FR2498736A1 - Gas burner for furnace or boiler - includes adjacently disposed fuel elements whose end faces at outlet orifices are located in different planes w.r.t. chamber plane - Google Patents

Abstract

The gas burner consists of a chamber (1) which contains fuel elements provided with axial and radial outlet orifices (3,4) respectively. Adjacent fuel elements are so arranged w.r.t. each other that their end faces (5) at the outlet orifices are located in different planes relative to the plane of the chamber. The gas burner ensures unobstructed outflow of the gas from each of the fuel elements into the flow of air, so as to produce a flame of its own at each of the fuel elements. A fuel element whose end face at the outlet orifices is located in a plane closer to that of the chamber than the end face at the outlet orifices of another fuel element, will heat up the walls of this latter fuel element and, consequently, warm up its gas to a high temp.

Description

 The present invention relates to the field of thermal and particularly relates to a gas burner.

 It can be applied with maximum efficiency to metallurgical smelting and heating foros, for smelting and overheating of cast iron and steel, as well as to boiler fires in thermal power stations.

 At present, natural gas, being the cheapest fuel, is being used more and more in industry for burning in heating, heat-treating and melting furnaces, as well as in power plant hearths. thermal. For this, it is often necessary to ensure economical combustion of the gas at high temperature, for example for the purpose of melting and overheating ferrous alloys such as cast iron and steel.

 A high flue gas combustion temperature can be achieved by reducing the length of the flue gas path and increasing the thermal stress in the flame volume, which is possible by optimizing the elements used in burner construction. to gas, by supplying the burner with hot air, by reheating the fuel gas before it is mixed with the air. However, these efficient gas combustion means are still insufficiently exploited, as a result of the use, in a series of cases, Omparfaite burners design. Number of existing burners can not function effectively and surely, whether it sells hot or sells cold.They are not suitable to work in combination with reclaimers, do not allow to burn the gas with obtaining light flames radiating the heat and quickly heating the materials.

A gas burner is known comprising a convergent nozzle, in the center of which is mounted a gas distribution tube with perforations arranged staggered for the gas outlet. In the known burner, the gas distribution tube protrudes beyond the edge of the nozzle, so the mixture of the gas with the air takes place at the outlet and out of the confines of the convergent nozzle ( see inventor's certificate
USSR 241,353, F 27 C 1/10, published 1969).

 The known gas burner can burn the gas in a hot air flow, with formation of a short light flame.

 However, for the realization of special processes, for example in metallurgical furnaces, it is necessary to produce form flames, in the section of which the composition of the gases, the luminosity and the temperature must be different, can not be obtained when using the known gas burner.

 There is also known a gas burner for steam and hot water boilers, chosen as a prototype of the present invention (see the book "Gas Burning Devices" by Maizels PB, Vigdorchik D. Ya. , editions of literature concerning civil engineering, Xoscou> published in 1964, p.

 This known burner comprises a chamber in which gas distribution tubes for the admission of the gas are fitted, having axial and radial set-up orifices for the gas.

 This burner is designed and constructed in such a way that, the pressures of the gas and the air admitted into the burner being equal, the gas-air mixture arrives in the hearth of the boiler with an air flow coefficient of 1, 05 to 1.1. When the lining is warmed, a transparent flame forms.

 However, for the realization of special processes, for example in metallurgical furnaces, this burner can not be used, because it does not make it possible to produce flames of form with different compositions of gases, luminosities and temperature in their section, and n does not ensure a good mixing of the gas-air mixture.

 It has therefore been proposed to create a gas burner in which the neighboring gas distribution pipes would be arranged, relative to one another, so as to ensure the production of short, form-shaped flames during the combustion of the gas. gas in a cold or hot air flow, lowering the oxidizing properties of the products of combustion and raising the combustion temperature.

 This problem is solved by a gas burner comprising a chamber in which are mounted gas distribution tubes having axial and radial outlet holes, characterized, according to the invention, in that the gas distribution tubes neighbors are arranged, relative to each other, so that their ends on the side of the outlet ports are located in different planes relative to the chamber layout plane.

