DEAR Cryogenic air separation unit.The water injection hole of the chilled water distributor is blocked, which causes the water level in the chilled water return tank to overflow to the orifice of the riser, and part of the water is carried into the purifier by air; too much spray water or poor separation effect of the water separation device (including the water capture layer on the top of the tower or the separate water separator) will also cause water entrainment;DEAR Cryogenic air separation unit.Serious explosion will cause damage to the whole equipment, and even casualties; minor explosion will occur in local position, which will reduce the purity of oxygen products and make it impossible to maintain normal production. Explosions are all related to the accumulation of flammable substances hydrocarbons in liquid oxygen.In the normal operation stage, on the surface, the rise and fall of the liquid oxygen surface is reflected from the condensing evaporator, which is actually the result of a series of heat transfer. How to convert the cooling capacity into liquid? When the condensing evaporator is in the stage of cooling capacity balance, if the liquid oxygen level is to rise, the expansion capacity or the pressure in front of the expander must be increased, that is, the cooling capacity will be increased.
If the nitrogen content of argon fraction is high, the temperature difference in the condenser of crude argon column will be reduced, even to zero. In this way, the crude argon condenses less or does not condense, which makes the crude nitrogen tower unable to work normally. This will reduce the extraction of argon fraction and the velocity of updraft, resulting in liquid leakage from the tray.The overall heating in cold state is the heating operation after parking. The main purpose is to remove the residual water, carbon dioxide, acetylene and other impurities, so as to prepare for the long-term operation or maintenance of the next cycle. Full heating in hot state is the heating operation before start-up. Its main purpose is to remove water and some solid debris.DEAR Cryogenic air separation unit.The oxygen content of liquid oxygen and liquid air in the air separation unit is high, which will cause the oxygen concentration to increase in local range after evaporation in the air. If there is a fire, there is a risk of combustion and explosion. A large amount of liquid oxygen was discharged into the trench in a chemical fertilizer plant, and the electric welding spark caused an explosion injury accident. Therefore, it is strictly forbidden to discharge the liquid into the trench at will, and it should be discharged into the liquid evaporation tank or special low temperature resistant metal discharge pit through pipeline.
Part of the liquid nitrogen is directly used as the reflux liquid of the lower tower, and part of the liquid nitrogen is supplied to the top of the upper tower after throttling and depressurizing to participate in the distillation process as the reflux liquid of the upper tower. Because the pressure of the lower tower is higher than that of the upper tower, the saturation temperature of gas nitrogen in the lower tower is higher than that of liquid oxygen in the upper tower.DEAR Cryogenic air separation unit.When oxygen is abundant and oxygen production needs to be reduced, the output of oxygen products should be reduced first, and then the air flow should be reduced accordingly, and the expansion air volume should be adjusted according to the main cooling liquid level. The liquid air and liquid nitrogen control valves sent to the upper tower should also be turned down according to the distillation conditions. It should be noted that the whole operation should be completed slowly and gradually in order to maintain the stability of distillation conditions in the reduction process.
