIBUTED; A PLURALITY OF ELONGATED HEAT REFLECTING VANES EXTENDING HORIZONTALLY ON BOTH SIDES OF SAID SERIES OF TUBES, SAID VANES EXTENDING OVER AND RESPECTIVELY ENGAGING SAID VANE SUPPORTING PROJECTIONS, SAID VANES BEING SPACED APART VERTICALLY AND EACH SLANTING DOWNWARDLY AND OUTWARDLY TO REFLECT TO SAID AREA HEAT RADIATED FROM SAID TUBES; AND SUPPORT MEANS SECURED TO SAID RIGID ASSEMBLY.

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