US3002512A - Gas heaters of the overhead type - Google Patents

Description

Oct. 3, 1961 J c w GAS HEATERS OF THE OVERHEAD TYPE Filed Feb. 3, 1958 INVENTOR. EDw/NJ Gown/v 4) LQIS Z/AAML W ATTORNEY 3,002,512 -GAS HEATERS OF THE OVERIEAD TYPE Edwin J. Cowan, 475 Gatewood Lane, Sierra Madre, Calif. Filed Feb. 3, 1958, Ser. No. 712,845

Claims. (Cl. 126-91) This invention relates to heating devices and more particularly to gas heating devices and still more particularly to gas heating devices of the overhead type; and has for its object the provision of an improved gas heater of the overhead type.

Another object is to provide a gas heater of the overhead type in' which a horizontally disposed primary heat radiating floor or body is provided in the bottom thereof for the downward radiation of heat therefrom to areas and objects in range of the bottom surface of said floor or bottom, and wherein means is provided to heat the upper surface of said floor directly by means of a gas burner disposed above the primary heat radiating floor or body.

A further object is to provide means eifective to promote a high rate of heat exchange between a gas burner emanating heat energy at one horizontal level and a primary heat radiating floor or body disposed in a horizontal plane adjacent to but below the horizontal level of said gas burner.

Still another object of the invention is to provide a low pressure gas heaterof the overhead type having an enclosed flame and a means to vent the gases of combustion therefrom which is characterized by having a bottom area thereof comprised of material adapted to function efliciently as a primaryheat radiating body, said body being disposed substantially in a horizontal plane andwherein a low pressure gas burner means is provided for heating said primary heat radiating body directly by heat transfer from saidburner, said gas burner means being disposed at a horizontal level adjacent to but above the horizontal level of said primary heat radiating body.

A further object is to provide a low pressure gas heater of the overhead type having a heat radiating area disposed in the floor or bottom thereof in a horizontal plane relative to the vertical plane of suspension of the heater and a low pressure gas burner means within the .heater disposed at a horizontal level above the said heat radiating area but adjacent thereto which is adapted to heat said area by the direct transfer of heat energy .thereto.

Other objects will be apparent as the invention is more fully hereinafter disclosed.

. Before further disclosure of the invention, reference Eshould be made to the accompanying drawings wherein are dislosed several specific embodiments or species of the invention.

In the drawings: FIGURE 1 is a top view of one specific embodiment of an overhead gas heater device conforming to the present invention;

FIGURE 2 is a sectional view of the same taken along plane 2-2 of FIGURE 1;

FIGURE 3 is a second sectional view of the same taken along plane 3-3 of FIGURE 2.

I Referring to FIGURES 1 to 3 inclusive, the overhead gas heater device shown therein is one adapted to be suspended from a ceiling by means of rods iii-4A) anchored at the upper end to the ceiling and secured at the other end to the top or cover of the heater, generally indicated by letter H, in any convenient or desired manner. The specific means for dependingly securing the heater H to the rods --1I) or to the ceiling, per se, forms no part of the present invention.

The heater H of the present invention consists of two nited States Pate fimfiiz Patented Oct. 3, 1961 annular concaved or bowl-like parts 1-2, each provided with a rim-flange 3-3 extending in the same direction outwardly from the rim-periphery which flanges 3-3 are adapted to be joined together by means of aplurality of bolts and nuts 4 with a sealing ring 5 secured therebetween to form the body part generally indicated as heater H. The lower part 2 constitutes a pan containing the burner head 14, and the upper part 1 'constitutes a top or cover. As best seen in FIG. 2, the bottom of the pan 2 is substantially fiat with the periphery curving upward to form sides.

The upper part or cover 1 of the heater H is provided with a vent or fine 6 opening to the interior of the body part and providing for the escape of gases or products of combustion from the interior of the heater and for the delivery of same to a chimney conducting the gases out of the room or enclosed area within which the heater H is located.

Flue 6 is provided with a downdraft diverter consisting of an opening or aperture 31 formed in the side of V the flue 6 and a baffle plate 32 spanning the interior of the flue 6 and located opposite aperture 31. A segment is cut from the plate 32 opposite the aperture 33., as shown at 33.

The upper cover part 1 of the heater H also is provided witha coaxial annular opening centered at the center transverse axis of the cover part if within which is seated and secured a depending tubular partition or wall 7, the lower edge of which lies in approximately the same plane as the engaging flanged rims of the parts 1 and 2.

Extending coaxially outward and overlying the opening defined by the tubular partition 7 is a plate or shield 8 mounted on a coaxial burner 9. The shield it protects the valve assembly thereabove from excessive heat.

Means, including a pressure-reducing valve 11 and a shut-off valve 12, each of common and well known design, is provided to feed gas from gas main l3 admixed with the proper amount of primary air for combustion to the burner head 14. The specific combination forming this means is, per se, no part of the present invention except as it is necessary and essential to the operation of the heater H.

