US2570554A - Radiant gas burner internally fired - Google Patents

Description

Oct. 9, 1951 B. HENWOOD RADIANT GAS BURNER INTERNALLY FIRED 2 Sheets-Sheet 1 Filed April 18, 1946 INVENTOR.

BY W

HTTJFA Ey J. B. HENWOOD RADIANT GAS BURNER INTERNALLY FIRED Oct. 9, 1951 2 Sheets-Sheet 2 Filed April 18, 1946 IN V EN TOR.

Patented Oct. 9, 1 951 RADIANT GAS BURNER INTERNALLY FIRED James B. Henwood, Bala-Cynwyd, Pa.-,- assignor to Selas Corporation of America, Philadelphia, Pa., a corporation of Pennsylvania Application April 18, 1946, Serial No. 663 003 My invention relates to gas burners, and is es.- pecially concerned with burners of the type in which a large fraction of the heat generated and developed by combustion of a combustible gas mixture is converted to radiant heat.

It has already been proposed to produce radiant heat in a body having an open cavity which is provided with an inner refractory lining or surface forming a combustion space. A combustible gas mixture is supplied to such space in which combustion of the mixture is accomplished to heat the surface thereof to incandescence. By accomplishing substantially all of the combustion of the mixture in the combustion space, high combustion temperatures are developed for effectively heating the surface or lining to a highly incandescent condition, thereby promoting the conversion of a large fraction of the heat developed and generated in the combustion space to radiant heat which is projected from the incandescent surface for doing useful work.

It is an object of the invention to provide an improvement in burners of this type, particularly to increase the heating capacity of a given size burner by projecting radiant heat from the refractory lining or surface thereof at a higher temperature or thermal head than heretofore.

The above and other objects and advantages ofthe invention will be more fully understood from the following description taken in conjunction with the accompanying drawings forming a part of this specification, and of which Fig. 1 is a frontelevation of a gas-fired radiant burner embodying the invention; Fig. 2 is a sectional view,-taken at line 2-2 of Fig. l, to illustrate the burner more clearly; Fig. 3 is an enlarged front view of the burner tip embodied in the burner of Figs. 1 and 2, partly broken away and in section, to illustrate details of the burner; and Figs. 4 and 5 are sectional views similar to Fig. 2 illustrating modifications of theinvention.

In Figs. 1 to 3 inclusive, I have illustrated one form of gas burner embodying the invention in which a large fraction or proportion of the heat generated and developed by combustion of a combustible gas mixture is converted ortranslated to radiant heat. The gas burner of Figs. 1 to 3 comprises a refractory burner block Ill of ceramic material provided with an outer metallic shell or jacket H. When. the burner block I0 "is mounted or incorporated in a refractory wall of heating apparatus like a kiln, furnace or lehr,

.for example, the ,outer metallic shell H is not necessary. As will be readily understood, a number .of burner blocks .IU may be distributed in=a Claims. (01. 158-99) wall of a heating chamber in any suitable niariner to produce the desired heating effect,

The burner block In is rectangular in cross section and formed of a number of ceramic parts or shapes including parts I2 and I3 which are united together by a suitable high temperature cement. As shown, the burner block 10 is formed with a central passage M which extends therethrough and terminates at a cup-shaped wall 15 formed at the front face of the refractory part [2. Within the passage I4 is disposed a metallic burner tube or sleeve l6 having the closed inner end thereof terminating in a cup-shaped space or cavity [1 at the front of the burner ID.

A passage I8 of sleeve [6 is adapted to be connected to a suitable source of supply of a premixed combustible gas mixture, it being understood that suitable controls (not shown) may be provided to control and adjust the pressure and rate at which such gas mixture is supplied to the burner Ill. The gas mixture in the passage 18 is subdivided into a plurality of gas streams by a multiplicity of discharge ports or small openings I9, 20 and 2| formed about the periphery of a wall section 22 of the sleeve 16. The gas mixture is discharged from the outlet ends of the discharge ports I9, 20 and 2 I, at the outer peripheral surface of the sleeve 5, and it is at these regions that the burner flames are produced and maintained.

The individual flames produced at the outlets of the discharge ports or openings l9 and 20 flare outwardly and project into narrow spaces 23 and 24 formed between three dished or concaveshaped wall members 25, 26 and 21. The individual flames produced at the Openings 2| flare outwardly and project into the cavity I! alongside the outer or exposed surface 28 of the outermost wall member 21.

