Tower level control
Thread Content
Now there is a distillation tower. A pump at the bottom of the tower is used to force the falling film reboiler to circulate, and part of the material is pumped out. Now calculate the liquid storage amount based on the highest liquid level at the bottom of the tower, and find that based on the discharged material, the liquid storage time is only less than 2 minutes. I am very worried that too little liquid storage will affect the forced circulation falling film reboiler. Ask the masters: Is the liquid storage volume too low? If too little, how to solve this problem.
I think we must first ensure that the liquid level at the bottom of the tower and the forced circulation volume are stable. The liquid storage volume is less than two minutes, so it is probably a bit small. Considering the fluctuation, should it be larger? The liquid level at the bottom of the tower can be controlled by the production volume at the bottom of the tower, and the forced circulation volume can be controlled by a single flow rate loop.
The answer above is correct. This is a conventional LC control method. But I would like to ask you what is the specific buffer value that is more reasonable?
The general design residence time is 5 minutes, and for large quantities it should be at least 3 minutes.
Stable feeding and discharging, pressure and temperature.
The liquid level at the bottom of the distillation tower is determined based on the reboiler outlet pipe and the reboiling heat load. The liquid level at the bottom of the column is linked to the re-discharge of the forced circulation pump. When the liquid level at the bottom of the column is lower than a certain level, the production self-regulating valve is closed.