US2362972A - Gas burner - Google Patents

Description

Nov. 21, 1944. H. L. BROWNBACK GAS BURNER Filed Dec. 26, 1939 2 Sheets-Sheet 1 Nov. 21, 1944. H. L. BRowNBAcK GAS BURNER 2 Sheets-Sheet 2 Patentecl Nov. 21, 1944 UNITED STATES PATENT OFFICE GAS BURNER Henry Lowe Brownback, Norristown, Pa. Application December 26, 1939, Serial No. 310,995 15 Claims. (Cl. 158-99) This invention is a novel improvement in gas burners, particularly adapted for use in cooking kettles, or by air currents if the gas is turned low, and such burners cannot be. used for broiling in.

the usual manner of placing the food to be broiled above the burner. Furthermore the heating-surface of such burners is not uniform, but is localized along the axes of the series of burner orifices.

The principal objects of my invention are to provide an improved sub surface combustion type burner designed to eliminate all of the above mentioned disadvantages and to provide a burner which will present an even fire resembling in heat distribution and appearance a fine charcoal fire, above which food can be broiled without absorbing any gas" taste; also to provide a burner in which the gas is burned into carbon dioxide by reason of multiple combustion steps, thus producing maximum heat from a given quantity of gas; also to provide a burner which willbe less subject to maladjustment than the ordinary burner, and in which provision is made to render same safe against overflowing pots and kettles; also to provide a burner in which there are no small burner orifices exposed to dirt, grease and corrosion as in the ordinary type burner, and hence to provide a burner in which there is no danger of clogging or choking the jet orifices.

I will explain the invention with reference to the accompanying drawings, which illustrate several practical embodiments thereof to enable others familiar with the art to'adopt and use the same; and will summarize in the claims the novel features of construction, and novel combinations of parts, for which protection is desired.

' In said drawings:

Fig. 1 is a vertical section through one form of my novel gas burner. Fig. 2 is a vertical section showing a modification'utilizing a pre-formed filter cartridge unit in the secondary mixing chamber of the burner. Fig. 3 is a vertical section through a further modification showing one form of cover used on the secondary mixing chamber. Fig. 4 is a'vertical section showing another form of cover for the secondary mixing chamber.

My novel gas burner preferably comprises a cup-shaped casing I, open at thetop and having a bottom plate Ia. provided with a contracted extension lb, the lower end of which is provided with a downwardly flaring hood lo, the parts lb and le forming the primary gas and air mixing chamber M' of. the burner. Extending upwardly into hood Ic is a gas nozzle 2 having an orifice 2a governed by amanually adjustable valve 3 to control the amount of gas entering from the gas pipe 2b into the primary mixing chamber M. Air enters the primary mixing chamber M at the lower open end of hood ic exteriorly of the nozzle 2, and preferably air regulating means is provided consisting of a pair of relatively adjustable superimposed perforated plates Id at the lower end of the hood Ic. If desired an air blower 6r other means for supplying forced draft of air intothe primary mixing chamber M may be provided.

Within the casing I and spaced from the lower end thereof is a. screen or grating 4 preferably extending across the casing and supported on an annular frame 4a fitted Within the walls of the casing. The chamber below the screen or grating 4 may be empty to provide a secondary mixing chamber M2'for the gas and air; or if desired said space below screen 4 may be filled with tinsel or the like to assist in mixing thegas and air therein. Above the screen or grate 4, the

casing I is packed with non-combustible porous packing material P (in Fig. 1) such as asbestos, rock wool, spun glass, or the like, forming a gas distributor and backfire trap. The upper face of packing P forms the bottom of the primary combustion chamber C, which chamber is formed in a casting '5 having a contracted lower end 5a into which the upper end of casing l enters, leaving a space 51) between the parts 50. and i through which the secondary air for the primary combuse tionchamber C enters.

Within the lower portion of casing 5 is a refractory lining 6 of substantial thickness to protect the walls of the casing and to prevent loss of heat therethrough. Lining 5 extends substantially half the height of casing 5: Seated in an annular recess at the top of the lining 6 is a grate I above which is disposed a screen 8. Above screen 8 is a refractory lining 6b extending to the top of the casing 5. Upon screen 8 is a layer,9 of carber C2. The bed, of aggregates above the screen 8 in the chamber provides for secondary combustion and heat distribution, the aggregates becoming incandescent by action of the combustion in the primary combustion chamber C, and the secondary combustion in the layer 9 maintains a. glowing bed of aggregates in chamber 5 giving a radiant heat with practically no flame.