Burner 9 is designed such that with respect to the vertical height of the heater H, the burner length is such as will locate the burner head 14 thereof adjacent to the bottom of the bowl or pan part 2 of the heater H. The outside periphery of the burner head is is provided with circumferentially spaced gas ports or openings 15, whose axes lie in a plane substantially normal to the axis of burner 9 and in a horizontal plane substantially parallel to the horizontal plane of the bottom wall of the pan part 2, thereby to direct the gas flame 16 emitted therefrom circumferentially over a substantial area of the said bottom and in relatively close proximity thereto.

' With this arrangement of the burner and burner parts, it will be recognized that the burning gases in circumferentially emitting from the plurality of ports 15 in the burner head 14 form an annulus of radially outward flame cones disposed in a substantially horizontal plane hugging or closely superjacent the horizontal inner or upper surface of the pan or bowl 2 and would normally tend to travel therealong following the arcuate inner surface thereof upwardly into the upper cover part 1 of the heater and thence out of the combustion chamber enclosed by parts 1 and 2 into the flue 6, the tubular portion 7 in the cover part 1 preventing these gases of combustion from passing out through the inlet opening defined by the partition 7.

Where the air-gas mixture supplied to the burner for combustion in the combustion chamber defined by the acoasre r r parts 1 and 2' consists of a low-pressure gas-air mixture, additional air is required for complete combustion. This additional air enters the combustion chamber through the opening defined by tubular partition 7, and mixes with the flame cones 16 at the base thereof, the-direction of; flow of this air being indicated by arrows. Air mixing continues radially outward from thetba'se of the flame cones. It will be noted that the flow ofthis air is through the space gap defined by the lower edge of the tubular partition 7 and the upper surface of the burner head 1 This space gap may be varied widely Without essential departure from the invention but in: general is utilized to control or regulate the velocity of the incoming air required for complete combustion. By increasing or decreasing this space gap, the .velocity' of the air is either decreased or increased and under any given set of conditions of heater size (diameter),' diameter of burner head relative thereto andpressure of the air-gas mixture being'fedto the burner'headsan optimum space gap providing the proper velocity ofair flow into the chamber for the functional result in view may be selected or determined withoutundue experimentation. The functional result desired for this air flow in the present invention is' to maintain the flame; 16 de-' pressed in a substantially horizontal plane over substan.' tially the greater area of the flame by: counteracting its normal tendency to rise upwardly as thepressure' of the gas-air mixture falls after passing through the port open ings' 15.

Air which is pie-mixed withthe combustible" gas before the gas ,lows into the burner head I4 is called primary air. Air which-'mixesfwith the lgas in the flame id after the gas has emergedJfromthebufner'ports 15, and which enters chemically'into" the combustion of the gas, is called secondary air. In this specification the term excess air refers to all of the outside air which is drawn into the combustion chamber through the'tubular inlet 7; A portion'of'this excess" air enters into the combustion processand becomes secondary air. that portion whichdoes not enter into? the combustion process but merely mixes with the'combustion gases and then flows out through'the exhaust fine 6 is, in this specification, called dilution air;

The attainment of thisfunctional result is not difficult nor critical where as iflllliS specific embodiment, the bottom wall of the heaterHis substantiallyimperforate. In this situation, substantially all of the excess air, i.e., secondary and dilution air, must enter the combustion zone through this space gap and the velocity of the air flow through the gap will function, as desired, to maintain' the flame depressed closely superjacent the bottom wall over the greater portion of the surface thereof to a greater or" lesser degree depending 'on'the velocity of the air and to carry the gases'of combustion toward the curved sides and upwardly ther'ealong into the upper cover chamber It for discharge into the flue 6.

The important result obtained'by the burner means anddepression of the flame is that the bottom part 'or pan is heated directly by heat exchange with the horizontally projected burning gases of combustion from the burner head 14 over its greater area and that this'res'ult is'attained relatively rapidly andefficieutly:

By comprising this bottom wall-of the pan 2,? at least, of material adapted to absorb heat rapidly and thebottom'surface of the wall, at least, of material adapted to radiate this absorbed heat eflectively and directlyrto objects and persons, directly under the surface and in view of a more efficient and efl'ective gas-fired overhead radiant heater device results.

It has been found that for mostpurposes and most installations, part 2 of the heater H maybe comprised of 'arnetal-lic composition such'as an oxidation-resistant ferrous metal alloy, preferably one which is .sufliciently malleable in sheet form to be fabricated as by stamping methods into the flanged bowl or panshape shown. A plurality of such oxidation-resistant ferrous metal alloys are available in the art and each has differing but favorable properties for the purposebf thisinvention. Alternatively, a number of copper alloys are available in the art for utilization in the forming of part 2 of the heater H. Many other types of alloys are also adapted for utility in this invention and the? specific. composition of the metallic pan part 2 i's'not' contemplated as being within the scope of this" invention;

