Patent ID: 7695591

Claim:
A controller for use in a washer for washing and dewatering cellulosic pulp material comprising a rotary drum including a plurality of axial compartment walls extending along said rotary drum so as to create a plurality of external axial compartments for washing said cellulosic pulp material, a stationary cylindrical casing enclosing said rotary drum thereby defining a ring-shaped space between said rotary drum and said stationary cylindrical casing, a plurality of axially extending seals disposed along said rotary drum thereby dividing said ring-shaped space into a plurality of zones for feeding, washing and discharging said cellulosic pulp material, said controller comprising a force sensor for sensing a force acting on at least one of said, plurality of axially extending seals in a direction outwardly from said rotary drum and a seal positioning member for moving said at least one of said plurality of axially extending seals in the radial direction with respect to said rotary drum in a predetermined pattern based upon the force measured by said force sensor.