US3192989A

US3192989A - Gas burner

Info

Publication number: US3192989A
Application number: US239879A
Authority: US
Inventors: Avy L Miller
Original assignee: Avy L Miller
Current assignee: TDY Industries LLC
Priority date: 1962-11-26
Filing date: 1962-11-26
Publication date: 1965-07-06
Anticipated expiration: 1982-07-06

Description

July 6, 1965 A. MlLLER 3,192,989

GAS BURNER Filed Nov. 26, 1962 3,192,989 GAS BURNER Avy L. Miller, 13246 Saticoy St., North Hollywood, Caiif. Filed Nov. 26, 1962, Ser. No. 239,879 11 Claims. (Cl. 158-114) The present invention relates generally to burners for` gaseous fuels, such as natural gas or artificial gaseous fuel, an example of which is a propane-air mixture having a B.t.u. content similar to natural gas. More particularly, the present invention relates to a gas burner of elongated form such as used in gas furnaces and water heaters of the horizontal heat exchange tube type.

In gas burners of the type under consideration it isdesired to minimize the over-all dimensions of the burner construction and hence of the equipment in which it is incorporated, without limiting the length of the fuel orifice portion of vthe burner. It is further desired to equalize the iow of fuel through the burner orifices regardless of their location with respect to the supply of gaseous fuel to the burner. The burner according to the present invention minimizes the dimensions of both its horizontal and vertical profiles and employs a distributing chamber construction for promoting -a uniform ame along the burner length.

A further consideration in the design of gas burners is that the burner orifices be large enough to minimize the danger of plugging thereof by foreign matter at the exterior of the burner, while, at the same time, preventing flash-back through the burner orifices which might establish burning within the burner itself. Such flash-back of flame through the burner orifices may occur with any gaseous fuel, but is particularly apt to occur when using an artificial gas-air mixture, such as propane-air, which mixture is injected into an originally air-filled burner chamber. The resultant mixture of chamber air with the United States Patent() mixed gas-air may produce an explosive mixture, which, v

if ignited through the large burner orifices, will cause flash-back and burning Within the burner chamber. According to the present invention ignition is delayed at the large -orilices until the incoming gaseous fuel has scavenged the air out of the burner chamber so that flash-back will no llonger occur. In the specific embodiment, initial ignition is secured through small burner orifices at the inlet end of the burner and outside of the heater zone in whichV orifice plugging is more likely to occur. Y

It is therefore an object ofthe present invention to provide an improved burner for gaseous fuels.

Another object of this invention is the provision'of an improved gas burner having shortened vertical and horizontal profiles and even distribution of gaseous fuel'flow through the burner orifices.

A further object of this invention is the provision of an improved gas burner construction having an optimum distribution chamber for even'distribution of gaseous fuel through the burner orifices, with minimized vertical and horizontal dimensions for the burner.

A still further object ofl this inventionlis the provision of an improved burner for gaseous fuels having relatively large burner orifices to minimize the exterior `plugging thereof, together with means for delaying ignitionv at these ,burner orifices until the air in the chamber supplying the same has been pushed out by the incoming fuel.

These and other objects and features of the invention will be readily apparent to those skilled in the art from the following specification and the appendedr drawing illustrating a presently preferred embodiment of the invention, in which `Y FIGURE l is a perspective viewA of a gaseous fuel .burner according to the present invention; Y

FlGURE 2 is a vertical longitudinal sectional view through the burner of FIGURE 1; and

FIGURE 3 is a transverse vertical sectional view at the line 3 3 of FIGURE 2.

The presently preferred embodiment ofthe invention selected for illustration and description herein comprises a burner 11 having a main orifice section 12 and an ignition orifice section 13. The burner has an elongated body 14 of which the inlet end 15 is generally circular in crosssection, with the walls diverging in Vopposite directions from a minimum-diameter venturi throat 16. The venturi passage is disposed about a gas inlet pipe 17 leading from a gaseous fuel supply manifold 18. Combustionair enters the venturi passage through the opening 19 and mixes with incoming fuel.

