Method and pulp washing machine for washing of pulp or any corresponding material
AssigneeFinbark Oy
InventorTimo Tapio Saalasti
Life of this patent
Estimating the term…
Abstract
In the pulp washing machine and method therefor, pulp to be washed is fed between the rotating drum and the pressing roll inside it, so that pulp passes along a spiral-formed track around the pressing roll, being thereby pressed several times. Washing liquid is fed to the pulp at one or several points along its track of movement, between the pressings and/or at the pressing position. Washing thus takes place partly as a diffusion and partly as a displacement washing process. Washing is efficient and reduces the breaking of pulp fibers down to a minimum.
Claims17
A method for washing pulp or any corresponding material, comprising the steps of:
- transporting the material to be washed between a rotating drum (1) and a rotating pressing roll (2) inside the drum, in a direction along a longitudinal axis of the drum from one end thereof, at least one of the drum and the pressing roll being perforated,
- pressing the material to be washed a plurality of times between the drum and the pressing roll during the transporting step, and
- wetting the material to be washed with washing liquid at least at one position during the transporting step.
A pulp washing machine for washing pulp or any corresponding material, comprising
- a rotatable drum (1),
- a rotatable pressing roll (2) rotatably fitted within the rotating drum (1),
- at least one of the drum (1) and the pressing roll (2) being perforated,
- means for feeding material to be washed into the space between the drum and the pressing roll from an inlet to an outlet end of the drum,
- means for moving the pressing roll (2) towards an inner surface of the drum so as to provide a pressing point for the material between the drum (1) and the pressing roll (2),
- means within the space between the drum and the pressing roll for advancing the material, when the drum and pressing roll rotate, along a spiral-formed track structure extending around the pressing roll (2), from the inlet end of the drum to an outlet end thereof, and
- liquid feeding means (3;12) for feeding washing liquid onto the material to be washed in at least one position along said spiral formed track thereof.
Dependencies are inferred from the claim text.