US2368490A - Gas and oil burner - Google Patents

Description

Jan. 30, 1945.

w. s. PATTERSON GAS AND OIL BURNER Filed March 50, 1945 INVENTOR flkradi Jlfersan 247 TURN/f Y Patented Jan. 30, 1945 Gas AND on. BURNER Ward S. Patterson, Chappaqua, N. Y., assi:nor to Combustion Engineering Company, Inc., New

York, -N. Y.

Application March 30, 1943, Serial No. 481,081

This invention relates to fuel burners tively. I

When blast furnace gas is burned as fuel to release heat in a furnace, the burner has fuel and air passages with cross-sectional areas proportioned for the correct ratio of air to fuel and certain suitable air Y velocities. When oil is .burned in the same burner to releaseapproximately the same amount of heat in the furnace, the air passages of the burner being designed for the blast furnace gas are then insufllcient in area to maintain suitable air velocities. This is accounted forv by the different air-quantities required bythe two fuels, oil requiring about thirty percent more than blast furnace gas. Therefore, when using oil as-fuel, the air velocities through the, burner passages would be about thirty per cent higher than when using blast furnace gas. Such velocities are undesirably high and require more power to move the air.

It i an object of this invention to provide an improved burner in which the above dimculties are overcome.

In the accompanying drawing:

Figure 1 is a longitudinal section through a burner embodying the invention; and

Figure 2 is a transverse section through the air valve and ports taken on the line 2-2 of Figure 1.

In the drawing, the burner designated as a whole by the numeral III has a cylindrical tube Ii disposed horizontally and itstip l2 projects into an aperture H in the furnace wall It. The burner 10 has a volute entrance section l5 through which blast furnace gas is supplied tangentially to the burner nozzle through a. pipe supply It.

Secondary air is delivered to theltip of burner In from a windbox "through which the burner and slot connection .to an operating ring 25. As

ring 25 is rotated clockwise the dampers 22 separate with respect to one another and open to permit secondary air to flow through chamber 20 around bumer I hand when the ring isrotated counterclockwise the dampers close and reduce the air flow.

lClaiin, (cuss-11).

nd par-4., ticularly to burners for using two fuels alterna- I 'It ha been found that whenair enters the windbox I! in one general direction, as downward in Fig. 1, a major part of the secondary air supply enters the annular chamber around burner through the upper part of "port 2|.

Little air enters around other parts of the,

burner, as at the lower part thereof. zThis'inequality of air supply through port 2| around the burner prevails in the travel of the air toward the furnace-through the annular chamber "and results in an uneven distribution" of the secondary air discharging into the furnace around the burner tip II. This in turn causes .40 P oj ts- Th nozzle section of burner Ill is, en-

furnace and inefllcient combustion. f

A baflle 26 having a conical outer surface 21 extends inwardly from the casing 28 of windbox,

I1 across the circumferential port 2| in'burner casing I8. The inner edge of bame 28.1s substantially in alinement with but spaced from the furnace -side edge of port 2| to provide a vertical annular opening 20 through which the windbox is in communication with the enclosed space around-port2L- 1 I 'Bame 25 prevents air from. flowing directly into port 2| from thewindbox l1 and causes it to flow through annular opening 30 around the entire circumference of battle 26 toward port 2| in a direction substantially parallel to the axis of the burner. Thence the air turns 90. into the a port 2| and again 90 intochamber 20 to pass toward the burner tip l2. By blocking the direct entry of the air intoiJort-ZI from any direction by means of banle 26 the velocity of the air from that direction is diminished and is no longer effective to cause an excess flow of air from that direction into the burner. Thus, all ofthe air is then forced to enter port 2| through opening 30 at right angles to its direction of flow in windbox, I! and then caused to make an abrupt turn into port 2| therebysubstantially equalizing resistance to air flow into the burner.

Adjacent its juncture with its conical nozzle tip |2 the fuel nozzle is provided with a plurality of apertures Olports ll Surrounding and 7 covering the ports 3| is a cylindrical sleeve 12 provided with a dance 83. Movement of sleeve 32 to cover or uncover ports 8| is accomplished byv rods 34 attached thereto.

When blast furnace gas is tobe burned-it flows from pipe l6 through burner tube ll into the furnace'while the air for combustion flows separately from. windbox I! through port III and annular conduit 20 around the nozzle tip l2 into the furnace to therein mix with and burn the thirty percent more than when burning blast furnace gas and consequently the air velocities through port 2| and conduit 20- are \msuitably high. This would result in a high windbox ir e -w sure requirement and a poor control of thee flame shape. v p g To overcome this ditflculty andto permit a maximum heat release with a; combination burner, the ports 3| are uncovered lag moving sleeve longitudinally of the fuel tube.

sleeve 32, acting as awalve, allows air from port 2| to flow into-the burner tube i! and thence to the furnace. 3 v

when the sleeve 32 is i 'itssrightfhand position, port 2! is extended or widened asthe flange 33 defining one side thereof recedes thereby proportionately increasing the area of the air opening from windbox l'l into the furnace via conduit 20, ports 3! andthe burner tube II. In order to maintain damper'control of the increased amount of air, the dampers 22 are made L-shaped to lie alongside flange '33 and wide enough to extend .over the extension of port 28 produced by retracting flange" 33.

' air supply port in the wall thereof opposite the The burner may be used with other fuels blast-furnace gas and oil where such fuels require substantially diflerent quantities of air for combustion.

5 What! claim is:

In a dual purpose iuel burner; a. nozzle tube arranged to be supplied at one end with gaseous fuel and to discharge it into a iurnace at its opposite end and provided with a plurality of 19 air ports in the wall thereof near its discharge end; a casing surrounding said nozzle tube and forming therewith an annular chamber through which air may flow around said nozzle to the" discharge end thereof a windbox contiguous to said casing, said casing being provided with an ports'insaid nozzle tube for admitting air to said chamber from said windbox; a secondary fuel nozzle co-axially positioned within said noz- 20 zle tube; a slide valve mounted on said nozzle tube; a flange on said slide valve extending across said annular chamber to the casing that forms the. outer wall of said chamber and so located with respect to the edge 01' the port in 25 said casing nearest the nozzle ti as'to narrow the width-of said port in said casing when said slide valve is positioned to close the ports in saidnozzle tube; and means conneoted to said slide valve for moving it in a direction away from the I 30 tip'of said'nozzle to uncover said ports and for' positioningsaid flange further away from the edge oi the port in said casing to increase the" width thereof.

36 WARD s. PATTERSON.

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