 With such a design, the gas burner ensures free development of the gas jets in the air flow near each gas distribution tube, with production of its own flame. in addition, each gas distribution tube, the end of which is located on the side of the outlet orifices, is situated in a plane closer to the plane in which the chamber is disposed, and its flame is heated by the walls of the gas distribution tube of which the end on the outlet side is located in a plane farther from the plane in which the chamber is arranged, so that the gas flowing in this tube is heated to a high temperature. gas distribution, mixing with the air, produces a short flame at high temperature, with high luminosity and giving less oxidizing combustion products; the mixing of the gas-air mixture improves and the combustion of the gas intensifies as a whole.

 The distance (11) between the ends of the neighboring gas distribution tubes located in different planes is, according to the invention, between 0.3 and 12 times the diameter (d) of these tubes.

 With such a design, the gas burner produces a short flame, the mixing of the gas-air mixture improves.

 When, in the gas burner, the distance (11) between the ends of the neighboring gas distribution tubes located in different planes is less than 0.3 times their diameter (d), the combustion temperature falls sharply, because, in this case, the gas is not heated in the gas distribution tubes, so its combustion is not complete.

 On the other hand, when the distance (11) between the ends of the neighboring gas distribution tubes located in different planes is greater than 12 times their diameter (d), the gas distribution tubes in the high temperature zones of the flames melt.

 Because, in the gas burner, the ends of the gas distribution tubes protrude out of the chamber for a length (12) of between 0.3 and 12 times their diameter (d), the gas burner provides the combustion gas in a short luminous flame with a high combustion temperature.

 Indeed, when the ends of the gas distribution tubes protrude outside the chamber juEluta distance (12) less than 0.3 times their diameter (d), the burner does not ensure a good mixing of the gas-air mixture, also does not produce a short flame, because it does not create an intense swirling of the gas jets, contributing to the approximation ~ front of the flanananation gas relative to the outlets of the gas distribution tubes.

 On the other hand, if the gas burner is constructed so that the ends of the gas distribution tubes protrude out of the chamber to a distance (12) greater than 12 times their diameter (d), then the entire burner can out of order because, in this case, there may be fusion of the gas distribution tubes located at the periphery of the gas burner chamber.

The invention will be better understood and other objects, details and advantages thereof will appear better in the light of the explanatory description which follows of various embodiments given solely by way of non-limiting examples with references to the drawings not shown. in which
FIG. 1 schematically represents an overall view of a gas burner according to the invention (longitudinal section)
FIG. 2 represents the burner of FIG. 1 (view from the front)
FIG. 3 represents a sectional view according to ItI-III of FIG. 2
FIG. 4 represents a gas burner according to the invention, in which the length of the gas distribution tubes increases or decreases successively
FIG. 5 shows a gas burner according to the invention, in which the length of the ends of the gas distribution tubes increases as one goes from the walls of the chamber to its axial line.
- Figure 6 shows a gas burner according to the invention, wherein the length of the ends of the gas distribution tubes decreases when going from the center of the chamber to its walls.

 The gas burner comprises a chamber 1 in which are mounted gas distribution tubes 2. The gas distribution tubes 2 comprise axial and radial outlet openings 4. The neighboring gas distribution tubes 2 are arranged, with respect to each other, so that their ends 5 having the outlet orifices 3, 4 are located in different planes with respect to the plane of the chamber 1. The distance (11) between the ends 5 of the neighboring gas distribution tubes 2 in different planes is between 0.3 and 12 times their diameter ( d). In addition, the ends 5 of the gas distribution tubes 2 protrude beyond the chamber 1 over a distance (12) of between 0.3 and 12 times their diameter (d).

 By combining the arrangement of the gas distribution tubes 2 in the chamber 1, it is possible to produce common flames that differ from one another in shape, temperature zones, gas compositions and brightness. Thus, for example, the successive increase or decrease in the length of the gas distribution tubes 2 (FIG. 4) makes it possible to produce uniform luminous flames by their composition and their temperature, both during the combustion of the gas in the air. when it is burned in cold air, said uniformity being obtained in sections of the flame parallel to the plane in which there are the projecting points of the end walls of the gas distribution tubes 2.

