Air separation

If valve V1 is set to automatic mode, what changes will occur in its opening degree from the start of pressure equalization until the end of that process? The condition is that it must be within the pressure setting range of the air compressor; in other words, the air compressor’s relief valve, anti-surge valve, and inlet guide vane are not adjusted. Thank you all for the discussion, I’ve learned a lot. !

This post was last edited by valua on 2016-11-15 at 10:30 – turn on first, then off. During voltage equalization, the tower pressure decreases and more liquid flows downward. With V1 in automatic mode and the liquid level setpoint remaining unchanged, its opening will gradually increase. If an argon system is in use, it is recommended to control the opening manually at this time to enhance the stability of the argon system. From the later stage of pressure equalization to the pressure release phase, the overall temperature inside the cryogenic tank rises, resulting in a shortage in cooling capacity. As a consequence, the amount of liquid in the tower decreases after pressure equalization, and the V1 valve will close partially or even completely. It is recommended to increase the guide vanes of the air compressor promptly during voltage equalization, adding 2%-3% to the total air volume.