US2355416A - Oil pilot with supplemental air supply - Google Patents

Description

Aug. 8, 1944. J. L.. BRI-:ESE

QIL PILOT WITH SUPPLEMENTAL AIR SUPPLY Filed July ll, 1941 2 Sheets-Sheet l www OOOOOOOOOOOOOOOOOOOOO) 09060000000000000000 j """3 Aug. 8, 1944.

J. L. BREESE OIL PILOT WITH SUPPLEMENTAL AIR SUPPLY Fiied July 11, 1941 Z'Sheets-Sheet 2 Patented ug. -8, 1944 OIL PILOT WITH SUPPLEMENTAL AIB SUPPLY James L. Breeae, Santa Fe, N. Mex., assigner to Oil Devices. Santa Fe, N. Mex., a limited parl'.-v

nership of Illinois Application July 11, 1941, Serial No. 401,917

3 Claims. (Cl. 158-91) My invention relates to an improvementin pilot lights for liquid hydrocarbon burners, and has for one purpose the provision of a pilot light which shall employ :the same liquid fuel supply as the burner as a whole.

Another purpose is the provision of an improved pilot light which permits avery low turndown.

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 plot 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.

I illustrate my invention more or less diagrammatically in the accompanying drawings wherein:

Fig. 1 is a vertical axial section;

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

Fig. 3 is an elevation of the chimney structure shown in Fig. 1;

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

Fig. 5 is a similar section through a further variation;

Fig. 6 is a similar section through a further variation;

Fig. 'l is a section on the line 1-1 of Fig. 6;

Fig. 8 is a partial section through a variant form of the device; and

Fig. 9 is a partial section through a still further variation.

Like parts are indicated by like symbols throughout the specification and drawings.

Referring to the drawings, I generally indicates a burner pot having a plurality of primary air inlets 2 located at various levels in the wall ofthe pot. I may employ any satisfactory means for admitting secondary air, but I illustrate herein a plurality of closely spaced secondary inlets 3 located adjacent the top of the pot. Any suitable means may be employed for supplying air through the apertures 2 and 3. I illustrate for example an outer housing or drum 4, which may be connected to the pot I as by the flange 5. 6 is an air inlet aperture at the bottom of the drum 4. 1 is any suitable fire ring having a central aperture 8. As herein shown, it may simply be superposed upon the top of the pot.

3 is a liquid fuel inlet line from any source of liquid fuel not herein shown. Any suitable valve means, diagrammatically indicated as 3a, may be used for varying or controlling the flow of fuel through the line 9; It will be understood, also. that any appropriate means for controlling the level of the fuel may also be employed, such as a conventional float chamber.

I0 generally indicates a nozzle fitting extendy ing inwardly through an aperture II in the wall of the drum 4 and 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 may be secured in relation to the pot. Extending beyond the screw threaded portion I2 and the nut I3 is the nozzle proper I4, placed somewhat above the bottom of the pot, and which may have its upper portion longitudinally slotted or cut away, as at I5.

I6 is an air tube, preferably located in the space between the pot wall and the drum 4 and extending upwardly in close proximity to the outer wall of the pot I. 'I'he top is open, as at I1, and is higher than the highest possible level of fuel delivery. Air may pass therethrough into the fuel passage I8 of the iltting I0. I3 is any suitable cleanout plug at the outer end of the tting III. I8a is a dam or offset portion in the passage I8, which is eifective to back up fuel in the passage I8.

20 generally indicates a pilot housing or chimney open at the top, as at 2|, and is herein shown as resting upon the bottom of the pot, but it will be understood that any suitable clearance may be indicated, as at 22, whereby excess oil may flow outwardly below the lower edge of the chim' ney. The chimney may be mounted in any suitable fashion in relation to the nozzle tting, as by the provision of a rear wall 23 having an edge portion extending into the slot 24 of the nut I3. 25 is an air inlet aperture in the pot aligned with the interior of the supplemental compartment 23. It will be noted that the chimney 2|) y and the compartment 26 are-both provided with of the pot I. The passage 30 has a downwardly bent end 32 which delivers air downwardly toward the nozzle tip.

Referring to Fig. 5, I illustrate a shorter chimney 20a and a passage member 30a similar to 3@ at its lower end.

Referring to theform of Fig.` 6, .'Irillustra'te a perforated box 4l) having an upper portion aligned with the air inlet aperture 3l and being downwardly and rearwardly-recurved as at 4|,

providing in effect a streamlined passage for the` direction of air toward the nozzle. the passage expanding in cross sectional area toward the bottom.

Referring to the form of Fig. 8, I illustrate a supplemental air inlet passage 50 located between the pot i and the drum 4, with an open top 5|. It is recurved at the bottom, as at 52, and delivers air into the pot in line with an aperture 53 in the foraminous housing 54 which surrounds the nozzle.

Referring to the form of Fig. 9, the foraminous housing 54 is connected with the air inlet aperture 3l' by a bent passage 55, whereby air from the space between the pot I and the drum 4 is de1ivered through'the top of the housing 54. Both housings 54 may be provided, if desired, with downwardly and inwardly inclined end walls 55, which may be either perforated or solid.