The gas flames maintained at the outlets of the discharge ports I9, 20 and 2| effect such heating of the wall members 25, 26 and 21 that the outer surface 28 at the cavity side of the wall member 21 is heated to a highly radiant condition, as will be explained presently. The rims or peripheral edge portions of the wall members 25, 28 and 21 are held in overlapping relation between the front outer edge portion of the refractory part-l2and the inwardly extending flange portion of the refractory shape l3, as indicated at 29 in Fig. 1.

At the outer edges or rim portions of the wall members 26 and 21 are provided a series of openings 30 and 3| through which heated products of combustion are discharged from the spaces23 3 and 24, respectively. In addition, a series of openings 32 is provided in the intermediate wall member 26, adjacent to the discharge openings 30 and 3|, to permit flow of heated gases between the spaces 23 and 24 at the outer extremities thereof.

The inner end of the sleeve l6 including the wall section 22 -..thereof1-serves as atipfor the burner H] to effect the desired distribution of the combustible gas mixture at the discharge ports or small openings 19, 20 and 2|. In order to avoid excessive heating of-theinner end-of the sleeve I6, a suitable cooling agent, such as Water, for example, is circulatedtherethrough. --I

accomplish this by providing in the passage '18;

of sleeve IS a tubular member 33 to whichaicooling agent is supplied through -.an .;inle t;connec.- tion 34.

The cooling agent passes through the tubular member 33 to a space 35 at the closed inner end of the sleeve [6 which :is located beyond the -d-ischarge ports 21 -From-space 35 the:cooling agent passes through aseries of slots or channels 33 which are formed in the vwall section 22:between the regions thereof in .whichthe openings 19,20 and 2| are provided, as shown :mostclearly in Fig. 3. The channels-or slots 36communicate with an outer passage-3l of the sleeve Hi from which the cooling agent discharged through I an outlet connection 38.

When it is desired to operate the burner H], a

-premixed combustiblegas mixture, such as, for example, air and ordinary city-gas,-natural-gas or the like, is supplied to passage 18 of the burner sleeve [6 from a-suitable source ofsupply. -When the burner Iii is initially placed in operation, the gas mixture supplied thereto flows through the passagelB, discharge portswand 29, and spaces 23 and 24 from which it is discharged through the openings 33 and 3|, respectively. The gas mixture in the passage 18 is -.also subdivided by the discharge .ports 2| into a plurality "of small gas streams which project from thesleeve 46- and can be ignited immediately.

;The combustible gas mixture v -is1initia'.lly :sup-

'plied to the burner :sleeve lfiaat a relatively low pressure which may. be equivalent to 5;or'56 inches -of water column, forexample,- so 'that the gas mixture discharged from the spaces 23= and 24 can be ignited to produce and maintain-flames at the openingsf301and 3'l. Whenz theJfiamesare being maintained at the. openings 13!! :a-nd 3| ,2 the pressure of the gas mixture supplied to the :burner i0 is then reduced sufificiently to cause the flames to back fire from-theopenings ipfl and' 3 I ontothe wall section 22 .of the .burnerzsleeve t6. i-When this occurs a plurality of .flames are .produced combustion of the :gasxmixturewis-:accomplished in these spaces before the gas mixturez-reaches the outlets 3!].and 3|. 'Fromrthempening$30-.and 3| are discharged .streams of heated gases-consisting substantially entirely of heated products of combustion.

The refractory wall members 25, 2 6 and 2'! are of such shape and the flames project at such an angle from the axis of the burner, taken axially of the burner sleeve [6, that the flames are closely adjacent to and follow the surfaces of the refractory wall members and yet the inner cones thereof do not impinge against the surfaces to cause objectionable low temperature spots or "regions to be formed. Thus,-a group of-gas flames project into the narrow space 23 from a first series of discharge ports I9 alongside of and closely adjacent to the front surface of the wall member 25, while another group of gas flames project from a;sec0nd series of "discharge ports 19 alongside of and-closely-adjacent to the rear surface of the intermediate wall member 25. Similarly, the gas fiamesproject into the space 24 from two series of discharge ports 23 at regions alongside of and adjacent to the front surface of the intermediate wall member 23 and the rear surface of the outermost wall memberrl'l.

