Patent ID: 8808499

Claim:
A method for processing pulp in an apparatus for washing and dewatering said pulp comprising first and second rotatable press rolls, each of said first and second rotatable press rolls including 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 juxtaposed with each other to define a press nip for passing 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 adjusted during operation, said method comprising including the distance between said first and second rotatable press rolls as one of said plurality of manipulated variables, setting at least one desired value for a specific controlled variable of a plurality of controlled variables, measuring said specific controlled variable, and adjusting at least two of said plurality of manipulated variables during operation of said apparatus, said distance between said first and second rotatable press rolls being one of said at least two of said plurality of manipulated variables, 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, wherein the said distance between said first and second rotatable press rolls is actively adjusted by means of at least a driving device controlled by a computer control device.