US2810433A - Burner for oil-fired gas generator - Google Patents

Description

Oct. 22, 1957 L. P. GAUCHER BURNER FOR OIL-FIRED GAS GENERATOR Filed Jan. 17, 1952 Mg, OIL

2 CONTAINING GAS IN VEN TOR.

L eon R Gaucher United States atent BURNER FOR OIL-FIRED GAS GENERATOR Leon P. Gaucher, Tuckahoe, N. Y., assignor to The Texas Company, a corporation of Delaware I Application January 17, 1952, Serial No. 266,840

2 Claims. (Cl. 158-74) This invention relates to fluid fuel burners and more particularly to fluid fuel burners of the kind used in flowtype synthesis gas generators. The latter are essentially closed reaction chambers, housing burners, and are primarily used for the partial combustion of gaseous, liquid, or partially vaporized liquid hydrocarbons in the manufacture of synthesis gas. For illustrative purposes, the burner shown on the attached sheet of drawings is of a type primarily used for the partial combustion of oil to form carbon monoxide and hydrogen.

In the past, burners of this type have been subject to frequent clogging of the fuel orifices, and there have been many attempts in the prior art to provide a burner of this type with adequate cooling means to prevent burner clogging and failure of the metal due to overheating. In spite of the fact that the oil or other liquid hydrocarbon may be supplied at a sufliciently high rate to give it a rather high velocity in the burner passageways and orifices, the amount of cooling to be derived from the supply of fuel alone has proved entirely inadequate. This appears to be due to the fact, in spite of the high velocity of flow of the fuel in the burner passageways and orifices, that there is always a thin film of liquid hydrocarbon on the surface of these passageways which is stationary, or at least moving at a very slow rate. It appears that due to the high temperatures encountered in these partial combustion processes, this film of slowly moving or stationary hydrocarbon will coke-up, with the result that the passageway becomes first restricted, and ultimately completely clogged, necessitating a shut-down of the generator-and removal of the burner elements for a thorough cleaning.

'It is an object of this invention to provide a burner head which will overcome these operational difliculties.

It is a further object of this invention to provide a burner head in which a blanket of steam is maintained at the burner'face, in' between the fuel and oxygen orifices.

' These and other objects of the invention will be apparent from the following description read in conjunction with the attached sheet of drawings in which:

Figure 1 is a top plan view of the burner; and

Figure 2 is a side elevation, in section, of a preferred embodiment of this invention.

The burner head which is generally indicated by the reference numeral is shown as being an annular casting having a substantially frusto-conical depression 11, which may be machined out of the upper or flame-exposed surface thereof. An annular cooling channel 12 surrounds the depression 11, and provides a means for supplying a coolant, such as water, in direct heat exchange relation to the hottest part of the burner head 10.

Positioned below and extending longitudinally from the burner head are first, second and third concentric annular members 13, 14, and 15 defining annular passageways 16, 17, and passageway 18. These passageways terminate at the burner head 10, and each is connected by further closed passageways 19, 20, and 21, re-

2,810,433 Patented Oct. 22, 19 57 ice steam, is supplied in the outermost passageway 16. Allthree fluids are, of course, supplied under pressure for ultimate mixing in the flame area of the burner. While water is fed to the passageway 17, it will be partly or even mostly vaporized in passageway 20 and issue into the reaction zone as steam. Advantageously vaporization is not complete until the point of discharge from the passageways 20, so as to obtain the maximum cooling of these passageways. Thus, a blanket of steam is maintained between the reactants at their point of issue into the reaction zone. Note also that the two passageways 21 which convey the liquid hydrocarbon to the flame area are inclined in parallel vertical planes, in order to impart substantially swirling motion to the liquid hydrocarbon as it enters the flame area.

While it is not definitely known, it is believed that the hottest area in burners of this type is that area immediately surrounding the oxygen passageways 19 at the point where they exit to the flame area. It is further believed that the introduction of Water (steam) at a point intermediate the oxygen and fuel openings serves several purposes. First, it provides introduction of a cooling medium at a critical point. Secondly, since the water is vaporized to steam in the burner head and enters the flame area with some force, it promotes more thorough mixingof the oxygen and hydrocarbon components of the supplied reactants. Thirdly, it is believed that the pressure of the issuing steam prevents droplets of unvaporized liquid hydrocarbon issuing from the passageways 21 from impinging upon the flame exposed surface of the burner and the openings therein. In that way the steam serves as a further aid in preventing cloggingof the several burner orifices. While it is true that the presence of the steam in this area of the flow generator may impair, to a limited extent, the efliciency of the operation, the other beneficial eifects listed above are so important, as regards permitting continuous operation with a minimum of shut downs, that the use of water or steam in this manner appears to be entirely justified.

While mention has been made of adding steam to the oxygen stream, nevertheless it is contemplated that the steam may be omitted and either relatively pure oxygen or enriched air, for example, air containing at least about 40% oxygen, charged to passageway 16.

Provision may be made for injecting some steam into the oil stream entering the conduit or passageway 18, particularlyin the case of relatively heavy viscous oils. Each of the reactant streams may be separately preheated to temperatures of 600 F. and higher prior to passage to the burner. Preheating the reactant streams to these high temperatures aggravates coke formation in the oil passage and on the face of the burner, particularly when charging heavy low-grade oil. The purpose of the burner of this invention is to prevent this coking.

