SU872565A1 - Method of automatic control of convertor gas outllet without burning - Google Patents

Description

one

The invention relates to ferrous metallurgy, more specifically to the production of steel in oxygen converters, and can be used in j control systems for the removal of converter gases without reburning.

A known method of controlling the discharge of converter gases without afterburning consists in supplying oxygen at a certain time to the gas outlet path of neutral gas or compressed air, which forms a layer of gas in the vapor path — a tampon separating the waste converter gases from excess air. from gases 5 with an excess of carbon monoxide, regulating the pressure of the converter gases under the flap of the converter, cooling the gases in the waste heat boiler and igniting the torch on the ignition plug of the candle that burns the converter gas. In this case, compressed air or inert gas is supplied according to a specific program from the beginning of the oxygen purge l. with

The disadvantage of this method of controlling the discharge of converter gases is that the moments of the beginning and end of the supply of neutral gases or compressed air are governed only by the start time of the oxygen 30

blowdowns and are not directly related to the gassing processes at each heat. In this case, carbon monoxide emissions into the atmosphere are possible and the risk of an explosion increases. The moments of switching on and off the pressure regulation of the converter gases under the converter flap, as well as the ignition of the torch on the spark plug, are also not associated with the process of gas release from the converter at each heat.

The closest to the invention is a method of controlling the conversion of the converter gases by creating a gas swab at the beginning and end of the purge, regulating the pressure of the converter gases under the caisson damper, analyzing the composition and controlling their flow, and burning the converter gases on the candle.

In this method, the formation of a gas tampon is carried out by burning KOHBepTopHEJx gases in the caisson at the beginning and at the end of the oxygen purge. Combustion is ensured by the growth of a large amount of air in the caisson at the maximum gas flow rate of the gas exhaust line G2.

The disadvantage of this method is the lack of volume control.

according to a gas tampon from fully burned gases in the gas exhaust path: overestimation of the volume leads to the release of a large amount of heat, which, in turn, will lead to the production of a large-capacity waste-heat boiler and an increase in construction costs. In addition, after the passage of a large tampon, there is a significant emission of carbon monoxide into the atmosphere, because at the maximum flow of exhaust gases the concentration of carbon monoxide in them remains for a long time below the value at which it can ignite on the candle. The moments of the start and end of pressure control in the caisson, as well as the ignition of the torch on the candle, are not associated with the process of gas emission from the converter, which is not constant from melting to melting,

The purpose of the invention. is to increase the intrinsic safety of the removal of gases and reduce the emission of carbon monoxide into the atmosphere.

The goal is achieved by agreeing to the method of automatically controlling the removal of converter gases without afterburning, including the formation of a gas tampon at the beginning and at the end of the oxygen purge, controlling the pressure of the converter gases under the damper of the caissons, controlling their composition in the candle, controlling them the flow rate and the afterburning of gases on the candle, at the beginning of the oxygen purge, determine the flow rate of the exhaust gases at a level of 40-60% of the maximum flow rate of gases in the gas exhaust path, is determined by the gas analyzer in From the utilizer, the beginning and the end of the formation of the first tampon at the beginning of the oxygen purge on the composition of the exhaust gases, ensuring the explosion-proof conditions, the ignition of the converter gases on the candle at the moment of the end of the tampon passage through the vapor path defined by the gas analyzer, at the entrance to the candle, regulating the converter gases under the flap is carried out from the moment of the end of the formation of the first tampon and the start of the oxygen blowing to the moment of the beginning of the formation of the second tampon at the end of the oxygen blowing, determined by the gas analyzer in the recovery boiler and the exhaust gas flow rate is set at the same level of 40-60% of the maximum before the start of the next purge.

The drawing shows an installation for removal of converter gases without afterburning, with the help of which the proposed method is implemented.

The installation contains a Converter 1, above which is located the valve 2 of the caisson 3 and the waste heat boiler 4,

passing to gas exhaust path 5, which carries a gas cleaning stage 6; Gas exhaust path 5 is equipped with a suction 7; outlet pipe 8 coming out of the suction is connected to a candle 9 equipped with a pilot 10. waste heat boiler 4, a device 13 for controlling the flow of flue gases and a gas analyzer 14 for the composition of waste gases at the inlet to the candle. The outputs of the computing device 11 are connected to the igniter 10 and the switching device 15, the output of which is connected to the actuator 16, the control gate of the gas cleaning stage 6 The pressure of the converter gases under the valve 2 of the caisson 3 is measured by a pressure sensor 1-7, the output of which is connected to the regulator 18, which controls the actuator 16 through the switching device 15.

The method is carried out as follows.

At the beginning of the oxygen purge on converter 1, the operator lowers the valve 2 of the caisson 3 onto the converter throat, thereby preparing the pressure control system consisting of a pressure sensor 17, a pressure regulator 18 and an actuator 16 for operation. At this time, the flow of waste converter gases are set at a constant value equal to 40-60% of the maximum gas flow determined by the performance of the vapor path 5. This flow rate is maintained by the actuator 16 from the signal set by you islitelnym device 11 and transmitted through switching device 15. By maintaining the exhaust gases flow in said suction is provided within a caisson 3, an amount of air which connecting Referring converter with hot gases, neutral forms sufficient combustion products. When the waste gas consumption is 40% of the maximum, a minimum amount of tampon is created, which guarantees its preservation from erosion as it passes through the gas bypass line and reliable separation of gases from the presence of oxygen from gases containing carbon monoxide. The presence of oxygen in the mixture of gases above 5.6% and carbon monoxide above 12.5% forms an explosive mixture of gases. When the waste gases flow 60% of the maximum, a deliberately reliable tampon of gases is formed, however, there is more air leaks and when the converter gases are burned, the maximum permissible amount of heat, according to the heat conditions of the boiler, is released. In addition, at high flow rates of exhaust gases, after the passage of a tampon, significant emissions of carbon monoxide into the atmosphere occur.

