When the large air separation unit needs to be temporarily stopped due to various faults, the following steps are to be followed.
Stop the operation of each product compressor; stop the operation of the booster turbine expansion unit; stop the operation of the medium-pressure liquid oxygen pump; stop the operation of the medium-pressure liquid argon pump; stop the operation of the booster compressor unit; switch the instrument air system to the standby pipeline; open the air turbine compressor outlet venting valve; open the product venting valve appropriately and close the product delivery valve; cut off the pipeline conveying the lower tower liquid air to the upper tower and the argon making part; stop the operation of the air turbine compressor. Shut down the air pre-cooling system; shut down the switching system of the molecular sieve purifier system.
The entire liquid shall be discharged when one of the following conditions occurs.
1. When the content of acetylene and other pure hydrocarbons in the main condensing evaporator liquid starts to exceed the normal operating value, the discharge of the liquid should be considered, and when the content of these impurities reaches the alarm value, the main cooling liquid should be discharged in its entirety.
2. When the liquid level in the main condensing evaporator drops to 50% of the normal operating level, the main cold liquid should be discharged in its entirety.
DEAR air separation in the normal large air separation unit temporary stopping process, there are standardized step requirements, and also to closely monitor the individual equipment pressure, can not overpressure.
