Industrial Burner

Abstract

The invention relates to an industrial burner of the combustion chamber type that is used for submerged combustion. The burner will operate on gas or oil as a fuel.

Description

SUMMARY OF THE INVENTION

The present invention relates to industrial burners, and more particularly to a submerged combustion type of burner that can use either gas or oil as the fuel.

It has been determined in the melting of various materials that good mixing and efficiency can be obtained by the introduction of hot products of combustion beneath the surface of the material. A burner for this purpose, using gas only as a fuel, is disclosed in Dolf et al. U.S. Pat. No. 3,260,587. In view of the shortage of gas in some locations and the varying price of fuel, it is desirable that a burner capable of using an alternate source of fuel be available.

The burner of the present invention is of the same type and for the same uses as the Dolf et al. burner except that its internal construction is entirely altered so that either gas or oil or a combination of the two may be used as fuel.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages and specific objects attained with its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of the invention.

IN THE DRAWINGS

FIG. 1 is a section through the burner;

FIG. 2 is a view taken on line 2--2 of FIG. 1; and

FIG. 3 is a sectional view of a portion of a modified burner.

DETAILED DESCRIPTION

Referring to the drawing, there is shown a burner which is enclosed in a substantially cylindrical metal casing consisting of spaced apart outer wall 1 and inner wall 2. One end of the walls is reduced in diameter, as shown, to form a restricted outlet opening 3. The cylindrical casing is lined with a high temperature ceramic liner 4, the interior of which is a combustion chamber 5. One end of the liner is reduced to correspond to the reduction in the casing, while the other end is closed by a distributor member 6 through which fuel and air are supplied to the combustion chamber 5. This member provides a space having an axial wall 7 provided with a plurality of tangential openings 8 and having an end wall 9 provided with a central opening 11 and a ring of smaller openings 12.

Gas fuel is supplied through a sleeve 13 which abuts closely against the outside of wall 9 and which is provided with a gas inlet 14. The other end of the sleeve is closed by a cap 15 to form a gas inlet chamber. Oil is supplied to the burner by an atomizer 16 which is mounted in a sleeve 17 that is concentric with sleeve 13 and is fastened to disc 15. The inner end of sleeve 17 has a flange 18 which is located concentrically in sleeve 13 by a plurality of spacers 19. The space between the periphery of flange 18 and sleeve 13 forms an annular gas passage 20. It is noted that a strainer 21 may be attached to the back of the atomizer.

A disc 22 is attached to the exterior of sleeve 13 which disc supports a cylindrical partition 23 that is received between the casing walls 1 and 2. This partition provides annular passages 24 and 25 through which the air flows to a chamber 26 before being discharged into combustion chamber 5 through openings 8. There is provided a disc 27 which is also attached to the exterior of sleeve 13 which disc is provided with an air inlet opening 28. This disc and the parts attached thereto are held in position by means of bolts extending therethrough into a flange 29 formed on the lower end of wall 1. It is noted that a series of small partitions 31 may be provided at the upper end of the casing at a point connecting passages 24 and 25 in order to even out the flow of the air around the annulus of the two passages 24 and 25.

The burner is ignited by means of a spark between an igniter rod 32 which is connected to one terminal of an electric source (not shown) and the wall 9 which is connected through a switch to the other terminal of said source to form a circuit. This igniter rod is held in position a short distance from the back surface of wall 9 by means of an insulator 33 that extends through flanges 15 and 18.

When starting the burner in operation, gas is always used regardless of the fuel to be used later on. After the burner has heated up it can be shifted to oil. When starting the burner, air and gas flow are adjusted to minimum rates with the ratio being adjusted to give a lean mixture. Under this condition some air will flow through opening 34 to cause a partial premix through gas passage 20 to produce a more favorable ratio for ignition. When the gas and air are flowing, the ignition circuit is closed, producing a spark between the end of igniter rod 32 and end wall 9 to ignite the mixture. Thereafter, the gas supply will be adjusted to bring the air-gas ratio to stoichiometric proportions. The supplies of gas and air can now be increased as desired to the maximum capacity of the burner. The air flowing through tangential openings 8 into the space therein is turbulently mixed with the gas flowing through passage 20 and opening 11. Gas flowing through ports 12 creates pilot flames that help stabilize the main combustion. This results in rapid combustion that is completed in chamber 5. Only hot products of combustion are exhausted through restricted discharge opening 3.

The air supplied to the burner flows through concentric passages 24 and 25 before being discharged into chamber 26 and through openings 8. During its passage the air is preheated, preferably, to about 700.degree. F, thus increasing the temperature of combustion. After the burner is first ignited and the air has reached a temperature of about 400.degree. F, oil can be supplied as the fuel. Fuel oil is almost completely vaporized at this temperature.

After the burner has been operating a sufficient time to heat up, the oil supply can be turned on and the gas cut off. Atomizer 16 sprays oil in fine droplets toward the combustion chamber 5 in a cone which is small enough to avoid impingement upon axial wall 7 of the distributor. The oil droplets are picked up, vaporized and mixed with the preheated air flowing through openings 8. The tangential path of the air increases turbulence and mixing so that combustion is completed in the combustion chamber with hot products of combustion being discharged at high velocity through the restricted outlet opening 3. If desired, both gas and oil can be supplied simultaneously to the burner as fuel. No difference is observed in the operation of the burner whether gas or oil or a combination of the two is being used as fuel.

For some uses it may be desirable to reduce somewhat the temperature of the jet of gases, and to increase the cooling of the outer end of the casing. The construction of FIG. 3 is used for this purpose. A portion of the air supplied to the burner will be exhausted through passage 36 to sweep across the inner surface of passage 3 thereby helping to cool it as well as tempering the exhausting products of combustion.

While in accordance with the provisions of the Statutes I have illustrated and described the best form of embodiment of my invention now known to me, it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit and scope of the invention set forth in the appended claims, and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

Claims

What is claimed is:

1. In an industrial burner, structure forming a refractory lined combustion chamber having a restricted opening at one end, a fuel distributor member at the opposite end of said chamber, said member being provided with a cylindrical space axially aligned with and open to said chamber, said space being bounded by a cylindrical wall and an end wall, a plurality of openings extending tangentially through said cylindrical wall, means to supply combustion air to said space through said openings, an axially extending opening in said end wall, means to supply a fuel gas to said space through said axially extending opening, an oil atomizer spaced axially from and concentric with said axially extending opening, and means to supply oil to said atomizer to be discharged thereby into said space.

2. The combination of claim 1 in which said means to supply combustion air includes a passage surrounding the lining of said combustion chamber.

3. The combination of claim 1 including an igniting rod, means to locate said rod with an end thereof located adjacent to said axially extending opening and said atomizer.

4. The combination of claim 1 in which said means to supply air includes a pair of connected concentric passages surrounding the refractory lining of said combustion chamber, means to direct air to the outer of said passages and means to direct air from the inner of said passages to said tangential openings.

5. The combination of claim 4 including means forming an additional passage between said inner concentric passage and said restricted opening.