For the purposeof igniting the air and gas mixture in the primary combustion chamber C, I provide a pilot consisting of a gas tube In entering the side of easing 5 and extending through lining 6, said tube having a jet orifice Illa at its inner end for the pilot flame which may be left burning at all times. The pilot flame provides double safety as any possible escape of gas due to a partially closed cock in gas pipe 2b would not pass directly into the air as in the ordinary burner but would collect in the primary combustion chamber C and would there be ignited by the pilot light IOa; and since the pilot Illa is disposed in the enclosed combustion chamber C there would be little likelihood of the pilot flame being extinguished by a sudden gust of wind. Above the pilot orifice Illa is a deflector plate Illb for the purpose of preventing any liquids which might drip .down into the primary-combustion chamber C from extinguishing the pilot flame.

Instead of using the filling P in the casing I as shown in Fig. 1, the filling can be made up as a cartridge shown in Fig. 2, similarly to the oilfilter cartridges used in motor cars, and this cartridge replaced periodically if found necessary or desirable. The pre-formed burner cartridge as shown consists of a metallic shell II of diameter and size to suit the internal dimensions of the casing I, said shell preferably having internal annular flanges I Ia at its ends. Within the shell II is a shell I2 of less height seated upon the lower flange Ila, and upon the top of shell I2 is a screen or grid I3 forming the top of the secondary mixing chamber M2. Above the screen or grid I3 is a packing of porous insulating material such as rock wool, asbestos, spun glass, or the like, and upon the top thereof is a screen or grid I5a upon which is a layer of asbestos fibre or the like I5 covered by a screen IGengaging the upper flange I la of the shell I I. The above construction forms a unit-which may be inserted as a cartridge intothe. casing I, which unit is inexpensive to manufacture and is readily removable from and replaceable in the casing. The cartridge shown in Fig. 2 also provides an eflicient backfire trap, and the gases passing up through the porous layers I4 and I5 are spread evenly throughout the mass ,so that the flame at the top of .layer l6 will burn evenly over the entire area of the casing I whichforms the bottom of the primary combustion chamber C.

It may be found desirable to provide covers upon the casing I such as shown in Figs, 3 and 4, as an added safety measure to protect the cartridge from any liquids which might .boil over and pass down through the combustion chambers C2 and C and which might thus soak the cartridge or injure same. The cover may consist of an overlapping series of conical rings '20 with spacers between adjacent rings as shown in Fig. 3; or the cover may consist of a conical plate 2| having louvres 22 formed therein as shown in Fig. 4, or may be otherwise formed to deflect any liquid which might drop through the combustion chambers from falling on the cartridge. In case a large volume of liquid was spilled on the heated layer 9 of non-combustible material suflicient to cool the latter and pass down through on the burner, such liquid would run down the conical covers and pass out of the secondary air inlets 5b without extinguishing the burner. Preferably 5 the cover is provided with a flange adapted to flt within the upper end of the casing I. When a cover is used the porous filling material P in the casing would preferably extend up to the underside thereof, and the porous insulating material .10 P would distribute the gas-air mixture evenly to the underside .of the protective cover and the mixture would pass through the slots. or louvres and burn,

The operation'of the burner as described is as 15 follows: In my novel burner the gas and air is fed into a primary mixing chamber M in the usual manner either by the injector action of a Bunsentype mixer. or by a forced draft blower type mixer, and the gas-air mixture is carried to the secondary mixing chamber M2 which is open at the top and may be empty or filled with tinsel or like material through which the mixture can circulate freely. The gas-air mixture then passes upwardly through grid or screen 4 or I3 into a bed of porous insulation P or l4-I5 in the casing I which distributes the gas-air mixture evenly at the upper surface thereof, at which point the gas-air mixture is burned, the porous insulation P or I4--I5 serving as a backfire trap to keep the heat of the flame from igniting the gas in the mixing chambers M, M2. The upper end of the porous insulation P or I4-I5 forms the bottom of the insulated primary combustion chamber C, in which chamber additional air from ducts 5b r is fed to the burning gas-air mixture. This additional air mixes with the original products of combustion, and passes with them upwardly through grate 7 upon which is placed the layer 9 of carborundum, aggregates or similar noncombustible material which is heated by the products of combustion to a high degree.

The layer 9 of combustible material serves the purpose of providing a fine, even, odorless, flameless or almost flameless heat, and the excess air and products of combustion containing carbon passing through'the heated layer are combined to burn any residual carbon monoxide into carbon dioxide, thus obtaining more heat from the fuel and eliminating carbon monoxide which is an active poison. This heat given off by the the primary combustion can be absorbed therein as is the case when using the ordinary Bunsentype burner; also any fat, etc., dripping from the material being broiled will drop onto the heated layer 9 and will there be burned without reach- 00 ing the primary combustion chamber C.

The actual combustion takes place in a substantially closed compartment (save for the secondary air inlets 5b which are protected from drafts) so that there is no danger that sudden air currents can extinguish the flame. Any gas leakage caused by accidental turning'on the gas cocks will not result in gas leaking into a room as any such gas passing must pass into the combustion chamber C where it will be ignited by the pilot light. Any grease falling on layer 9 during broiling cannot clog the burner, as it will be consumed directly on the heated and glowing layer.

