A method for controlling stable SO2 emissions during coke oven reversing

Abstract

This invention discloses a method for controlling stable SO2 emissions during coke oven reversing, which adopts the following methods: 1) Modifying the working program of the main gas regulating valve to lock the opening of the main gas regulating valve when shutting off the gas during reversing, so as to ensure that the change in the opening of the main gas regulating valve is minimal throughout the reversing process, so as to ensure that the gas flow into the heating system tends to be stable; 2) Modifying the working program of the flue suction regulating actuator to maintain the original opening before shutting off the gas during reversing; 3) Adjusting the throttle valve of the hydraulic station of the reversing machine to control the action time of the gas exchange cylinder, so that when the exchange cock moves forward and reverse, the time from opening to closing in the forward and reverse directions, and from closing to opening in the reverse and forward directions, is extended from the current 10s to 25s.

Description

Technical Field

[0001] This invention relates to a method for controlling stable SO2 emissions during coke oven reversing. Background Technology

[0002] Modern coke ovens using coke oven gas for heating and reversing involve three steps: shutting off the gas, exchanging air and waste gas, and starting the gas. After shutting off the gas, the main coke oven gas pipe generates a static pressure head, and the pipe pressure matches the external network pressure. At this time, according to the set flow rate adjustment, the main gas pipe regulating valve will be fully opened. During the gas starting process, the exchange valve is fully opened. Because the main pipe pressure is higher than during normal heating, a large amount of gas enters the combustion system instantaneously when the exchange valve opens. At this time, because the suction is set within a certain range, it is very easy to cause incomplete combustion of coke oven gas and excessive particulate matter. It can also lead to higher particulate matter and SO2 emissions than during the non-reversing period, with large fluctuations throughout the heating cycle. In addition, during the process of adjusting the gas flow rate to the set value, the main gas pipe regulating valve takes a long time to stabilize due to its own characteristics. This results in a longer stabilization time for the gas flow rate after reversal, and SO2 emissions fluctuate significantly throughout the heating cycle. Summary of the Invention

[0003] In order to reduce the fluctuation range of gas flow rate during the gas switching process, shorten the adjustment time of the gas regulating valve during the switching period, and stabilize the gas supply flow rate during coke oven heating, this invention provides a method for controlling the stable emission of SO2 during coke oven switching.

[0004] The specific technical solution of this invention is as follows: a method for controlling stable SO2 emissions during coke oven reversing, which adopts the following methods: 1) Modifying the working program of the main gas regulating valve to lock the opening of the main gas regulating valve when shutting off the gas during reversing, so as to ensure that the change in the opening of the main gas regulating valve is minimal during the entire reversing process, so as to ensure that the gas flow into the heating system tends to be stable; 2) Modifying the working program of the flue suction regulating actuator to maintain the original opening before shutting off the gas during reversing; 3) Adjusting the throttle valve of the hydraulic station of the reversing machine to control the action time of the gas exchange cylinder, so that when the exchange cylinder moves forward and backward, the time from opening to closing in the forward and reverse directions, and from closing to opening in the reverse and forward directions, is extended from the current 10s to 25s.

[0005] Beneficial effects of the invention: Through the implementation of the above three steps, the invention achieves the following effects: 1) The adjustment time of the gas regulating valve during the reversing period is shortened from 1 minute to 10 seconds, and the fluctuation range of the supply flow rate of coke oven heating gas within one exchange cycle is reduced from the original 2000 m³ / min. 3 Reduced to 1500m 3 The two coke ovens exchange gas four times per hour, reducing the adjustment time by 200 seconds and saving 27 cubic meters of gas per hour. 3 / h, saving 236,500 m³ of gas annually. 3 According to 0.2 yuan / m 3 1) Annual cost savings of 47,300 yuan; 2) Extending the gas shut-off time from 10 seconds to 25 seconds allows for effective combustion of residual gas, reducing the occurrence of "explosions," while simultaneously reducing particulate matter levels by approximately 2 mg / m³ according to online monitoring data from the coke oven chimney. 3 ;3) The SO2 fluctuation in coke oven flue gas decreased by 15 mg / m³ at the moment of reversal. 3 This method not only effectively avoids environmental pollution incidents caused by untimely adjustment of desulfurization and denitrification devices, but also saves 20 kg / h of desulfurizing agent, resulting in annual cost savings of 315,000 yuan based on a cost of 1,800 yuan / ton. This method can be directly applied to various types of coke ovens using hydraulic exchangers, main gas pressure regulating valves, and automatic flue gas suction adjustment mechanisms. Implementation

[0006] A method for controlling stable SO2 emissions during coke oven reversing employs the following steps: 1) Modifying the operating program of the main gas regulating valve to lock the opening of the main gas regulating valve when shutting off the gas during reversing, ensuring minimal change in the opening of the main gas regulating valve throughout the reversing process, thereby stabilizing the gas flow into the heating system; 2) Modifying the operating program of the flue gas suction regulating actuator to maintain the original opening before shutting off the gas during reversing; 3) Adjusting the throttle valve of the reversing machine hydraulic station to control the action time of the gas exchange cylinder, extending the time from forward and reverse opening to closing, and from closing to reverse and forward opening, from the current 10s to 25s when the exchange cock moves in both directions.

Claims

1. A method for controlling stable SO2 emissions during coke oven reversing, characterized in that... The following methods were adopted: 1) Modify the working program of the main gas regulating valve to lock the opening of the main gas regulating valve when switching to shut off the gas, so as to ensure that the change in the opening of the main gas regulating valve is minimal during the entire switching process, so as to ensure that the gas flow into the heating system tends to be stable; 2) Modify the working program of the flue suction regulating actuator to maintain the original opening before shutting off the gas during the switching period; 3) Adjust the throttle valve of the hydraulic station of the switching machine to control the action time of the gas exchange cylinder, so that when the exchange cock moves in the forward and reverse directions, the time from opening to closing in the forward and reverse directions, and from closing to opening in the reverse and forward directions, is extended from the current 10s to 25s.