Title:
GAS FUEL BLOWPIPE FOR BURNING REACTION GAS MIXTURES
United States Patent 3825400
Abstract:
A blowpipe for burning reaction gas mixtures separating in reactors and furnaces the fuel gas area from the burning area, comprises a burner and a partition installed in parallel to each other and interconnected by a shell forming therebetween a chamber for the oxidiser. The distribution tubes with the burning area, with some of the ends of the distribution tubes being fastened hermetically to the partition, and the other ends are located in the channels of the burner along the fit ensuring under the operating conditions their axial movement and heat transfer to the burner. Formed on the walls of distribution tubes are slots serving to supply the oxidiser from the chamber for the oxidiser to the burning area. Cavities for a cooling liquid or refrigerant are formed in the burner and the partition.
Application Number:
05/352029
Publication Date:
07/23/1974
International Classes:
F23D14/78; F23D14/72; (IPC1-7): F23D15/04
Field of Search:
431/160,328 239
Primary Examiner:
Favors, Edward G.
Attorney, Agent or Firm:
Waters, Roditi, Schwartz & Nissen
Claims:
What is claimed is
1. A blowpipe for burning reaction gas mixtures separating a fuel gas area from a burning area in reactors and furnaces, comprising: a burner and a partition arranged in parallel relationship to each other and each having cavities therein for circulation of a cooling liquid; a shell extending along the periphery of said burner and of said partition so as to hermetically interconnect them and form a chamber therebetween; a branch pipe for supplying an oxidizer to said chamber, distribution tubes passing through said chamber and connecting said fuel gas area with said burning area; channels formed in said burner; one of the ends of each of said distribution tubes being arranged in said burner channels at a fit facilitating their axial displacement under operating conditions and providing surface contact for heat transfer from the tubes to said burner; the other ends of each of said distribution tubes being hermetically fastened to said partition; and slots being formed in the outer walls of said distribution tubes providing passageways for flow of the oxidizer from said chamber to said burning area.
2. A blowpipe as claimed in claim 1, said slots in the walls of said distribution tubes being formed along a helix so as to impart rotation to the oxidizer jets.
Description:
The invention relates to blowpipes for burning reaction gas mixtures used in reactors and furnaces for the diffusion (torch) burning of the fuel gas held in contact with the oxidiser, as well as for kinetic burning of reaction mixtures of the fuel gas and the oxidiser having a high speed of flame spreading.
The blowpipe according to the invention can most effectively be applied to reactors of the oxidising pyrolysis of hydrocarbons for obtaining acetylene and/or synthesis gas (CO + H2) as well as to various furnaces and boiler installations that require a high thermal intensity of the flame front.
There is known a blowpipe for burning reaction gas mixtures which is used in reactors and furnaces to separate therein the fuel gas area from the burning area.
The known blowpipe comprises a burner and a partition installed in parallel, these being connected hermetically along the periphery by a shell forming therebetween a chamber equipped with a branch pipe for supplying the oxidiser to the chamber. The distribution tubes, communicating the fuel gas area with the burning area, pass through the said chamber. Some of the ends of the distribution tubes are hermetically installed in the partition, and some other ends are located in the channels formed in the burner and equipped with the centering ribs.
In the process of operation of the blowpipe the mixing of the fuel gas with the oxidiser is effected in the burning area where the fuel gas is supplied along the distribution tubes, and the oxidiser is fed from the chamber for the oxidiser through annular clearances formed between the walls of the distribution tubes and the channels in the burner.
A disadvantage of the known device consists in its low dependability in service which involves high temperature stresses occurring in the construction, deformation of the burner, melting away of the ends of the distribution tubes disposed in the burner channels, thereby resulting in damage caused to the blowpipe. This prevents the blowpipe from being employed in high-capacity reactors and furnaces in view of accident hazards.
For the same reasons the known blowpipe cannot be used for burning the pre-prepared reaction mixtures of the fuel gas and the oxidiser providing maximum heat throughput of the flame front.
An object of the invention is to provide such a blowpipe that would ensure safe and continual operation under conditions of maximum heat throughput of the flame front.
This object is accomplished in the blowpipe for burning gas mixtures which separates the fuel gas area from the burning area in reactors and furnaces and comprises a burner and a partition installed in parallel to each other and hermetically connected along the periphery by the shell forming therebetween a chamber equipped with a branch pipe supplying the oxidiser to the chamber wherein the distribution tubes passing through the said chamber for the oxidiser and communicating the fuel gas area with the burning area, with some ends thereof being hermetically installed in the partition and some other ends being located in the channels formed in the burner, according to the invention, the burner and the partition are fitted out with cavities having branch pipes for the passage of a refrigerant, which may be any suitable cooling liquid such as, for example, condensate or water which is free of hard salts passing or circulating through the cavities of the burner and partition. The ends of the distribution tubes are located in the channels of the burner with a fit or tolerance which allows for their axial movement during operation while providing for heat transfer to the burner, and on the outer walls of the distribution tubes there are slots serving to supply the oxidiser from the chamber for the oxidiser to the burning area.