The portion of the burner body 14 inwardly of the venturi throat 16 eneloses a diffusion tube portion 21 of progressively increasing area, and a distribution chamber 22. The diffusion tube portion of the burner extends to the Vertical plane passing through the point 23, while the distribution chamber extends from the plane passing through the point 24. It is therefore seen that the diffusion tube and distribution chamber of'thegburner overlap to decrease the over-all length or horizontal profile of the burner. Feedingthe gaseous fuel to the burnerl distribution chamber at an end thereof decreases the overall height or vertical profile of the burner. The gaseous fuel expands and slows in the diffusion tube 21 to convert Vits kinetic energy due to its liow velocity intopressure.

The top wall of the body portion 14 o f the burner is provided with transversely-extending, hollow, upward pro-` jections 25 which also extend outwardly from the main body of the burner and form a plurality of transverse chambers 26 communicating with the distribution chamber 22. In the top walls of the projections 25 are disposed the relatively large diameter main burner orifices 27.`

From the point 23 to the end of the burner the crosssectional area of the distribution chamber 22 decreases, preferably along a substantially exponential curve at the bottom wall 28,'with the

side walls

30 and 30 of the body portion 14 at this mainoriiice section of the burner being substantially flat. The curve' of the Wall 28 is modified at the end 29 of the burner to provide a thickening of the body of the burner thereat for increased strength.

A supporting arm 31 is integrali with and extends from the closed end of the burner to be received within a suitable supporting socket 32; At its inletend, the burner is provided with `an angle mounting bracket `33 integral therewith adapted to engage a supporting ledge 34. An integral rib 35 depends from the inlet end of the burner Y to engage a stationary support 36. Y

A pair of transverse spoilers or baie

plates

37 and 3 are mounted across the; inlet portion of the distribution chamber 22 and spaced from both the top and bottom t walls thereof. The

baiies

37 and 38 impede the free lioW of gaseous fuel through the distribution chamber, cause turbulence, and by decreasing the velocity of flow, con- Agaseous fuel intofpressure in the centralrpart of thedistribution chamber 22 to insure vthe proper fiow of gaseous fuelV through the burner orifices located thereatf VIf not otherwise prevented, theV gaseous fuel owing through the distribution chamber 22 will -impinge on the end wall of the chamberrand have a high rate of flowthrough -tend to solidify and clog the burner orifices.

3% then end burner orifices. To convert this flow velocity into pressure energy, a further baie 41 extends across the chamber 22, projecting upwardly from the bottom wall The expanding area of the diffusion tube, the

bafiies

37, 38, -39 and 41, and the exponential bottom wall 2S all combine to effect a proper pressure distribution within the distribution chamber 22, so that substantially uniform flow of gaseous fuel is effected through the burner orifices 27. e

Under certain conditions of operation, eg., in water heaters,particularly of thescontinuous fiow type, the outer surfaces of the heat exchange tubes will be below the `dew point of the combustion gases, `so that water will ,fill with the ambient air, and the incoming gaseous fuel may mix with this air so as to produce an explosive mixture within the distribution chamber 22; If thereafter the burner is ignited through the relatively large orifices 27, flash-back of flame may occur and burning be Vestabilshed within the distribution chamber 22.

To prevent such flash-back action, an ignition section 13 is provided for the burner. This ignition section is lmade up of one or more (two being shown in the draw- Vmg) top body wall projections 45 providing chambers 46 communicating with the distribution chamber 22 at its inlet end and therefore located between the inlet of the burner and the main burner orifices 27. The top walls o f the projections 45'are provided with relatively small diameter orifices 47 whichk are located outside of the zone .of condensate fall so that they are less likely to become clogged or plugged. A pilot burner 4S is located adjacent to one end of the projections 45, preferably alongside the -last orifice t t7 therein. The pilot burner 48 is continuously -supplied with gas, as indicated by the legend, and burns constantly to provide an ignition flame for the burner fuel.