The successive elongation of the ends of the gas distribution tubes 2 when going from the walls of the chamber 1 to its axial line (FIG. 5) makes it possible to produce a high luminous and high temperature projection zone at the center of the common flame. I>'successive elongation of the ends of the gas distribution tubes 2 when going from the center of the chamber 1 to its walls (Figure 6), contributing to obtaining a more intense brightness of the common flame in its peripheral areas . It is also possible to arrange the gas distribution tubes 2 relative to each other in much more complicated combinations and thus obtain flames of various complex shapes. By moving the tubes 2 in the chamber 1, the shape can be changed. and the dieensions of the common flame, as well as the arrangement of its zones, hung the operation of the burner
The chamber 1 may have in its exit section the shape of a rectangle, a cross, a U, a T, a circle, an oval, a triangle, a polygon or a more complex figure, which allows to adapt the design gas burners according to the invention for use in hearths and furnaces of any shape.

 The gas burner operates as follows.

 Cold or hot air is admitted into the chamber 1, and then the combustible gas is admitted into the gas distribution tubes 2. Exiting through the axial and radial orifices 3, 4 of the gas distribution tubes 2, the fuel gas mixes with the air and ignites. Since the gas is distributed in the stream of air in the form of jets, there is a strong swirling near each gas distribution tube 2 which contributes to the approximation of the ignition front of the gas with respect to the outlet orifices 3, 4 As the ends 5 of the neighboring gas distribution tubes 2 are located in different planes, the gas jets from each gas distribution tube 2 develop freely in the air flow. by forming the flame of this tube, each gas distribution tube 2 disposed more deeply warms its flame by the walls of the tube 2 of gas distribution exceeding it, also the gas admitted by this tube is brought to a high temperature .

Exiting through the openings 3, 4 of the gas distribution tube 2, the heated gas generates, by mixing with the air, a short flame at high temperature and high brightness, as well as less oxidizing combustion products.

 The gas burner according to the invention makes it possible to produce short, bright, shaped flames, with admission of hot or cold air, to lower the oxidizing properties of the combustion products, which is essential for the normal course of operation. process in a cupola, around if the load contains steel.

 The possibility of producing short, bright flames when natural gas is burned in a cold air flow makes it possible to intensify the radiation heat transfer, to increase the thermal efficiency of the thermal appliances, to reduce the wear of the heat. padding and dimensions of the burner chambers.

 The gas burner subject of the invention ensures reliability and safe operation, without jumps or detachment of the flame; its ignition is easy. Thanks to the formation of swirlings in the gas-air mixture flows at each gas burner, during ignition the flame front propagates rapidly, which contributes to the stabilization of the combustion, to the decrease of the length The gas burner according to the invention can operate with low, medium and high pressures of gas and air, the flow coefficients being larger or smaller than those of the flame. I'unité. The gas used may be of various kinds natural gas, acetylene, propane, butane, hydrogen, byproduct manufacturing, gasogen gas, coke gas, cupola gas, and a mixture of combustible gases.

The air can be enriched with oxygen, or pure oxygen can be used as the oxidizer.

 Of course, the invention is not limited to the embodiments described and shown which have been given by way of example. In particular, it includes all the means constituting technical equivalents of the means described and their combinations. If they are executed according to its spirit and read in zabre within the framework of the protection as claimed,

Claims (3)

 A gas burner, comprising a chamber (1) in which gas distribution pipes (2) having axial (3) and radial (4) outlet ports are mounted, characterized in that the gas distribution pipes (2) mutually adjacent are disposed relative to each other so that theirbouts (5) having the outlet openings (3, 4) are located in different planes with respect to the chamber layout plane (1). ).  2. Gas burner according to claim 1, characterized in that the distance (11) between the ends, located in the adjacent planes, of neighboring gas distribution pipes is between 0.3 and 12 times the diameter (d) of these tubes.  3. Gas burner according to one of claims 1 and 2, characterized in that the ends of the gas distribution tubes protrude out of the chamber over a distance (12) between 0.3 and 12 times their diameter (d). ).