US2351481A - Foraminous pilot baffle for pot-type burners - Google Patents

Description

June 13, J. L. BREEsl:

FORAMINOUS rlLoT BAFFLE FOR POT TYPE BURNERS Filed April 1}, 1941 W W H m 1.0 o e. E Q r 0 r o o o ,M 0/ v o 0 0 l M O 0 i o 0 r o o u o m o O 9 o O I O a O o 0 r w 0 inlet apertures ll,

Patented June 13, 1944 FORAMINOUS PILOT RAFFLE FOR POT- TYPE BURNERS James L. Breese, Santa Fe, N. Mex., assignor to Oil Devices, Santa Fe, N. Mex a limited partnership of Illinois Application April 11, 1941, Serial No. 388,074

4 Claims.

My invention relates to an improvement in liquid hydrocarbon burners and has for one purpose the provision of an improved pilot means for providing a minimum turndown.

Another purpose is to provide a pilot ring which shall eliminate any smoky period during the time when flre is being increased from the pilot stage to an intermediate or full combustion stage.

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 drawing where- Fig. 1 is a vertical axial section; and

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

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

Referring to the drawing, l is an outer heater drum or housing. It may be mounted for example on legs 2, as shown, with a bottom 3 having an air inlet aperture 4. 5 is a supporting ring positioned within the drum I. Supported thereupon is a pot 6, having a preferably concave bottom 1. The pot may have an outwardly extending flange 8 to rest upon the upturned flange of the ring 5. 9 is any suitable removable fire ring having a central aperture, as at i0. H is any suitable fuel inlet means in communication with the fuel pipe II, which may be controlled by any suitable valve, as at l3.

It will be understood that any suitable valve control means may be employed, whether automatic or manual control, in order that the volume of flow of liquid hydrocarbon upon the pot bottom I may be varied. A side of the pot 8 is provided with a plurality'of primary air herein shown as located in horizontal rows at various levels. Secondary air may be admitted adjacent the top of the pot by any suitable means. I illustrate a row of larger and more closely spaced air inlets l5. It indicates a pilot baflle, herein shown as a truncated cone, centrally apertured as at l1. Its outer edge clears the opposed inner face of the pot, as at l8, to provide a circumferential space.

l9 .indicate any suitable supporting and centering pins, or the like. It will be understood, however, that the pilot bailie may be supported in any suitable manner, and the pins l9 are merely illustrative of a practical solution of the supporting problem. The ring I6 is provided with a plurality of small air apertures 29, which are distributed generally uniformly throughout the area of the ring.

The liquid hydrocarbon admitted through the means I I is vaporized in response to the heat of combustion in the pot. The vaporized hydrocarbon rises in the pot and becomes mixed up with the primary air flowing in through the primary air inlets l4 to form a primary incompletely combustible mixture. The primary mixture then rises in the pot until it is mixed with a secondary air supply which flows in through the apertures l5, and when the pot is at high fire, combustion takes place at or above the level of the secondary air inlet apertures Ii. The fire is controlled by varying the supply of liquid hydrocarbon, for example by the control of any suitable valve, such as It.

It is advantageous in burners of this type to prov de a minimum turndown so that what is in effect a pilot fire may be obtained. Assume that the pot is burning at full flame, withthe full flow of hydrocarbon, and the valve is operated to reduce the supply to a pilot flow, then insufficient of the liquid hydrocarbon is vaporized to maintain the combustion at the top of the pot, and the level of combustion drops until it reaches the pilot baflle l6. Thereafter the lowest row of primary air inlet apertures ll constitutes the primary air supply, and the apertures l4 above the baflles 16 no longer constitute a source of primary air. Instead, they perform the function of providing secondary air for the the mixture of air and vaporized hydrocarbon taking place below the baffle l6.

Where a solid bafile ring is employed, there is a slightly smoky period just above the high pilot stage. By employing a foraminous pilot ring, as herein described and shown, I obviate this slightly smoky period, due to the fact that a certain amountof the gas, ,or vaporized hydrocarbon mixed with air, seeps through the small perforations 20, and bumes with a clean flame, eliminating any smoky stage or period, and consequent carbon deposit.

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 drawing to be taken as in a broad sense illustrative or diagrammatic, rather than as limiting me to my precise showing.

For example, a wide latitude is possible in the formation of the baflie rings and the arrangements of the apertures therein. The rings .While this arrangement is practical, it can, oi.

course. be varied. I

It will also be observed that the central aperture of the bailie I1 is of a diameter substantially exceeding the radial width of the surrounding portion of the baiile.

In the structure or the present application, the upwardly frusto-conic ring it is shown as located immediately above the lowest row of primary air inlets I4. It is adaptable for use as a pilot ring. When the burner is burning at relatively low capacity, due to the reduction of the flow of fuel. to the interior of the pot, the lowest row of primary holes below the ring It provides the primary air necessary to support combustion. The primary air inlets I located above the ring I6 provide secondary air and combustion takes place at or immediately above the level of the aperture ll. This is in contrast to the operation of the structure shown in my co-pendlng application Serial No. 388,073, filed on April 11, 1941, in which a downwardly frusto-conic ring is interposed between the highest row of primary air inlets and the secondary air inlets at the top of the pot.

I claim:

1. In combination. a burner pot having a side wall having a plurality of primary air inlet apertures located therein at various levels, means adjacent the top of the pot for admitting secondary air, means for delivering a liquid fuel to the bottom of the pot, and a pilot baille located intermediate the upper and lower primary air inlet apertures and including an annulus having a large central aperture the diameter oi! which substantially exceeds the radial width 01' the surrounding annulus, said annulus being provided with a plurality of generally uniformly spaced small apertures.

2. In combination with a burner pot having a substantially cylindrical side wall provided with a plurality of primary air inlet apertures, and secondary air inlet means adjacent the top of the pot, a centrally apertured baille located intermediate the highest and lowest of the primary air inlet apertures, said baiile including a thin annular body having a large central aperture, said annular body being provided through out its area with a plurality of generally uniformly spaced small apertures.

3. In combination with a burner pot having a substantially cylindrical side wall provided with a plurality of primary air inlet apertures, and secondary air inlet means adjacent the top 01' the pot, a centrally apertured baiile located intermediate the highest and lowest of the primary air inlet apertures, said baiiie including a thin annular body having a large central aperture, said annular body being provided throughout its area with a plurality of generally uniformly spaced small apertures, and said annular body being upwardly i'rusto-conic.

4. In combination with a burner pot having a substantially cylindrical side wall provided with a plurality of primary air inlet apertures, and secondary air inlet means adjacent the top 01' the pot, a centrally apertured baflie located intermediate the highest and lowest of the primary air inlet apertures, said baflle including a thin annular body having ture, ,said annular body being provided with a plurality 01' generally uniformly spaced small apertures located at various radial distances from the edge of the annular body which defines said large central aperture, said apertures extending throughout the area of said annular body.

JAMES L. BREESE.

a large central aper-

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