Issues encountered during the commissioning of air separation units
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Dear experts, hello. Our air separation unit is manufactured by Hangyang. Recently, during operation, we encountered a situation that is difficult to understand; we hope that the experts can help us resolve it. Our air separation process is a internally compressed argon-based system. While driving, the liquid level in the lower column fluctuates significantly, ranging between approximately 800 and 13,000. It is also difficult to guide liquid into the upper column using valve V1, and the charging valve is already open. (At the beginning, there was no liquid level in the lower column, while the liquid level in the main cooler was high. We first started the product oxygen pump, and then the liquid level in the main cooler began to decrease gradually.) Action taken: We first reduced the output of the oxygen pump; as a result, liquid accumulated in the main cooler. Meanwhile, we noticed that the fluctuations in the liquid level in the lower column became smaller. So we started the product nitrogen pump and directed liquid upward to the upper column through the crude argon two-column condenser. At this point, the liquid level began to drop. However, over time, liquid started to accumulate in the crude argon condenser, and the liquid level in the lower column began to rise again. Later, our team went to the site and tapped on v1 a few times, and the operating conditions gradually stabilized. I think the fact that the personnel on site were tapping on V1 is not necessarily the key to the problem; therefore, I would appreciate it if the experts could help. Thank you
Liquid nitrogen is fed from the crude argon two-column condenser to the upper column; can you operate your liquid nitrogen reflux valve by yourself? ~~If tapping V1 works, then you are suspecting that V1 is stuck and not moving? ~~In my opinion, the reasons for the malfunction are as follows: 1. V1 is indeed stuck and cannot be opened fully, which causes the liquid level of the liquid-air mixture in the lower tower to rise. 2. The pipeline from Air Liquide to the upper tower is designed to be too small, or the V1 model selected is too small. 3. The valve for feeding liquid nitrogen into the upper tower is not fully open. 4. Liquid suspension may occur inside the lower tower.
I think the inflation valve on version 1 is set too high, and the gas blocks the pipeline; when we drive we only turn it up a little – if we turn it up too much, no liquid will flow in
We’ve tried turning the inflation valve of the V1 valve all the way off and then turning it on 3 full turns, but it doesn’t have much effect
We are parking the unit for 3 days, transferring all the liquid nitrogen from the lower tower to the upper tower. In such a situation, could tower flooding occur? Thank you
Basically not; once the main condensation evaporator starts operating, the liquid in the upper tower evaporates very quickly~~