The gas flames projectifrom gdischargeiiports 2.! at'regions alongside of and; closely adjacentato the front or exposed surface 28 of the outermost wall member-.21. LThesegasfiames'maintainedat the cavity=side ofzthenutermost wall memberi2l effect such fheatingzof the router; surface r.28-';that the latter is .heated to :incandescence. -The',s gas mixture introduced-intothe cavityji'ioissubjected .to the intense radiant heat of the .outer :wal1=.surface 28, sothat substantially .completexburning of the gas .mixturemay-beaccomplished in ,the cavity beforethe:heatedigasesrpass xfromthe'open ends of .thecavity.

.The cavity side-2130f :the outermostref'ractory wall member 2? servesas a: heatradiatingsurface which is heatedcto a :high incandescentwtemperature and from which radiant heatis. projected: for doing useful'work. ,In .order toaproject radiant ,heat from the. surfaceZBofthe 'wall mernber 21;.at the highest possible temperature, ..combusticn:-of thexgas mixture: iseffectedatthe rear: side or surface thereof :as wellasaatzthe;exposed front-.side or 'surface'r28.

To effect optimumheatingzof:the1rear surface of the wall-member;Z'LtheJcombustiOn of thagas mixture is accomplished inzthe .icombustion space 24 whose .depth is relatively ,smallor shallow-and approximately :the .same ;over1a.:;maj or portion 201 its cross sectional area. :Due to the intense heat ing accomplished in the confined .combustion space 24 and theflamesawhichprojectcloselyadjacent to and alongside thezrear.surface;.-of:=the .outermost wall-.memberfl1,. such rear surfacexcan .be maintained .atran incandescent temperature at least as high aszthe. temperature .to awhich'fizhe heat radiating surface 28.;is -;rnaintained :Joy -the flames which project.ctrommhezdischarge ports 21.

Since the .rear side of the ewallzmember :21 forms a part :of .the iinner.refractory-lining.of the combustion space 724 :.to-.-which combustible gas mixture-is suppliedathrough vtwogroups. or series of discharge .ports ;20 while;combus.tible .gas. mixture is suppliedsthrough only ;one;group or series ..of discharge. ports-E21 .:over :the :outer surface 128,. it will .:beevidentithati the rear :surface of the outermost wallmember Zlmay he maintained at .a higher temperature :than-the exposed heat radiating surface328. :Undersuch operating conditions, heating of the reansu'rfaee of the wall memberlZ'l promotes :heating..of:;the opposite exposed ,surfaceg28. to aihighcincandescent temperature by conductionof .heat-lth-rough "the wall member. Hence; by pumping heattrom the rear side or surface oflthe wall member ii'il 5. to'the opposing heat radiatingsurface 28. the latter will be maintained at a high temperature or thermal head. Moreover, the gas streams issuing from the discharge ports 2| will be highly heated due to such pumping of heat through the wall member 21 to the heat radiating surface 28, thereby intensifying the combustion reaction and effecting combustion at the heat radiati surface 28 at an increased temperature.

The flames projected from one group of discharge ports 20 at regions closely adjacent to and alongside of the front surface of the intermediate wall member 26 not only promote the development of high temperature heating gases in the combustion space 24 but also effectively heat the front surface of that wall member to incandescence. Hence, the rear side or surface of the outermost wall member 21 is subjected to heat radiated from the front surface of the intermediate wall member 26, thereby contributing to the pumping of heat to the exposed heat radiating surface 28 to maintain the latter at the highest possible temperature.

The heated gases generated and developed in the combustion space 24 act to thermally shield the highly heated rear side or surface of the outermost wall member 21. By effecting com-. bustion of the gas mixture at the rear side of the intermediate wall member 26, the surface at the rear side is heated'to an incandescent temperature approaching the temperature to which the front surface of the wall member 26 is heated, thereby contributing to the heating of the intermediate wall member and the radiation of heat therefrom to the outermost wall member 21.