The burner of this invention is particularly useful in flow-type gas generators. U. S. Patent No. 2,582,938, issued January 15, 1952, to Leon P. Gaucher and Du Bois Eastman, for Manufacture of Synthesis Gas discloses one example of a gas generator with which this invention can be used. This type of generator is free from catalyst or packing material and is characterized by having an internal surface area of not more than about 1.5 times the area of a sphere of equal volume. It is operated under pressures ranging from atmospheric to 600 pounds per square inch gauge or higher and at temperatures ranging from about 2000 to 3000 F., the re- 3 action temperature being maintained autogenously except for the aforementioned preheating of the reactants.

One or more burners may be provided for the generator, depending upon the generator size. In a typical burner for a generator of about 2 cubic feet internal volume, and capable of producing about 25,000 cubic feet of synthesis gas per hour, the annular passageway 16 is about .10 inch wide, the annular passageway 17 is about .06 inch wide, while the passageway 18 is about .12 inch in diameter. The two oil orifices or passageways 21 are about .05 inch in diameter. The passageways 19 are about .12 inch in diameter, while the passageways 20 are about .06 inch in diameter.

The longitudinal axes of the passageways 19 and 21 form angles of about 20 to 30 with the longitudinal axis of the passageway 18, while the axes of the passageways 20 form angles of about 45 therewith.

From the foregoing it will be apparent to those skilled in the art that a greatly improved burner head has been shown and described herein. It will be equally apparent that the specific structure shown in the accompanying drawings is merely illustrative of a preferred embodiment, and that many structural variations are possible within the scope of the appended claims.

I claim:

1. A burner assembly for use in a flow type gas generator for conveying to the generator reaction zone a stream of hydrocarbon and a stream of oxygen containing gas comprising: an elongated burner terminating in a flame exposed burner head having a substantially flat surface portion disposed perpendicular to the longitudinal axis of said burner and a single frusto-conical shaped depression located centrally of said flat surface portion and converging inwardly continuously from said flat surface to a horizontal plane surface spaced inwardly from said flat surface; a first reactant conduit leading to said head and terminating in at least one reactant discharge opening in said plane surface of the base of said frusto conical shaped depression of said burner head; means for supplying fluid fuel to said first reactant conduit; a second reactant conduit coaxial with and disposed about said first reactant conduit and terminating in at least one reactant discharge opening in the conical side wall of said frusto-conical depression of said burner head; means for supplying an oxygen containing gas to said second reactant conduit; a coolant conduit coaxial with and disposed between said first and second reactant conduits and terminating at the conical side wall of said frustoconical depression in a plurality of openings arranged in a circular pattern and being disposed intermediate said reactant discharge openings; means for supplying water to said coolant conduit, whereby water conducted through said burner in said coolant conduit will be vaporized into steam which issues from said plurality of openings, thereby efiectively cooling said burner; and an annular coolant chamber in said burner head located under said flat surface portion and disposed around all of said discharge openings.

2. A burner assembly for use in a flow type gas generator for conveying to the generator reaction zone a stream of hydrocarbon and a stream of oxygen containing gas comprising: an elongated burner terminating in a flame exposed burner head having a fiat surface disposed in a plane perpendicular to the longitudinal axis of said burner and a single shallow frusto-conical shaped depression in the center thereof; means defining an axial hydrocarbon passageway in said burner terminating in a plurality of openings at the surface of said depression and being disposed angularly with respect to each other and with respect to the axis of said passageway to impart a swirling movement to the hydrocarbon issuing therefrom; means for feeding a fluid hydrocarbon to said passageway; means in said burner defining an annular oxidizer passageway disposed about and concentric with said hydrocarbon passageway and terminating in a plurality of orifices arranged in a circular pattern at the conical side wall of said frusto-conical depression; means for feeding an oxygen containing gas to said last recited passageway; means in said burner defining an annular coolant passageway concentric with and intermediate said hydrocarbon and oxidizer passageways, and terminating at the conical side wall of said flame exposed burner head in a plurality of openings arranged in a circular pattern intermediate said hydrocarbon openings and said oxidizer orifices; means for supplying water to said coolant passageway, whereby water conducted through said burner in said coolant passageway will be vaporized into steam which issues from said plurality of openings to effectively cool said burner; means defining an annular coolant passageway in said burner head underneath the flat surface of said flame exposed burner head, said annular passageway being disposed about all of said other passageways and discharge openings and orifices; and means for feeding a coolant through said last recited coolant passageway.

References Cited in the file of this patent UNITED STATES PATENTS 733,693 Bladon July 14, 1903 872,288 Koons Nov. 26, 1907 903,736 Lee Nov. 10, 1908 1,228,818 Pictet June 5, 1917 1,796,299 Nolan Mar. 17, 1931 1,830,574 Thwing Nov. 3, 1931 1,841,698 Barber Jan. 19, 1932 2,231,244 Berthiaume et a1 Feb. 11, 1941 2,310,704 Mulholland Feb. 9, 1943 2,368,373- Morrell Jan. 30, 1945 2,453,378 Lubbock Nov. 9, 1948 2,609,658 Goddard Sept. 9, 1952

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