US2373310A - Tubular pilot - Google Patents

Description

April 1o, 1945. B, HAYTER 2,373,310

T UBULAR PILOT Filed July 11, 1941 2 sheets-sheet 1 April 1o, 1945. B. HAYTER TUBULAR PILOT Filed July 11, 1941 2 sheets-sheet`2 Patented Apr. 10, 1945 TUBULAR PILOT Brucel Hayter, Santa Fe, N. Mex., assignor to Oil Devices, Santa Fe, N. Mex., a limited partnership of Illinois Application Jury 11, 1941,-seria1N'0. 401,890 3 Claims. (Cl. 158-91) My invention relates to an improvement in pilot lights forv liquid hydrocarbon burners, and has for one purpose the provision of a pilot light which shall employ thesame liquid fuel supply as the burner as a whole.

Another purpose is the provision of an improved pilot light which permits a very low Iturndown.

Another purpose is the provision of a pilot light which produces a minimum of smoking or carbon deposit.

Another purpose is the provision of an improved pilot light in which a pilot chamber is provided within and in communication with a pot type burner and associated with the normal liquid fuel supply means.

Other purposes will appear from time to time in the course of the specification and claims.

I illustrate my invention more or less diagram matcally in the accompanyingdrawings wherein: f

' Fig. 1 is a vertical axial section;

Fig. 2 is a section on the line 2 2 of Fig. 1;

Fig. 3 is a setion on the line 3 3 of Fig, 1;

Fig, 4 is a partial section similar to Fig. l through a variant form of the device;

Fig. 5 is a section on-the line'E-- 0f Fig. 4;

Fig. 6 is a section similar to Fig. 4 of a further variation of the device; and

Fig. '7 is a similar section of a still further variation.

propriete means for controlling the level of the fuel may also be employed.

I Il generally indicates a nozzle iittingextending v inwardly through `an aperture II in the Wall of Like parts are indicated 'by like symbols y 4outer housing or drum d which surrounds Athe Ipot I. 5 is a flange which extends inwardly from the drum l and supports the top flange of the pot. 6 is an air inlet aperture at the bottom of f the drum 4. 'l is any suitable fire ring having -a central aperture 8. As herein shown, it may simply be superposed upon the top of the pot.

9 is a liquid fuel inlet line from any source of liquid fuel not herein shown. Any suitable valve means not herein shown may be employed for varying or controlling the flow of fuel along the line 9. It will be understood also that any apthe drum 4 vand abutting against the outer face of the pot. I. I2 is a screw threaded portion projecting inwardly into the interior of the pot. I3 is a nut whereby the fitting I0 maybe secured in relation to the pot. Extending beyond the screw threaded portion I2 and the nut I3 is the nozzle proper Ill, placed somewhat above the bottom of the pot, and which may lhave its upper portion longitudinally slotted or cut away as at I5.

I6 is an air tube, preferably located inthe space between the pot I and the drum 4 and extending upwardly in close proximity to the outer wall of the pot I. Its top is open, as at Ilwhere by air may pass into the fuel passage I8 of theI fitting I0.

I9 is any suitable cleanout plug at the outer end of the tting I0.

20 generally indicates a foraminous pilot tube. f

It may be supported on the i'loor of the pot, for

example, by any suitable downwardly extending flange or llanges 2I. In the form of Figs. 1 and 2 it is indicated as a foraminous tube having an upturned lip 22, adjacent the outer end, providing an open end for the tube which is aligned with the central axis of the pot I. The inner end of the tube may extend about the nozzle lli and may for example a'but against the nut I3.

' In the form of Fig. 4 a foraminous tube 30 may be employed, which may be clipped on the end of the nozzle, as for example'by spring fingers o r the like 3l. The end may be closed, as at 32, or if desired, the closed end 312 may be omitted. It will be understood, of course, that the tube 30, may be supported, if desired, from the bottom of the pot, as is the tube 20.

In the form of Fig. 6 the foraminous tube 35 is employed, which is herein shown as open ended. It may be supported on the end of the nozzle as by spring ngers or the like 36, and it may be provided with a Venturi cone 3l. It may be advantageous, in connection with this Venturi cone, to employ oversize apertures 38 for locally increasing the air supply to the interior of the tube 3-5.

In the form of Fig. 7 the tube `35, in place of the sheet metal cone 3l, is provided with a Venturi element 40, which may be fitted within the inner end of the tube.

It will be realized that, whereas I have described and illustrated `a practical and operative device, nevertheless many changes may be made in the size, shape, number and disposition of parts without departing from the spirit of my invention. I therefore wish my description and drawings to be taken as in a .broad sense illustrative or diagrammatic, rather than as limiting me to my precise showing. The use and operation of my invention are as follows:

In the employment of pot type burners a liquid hydrocarbon may be supplied to the bottom of the pot, as in the forms herein shown. The liquid fuel is vaporized on the bottom of the pot in response to the heat of combustion taking place in the upper portion of the pot or above the pot. As the vaporized hydrocarbon rises, it mixes with the primary air flowing in through the apertures 2, to produce an initial mixture of air and vaporized hydrocarbon which is converted to the final combustible mixture by the secondary air flowing in through the apertures 3.,

At high stages of combustion, when a full supply of fuel flows through the line 9 and the nozzle lf3, the final mixture burns at or above the level I nd it advantageous also to provide a limiting means or shoulder, as shown for example at isa, to act as a dam and to backup some of the 'oil in the bottom of the inlet nozzle or passage. y

In the event that any carbon accumulates at the back of the dam and is not swept through the nozzle by the airand iuel owing therethrough, it has a wick action equivalent to the damming up of fuel in the bottom of the nozzle.