In the ignition operation when-fuel is supplied to the burner, the initial mixture of gaseous fuel and the air enclosed within the diffusion tube21 passes out through the small orifices 47 and is ignited by the flame of pilot burner 4S. Due to the small diameter of the orifices 47, there is little or no danger of a flash-back of flame through :these small orifices whose walls would cool any flame attempting to pass therethrough below the ignition temperature. Ignition of fuel will occur Vin succession across orifices 47 in the projection or projections 45, and by the time it jumps to the adjacent large burner orifices 27,' the 'explosive mixture will have been scavenged from the distribution chamber 22 thereat, so that the fuel mixture Ycoming through'the large openings will be a proper mixture for combustion, and flash-back will not occur. The time delay is very short, but so is thetime required to iscavenge the excess air andl fuel mixture from the distribution chamber. Inmany instances a single projection 45 will give a sufficient delay to prevent flash-back through `the large burner orifices, but if Ygreater delay time isdesired, two or a larger number of projections with small orifices may be provided in the ignition section. As a further refinement to insure proper ignition, a supplementary orifice 49 may be provided at the edge of the projection 45 to direct the fuel issuing therefrom at an angle directly into the flamefrom the pilot burner 48.

Flash-back through the large burner orifices may occur with gaseous fuel, but is particularly likely to occur with an artificial gas-air mixture, where the artificial gas,

such as propane, is diluted with air to secure the same Btu. content as natural gas, for example, 1400 B.t.u.

per cubic foot. This air and gas mixture mixes with the initial air in the diffusion chamber 2l and the distribution chamber 22 to produce a resulting mixture which might be explosive and tend to flash back if ignited at the larger diameter orifices 27. rfhe smallerr orifices 47 provide for safe ignition of the fuel thereat and give a short 1o time in which the explosive mixture is scavenged from the distribution chamber.

While a certain preferred embodiment of the invention has been specifically illustrated and described, it will be understood that the invention is not limited thereto, as

l5 many variations will be apparent to those skilled in the art, and the invention is to be given its broadest interpretation within the terms of the following claims.

I claim:

l. A Vgas burner having an elongated body providing a distribution chamber at one end and a forwardly diverging diffusion chamber at its opposite end communieating with the adjacent end of the distribution chamber, said diffusion chamber having a fuel inlet end opposite the end communicating with said distribution chamber;

Vmeans providing burner exit orifices for the gaseous fuel at the top of said body portion and extending substantially throughout the length of the distribution chamber in communication therewith, the bottoni wall of said distribution chamber progressively approaching the top 39 wall to decrease the cross-sectional area of the distribution chamber from the end of the diffusion chamber to the closed end of the distribution chamber; and a transverse baffle in the inlet portion of the distribution chami ber` between the side walls and spaced from the top and 3U bottom `walls thereof and with the plane of the baille 4substantially at right angles to the axis of the burner body to slow the ow of gaseous fuel and cause turbulence to increase the pressure Vwithin the distribution chamber.

2. The gas burner as defined in claim i in which the i0 bottom wall of the distribution chamber follows substantially anexponential curve from the diffusion chamber to adjacent the closed end of the distribution chamber.

3. A gas burner having an elongated body providing -a distribution chamber at one end and a diffusion cham- 1" Vber at its opposite end communicating with the adjacent end of the distribution chamber; means for providing for the entrance of gaseous fuel and combustion air at the inlet end of said diffusion chamber opposite said distribution chamber; meansproviding exit orifices for the gaseous 0 fuel at the top of said body portion `and extending substantially throughout the length of the distribution chamber in communication therewith, the bottom wall of said distribution chamber progressively approaching the top wall to decrease the `cross-sectional area of the distribution chamber from the end of the diffusion chamber to the4 closed end of the distribution chamber; and a transverse baffle in the inlet portion of the distribution chamber between the side walls and spaced from the top and bottom walls thereof to slow the fiow of gaseous fuel and cause turbulence therein to increase the pressure within the distribution chamber, the burner orifices above the major length of said distribution chamber having a relatively large diameter to lessen the probability of plugging of the orificeswith external foreign matter depositing on the burner, the burner orifices at the inlet end of the distribution chamber having a relatively smaller diameter to provide for initial ignition thereat Without danger of hash-back of flame therethrough and providing a short 70 time delay before ignition at the larger burner orifices in Awhich initial air may be scavenged from the distribution chamber and flash-back of flame through the larger burner orifices inhibited.