Such an arrangement, involving the cooling liquid or continually flowing through the cavities of the burner and the partition, makes it possible to protect the blowpipe against deformations and melting away of the ends of the distribution tubes, thereby ensuring reliable and continuous operation. Besides, while controlling the temperature of the refrigerant, it is possible to effect a timely cut-off of the oxidiser supply at the burner outlet in case the blowpipe malfunctions, and thereby to ensure complete safety of its operation.
It is expedient that the slots in the walls of the distribution tubes be formed along screw lines cooling liquid or in order to impart rotational movement to the flows of the oxidiser, this being especially important during the diffusion burning of the fuel gas, since the protrusion of the coiled flows of the oxidiser into the burning area intensifies the processes of mixing and burning at the expense of increasing the degree of turbulence.
The invention is further illustrated by the discription of embodiments with reference to the accompanying drawings, in which:
FIG. 1 is a cross-section of the blowpipe, according to the invention;
FIG. 2 is the cross-section taken along the line II--II of FIG. 1.
The blowpipe comprises a burner 1 (FIG. 1) with channels 2 and a partition 3 installed in parallel and inreconnected hermetically by a shell 4 so as to form a chamber 5 therebetween to which the oxidiser is supplied through a branch pipe 6. Passing through the chamber 5 for the oxidiser at a certain distance from each other are distribution tubes 7 whose upper ends are hermetically installed (pressed in and welded) in the partition and the lower ends are located in the channels 2 of the burner 1 along the fit which ensures their axial movement and heat transfer to the burner 1.
The burner 1 and the partition 3 are equipped with cavities 8 and 9 for the passage of the cooling liquid or fed to the blowpipe through branch pipes 10 and 11 and coming out through branch pipes 12 and 13. The blowpipe installed in the reactor or furnace separates therein a fuel gas area 14 from a burning area 15.
Slots 16 are formed in the walls of the distribution tubes 7 (FIGS. 1, 2) for the passage of the oxidiser from the chamber 5 to the burning area 15. The slots 16 can be both longitudinal, as is shown in the drawing, and screwlined (not shown in the drawing).
The blowpipe can operate in the mode of diffusion burning of the fuel gas which contacts the oxidiser in the burning area 15 (FIG. 1), and in the mode of burning the pre-prepared reaction mixture of the fuel gas with the oxidiser.
The blowpipe operates in the mode of diffusion burning the fuel gas in the following manner.
The fuel gas is fed from the area 14 through the distribution tubes 7 in the form of a plurality of jets to the burning area 15. The jets of the oxidiser which are supplied herein from the chamber 5 through the slots 16 mix up with the jets of the fuel gas and form the flame front.
The initial ignition is accomplished by a special igniting torch (not shown in the drawing) which is brought to the burner 1 through the burning area 15. The cooling liquid or (condensate) is supplied through the branch pipes 10 and 11 passing continually in the cavities 8 and 9, cooling the burner 1, the ends of the distribution tubes 7 and the partition 3 and comes out through the branch pipes 12 and 13.
The performance of the proposed blowpipe in the mode of burning the pre-prepared reaction mixture of the fuel gas with the oxidiser will be regarded while utilising it for the process of the oxidising pyrolysis of hydrocarbons for obtaining acetylene and synthesis gas.
This process involves gaseous hydrocarbons (e.g. methane) pre-mixed with the oxidiser (oxygen), with the resultant mixture being supplied from the area 14 through the distribution tubes 7 to the burning area 15 at a speed exceeding that of distribution of flame for the given compound of the methane-oxygen mixture. Acetylene and synthesis gas (CO + H2) are formed in the flame of the incomplete burning.
The process of the incomplete burning of the hydrocarbons is characterised by a low stability, therefore, to ensure a uniform ignition of the reaction mixture in the cross-section of the burning area 15 and to eliminate flame-out, use is generally made of an artificial stabilisation of the process by introducing auxiliary jets of the oxidiser into the flame front.
The concentration of acetylene in the resultant gases of the pyrolysis largely depends on the number of the introduced auxiliary oxidiser jets and on the speed of the burning of the reaction mixture.
Optimal conditions are offered by the proposed blowpipe which makes it possible to introduce uniformly and in the necessary amount the auxiliary oxidiser jets into the flame front through the slots 16 of the distribution tubes 7.
In this case, for increasing the effectiveness of the pyrolysis process and the stabilisation of the flame front, it is expedient to use ozone-oxygen mixture with a concentration of ozone equal to 10-20 g/Nm3 as a stabiliser. Ozone being disintegrated in the burning area 15, forms atomic oxygen which contributes to speeding up the generation of active centres and to instantaneous ignition of the reaction mixture.
The aplication of the proposed blowpipe in the reactors of incomplete burning of methane in oxygen with a stabilisation of the flame front by an ozone-oxygen mixture makes it possible to obtain high outputs of acetylene.