How to produce lean gas in the gas production section

Inert gas manufacturing: ①1. Check in detail the valves, primary doors and square doors of each system of the inert gas furnace. They should be in a running state. ②. Drain the accumulated water in the down blow pipeline and open the outlet valve of the air purifier. ③. Check the carbon layer height and maintain it at 2.8~3.0m (∮3.0m furnace) or 3.2~3.6m (∮3.6m furnace). Add 100~150kg of coal each time, and open high-pressure steam to blow out the furnace bottom and the three-way valve for 15 minutes. (Be careful to prevent the gas scrubbing box from connecting with the lower blowpipe, and the upper blowpipe and the lower blowpipe from the steam purge valve, causing high O2). ④1. Close the high-pressure steam purge valve, cover the fire hole, switch the computer to manual, blow air into the furnace to heat up, the air volume should be small, from small to large, check the temperature and pressure everywhere, observe the chimney venting situation, when white smoke appears in the fire hole, close the chimney valve, and at the same time take samples from the upper part of the combustion chamber for analysis. ⑤. When stopping gas production, first open the chimney valve, then turn off the air, open the chimney suction, and determine the amount of coal added depending on the temperature on the furnace and the height of the charcoal layer. ⑥. After the first furnace trial production, stop the furnace to check the height of the fire layer and carbon layer. Coal should be added for 2 to 5 seconds each time the gas is produced. ⑦. After the second furnace gas production is qualified, it will be sent to the 10000m3 gas cabinet for exhaust replacement work. The furnace bar speed is determined according to the furnace bar temperature, carbon layer height, and fire layer conditions. ⑧. The temperature on the furnace should not exceed 700℃ to prevent the furnace from scarring. If the furnace temperature is too high, the water and gas can be vented in the middle to reduce the furnace temperature. ⑨, inert gas components: CO2 16~20% O2＜1.0% CO+H2＜8.% Inert gas replacement operation: ①Inert gas exhaust air: a. The gas cabinet is in the lowest position, inert gas is fed into the gas cabinet, the vent valves of each pipeline and equipment are opened, and the vent valve at the top of the atmospheric cabinet is opened. After 3 to 4 furnaces, close the vent valves of pipeline equipment. b. After the analysis of the top of the large gas tank is qualified, close the vent valve, increase the gas tank to 8500m3, and replace it in the subsequent process. c. After the synthetic end is qualified, stop making inert gas and change to water gas. ②Coal gas replacement inert gas: a. Notify the shift leader to switch the microcomputer to the automatic operation position to raise the carbon layer and produce water and gas. b. The replacement method is the same as before, and the oxygen content is strictly controlled. ③Inert gas replacement gas: The method is the same as before, but since it is coal gas, the O2 content should be strictly controlled when making inert gas. ④air replacement inert gas: a. The method is that a gas furnace is turned off, and the air is sent into the system by an air blower through the furnace for replacement. b. Strictly analyze the CO+H2 content, the replacement time should be long, and the vent pipes everywhere should be opened to ensure safe shutdown and maintenance.

The replacement gas used for start-up or maintenance of the gas generator is generally nitrogen. If there is no nitrogen, the gas generator can be used to produce blowing gas containing a small amount of combustible gas and oxygen, that is, the lean gas in the gas making section, which is blowing gas with (CO+H2) ≤ 6% and O2 < 1%. step: In the blowing stage, air burns with C in the gas generator to generate blowing air. The blowing air is introduced into the combustion chamber and an appropriate amount of secondary air is introduced to burn off the CO and H2 in the blowing air. In this way, an inert gas with (CO+H2) ≤ 6% and O2 < 1% is obtained. As lean gas accumulates more and more, the temperature inside the gas furnace becomes higher and higher. At this time, steam is introduced intermittently to lower the furnace temperature, which is equivalent to the upward blowing stage during gas production. The difference is that the generated gas is vented, so that the required lean gas can be produced.

When the entire plant is shut down or started for annual overhaul, a gas furnace is often used to produce inert gas. The principle of making inert gas is that the gas furnace uses air as the gasification agent to produce air gas under low carbon layer regulation. The CO and a small amount of H2 in the air gas are burned by adding secondary air in the combustion chamber, and finally obtain CO+H2