4. A gas burner having an elongated body yproviding 75a distribution `chamber at one end and a diffusion chamvber at its opposite end communicating with the adjacent end of the distribution chamber; means providing for the entrance of gaseous fuel and combustion air at the inlet end of said diffusion chamber opposite said distribution ber in communication therewith, said diffusion and distribution chambers overlapping a substantial distance so -that the incoming fuel continues to expand within the inlet end of the distribution chamber, said distribution chamber having substantially parallel side walls and a bottom wall which progressively approaches the top wall to decrease the cross-sectional area of the distribution `chamber from the end of the diffusion chamber overlap ,to adjacent the closed end of the distribution chamber;

and a transverse baffle in the inlet portion of the distribution chamber extending between the side walls and spaced from the top and bottom walls thereof to further ,slow the ow of gaseous fuel and cause turbulence and increase in pressure within the chamber, the burner orifices above the major length of said distribution chamber having a relatively large diameter to lessen the probability of pluggingof the orifices with external foreign matter .depositing on the burner, the burner orifices at the inletend of the distribution chamber having a relatively smaller vlarger burner orifices inhibited.

5. A gas burner having an elongated body providing a distribution chamber at one end and a diffusion chamber Vat its opposite end Acommunicating with the adjacent endA of the distribution chamber, said diffusion chamber having a main fuel supply inlet end opposite the end communicating with said distribution chamber for passage of gaseous fuel from a gas source through the diffusion chamber into the distribution chamber; means providing burner exit orifices for the gaseous fuel at the top of said body portion extending substantially throughout the length of the distribution chamber in communication therewith, the orifices at the fuel supply inlet end of said distribution chamber having a relatively smaller diameter and providing for initial ignition without danger of flashback and for a small time delay in the spreading of ignition to the remaining orifices; and said remaining orifices having a relatively larger diameter to inhibit plugging thereof from external deposited material.

6. A gas burner having an elongated body providing a distribution chamber at one end and a diffusion chamber at its opposite end communicating with the adjacent end of the distribution chamber, said diffusion chamber having a main fuel supply inlet end opposite the end communicating with said distribution chamber for passage of gaseous fuel from a gas source through the diffusion chamber into the distribution chamber; and means providing burner exit orifices for the gaseous fuel at the top of said body portion extending substantially throughout the length of the distribution chamber in communication therewith, the orifices at the fuel supply inlet end of said distribution chamber having a relatively smaller diameter and providing for initial ignition without danger of ash-back and for a small time delay in the spreading of ignition to the remaining orifices, and said remaining orifices having a relatively larger diameter to inhibit plugging thereof from external deposited material, said inlet end smaller diameter orifices covering a sufficient distance to provide for scavenging of initial air and any explosive mixture of gaseous fuel therewith from the distribution chamber before the fuel is ignited at the larger diameter orifices.

7. A gas burner having an elongated body providing a distribution chamber at one end and a forwardly diverging diffusion chamber at its opposite end conmmunicating with the adjacent end of the distribution chamber, said diffusion chamber having a fuel inlet end opposite the end communicating with said distribution chamber; means providing burner exit orifices for the gaseous fuel at the top of said body portion and extending substantially throughout the length of the distribution chamber in communication therewith, the bottom wall of said distribution chamber progressively approaching the top wall to decrease the cross-sectional area of the distribution chamber from the end of the diffusion chamber .tothe closed end of the distribution chamber; a transverse bafe in the inlet portion of the distribution chamber between the side walls and spaced from the top and bottom walls thereof and with the plane of the baffle substantially at right angles to the axis of the burner body, to slow the flow of gaseous fuel and cause turbulence to increase the pressure within the distribution chamber; and a second transverse bafiie in contact with and extending upwardly from the inclined bottom wall centrally of the distribution chamber a sufficient distance to further impede flow and cause turbulence and pressure increase thereat.

