Distillation problem
Thread Content
In a constant-pressure distillation column, why does the reflux rate gradually decrease when parameters such as the top pressure, reflux temperature, bottom temperature, sensitivity plate temperature, and feed composition remain unchanged?
For external reflux, it could be due to a clogged reflux pipe, poor cooling performance of the tower top condenser, an increased amount of product taken out, or instrument issues.
If the mid-section reflux flow is high, more heat is removed; the load at the tower top decreases, and the top reflux flow reduces.
If the extraction rate remains unchanged but the level in the return tank drops, it is a problem with the heat exchanger. If the extraction rate stays the same and the level in the return tank does not change, it is an issue with the instruments. If the extraction rate is normal and there is no problem with the heat exchanger but the level in the return tank rises, it is a problem with the pump