SU981377A1 - Method for automatically controlling operations for removing converter gases without afterburning - Google Patents

Description

(54) METHOD FOR AUTOMATIC CONTROL OF OPERATIONS OF CONVERTER

one

The invention relates to ferrous metallurgy, more specifically to the production of steel in oxygen converters, and can be used in control systems for flue gas from the converter without post-combustion.

A known method of controlling the removal of converter gases without afterburning involves creating a gas separating gas tampon at the beginning and end of the purge to prevent the formation of explosive mixtures, regulating the pressure of the converter gases under the caisson damper, controlling the flow of exhaust gases, burning gases on the candle.

A separating tampon is formed as a result of the complete combustion of the bore gas, i.e. at an air excess factor of 1. When regulating the pressure under the caisson damper, air is allowed to leak into the duct and the converter gas is burned at oSOD. According to this method, a separating tampon is formed as a result of GASES WITHOUT BURNING

unsupervised large air infiltration into the caisson at a maximum flow rate of waste gases flj.

The disadvantage of this method is the lack of regulation of the volume formed in the cooler gas cooler of fully combusted gases. The overestimation of the tampon volume leads to the release of a large amount of heat, which causes the design of the boiler

10 lditel high power and increased construction costs. In addition, after the passage of a large tampon, there is a significant release of CO into the atmosphere, since at maximum discharge of the exhaust gases, the concentration of carbon monoxide in them remains for a long time below the value at which its possible ignition of the candle on the candle (about 30% of CO). Disposal of the converter gas 20 in such conditions is ineffective .. Moo-. The pressure start and end control elements under the caisson damper, and the spark plugs on the candle are not associated with the process of gas release from the converter, all operations are performed by the operator manually. The closest to the invention is a method of automatically controlling the discharge of converter gases without afterburning, consisting in the formation of tampons at the beginning and end of the oxygen purge at a certain constant value of the flow of exhaust gases (40-60% of the maximum), turning the control system on and off pressure under the casson damper according to the gas analysis information in the boiler-cooler and ignition of the converter gas on the spark plug according to the gas analysis information at the inlet to the spark plug 2j The disadvantage of this method is also no volume control, generated in the boiler of the gas cooler tampon. The formation of a tampon occurs spontaneously in time and therefore this operation cannot be automated. By reducing the waste gas flow during the formation of a tampon bottle, the peak load on the cooler is partially reduced and CO emissions to the atmosphere are partially reduced. The moments of the beginning and the end of gas removal operations are not optimally defined and not regulated, which also does not allow to automate the process of gas removal. The purpose of the invention is to improve the reliability of the operation of exhaust gases, reducing emissions of carbon monoxide into the atmosphere and increasing the output of the converter vase for disposal. The goal is achieved by the method of automatic control of non-afterburner removal gases of the converter gases, including oxygen blowing with the formation of a separation swab at the beginning and end of the purge, determining the moment of firing ignition, controlling the flow of flue gases by pressure under the caisson damper and burning gases the candle or their disposal, from the beginning of the oxygen blowing, regulate the pressure under the caisson damper, corresponding to the complete combustion of the converter gases at oL - 1, pressure regulation a shutter coffer according to withdrawal of gas without afterburning in the caisson at of / -0.1, was initiated, the time delay from the moment of ignition of melting equal to 0.2-1 min combustion th con

gas on the candle or its utilization begins after a time delay from the moment the control is transferred to

Claims (2)