8. A gas burner having an elongated body providing a distribution chamber at one end and a forwardly diverging diffusion chamber at its opposite end communicating with the adjacent end of the distribution chamber, said diffusion chamber having a fuel inlet end opposite the end communicating with said distribution chamber;

Vmeans providing burner exit orifices for the gaseous fuel at the top of said body portion and extending substan- -tially throughout the length of the distribution chamber in communication therewith, said diffusion and distribution chambers overlapping a substantial distance in which the diffusion chamber continues to diverge so that the incoming fuel continues to expand with reduction in velocity and increase in pressure within the inlet end of i the distribution chamber, said'distribution chamber having substantially'parallel side walls and a bottom wall lwhich progressively approaches the top wall to Vdecrease the cross-sectional area of the distribution chamber from.

Ythe end of the diffusion chamber overlap to adjacent the closed end of the distribution chamber; and a transverse baffie in the inlet portion of the distribution chamber extending between the side walls andV spaced from the top and bottom walls thereof and with the plane of the bafiie substantially at right angles to the axis of the burner body to further slow the fiow of gaseous fuel and cause turbulence and increase in pressure within the chamber.

9. A gas burner having an elongated body providing a distribution chamber at one end and a forwardly diverging diffusion chamber at its opposite 4end communieating with the adjacent end of the distribution chamber, said diffusion chamber having a fuelnlet end opposite the end communicating with said distribution chamber; means providing burner exit orifices vfor the gaseous fuel at the top of said body portion andV extending substantially throughout the length of the distribution chamber in communication therewith, said diffusion and distribution chambers overlapping .a substantial distance in which the diffusion chamber continues to diverge so that the incoming'fuel continues to expand with reduction in velocity and increase in pressure Within the inlet end of the distribution chamber, said distribution chamber having substantially parallel side walls and a bottom wall which progressively approaches the top wall to decrease the cross-sectional area of the distribution chamber from the end of the diffusion chamber overlap to adjacent the closed end of the distribution chamber, said bottom wall Y following substantially an exponential curve from the end of the diffusion chamber overlap to adjacent the closed end of the distribution chamber; and a transverse bafiie in the inlet portion of the distribution chamber extending between the side walls `and spaced from the top and bottom walls thereof and with the plane of the baille substantially at right angles to the axis of the burner body to further slow the flow of gaseous fuel and cause turbulence and increase in pressurewithin the chamber.

1G. A gas burner having an elongated body providing a distribution chamber at one end and a forwardly diverging diffusion chamber at its opposite end communieating with the adjacent end of the distribution chamber, said diffusion chamber having aV fuel inlet end opposite the end communicating with said distribution chamber; means providing burner exit orices for the gaseous fuel atrthe top of said body portion and extending substantially throughout the length of the distribution chamber in communication therewith, said diffusion and distribution chambers overlapping a substantial distance in which the diffusion chamber continues to diverge so that .the incoming fuel continues to expand with reduction in velocity and increase in pressure within the inlet end of the distribution chamber, said distribution chamber having substantially parallel side walls and a bottom Wall which progrestively approaches the top wall to decrease the cross-sectional area of the distribution chamber from the end of the diffusion chamber overlap to adjacent the closed end of the distribution chamber; a transverse baffle in the inlet portion of the distribution chamber extending etween the side walls and spaced from the top and bottom walls thereof and with the plane of the baie substantially at right angles to the axis of the burner body to further slow the ow of gaseous fuel and cause turbulence and increase in pressure Within the chamber; and a transverse bafe in contact with and extending upwardly from the inclined bottom wall generally centrally of the distribution chamber a sufficient distance to further impede fuel ow and cause turbulence and pressure i11- crease in the central portion of thel chamber.