Moreover, by accomplishing combustion of the gas mixture at the rear side of the wall member 26 in the confined combustion space 23, intense heating is accomplished therein which heats the entire inner lining of the space 23 to incandescence. In this way the heat loss rearwardly from the outermost and intermediate wall membars) 26 and 21 is effectively retarded so that, for a given size radiant burner of the type herein described, the heating capacity is appreciably increased and a source of radiant heat is provided which is at an extremely high temperature or thermal head. 7 V

In the embodiment of Figs. 1 to 3 the heated gases generated and developed in the combustion spaces 23 and 24 are efiectively utilized by discharging such gases through the openings 30 and 3| at the front face of the burner ID. The heated gases discharged from the openings 30 and 3| mix with the high temperature heated gases generated and developed in the cavity I1 and pass outwardly from the latter to promote convection heating which augments the transfer of heat to work by radiant heat rays projected from the heat radiating surface 28. Such convection heating is utilized advantageously when, a number of radiant burners like the burner in are mounted or incorporated in the refractory walls of an enclosed heating space.

All or a part of the heated gases generated or developed by combustion of the combustible gas mixture may be withheld from the burner cavity 11. In Fig. 4 is illustrated a modification of the invention in which a part of the heated gases are discharged rearwardly from a burner Illa. The burner Illa is generally like the burner In just described and similar parts are'referred to by the same reference numerals. The burner I Ba differs from the burner Ill just described in that only two refractory wall members 21a and 26a are disposed in nested spaced-apart relation in the cup-shaped opening at the front of the re-- fractory part l2. The outer peripheral edge portion of the wall member 26a is secured at 39, as by cement, for example, to the front outer edge portion of the refractory part I 2. Similar 1y, theouter peripheral edge portion of the wall; member 21a is secured at 40, as by cement, for example, to the inwardly extending flange portion of the refractory part I3.

The gas mixture supplied to the passage l8 of sleeve IS in burner Illa passes through discharge ports 2| to produce a multiplicity of gas streams adjacent to and alongside the exposed surface 28a of the outer wall member 21a. The gas mixture also passes from the passage l8 through discharge ports 20 into the combustion space 24a. The heated gases developed by combustion of the gas mixture in space 24a flow through and outlet 30a of annular form into a number of spacedapart passages 4| which extend rearwardly from the front face of the burner 10a. The rear ends of the passages 4| communicate with an annular manifold 42 having an outlet 43.

. In the burner Illa of Fig. 4, the heat radiating surface 28a of the outer wall member is heated to a high temperature in a manner generally like that described above in connection with the em-v bodiment of Figs. 1 to 3. By effecting combustion of the gas mixture at the rear surface of the outer wall member 21a and accomplishing such combustion in the confined space 24a, the rear surface of the wall member 21a is heated to a higher temperature than the heat radiating surface 28a, so that flow of heat takes place by conduction through the wall member to the heat radiating surface from which radiant heat is projected.

While a second combustion space is not provided at the rear side of the wall member 260 in the burner Be, as in the embodiment first described, the rear side of the outer wall member 21a is still effectively shielded thermally by the heated gases in the combustion space 24a. Further, the heat radiated from the front surface of the inner Wall member 26a contributes to maintaining the rear surface of the outer wall member 2111 at a high incandescent temperature.

In order to reduce heat loss from the inner wall member 26a to the refractory part l2, gaps 44 are provided between these parts. Similar gaps 44 are provided in the embodiment of Figs. 1 to 3 between the innermost wall member 25 and the refractory part I 2. The gaps 44 form dead air. spaces which serve to thermally shield the inner wall members 25 and 26a in the burners l9 and Illa, respectively. Since the wall member 26a in the burner Illa only engages the refractory wall part l2 at the inner and outer regions of the cupshaped wall l5, a poo-r thermal conductive path is provided between these parts. By keeping the heat loss from the inner wall member 26a to a minimum, the inner wall surfaces of the combustion space 24a are maintained at a high incandescent temperature to promote heating of the exposed heat radiating surface 28a to a highly radiant condition.

. The burner [0b in Fig. 5 illustrates another modification ,of the invention in which all of the heated gases generated and developed by combustion of the combustible gas mixture are withheld from the burner cavity. In Fig. 5, in which parts similar to those in Figs. 1 to 4 are referred to by like reference numerals, the gas mixture passes from the passage l8 of sleeve IG- only through discharge ports 20 into the space 2412 formed :hetween spaced-apart iwall members 21b and .z-eb. rh ated gases developed and nera ed by combustion of the gas mixture in the space 1274b flow through openings 55 at the outer extremity of the wall member 2511 :into a second SPZLQB'fifi which overlies it espace 24b. Thehighly heated gases flow through the space it .and pass therefrom into a central op nin in communicates with an outlet d8 through-which the heated gases are discharged fromzthe'burner lflb. In order to position the .burner sleeve l6 accurately in the opening an apertured spider 4.9 may be provided in :the opening ill intermediate the ends thereof.