The gas passes through the boiler room 5, the gas exhaust path 6 with the gas cleaning 7 and the smoke exhauster 8, through the rocker plate 0, l, equal to the passage time of gases through the entire gas outlet path with the minimum flow of exhaust gases, pressure control under the caisson flap continues during the inter-purge period. In the case of removal of the converter gas with its subsequent utilization at the end of the purge, the exhaust gases are transferred to the candle through a time delay from the time it begins to regulate it /, equal to the time of gases passing through the entire exhaust pipe with the minimum gas consumption. FIG. Figure 1 shows the installation of removal of converter gases without afterburning; . in fig. 2 - the change in the output of the converter gas a, the controlled flow of exhaust gases b and the change in the coefficient of excess air in the course of the converter melting. The installation contains converter 1 located in cover 2. Above converter 1 there are caisson shutters 3, caisson 4, boiler-cooler 5, which goes to gas exhaust path 6, containing adjustable stage 7 of gas cleaning, exhaust fan 8 and candle 9 with igniting device 10 In the presence of converter gas utilization, the installation contains a gas pipeline 11 and a reversing valve 12. The pressure control system under the caisson valve 3 contains a pressure sensor 13 connected to the regulator 14, which is connected to the actuator 15. The system egulirovani pressure also comprises tchi backside pressure to 16 (v / 1), a pressure dial 17 (J - 0,1), the switching device 18, connected to the dual relay 19 time, and a minimum flow sensor 20. The method is as follows. From the moment the heat is ignited on converter 1 in cover 2, gas pressure is measured under pressure valve 3 by pressure sensor 13, the signal of which is fed to regulator 14 (moment in Fig. 2). At this time, the pressure setting device 16 (of. -1) is connected to the controller 14 by means of the switching device 18. The regulator 14, through the actuator 15, controls the gas cleaning regulator 7 so that in the caisson 3 there occurs a complete combustion of the converter gas to form neutral gases. This tampon 12 is passed to candle 9 and is emitted into the atmosphere. Through a time delay AT-t equal to 0.2-1 minutes at time g (Fig. 2), time relay 19 connects to controller 14 instead of unit 16 pressure to pressure regulator 17, corresponding to, 1, to controller 14. The pressure regulator 14 sharply limits the air in the caisson 4, allowing for the removal of converter gases without afterburning in the caisson. From this point on, in the caisson 4, the CO gas concentration increased by 30% and the time relay 19 starts the time DTD, sufficient for the gases to pass from the caisson 4 to the end of the candle 9, and by the time ATg, the time relay 19 gives a command to the igniter 10 which ignites the converter gas (moment 3 in Fig. 2). In the event of a reset, the time relay 19 gives the command to switch the change-over valve 12 which directs the converter gas to utilization. At the end of the purge, when the pressure control system reduces the flow rate of the cooling gases to the minimum, according to the gas emission from the converter, the lower position regulator, gives a signal to the switching device 18, which switches the pressure setting device 17 ("0.1) to the pressure setting device 16 (oi 1; time e in Fig. 2). When this dual time relay 19 starts the countdown time DGG after which the device 12 transfers gas from the gas pipeline 11 to the candle 9 (time e in Fig. 2). Moment W in FIG. 2 corresponds to the end of the purge. The length of time from d to s (or, equivalently, from d to e) corresponds to the utilization of the converter gas. Due to the irregularity of the output of the converter gas, the unregulated tampon is of considerable size and its transit time is indeterminate. According to the proposed method, a tampon begins to form (by adjusting) immediately after the start of the purge and the start of gas release 1 from the converter (moment in Fig. 2). With a minimum consumption of waste gases for the formation of such a tampon takes no more than 0.2 minutes. In the case of slow evolution of gassing, the maximum time for tampon formation is 1 min. Therefore, the limit settings of the setter of the end of tampon formation from the start of the purge T are 0.2-1 minutes. Most of the time of tampon formation (up to 1 min), in this case does not lead to CO emissions into the atmosphere, complete combustion of gases. The total time of collection of gas for disposal, according to the proposed method, can be increased by 20-30%. At the end of the purge, the pressure under the caisson damper becomes zero, i.e. less than specified and the control system automatically keeps the regulator in a position corresponding to the minimum capacity. At the same time, during the entire interstitial period, the productivity and, consequently, the electric energy consumption by the smoke exhauster is minimal. Using the method of automatic regulation of operations for removal of converter gases without afterburning allows for more reliable and fully automated operation of the system for removal of converter gases. This increases the explosiveness of the gas removal system, reduces CO emissions to the atmosphere, increases the yield of gas when it is disposed of, and saves electricity. The use of the method provides an increase in the removal of the converter gas for utilization by approximately 25%. The savings from an increase in the amount of gas withdrawn is about 450 thousand rubles / year. The savings due to the reduction of electricity consumption by smoke exhausters by the proposed method as compared with the unregulated one is 30%, namely, 160 thousand rubles / year. Thus, the total savings from the use of the proposed method of automatic regulation of operations for the removal of converter gases without afterburning is about 889 thousand rubles / year. In addition to the effect in monetary terms, the effectiveness of the implementation of the proposed method is expressed in the improvement of the air basin by reducing CO emissions into the atmosphere and in facilitating the work of the steelworker operator. Claim 1. Method of automatic control of removal of converter gases without afterburning, including oxygen purging with the formation of a separating gas tampon at the beginning and end of the blow, determination of the moment of ignition of the melt, control of the flow of flue gases by pressure under the caisson damper and combustion of gases candle or their utipizatsnyu, from l. and in order to improve the reliability of gas injection operations, reduce carbon monoxide emissions into the atmosphere and increase the output of the converter gas for disposal, from the beginning of the oxygen purge regulate the pressure under the caisson damper corresponding to full combustion of converter gases with an excess air ratio oi. - 1, the pressure regulation under the caisson damper, corresponding to the exhaust of gases without afterburning in the caisson at A - OD, starts after a time delay from the moment of ignition of the heat, equal to 0-2-1 minutes, the converter gas is burned on the candle or its Recycling begins after a time delay from the moment of transferring the regulation to of.-0.1, equal to the time 9 77 for the passage of gases through the entire gas exhaust duct with the minimum consumption of exhaust gases, pressure control under the caisson damper is continued during the interstitial period. 2. A method according to claim 1, characterized in that when diverting the converter gas with its subsequent disposal at the end of the purge, the exhaust gases are transferred to the candle through an exposure time from the beginning of the regulation from 1 to equal to the passage time of the gases throughout the gas outlet a path with a minimum gas flow. Sources of information taken into account in the examination 1. Berezhinsky A., I., Zimmerman A. F. Cooling and cleaning of gases in oxygen converters. M., Metallurgists, 1975, 0. 15-17. 2. USSR author's certificate for application number 2775936 / 22-02, cl. C 21 C 5 / 4O, 1979.