Cover part 1 ofltheheater H- may be comprised of the same metallic composition as comprising pan part 2 or it may alternately be comprised of material less absorptive of heat radiation or it may be surfacedexteriorly with thermal insulating material, such as asbestos,... or glass wool, so as to adapt the device to be dependingly sustained in closer spaced relation to a ceiling without fire hazard. i

it is believed apparent from'the above disclosure and accompanying drawings illustrating the same that. the pr es'entin e'rition is adapted to Wide utility in the art and that many modifications, changesandaltera'tions may be made therein" without essentialdeparturetheretronr and all such changes, modifications and adaptations ofthe invention as herein disclosed and illustrated in the drawings are contemplated as may fall within the scope of the appended claims What is clairr'ied'is:

1. Heater comprising a bowl made of non-combustible material and having a geizterallyflat bottomadapted to radiateh'eat, a burner head disposed adjacentsaid bottom and having burner ports directed in a-substantially' horizontal plane, thereby to" emit burnable gas to form a flame superjacent a substantialer'ea'of said bottom, said area being-substantially imperforate, thereby to preclude theintroduction"of'eircessair' into the burner flame from beneath the name; a cover substantially covering" said boa/Land conduit'means for admittingeitcss an into said bowland terminatingimmediately above'the level of said burner head, whereby substantially allof th'e excess air which mixes'with the flame 'does so'troin above the flame said'cover' being "spacedappreoiably' above the level of the terminationof'said encess air'condiiit means, there being a substantially unobstructed space" abeve the level of said ports to alevel substantially above the'level of'the termination of said excess air conduit means','whereby'a layer of excess air is formed aboyc'the flame'over substantially its entire extent to maiu'taidthe'flarne" de pressed toward said'bottoin. I

2. Heater comprising a pan'made' of non-combustible material and having a generally flat bottom adap'tedto radiate heat, a burner head disposed adjacent saidbotto'rn and having burner ports directed in a substantially horizontal plane paralleling said bottom,.thereby to emit gas to forms flame closely superjacen't' said 'bottoni'fsaicl bottom being substantially imperforat'e, thereby to preclude the introduction of excess "air' intdth'elfla'me from beneath the flame, anercess air'inlet conduit directed downwardly andh'aving its discharge 'e'dge'locate'd above the burner ports and rearwardly thereof with'resp'ect to flow of gas from said ports, a cover forsaid heater. substantially covering said pan" and located appreciably above the discharge edge of said exc'ess air. conduit, whereby a layer of excess air is formed 'super'adjacentthe flame over substantialiy its entire area, thereby to maintain the flame depressedtoward said bottom, and means at the top of said heater for"discharging'combustion products therefrom. v p

3. Heater comprising a bowlrnade; of non cjombustible material and having a substantiallyfia't bottom adapted to radiate heat, a generally circular burner havingburner ports directed substantially parallel'to said bottom, thereby to emit a burnable gas to form a-flame superjacent a substantial area of said bottom, said area being substantially imperforate, thereby to preclude tlieintroduction of appreciable excess air into the flame from beneath the flame, a cover substantially covering said bowlpan excess air inlet conduit extending downwardly into said bowl and terminating in a discharge edge spaced appreciably below said cover and immediately above said burner ports, thereby to introduce excess air into the heater above the flame for maintaining the flame depressed toward said bottom, and means at the top of said bowl for discharging combustion products therefrom.

4. Heater adapted for overhead installation comprising a bowl made of non-combustible material and having a substantially flat bottom adapted to radiate heat, a generally circular burner head disposed adjacent said bottom and having burner ports directed outward to form a flame substantially parallel to said bottom, a cover substant-ially covering said bowl and spaced appreciably above said burner ports, an excess air inlet conduit passing through said cover and extending downwardly to terminate in a discharge edge disposed above said burner ports and spaced appreciably below the inner surface of said cover, whereby a layer of excess air is formed above the flame and substantially covering the same, thereby to depress the flame toward said bottom, and means at the top of said bowl for discharging combustion products therefrom.

5. Heater adapted for overhead installation comprising a bowl made of non-combustible material and having a substantially flat bottom adapted to radiate heat, a generally circular burner head disposed adjacent said bottom and having burner ports directed outward to form a flame substantially parallel to said bottom and immediately superjacent thereto over a substantial area thereof,

said area being substantially imperforate, thereby to preclude the introduction of excess air into the flame from beneath the flame, a cover substantially covering said bowl and spaced appreciably above said burner ports, an excess air inlet conduit passing through said cover and extending downwardly to terminate in a discharge edge disposed above said burner ports and spaced appreciably below the inner surface of said cover, whereby a layer of excess air is formed above the flame and substantially covering the same, thereby to depress the flame toward said bottom, and means at the top of said bowl for discharging combustion products therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 1,156,198 Wissinger Oct. 12, 1915 1,639,114 Smith Aug. 16, 1927 1,762,878 Moreton June 10, 1930 2,017,562 Brown Oct. 15, 1935 2,361,097 Hess Oct. 24, 1944 2,542,750 Butz Feb. 20, 1951 2,570,554 Henwood Oct. 9, 1951 2,759,472 Cartter Aug. 21, 1956 2,806,465 Hess Sept. 17, 1957 2,838,042 Chen June 10, 1958 2,908,267 Hess Oct. 13, 1959 FOREIGN PATENTS 847,625 France July 3, 1939

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