In the burner ldb the inner refractory'wall-surfaces of the combustion space 241) are heated :to

=escent temperature by the burning of the .gas mixtureaccomplished therein. .After the burner JEib has been in operation for an interval of time, .the refractory wall member 23b is heated to incandescence in its entirety and radiant heat is projected from the exposed outer surface 281). Although :no combustion of the gas mixture is effected. at the exposed surface 28b of theouter wall member 2%, such outer exposed surface is heated to a highly radiant condition by -conduction of heat through the outer wall member from the rear surface thereof. The fact that combustion of the gas mixture is accomplished at the rear surface of the outer wall memher 2lb, in the confined and narrow space 241), contributes significantly to the pumping of heat to the exposed heat radiating surface 28b to maintain the latter at a highly radiant condition.

In addition, the gas flames projected from the discharge ports 25 are closely adjacent to and alongside of the rear and front surfaces of the wall members ill) and 251), respectively, so that the gas mixture is subjected to radiant heating,

thereby intensifying the combustion reaction and effecting such combustion at extremely high temperatures. By flowing the heated gases through the relatively narrow space 45, such heated gases sweep over the rear surface of the wall member 26b and the cup-shaped wall 5 to heat these surfaces to incandescence. In this manner the heat loss from the inner wall member 2617 is effectively retarded and the front surf-ace of the wall member 25?) is maintained at a high incandescent temperature.

In view of the foregoing, it will now be understood that a radiant burner has been provided which is capable of releasing an exceedingly large amount of heat at a high thermal head in a given interval of time. The concave-shaped wall members are formed of suitable refractory material having good thermal conductive properties, such as silicon carbide or beryllium oxide, for example, which is capable of withstanding thermal shock and the high temperatures produced at the exposed heat radiating surface and in the crescent-shaped combustion spaces formed between the wall members.

The refractory wall members are of sufficient thickness to stand up under the burner operation.

conditions encountered. By way of example and without limitation, concave-shaped wall members one-fourth inch thick and formed of silicon carbide have been successfully employed in a burner generally like that of Figs. 1 to 3 having a heat radiating surface 28 of about 175 square inches. In such a burner like that being referred to and having only a single crescent-shaped combustion space about three-eighths inch deep formed .be-

tween two refractory wall members, the burner was operated :satisf actorily when supplied with .a gas mixture ,of air and ordinary city gas at ;a rate of about 500 009 B. t. in. per, hour. ,Under. such operating conditions the exposed heat ra-, diating surface was heated to temperatures [of 2800 .F. and higher when the burner was oper-v atedi-n the open.

The burner of the invention operates satisfac-e torily withslow :burning gases, such as methane and natural gas, for example, because the ex-- posed heat radiating surface is maintained :at an incandenscent temperature which is always :well above {the ignition temperature. Eurther, in my improved .burner the problem of blowoff of the gas flames, at. customary gas. mixture de livery pressures ranging up to five pounds per square inch, is completely absent.

lnxradiant burners of the kind described and illustrated, the concave-shaped wall membersare for-med with central apertures and lit snugly about the burner sleeve 15. While the refrace tory wall members fit snugly about the burner sleeve 1' t, a gas-tight. seal is not obtained between these parts because a slight space .must .:be provided therebetween to allow for expansion'which results when high burner temperatures are produced. The slight leakage :of .gas .mixture that occurs about the burner sleeve 46 at the apertures in the refractory 'wall members is insignificant, because the gases will pass .into the paths of flow provided which offer considerably less resistance to the flow of the gases. Moreover, any gases passing through theirefractory wall members about the burner sleeve is are carried along the surface .of the wall members by the injection action .of the gas streams issuing from the discharge ports of the burner sleeve.

Due to the slight spacing of the refractory wall members about the burner sleeve i=6, it has been found that the burners herein described may be initially ignited by simply applying a needle-like flame at the periphery of the burner sleeve which projects .into the combustion space or spaces at the rear of the outer refractory wall member.

-While several embodiments of the invention have been shown and described, such variations and modifications are contemplated which fall within the true spirit and scope of the invention, as pointed out in the followin claims.

