Patent ID: 9200407
Filing Date: 2015-12-01
Classification: B30B,D21C,D21D,D21F

Abstract:
1. A system for controlling apparatus for washing and dewatering pulp comprising first and second rotatable press rolls, each of said first and second rotatable press rolls having a permeable outer surface, and a vat in which said first and second rotatable press rolls are installed, said first and second rotatable press rolls being juxtaposed with each other to define a press nip for pressing said pulp therebetween, feed means for feeding said pulp in the direction of rotation of said first and second rotatable press rolls through said press nip, at least one of said first and second rotatable press rolls being movable in relation to the other of said first and second rotatable press rolls to vary said press nip, whereby the processing of said pulp in said apparatus is determined by a plurality of manipulated variables which are variable during operation of said apparatus, said system comprising setting means for setting at least one desired value for a specific controlled variable of a plurality of controlled variables, measuring means comprising at least one sensor for measuring said specific control parameter, said plurality of manipulated variables including the distance between said first and second rotatable press rolls, and including adjustment means for adjusting at least two of said plurality of manipulated variables during operation of said apparatus, said plurality of manipulated variables including the distance between said first and second rotatable press rolls, in order to maintain the difference between said at least one desired value and the value of said measured specific controlled variable below a predetermined difference.