Immediately after passing the tamyon, it is necessary to turn on the pressure control system, which will quickly limit the afterburning of gases in the caisson and the rich composition of the exhaust gases before being able to burn them on the candle. The moment of activation of the pressure control is determined by the composition of the converter gases at the beginning of the vapor path 5 and the flow of flue gases. After receiving signals from the gas analyzer 12 of the bypass gas flow metering device 13, the computing device 11 switches the coaxial / antirting device 15. As a result, the pressure sensor 17 gives a signal corresponding to the pressure of the converter gases under the gate 2 of the converter 1 to the pressure regulator 18, a signal which through the switching device 15 is supplied to the actuator 16, which is connected to the gate at the gas cleaning stage 6. Partial closure of this gate will reduce the consumption of waste converter gases, and by reducing the afterburning of the converter gases above the throat of the converter 1, the content of carbon monoxide in gases quickly increases.

As soon as the gas analyzer 14, mounted on the nozzle 8 behind the suction 7, detects the passage of the gas tampon through the nozzle 8 and the presence of carbon monoxide in the amount of more than 12.5% in the off-gas of the converter gases in the absence of oxygen, the computing device 11 gives a signal to the igniter 10 to burn the waste gases on the candle 9. At the same time, the emission of carbon monoxide into the atmosphere is sharply reduced while the explosion safety is increased.

At the end of the oxygen purge, when the content of carbon monoxide in the off-gas converter gases in the recovery boiler 4 is reduced to 12.5%, the computing device 11 via the switching device 15 gives a signal to turn off the pressure control system and set the flow rate of the off-gas converter gases equal to 40 60% of the maximum. In this case, due to the additional air leaks, a gas tampon of sufficient volume is formed. In the inter-purge period, the hetsos 7 operates at 40-60% of its productivity, which saves energy.

Using the proposed method of controlling the removal of converter gases without afterburning, in comparison with the known methods, provides an increase in the explosion safety of the system and the removal of converter gases, a decrease in the emission of carbon monoxide into the atmosphere, and a decrease in thermal load.

0 to the waste-heat boiler, as well as automatic regulation of all operations for removal of converter gases without afterburning.

invention formula

five

The method of controlling the removal of converter gases without afterburning, including oxygen purging with the formation of a separation gas tampon at the beginning and end of the oxygen purge /, controlling the flow of exhaust gases by pressure under the caisson damper, controlling their composition in the recovery boiler and at the inlet to the candle, control of their consumption and afterburning of the gas on the candle, characterized in that, in order to increase the explosion safety of the exhaust gases and reduce emissions of carbon monoxide into the atmosphere, at the beginning of the oxygen

0 purging sets the flue gas flow rate at 40-60% of the maximum, regulating the flue gas flow rate under the caisson damper starts at the time of the end of the formation of a gas separation pad, which is determined by the gas analyzers in the recovery boiler to achieve carbon monoxide 12 , 5% with an oxygen content of less than 5.6, the afterburning of the exhaust gases at the candle start at the moment when the carbon monoxide content reaches more than 12.5%, as determined by the composition analyzer. enii oxide content

5 carbon in the waste gases of the waste-heat boiler less than 12.5% set the flow of exhaust gases at the level of 40-. 60% of the maximum.

Information sources,

0 taken into account in the examination

1. Japanese Patent No. 42-23682, cl. 10 A 536.3, 1967.

2. Berezhinsky A.I. and Zimmer -G man A.F. Cooling and gas cleaning

5 oxygen convectors, m., Metallurgi, 1975, p.15-17.

Claims (1)

Claim A method for controlling the discharge of converter gases without afterburning, including oxygen purging with the formation of a separation gas tampon at the beginning and at the end of oxygen purging ^, regulating the flow of exhaust gases by pressure under the caisson flap, monitoring their composition in the recovery boiler and at the entrance to the spark plug, monitoring them the flow rate and afterburning of gases on the candle, characterized in that, in order to increase the explosion safety of the gas outlet and reduce carbon monoxide emissions into the atmosphere, the waste flow rate is set at the beginning of the oxygen purge flue gases at a level of 40-60% of the maximum, the regulation of the flow of exhaust gases by pressure under the caisson flap starts at the end of the formation of the gas separation tampon, which is determined by gas analyzers in the recovery boiler to achieve a carbon monoxide content of 12.5% with an oxygen content of less than 5.6, afterburning of exhaust gases on a candle starts at the moment of reaching a carbon monoxide content of more than 12.5%, determined by an analyzer of gases at the inlet to the candle, and with a decrease in the carbon monoxide content in the exhaust x gases of the recovery boiler at least 12.5% flue gas flow rate is set at 40, 60% of maximum.