SU1235909A1 - Method of heating blast - Google Patents

Description

The invention relates to methods for operating regenerative air heaters and can be used in the steel industry and mechanical engineering for heating the blast for blast furnaces and cupola furnaces.

The aim of the invention is to increase the temperature of the blow and reduce fuel consumption and material consumption.

The drawing shows a diagram of a regenerative air heater.

The regenerative ductwork system is represented by regenerators A and B, where a cold blast is fed through the channels with valves 1 and 2 and a hot blast is led through the channels with valves 3 and 4. The flue gases are discharged through channels with valves 5 and 6. Air through the channel with valve 7 into the common combustion chamber 8 is supplied with combustion air, and the combustion chamber 8 is connected to regenerators A and B with a diaphragm directional bypass system 9. The regenerators are equipped with a smoke exhauster 10, blower 11, fan 12 with valve 13.

The method is carried out as follows.

Fuel and air are continuously supplied to the common combustion chamber 8 in a stoichiometric ratio, the flow of the mixture being regulated by the valve 7 so that the pressure maintained in the chamber 8 is equal to the pressure of the hot blow. As a result of this method of heating the system, continuous combustion of fuel and constant pressure in the combustion chamber 8 are provided, which eliminates water hammering, simplifies the equipment and maintenance of the heating system, and improves occupational safety conditions.

Suppose that regenerator A is heated, In this case, valves I, 3 and 6 are closed, and valves 2.4 and 5 are open. Through valve 2, regenerator B and valve 4, a hot blast goes to the unit (blast furnace, cupola), and due to the equality of the pressures in the regenerator Biv to the combustion chamber 8, the gases interpenetrate from the volume into o (there are no 5 pressure drops due to the pressure difference then it is in itself incommensurable in comparison with the amount of blowing, and besides

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but the diaphragm directional bypass system 9 between the combustion chamber 8 and the regenerators A and B, facilitates the exit of flue gases from the combustion chamber 8 and prevents the entrance to the combustion chamber 8 to blow.

Due to this method of delimiting the volumes of the combustion chamber 8 and the regenerator B, there are no losses to blow into the flue gases, which is an advantage compared to the valve cut-off, which is characterized by losses due to valve leaks and unreliable operation due to difficult operating conditions. .

The flue gases into the regenerator A come from the combustion chamber 8 under the action of a pressure differential between them through the diaphragm directional bypass system 9 .. The discharge in the chamber A of the regenerator is created by the exhaust fan 10. In this case, the pressure in the combustion chamber 8 does not change, since the flow of gases from Combustion of fuel into chamber 8 is equal to their loss through the bypass system 9.

The valves, of the system, are accomplished by fully closing valve 5, then simultaneously opening valve 1 and 3 and closing valve 2 and 4, and then opening valve 6.

When the valve 5 is completely closed, the smoke system remains disconnected both from regenerator A and from regenerator B until valve 6 is opened. The pressure of gases in the regenerator A increases, and the pressure differential between the combustion chamber 8 and the regenerator A decreases. Accordingly, the gas loss from the combustion chamber 8 and, consequently, the fuel consumption with the combustion products compensating for this gas loss, is also reduced. Therefore, during the valve switching period, the fuel consumption for heating the regenerators is minimal, sufficient only to maintain the pressure of the system of the combustion chamber 8 and the regenerators A and B.

After the valve is reversed, the system returns to a position that is symmetrical to the original, with the difference that the regenerator B is now heated, and the regenerator A heats the blast.

Thus, the use of the above flue gas cutoffs allows

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It is necessary to eliminate the drawbacks inherent in the valve cut-off, namely to increase the blowing temperature, simplify maintenance, reliability of operation and reduce the material consumption of the shut-off system. Due to the absence of an involuntary discharge of flue gases into the flue pipe, mine regenerators A and B, during the period of valve recalculation, the specific fuel consumption for heating to blow is reduced.

Example. Blower 1I produces 12 thousand m of air. Of these, 8 thousand m is heated to 800 ° C, 4 thousand m is fed for combustion into the combustion chamber. Pressure to blow 2000 kgf / m. The pressure in the furnace also

Editor G. Volkova

 Compiled by R.Seifulov Tehred jl. Anic move

Order 3061/23 Circulation 552Subscription

VNISh State Committee of the USSR

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, Project a Ya Street | four

094

2000 kgf / m Combustion air from the collector is taken by fan 12 to increase its pressure by 400 kgf / m. Consumption of natural gas 350-400. The temperature of the combustion products is 1400 C. The diameter of the outlet of the nozzle on the side of the regenerator is 150 mm. Analysis of the combustion products after the regenerator and the operation of the vat show that there is no discharge to blow through the combustion chamber and the regenerator into the chimney.

The use of the proposed method. The ba allows you to increase the yield per ton of casting with a simultaneous increase in the productivity of the cupola.

Correspondent JM Mac Simishinets

Claims (1)

METHOD FOR HEATING BLOWS in regenerative air heaters with a common combustion chamber and continuous supply of blast, characterized in that, in order to increase the temperature of the blast, reduce fuel consumption, the pressure of the combustion products is maintained in the common combustion chamber equal to the blast pressure by changing the fuel consumption and combustion air. e <o SU. „1235909 Air x Floating