Process:
Adding defoamer to the pulp eases water removal. The pulp goes in a vacuum drum washer, which is a rotating cylinder with a screen all around. This drum lays in a pulp vat. As pulp enters the vat continuously, the drum sucks up a pulp mat, and the dirty water goes through the drum in to a tank on the lower floors. The drum speed presently adjusts to control the level in the vat, so the vat does not overflow. If the drum speeds up too much, water removal is bad and the final pulp is dirtier. This is when the operators add more defoamer to improve water removal, so the vat level can be maintained with a lower drum speed.
Problem:
I want to pump my defoamer in automatic to maintain the drum speed at a certain value. This way, if the drum starts to speed up, the defoamer will automatically increase to slow it down.
Would something like to PID llops in cascade work?
PID 1: Control Level with speed of DRUM
PID 2: Control DRUM SPEED with defoamer pump speed
How can this be implemented?
Adding defoamer to the pulp eases water removal. The pulp goes in a vacuum drum washer, which is a rotating cylinder with a screen all around. This drum lays in a pulp vat. As pulp enters the vat continuously, the drum sucks up a pulp mat, and the dirty water goes through the drum in to a tank on the lower floors. The drum speed presently adjusts to control the level in the vat, so the vat does not overflow. If the drum speeds up too much, water removal is bad and the final pulp is dirtier. This is when the operators add more defoamer to improve water removal, so the vat level can be maintained with a lower drum speed.
Problem:
I want to pump my defoamer in automatic to maintain the drum speed at a certain value. This way, if the drum starts to speed up, the defoamer will automatically increase to slow it down.
Would something like to PID llops in cascade work?
PID 1: Control Level with speed of DRUM
PID 2: Control DRUM SPEED with defoamer pump speed
How can this be implemented?