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 i4, the final mixture burns at or above the level of the secondary inlets 3, and the heat of combustion causes the Vaporization of the fuel progressively supplied to the bottom of the pot. The fire is controlled by controlling the volume of fuel delivered from the nozzle I4. When, by the use of any suitable valve control means, the supply of the liquid hydrocarbon is reduced to a. minimum, the small volume then is vaporized and burned at or in the various chimneys or perforated housings shown in various forms of the device.

Primary air may be supplied to the fuel flowing through the nozzle by means of the air tube I6. The nozzle and the liquid hydrocarbon owing through it are heated by the pilot combustion, and the hydrocarbon is vaporized by the time it reaches the end of the nozzle I4. This primary mixture of vaporized hydrocarbon and of the air flowing in through the air tube IB receives an additional supply of air through the walls of the various chimneys or pilot housings, and final combustion takes place in or about `the pilot piece or housing.

I find it advantageous to slot or cut away the nozzle tia-asat i 5,-` and the mixture of Y' air and hydrocarbon'freceives additional air-as it -iiovvsy along the terminal ,portion of the -nozzle i4.- As soon'as high fire is desired and the flow oi Vfuel is increased,v the fuel then flows in increasing volume 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 effect I provide a rather definitely dened zone or area which is kept at a temperature considerably above theV evaporation temperature of the oil, and itheliquid oil flowing through the passage i8 reachesthis area or zone at a temperature below its cracking point.

I find it desirable to make the nozzle of steel so that it will not readily transmit the heat back to the liquid hydrocarbon. I employ a nozzle which protrudes well into the combustion zone, and I make the side wall of the nozzle as thin as is possible with the necessary mechanical strength. By slotting or cutting away the top of the nozzle, as at i5, I obtain the result that the point of evaporation can be anywhere in the trough so provided without permitting the fuel to drop off as a liquid; also, without heating the liquid too far back into the nozzle. y

I find it advantageous also to provide a limiting means or shoulder, as shown for example at 18a. to act as a dam and to lback up some of the oil in the bottom of the inlet nozzle or passage. In the event that any carbon accumulates behind the dam and is not swept through the nozzle by the air and fuel flowing 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 gas is mixed with air issuing from the same pipe at a velocity sufficient 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. 'I'he air coming through the oil pipe or nozzle serves as the primary air only, and the heat applied to the end of the nozzle converts the oil, gas and air into a dry gas. This mixture then receives sufficient secondary air in the pot to maintain final and smokeless combustion.

I find it advantageous to deliver an excess of outside air to the pilot zone. This may be done by a variety of mechanisms. For example, in Fig. 1 I have what is in eiIect an inside distributor 26, which receives air from outside the pot through the large aperture 25 and disperses itin the pilot area defined by the chimney 20'., In the form of Fig. 4 this outside air is downwardly delivered by the passage 30, 32, directly toward the nozzle. In Fig. 5 it is dispersed by the mushroom 33. In Fig. 6 the pilot piece or chimney is formed to direct air from the aperture 3i to the nozzle. In the form of Fig. 8 air through the passage 50 is directed into the pilot piece or housing 54, in general parallelism with the flow of liquid hydrocarbon along the nozzle and moves in the same direction as the flame. In theform of Fig. 9 the outside air is delivered through the pasage 55 directly downwardly into the foraminous box or pilot piece 54.

I claim:

1. In combination with a pot type burner including a pot with a circumferential wall, having a plurality of air inlet apertures located at various levels and a liquid fuel, line extending thereto, a fuel nozzle adapted for pilot combustion and extending into the lower portionof the pot adjacent but above the bottom thereof, means for supplying air to the inowing stream of fuel before it leaves the nozzle. a foraminous pilot piece located within'said pot and adjacent said nozzle and adapted to receive the stream of fuel and air delivered from said nozzle, said pilot piece defining, with an adjacent part of the pot wall, a space of much smaller cubic content than the rest of the space within the pot, and means for delivering to the interior of said pilot piece an excess supply of air from outside the pot, including an air distributor located within an upper portion of said pilot piece.

2. In combination with a pot type burner, having a burner pot with a circumferential Wall having a plurality of air inlet apertures located at various levels and a liquid fuel pipe extending thereto, a fuel nozzle in communication with said pipe, and extending a substantial distance into the interior of the pot, said nozzle being subjected to the heat of combustion in the pot and being adapted to serve as a vaporizing means for liquid fuel delivered therethrough, means for supplying air to the fuel passing through said nozzle at a point exterior to the pot, a foraminous pilot piece located within said pot and surround- 10 ing thereto, a fuel nozzle in communication with said pipe, and extending a substantial distance into the interior of the pot, said nozzle being subjected to the heat of combustion in the pot and being adapted to serve as a vaporizing means l5 for liquid fuel delivered therethrough, means for supplying air to the fuel passing through said nozzle at a point exterior to the pot, a foraminous pilot piece located within said Apot and surrounding the area in which the fuel from said nozzle 20 is initially received when it enters the pot, and

means for delivering to the interior of said pilot piece a supply of air in excess of the air supplied to other parts of the interior of the pot, said foraminous pilot piece being in contact with 35 wall of the pot, the pot wall, in line with said pilot piece, having one or more apertures of substantially greater size than the air inlet apertures distributed about the rest of the pot.

30 JAMES L. BREESE.

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