Abstract: Apparatus for washing cellulose pulp including a drum with a filtering member on its outer shell and stationary housings encircling the drum. A pressurized washing liquid is applied against the cellulose pulp which is in the form of a fiber web upon the filtering member and compartments affixed within the drum receive a suspension liquid displaced from the washing liquid. Pure washing liquid introduced against the rotation of the drum is applied against the fiber web forcing suspension liquid to pass through the filter and into compartments under the housing. A valve combines the suspension liquid flow from the compartments and conducts the flow to a supply connector at the next-to-last housing taken in the direction of rotation of the drum. This displaced suspension liquid displaces liquid from the pulp web with flow resistances encountered by the washing liquid between different housings causing pressure differential between washing liquids in different housings.