Purity of liquid nitrogen at the top of the tower
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If the purity of liquid nitrogen at the top of the tower deteriorates, should the reflux ratio at that point be increased? Should we increase the bottom reflux ratio?
The purity of the liquid nitrogen is poor; adjust the valve controlling the flow of liquid nitrogen into the upper column to ensure more reflux liquid flows in the lower column for distillation.
How can there be liquid nitrogen in the upper tower? Has the nitrogen purity at the tower outlet decreased? Then the reflux needs to be increased
The liquid nitrogen going to the upper column also comes from the lower column~~Therefore, it is necessary to adjust the reflux ratio of the lower column; increasing this ratio reduces the purity of the liquid nitrogen~~Of course, it is important to ensure that the source of liquid nitrogen is indeed the lower column only, as in some nitrogen circulation systems, there is also a stream of liquid nitrogen that enters the upper column after passing through the expander~~
I’ve never seen such a process; how can liquid nitrogen be produced in the tower? Why is analysis necessary? ! ! ? ? ?
The purity of liquid nitrogen at the upper tower decreases, resulting in an increased reflux ratio at the lower tower
But upon analysis, the purity of the liquid nitrogen at the bottom is normal; if it’s normal, then why increase the reflux ratio there?
Liquid nitrogen is produced in the upper column; there is a liquid nitrogen extraction point between valve V3 and pure nitrogen. If the purity of the liquid nitrogen in the upper column is compromised, the valve controlling that liquid nitrogen can be reduced to its minimum position or even closed completely, thereby increasing the load on the expander and causing the temperature in the upper column to drop
It’s mainly because you’re extracting too much liquid nitrogen from the tower, and the temperature in the tower is too high
Explaining the specific process makes the diagnosis more targeted.