11. A gas burner having an elongated body providing a distribution chamber at one end and a forwardly diverging diffusion chamber at its opposite end communicating with the adjacent end of the distribution chamber, said diffusion chamber having a fuel inlet end opposite the end communicating with said distribution chamber; means providing burner exit oriiices for the gaseous fuel at the top of said body portion and extending substantially throughout the length of the distribution chamber in communication therewith, said diffusion and distribution chambers overlapping a substantial distance in which the diffusion chamber continues to diverge so that the incoming fuel continues to expand with reduction in velocity and increase in pressure within the inlet end of the distribution chamber, said distribution chamber having substantially parallelside walls and a bottom wall which progressively approaches the top wall to decrease the cross-sectional area of the distribution chamber from the end of the diffusion chamber overlap to adjacent the closed end of the distribution chamber; a transverse baffle in the inlet portion of the distribution chamber extending between the side walls and spaced from the top and bottom walls thereof and with the plane of the bafe substantially at right angles to the axis of the burner body to further slow the ow of gaseous fuel and cause turbulence and increase in pressure within the chamber; a transverse batile in contact with and extending upwardly from the inclined bottom Wall generally centrally of the distribution chamber a suiicient distance to further irnpede fuel ow and cause turbulence and pressure increase in the central portion of the chamber; and a transverse baie in contact with and extending upwardly from the bottom wall adjacent the closed end of the distribution chamber to impede gaseous ow and cause turbulence thereat and shield the chamber end from direct impact by the tiowing gas.

References Cited by the Examiner UNITED STATES PATENTS l,077,073 10/13 HOOk.

1,451,072 4/23 Holistetter 158-104 1,823,621 9/31 Methudy 158-115 1,830,393 11/31 Guerink et al. 158-104 X 1,836,370 12/31 Gercich et al 158-104 X 2,755,851 7/56 Dow et al. 158-114 2,808,047 10/57 .laye et al.

FOREIGN PATENTS Y 4,205 1910 Great Britain.

JAMES W. WESTHAVER, Primary Examiner. FREDERICK L. MATTESON, JR., Examiner.

Claims

1. A GAS BURNER HAVING AN ELONGATED BODY PROVIDING A DISTRIBUTION CHAMBER AT ONE END AND A FORWARDLY DIVERGING DIFFUSION CHAMBER AT ITS OPPOSITE END COMMUNICATING WITH THE ADJACENT END OF THE DISTRIBUTION CHAMBER, SAID DIFFUSION CHAMBER HAVING A FUEL INLET END OPPOSITE THE END COMMUNICATING WITH SAID DISTRIBUTION CHAMBER; MEANS PROVIDING BURNER EXIT ORIFICES FOR THE GASEOUS FUEL AT THE TOP OF SAID BODY PORTION AND EXTENDING SUBSTANTIALLY THROUGHOUT THE LENGTH OF THE DISTRIBUTION CHAMBER IN COMMUNICATION THEREWITH, THE BOTTOM WALL OF SAID DISTRIBUTION CHAMBER PROGRESSIVELY APPROACHING THE TOP WALL TO DECREASE THE CROSS-SECTIONAL AREA OF THE DISTRIBUTION CHAMBER FROM THE END OF THE DIFFUSION CHAMBER TO THE CLOSED END OF THE DISTRIBUTION CHAMBER; AND A TRANSVERSE BAFFLE IN THE INLET PORTION OF THE DISTRIBUTION CHAMBER BETWEEN THE SIDE WALLS AND SPACED FROM THE TOP AND BOTTOM WALLS THEREOF AND WITH THE PLANE OF THE BAFFLE SUBSTANTIALLY AT RIGHT ANGLES TO THE AXIS OF THE BURNER BODY TO SLOW THE FLOW OF GASEOUS FLOW AND CAUSE TURBULENCE TO INCREASE THE PRESSURE WITHIN THE DISTRIBUTION CHAMBER.