Basically, What I provide is a small smokeless oil burner operating at the tip of the main oil supply pipe. .The oil is vaporized before leaving the end of the pipe, and the dry ygas is mixed with air issuing from the same pipe at a velocity sufcient to stop burning back in the oil inlet. This gas and air mixture is then burned at a point near enough to the nozzle to provide the proper heat for vaporizing the oil before it leaves the nozzle.

of the secondary inlets il, and the heat of combustion causes the vaporization o1" the fuel progressively supplied to the bottom of the pot. The nre is controlled by controlling the volume of fuel delivered from the nozzle It. When, bythe use of any suitable valve control means, the supply oi the liquid hydrocarbon is reduced to a minimum, the small volume then is vaporized and burned at or about the pilot piece or shell or tu.

This primary mixture of vaporized hydrocarbon and air ow'ing in through the air tube it is burned within the pilot piece 2D or 30, the function of the holes inthe pilot piece being to balance the pressure inside the combustion compartment thus formed. Final combustion begins in the `pilot piece or housing and extends out through the holes. The pilot piece picks up'heat `from the heat of combustion and'radiates it back side of the pilot piece.

I find .it advantageous to slot or cut away the nozzle tip, as shown at l5, andthe mixture of air and hydrocarbon receives additional air as it ows along the terminal portion of the nozzle it. As soon as high fire isdesired and the ilow of fuel is increased, the fuel then flows in increasing v'olume down upon the bottom of the pot, and the level of combustion rises as the fuel supply increases, until full combustion has taken place at or above the secondary apertures 3.

In veffect I provide a rather deiinitely dened zone or area which is kept at a temperature considerably above the evaporation temperature of the oil, and the liquid oil owing through the passage la reaches this area or' zone at a temperature above vaporization. The hydrocarbon cracks but does not thereafter contact the liquid oil. As soon as the fuel is cracked, any solid particles are carried along with the air away from the liquid and are virtually in a gaseous state.

I nd it desirable to make the nozzle. of steel so that it will not readily transmit the heat back to the liquid hydrocarbon. lI employ a nozzle The air comingV through the oil pipe or nozzle supplies the primary air only, 'and the heat applied to the end of the nozzle supplies the means I which receives suiiicient heat completely to vaporize the liquid hydrocarbon before it escapes from the nozzle.- In order to keep the gas thus f formed from backring into the nozzle, air 'is delivered at a rate of flow above that of iiame propagation. Secondly, in order to maintain the nozzle heated to a sufficient temperature for complete vaporization of the fuel, it is necessary, not only that the nozzle extendin'to the pot, but that means be employed to localizepilotcombustion and to return heat to the nozzle tip.

I may iind it advantageous. as in the form of Figs. l to 3, to carry the tube 20 to the center of the pot( l and to have it discharge generally upwardly in the center of the pot. In the form of Figs. 1 and following, the end of the nozzle ld extends within the end of the pilot tube 20. Under some circumstances this is not necessary. I

' illustrate, for example, in Fig. 4 a tube 30 which which protrudes well into the combustion zone,

and I make the sidewall of the nozzle as thin as is possible with the necessary mechanical strength.. By slotting or cutting away the top of the nozzlefasy at l5, I obtain the result that thepoint of evaporation can be anywhere in the Atrough. so provided without permitting the fuel to drop ou as a liquid; also, without vaporizin the liquid too far back into the nozzle. l v

is aligned with but does not actually surround the end of the nozzle. y

' In the form of Figs. 6 and l I find it preferable to employ a Venturi collar within the tube' to increase the speed of movement of the air outwardly across the nozzle. The nozzle in Figs.l 4, 5 and 6 is notshown as actually slotted, but it will be understood that it may be slotted vor open at the top, as shown in the form of Figs. 1 to 3, or it may be left solid, as shown in Figs. 4 to '7.

In effect, after the combustible' gas hasbeen formed, I provide a supplemental combustion chamber which lies wholly within the pot itself, and I do not wish to be limited-in my claims to any speciiic form of localizing and heat reflecting means except so far as the limitation is spe-f cicalLv written into the claims.

' An important feature of my device is that the liquid hydrocarbon may be fed by gravity along the pipe, and a sumcient primary air supply is bottom thereof, and a generally radial tubular foraminous pilot member axially aligned with said nozzle and extending radially a substantially distance toward the center of the burner pot and having at its inner end a, discharge aperture adapted to permit the movement of gases into the burner pot, said nozzle being adapted and 1ocated to discharge fuel into'the outer end of the tubular pilot member.

2. In combination, in a pot type burner, a burner pot'having a circumferential -side wallr'and a bottom, a .liquid fuel pipe 'extending to the pot, a fuel nozzle in communication with the fuel pipe, extending generally radially and horizontally into the lower portion of the burner pot at a level adjacent the bottom thereof, and a generally radial tial distance toward the center of the burner pot 'and having at its inner 'end a discharge aperture adapted to permit the movement of gases into the burner pot, said tubular pilot member being supported at its inner end from the bottom of the pot and being supported at its outerend upon the fuel nozzle, said nozzle being adapted and located to discharge fuel into the outer end of the tubular pilot member.

3. In combination, in a pot type burner, a burner pot, having a sidewall and a bottom, a liquid fuel pipe extending to said pot, a fuel nozzle, in communication with the fuel pipe, extending generally radially into a lower portion of the burner pot, -said nozzle being adjacent but above the bottom of the' pot, and a tubular foraminous pilot member aligned with and in communication with the nozzle and extending generally radially from the nozzle and substantially toxthe center .of the burner pot, its outer end being positioned to receive fuel delivered from the nozzle, said pilot member having an upwardly turned terminal portion adjacent the axis of the burner pot, adapted to permit the movement of gases upwardlyin the center of the pot.

BRUCE HAYTER.

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