Thus my burner provides an even, flowing, in-

15 tense heat, eliminating danger from carbon excess pressures in'the otherwise closed chamber,

and these inlets 5b are pointed down away fromany persons or any combustible material which might be in the path of any gas flash.

' The burner will operate-regardless of the position in which it is placed, whether vertical, horizontal or otherwise, since the porous sections serve to thoroughly distribute the gases passing through to the primary combustion chamber, irrespective of the angularity of the axis of the burner; and the same flameless refractory bed appears at the surface of the aggregates regardless of the position of the burner.

.Bumer units as above described may be used in place of the customary burners in any types of gas cooking or heating stoves-or boilers.

I claim: v

1 A gas burner having a mixing chamber at one end and having its opposite end open; means for introducing gas and air into said chamber; non-combustible porous packing in the open end of said burner through which the gas-air mixture diffuses; an insulated casing forming a primary combustion chamber into which the open end of the burner projects; means for admitting secondary air into the combustion chamber; said casing also forming a secondary combustion chamber adjacent said primary chamber; and a.

porous relatively thick layer of non-combustible material separating said primary and secondary combustion chambers and adapted to be heated to a high degree by the products of combustion.

2. In a gas burner as set forth in claim 1, a preformed cartridge-like unit containing said packing; said unit substantially conforming with the size and shape of said burner and filling the upper portion thereof and being insertable and removable therefrom through said open end.

3."In a gas burner'as set forth in claim 1, a preformed cartridge-like unit containing said packing insertable and removable therefrom through said open end; said unit comprising a shell conforming with the length and shape of said burner and filling the upper portion thereof and being open at both ends, a screen extending across said shell and spaced from one end, a second screen across the other end, and said packing-being disposed between said screens.

4. In a gas burner as set forth in claim 1, a

conical cover over the porous packing, said cover having concentric series of stepped portions provided with openings between the steps so as to divert liquids from passing therethrough while permitting the gas-air mixture to enter the primary combustion chamber therethrough.

5. In a gas burner as set forth in claim 1, a cover over the porous packing of said mixing 1 chamber adapted to divert liquids therefrom while permitting the gas-air mixture to enter the primary combustion chamber; said cover comprising a superimposed series of conical rings of progressively decreasing diameters, the overlapping faces of adjacent disks being spaced apart.

6. In a gas burner as set forth in claim 1, a cover over the porous packing of. said mixing chamber adapted to divert liquids therefrom while permitting the gas-air mixture to enter the primary combustion chamber; said cover comprising a conical-shaped cap having. series of louvres formed therein.

7. A gas burner having a mixing chamber;.

combustion chamber adjacent said primary combustion chamber; and a porous relatively thick layer of non-combustible material separating said primary and secondary combustion chambers and adapted to be heated to a high degree by the products-of combustion.

8. In a gas burner as set forth in-claim 7, a

preformed unit containing said packing for said secondary mixing chamber; said unit substantialy conforming with the size and shape of said chamber and filling the upper portion thereof and being insertable and removable therefrom through .said open end; and said unit comprising a shell open at both ends, a screen extending across said shell and spaced from one' end, a second screen across the other end, and said packing being disposed between said screens.

9. For a gas burner having a mixing chamber having side walls and open at.its upper end; the lower end being closed-and provided with an inlet for-introducing gas and air into said chamber; a preformed unit confined within said chamber containing non-combustible porous packing, and substantially conforming with the area and shape of said mixing chamber and filling the upper portion thereof, said unit being insertable and removable therefrom through said open end; a casing forming a primary combustion chamber into which the open'end of the mixing chamber projects; a secondary combustion chamber adjacent said primary chamber; and a porous relatively thick layer of non-combustible material separating said primary and secondary combustion chambers and adapted to be heated to a high degree by the products of combustion. I

10. In a gas burner as set forth in claim 9, said unit comprising a shell open at both ends, a screen extending across said shell and spaced from one end, a second screen across the other end, and said porous packing being disposed between said screens.

11. In a gas burner, a gas-air mixing chamber open at its upper end; said chamber having side walls and a bottom wall provided with a gas-air mixture inlet, a non-combustible porous packing .in said chamber above the bottom wall through 12. In a gas burner as set forth in claim 11,

said cover comprising a superimposed series of conical rings of progressively decreasing diameters, the overlapping faces of adjacent disks be ingspaced apart.

13. In a gas burner as set forth in claim 11, said cover comprising a conical-shaped cap having series ofalouvres formed therein.

14. In a gas burner as set forth in claim 1i,.a

15. In a gas burner as set forth in claim 11, a

pre-formed unit containing said packing for said mixing chamber, insertable and removable therefrom through said open end; said unit comprising a shell conforming with the length and shape of said mixing chamber and being open at both ends, a screen extending across said shell and spaced from one end, a second screen across the other end, and said packing being disposed between said screens.

HENRY LOWE BROWNBACK.

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