What is claimed is:

l. A gas burner comprising a burner block having a central passage therethrough terminating at the small end of a cup-shaped depres sion at one face of the block, means including inner and outer cup-shaped wall members of refractory material nested in the depression and in spaced apart relation to provide a combustion space therebetween, the outer wall member forming a cavity and having the outer or exposed surface thereof providing a heat radiating surface, at least said inner wall member having a central aperture therein, passage means for a combustible gas mixture disposed in the central passage of said block and passing through the aperture in said inner wall member, said; passage means providing a series of flame'projecting orifices for projecting flames into the combustion space, and means forming an outlet for said combustion space adjacent to theouter; peripheral edge portion thereof.

2. A gas burner as set forth in claim 1, in which said burner block is formed with passage means. communicating with the outlet of the combus-.-.

tion space for discharging heated gases from said block at a region removed from said one face.

3. A gas burner as set forth in claim 1, in which the outer wall member adjacent the peripheral edge portion thereof is formed with a series of openings constituting the outlet for the combustion space.

4. A gas burner comprising a burner block having a central passage therethrough terminating at the small end of a cup-shaped opening at the one face of the block. inner and outer cup-shaped wall members of refractory material nested in the opening and in spaced apart relation to provide a combustion space therebetween, the outer wall member forming a cavity opening outwardly and having the outer or exposed surface providing a heat radiating surface, said inner and outer wall members each having a central aperture substantially in alignment with the passage in the block, passage means for supplying a combustible gas mixture disposed in the block and passing through the apertures in the inner and outer wall members, said passage means providing a series of flame projecting ori- .fices for projecting flames into said combustion space and another series of flame projecting orifices for projecting flames closely adjacent to and alongside the exposed or outer surface of the outer wall member, and said combustion space having an outlet adjacent to the outer peripheral portion thereof.

5. A gas burner as set forth in claim 4, including means for circulating a cooling agent through said combustible gas mixture supply means, especially the portion thereof adjacent to said inner and outer wall members.

6. A gas burner comprising a block of refractory material having a depression formed in one face thereof and an opening leading from the bottom of the depression to an opposite face of the block, a pair of cup-shaped wall members each having a flange on its periphery, said members being of different radii whereby when one is placed within the other a space will be left between them, means to attach said members by their flanges within the depression formed in said block, means to supply a combustible fuel mixture adjacent to the bottom of the space formed between said members to be burned therein, said means extending through the opening in said block, and means forming exhaust openings adjacent to the periphery of said space through which the products of combustion may be withdrawn.

'7. A gas burner comprising a block of refractory material having a cup-shaped depression formed in one face thereof and an opening extending from the bottom of. said depression to an opposite face of said block, a concave-shaped wall member mounted in said depression and spaced from said block to form a space of substantially the same shape as said depression in section, a fuel mixture supply means extending through said opening and an aperture in said member aligned with said opening, said means being provided with orifices through which thefuel mixture can flow to be burned in the' cup formed by said member to heat the front thereof, and with a plurality of orifices through which. the fuel mixture can be discharged to burn in. said space to heat the back of said member.

8. A gas burner comprising a block of refractory material formed with a cup-shaped depression in one face thereof and a passage extending from the bottom of said depression to an oppd'site face of said block, means having front and back faces enclosing a space forwardly of the surface of said depression substantially coextensive in size with said depression, and substantially of a uniform thickness, fuel supply means extending through said passage, said last mentioned means being provided with orifices opening into said space and through which fuel may be discharged to be burned in said space to heat the front face of said enclosing means by conduction through the material between said front face and said space.

9. The combination of claim 8 in which said fuel supply means is also provided with orifices extending in front of said enclosing means through which fuel can be discharged to 'be burned alongside of said front face to heat the latter directly.

10. A gas burner comprising a block of refractory material having a cup-shaped cavity formed in one face thereof and an opening extending through the block from the bottom of the cavity to an opposite face, first and second cup-shaped members received in nested relation in said cavity, said members being so shaped that a space is left between them, and each being provided with a flange at its periphery to engage said first mentioned face of the block and by means of which they can be definitely located, each member also being provided with an aperture aligned with said opening, and means extending through said opening and apertures through which a fuel mixture may be supplied. said means being provided with a plurality of orifices in front of said first cup-shaped member and a plurality of orifices opening between said cup-shaped members.

JAMES B. HENWOOD.

REFERENCES CITEDv The following references are of record in the flle of this patent:

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