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Start-up operation of the purified argon tower. The purpose of starting the purified argon tower is to remove the nitrogen from the purified argon tower, restore the pressure of the purified argon tower to normal, and then send the crude argon into the purified argon column to obtain purified argon through rectification. After many practical operations and theoretical studies* .Here I will share with you my operating method of starting the refined argon tower and my understanding of the theoretical basis. Please give me your advice! 1. Operation method 1. Increase the setting value of PV4121 so that it will not open during the condenser liquid accumulation process. Slowly turn off LV4121 to control the condenser liquid level to normal. 2. Open LV4122.2 to drain the liquid in the tower, open the discharge V4984 of the purified argon reboiler and the purified argon condensation side discharge FV4924, V4988. Control the opening of HV4119 according to the pressure When the liquid in the reboiler is completely drained, V4984 is turned off, and LV4122.2 is turned off after the liquid is drained out. In about 30 minutes, V4988 is turned off when the pressure of the refined argon tower reaches about the normal value (100mb). 3. After the pressure of the refined argon tower becomes stable, slowly close FV4132.2 and open FV4132.1 to bring the amount of feed into the refined argon tower to normal, and slowly reduce the setting value of PV4121 until the pressure reaches about 520mb. 2. Theoretical basis The adjustment of product purity in the distillation tower, in addition to considering the material balance factor, is actually the adjustment of the reflux ratio in the distillation tower. When the nitrogen content of the purified argon in the purified argon tower is high, reducing the reflux ratio in the purified argon tower will reduce the nitrogen content of the purified argon. This is because the higher-temperature ascending gas in the purified argon tower and the lower-temperature downstream liquid are mixed in the packing for mass transfer. Heat transfer. When the reflux ratio in the tower is small, the temperature of the gas-liquid mixture will be biased towards the rising vapor side, so the temperature rise of the downstream liquid is larger, the liquid evaporates more, and more nitrogen components are evaporated in the liquid. In this way, the purity of argon in the downstream liquid leaving this layer of packing is high. This layer by layer will eventually increase the purity of argon at the bottom of the argon purification tower. To reduce the reflux ratio in the tower, the tower must be enlarged. The amount of rising steam in the purified argon reboiler can be increased, or the amount of downstream liquid can be reduced. Turning on HV4119 can increase the flow rate of the liquid air in the lower tower into the refined argon reboiler. The liquid air in the lower tower serves as the heat source of the purified argon reboiler and exchanges heat with the semen argon through the refined argon reboiler. When the flow rate increases, the amount of heat brought into the evaporator per unit time increases, resulting in an increase in the amount of rising steam in the purified argon tower and a decrease in the reflux ratio in the tower. , thereby reducing the nitrogen content of refined argon. PV4121 is used to control the pressure on the liquid nitrogen side of the condenser of the refined argon tower. Increasing the pressure of PV4121 can increase the evaporation temperature of the liquid air. This increases the temperature of the liquid air, reduces the heat transfer temperature difference of the condenser of the refined argon tower, reduces the condensation of gas in the tower, reduces the amount of downstream liquid in the refined argon tower, and reduces the reflux ratio. Thus, the nitrogen content of refined argon is reduced. Increasing the setting value of PV4121 during the liquid accumulation stage of the pure argon condenser can turn off PV4121 to prevent heat exchange between the liquid air and the gas in the pure argon tower. This ensures the stability of the pressure of the pure argon tower and the rapid accumulation of sufficient liquid air level, shortening the argon charging time. If If the liquid level of the purified argon reboiler is too high, the purified argon reboiler will not work and the liquid must be drained manually. During the startup process of the purified argon tower, turning on the argon side discharge V4988 of the purified argon condenser can increase the discharge speed of the purified argon tower and reduce the startup time of the purified argon tower. 3. Misunderstandings that should be avoided during operation. If the shutdown time is long, the nitrogen content in the refined argon tower is high. It takes a long time to discharge the crude argon to the refined argon tower for replacement. Otherwise, when sending the crude argon to the refined argon tower, the pressure resistance will fluctuate greatly, and more argon products will be discharged together with the nitrogen. In addition, due to the refined argon The discharge pipe diameter of the argon tower is small, and the pressure of the refined argon tower is not easy to return to normal. The adjustment speed of PV4121 should not be too fast, because adjusting the pressure of PV4121 is equivalent to changing the load of the condenser of the refined argon tower. Adjusting too fast will cause the liquid air consumption to be faster, resulting in large fluctuations in the operating conditions of the refined argon tower and the crude argon tower.