The distribution of argon in the upper tower is not fixed and unchanging. When the purity of oxygen and nitrogen changes, that is, there is a slight change in the operating conditions, the distribution of argon in the tower also changes accordingly. However, the position of the argon fraction extraction port remains fixed, so the composition of the argon fraction extraction port will also change. The specific impact is as follows:
If the oxygen content of the argon fraction is too high, it will lead to an increase in the oxygen content of the crude argon product, a decrease in yield, and a decrease in the extraction rate of argon. It may also cause the temperature of the deoxygenation furnace to be too high.
If the nitrogen content of the argon fraction is high, the temperature difference in the condenser of the crude argon tower will decrease, even to zero. In this way, the condensation amount of crude argon gas decreases or does not condense, making the crude nitrogen tower unable to work properly. This will reduce the extraction amount of argon fraction, slow down the upward airflow speed, and cause liquid leakage on the tray. Moreover, as the extraction amount of argon fraction decreases, the reflux ratio of the upper tower also decreases accordingly, and the oxygen purity increases, resulting in a corresponding decrease in nitrogen content in the argon fraction. So, the temperature difference of the condenser evaporator will expand again, and the fraction extraction amount will automatically increase, and the nitrogen content in the argon fraction will also increase accordingly. This repeated change prevents the crude argon tower from working properly. Therefore, the crude argon tower can only be put into operation when the operating conditions of the air separation equipment are particularly stable and the oxygen and nitrogen purity meet the requirements.
