The gas burner

With the advent of g. g., invented into 1855 by German chemist R. By Bunsen, the consumption of combustible gases sharply grew at first for illuminating the streets it was municipal, and then for other purposes. The multidepartmental nature of the application of g. g. caused the variety of constructions and principles of their device. Distinguish g. g. diffusion, injection, two-wire, kombinirovannye and gas-turbine. By the value of the gas pressure, supplied in g. g., distinguish burners low [ to 5 kN/m² (0,05 kgf/cm²) ], average [ 5-300 kN/m² (0,05-3,0 kgf/cm²) ] and high [ SV. 300 kN/m² (3,0 kgf/cm²) ] pressure. Depending on the method of combusting the gas g. g. they are torch (partial and incomplete mixing of gas with air) and flameless (complete it will tell before hand, mixing).

Osn elements g. g.: mixer and burner cap with the stabilizer. Depending on designation and operating conditions g. g. its elements have different design concept.

In diffusion g. g. into the combustion chamber gas and air brings. The mixing of gas and air occurs in the combustion chamber. Majority diffusion g. g. is mounted on the walls of furnace or furnace. In the boilers won acceptance Vol. n. hearth g. g., which are placed inside the furnace, in its lower part. Hearth g. g. consists of one or several gazoraspredelit. of the pipes, in which are drilled the openings. Perforated pipe is established on the fire grate or the hearth of furnace in the slit channel, lined from the refractory brick. The required quantity of air enters through the fireproof slit channel. With this device the combustion of the streams of gas, which emerge from the static openings, begins in the fireproof channel and concludes in the furnace cavity. Hearth burners create low resistance to the passage of gas; therefore they can work without it will force, blowing. Diffusion g. g. are characterized by more uniform temperature along the length of torch. However, these g. g. require the increased excess air ratio (in comparison with inzhekts.), are created the lower thermal stresses of furnace cavity and the worse conditions for the afterburning of gas in the tail section of the torch, which can lead to the incomplete combustion of gas.

Diffusion g. g. use in the industr. furnaces and the boilers, where is required uniform rate -.pa along the length of torch. In the some processes of diffusion g. g. they are irreplaceable. For example, in the glass, open-hearth and other furnaces, when air proceeding with combustion podogrevayetsya to temperatures, which exceed the ignition point of combustible gas with air. Successfully adapt diffusion g. g., also, in the some hot-water boilers.

In the injector burners the combustion air is sucked in (it is injected) due to the energy of gas jet and their mutual mixing it occurs inside burner housing. Sometimes in injection g. g. the suction of the necessary quantity of combustible gas, whose the pressure is close to the atmospheric, is achieved by energy of airstream. In the burners of the complete mixing (with the gas it gets mixed entire necessary for the combustion air), which operate on gas sr. of pressure, is formed short flame jet, and combustion completes in the minimum furnace cavity. Into injection g. g. of partial mixing enters only part (40-60%) of air (Vol. n. primary air) requiring for the combustion, which is mixed up with the gas. A remaining quantity of air (Vol. n. secondary air) proceeds to flame jet from the atmosphere due to the injecting action of air-gas jets and rarefaction in the furnaces. In contrast to injection g. g. of mean pressure, in the low-pressure torches is formed uniform gas-air mixture with the content of gas of more than upper inflammability limit; these g. g. are steady in the work and have the broad band of thermal load.

For the smooth burning of gas-air mixture in injection g. g. of average and high pressure the stabilizers use: it will supplement, the igniting torches around osn of flow (burner with the annular stabilizer), the ceram. tunnels, inside which it occurs the combustion of gas-air mixture, and the lamellar stabilizers, which create turbulence on the magnetic path.

In the furnaces it means, the sizes of injection g. g. they gather into the blocks of 2 even more than burners.

Wide application obtained injection g. g. infrared radiation (Vol. n. the flameless burners), in which osn a quantity of heat obtained with the combustion is transferred by emission, since gas burns on the radiating surface by thin layer, without the visible torch. Ceram. nozzles or metallic grids serve as radiating surface. These burners use for the heating of accomodations with the large multiplicity of the exchange of air (sport halls, trading, accomodation, hot-house, etc.), for the drying of the painted surfaces (cloths, paper, etc.), the warming-up of frozen soil and bulk materials, in the industrial furnaces. For the uniform heating of large surfaces (furnaces of neftepererabat. of plants and other industr. furnaces) use Vol. n. the panel injection radiating burners (Fig. 1). In these burners the gas-air mixture from the mixer falls into the general duct, and further along the tubes mixture is distributed on the section to the tunnels, in which occurs its combustion. Panel burners have small overall sizes and broad band of regulation, little they are sensitive to the counterpressure in the furnace camera.

Wide acceptance obtained the two-wire burners (s it will force, by the supply of air), in which air necessary for the combustion will be given with fan. Two-wire (Vol. n. blasting) g. g. work on the gas of low and sr. of pressure. Burners have small overall sizes, they possess large productivity with the noiseless run; it is possible to use them in the combustion systems with different value of counterpressure and to regulate the relationship of gas and air. For the decrease of the length of flame jet gas, and sometimes also the air flow crush into the separate thin streams, turn the flows of gas and air at angle to each other.

For the operational passage from one form of fuel to another (especially in the winter months), and it is also for the joint combustion of different specific the fuel use the kombinirovannye burners: gas-oil and powder-gas. The kombinirovanneye burners use also, when it is necessary to create the luminous flame or when on the gas it is not possible to ensure the necessary temperature in the furnace. Gas-oil burner (Fig. 2) consists of gas, air. and liquid of the parts, which ensure respectively the supply of necessary for combusting the quantity of gas, air and petroleum residue. In the powder-gas burner for combusting the natural gas in the large boilers of elec. stations the gas enters through the outlying openings and is sent toward to center, being mixed up along the way with the twisted airflow. Burner is supplied teleskopich. with device with the screw drive, which makes it possible to remove inward the pipe, along which will be given in the furnace air- dust mixture with the work it is boiler on gas fuel. Teleskopich. device prevents the entry of dust into the slot between the mobile and stationary parts of pipe.

Increases the application of the gas-turbine burners, in which the supply of air is accomplished by the axial-flow blower, the powered by gas turbine. These g. g. are proposed in the beginning. 20 v. (turbogorelka Of eykarta). Under the action of the reaction force of exhaust gas the impeller, shaft and fan are set into rotation to the side, opposite to the outflow of gas. Producer to nost' burner is regulated by the value of the pressure of gas entering. Gas-turbine burners can be used in the furnaces it is boiler. Promising are high-pressure turbine g. g. with the the samopodachey of air through the recuperators and the air. economizers; gas-oil g. g. of large productivity, which work in heated and cold air. On the application of g. g. for welding and cutting the metals see in st. Torch welding and flame cutting.

Lit.: Staskevich n. l., reference management on the gas supply, l., 1960; Mikheev v. p., gas fuel- and his combustion, l., 1966; Use of gas in industrial furnaces, l., 1967.

N. i. ryabtsev.