Abstract: A single roll wash press comprising a housing and a drum rotatably mounted within the housing. The drum includes a perforated outer wall and a longitudinally extending centerline axis and is rotatable about the axis. The press further comprises a means for receiving a flow of pulp having an initial consistency ranging from about 2% o.d. to about 6% o.d. such that the pulp flows in the direction of drum rotation, and a means for defining a divergent formation zone and for forming a mat of the pulp on the drum within the divergent formation zone. The means for defining and forming comprises a first arcuate portion of the housing with the formation zone being divergent between upstream and downstream ends thereof. The upstream end of the divergent formation zone communicates with the means for receiving the flow of the pulp. The press further includes a means for washing the pulp mat within a displacement zone disposed downstream of the extraction zone.

Abstract: In a pulp washing method which employs a dilution stage, followed by an extraction stage, and followed, in turn by a dilution stage, filtrates from the extraction stage and the displacement stage are segregated so that at least a part of the filtrate from the extraction stage may be removed from the pulp washing.

Abstract: A single roll wash press comprising a housing and a drum rotatably mounted within the housing. The drum includes a perforated outer wall and a longitudinally extending centerline axis and is rotatable about the axis. The press further comprises a means for receiving a flow of pulp having an initial consistency ranging from about 2% o.d. to about 6% o.d. such that the pulp flows in the direction of drum rotation, and a means for defining a divergent formation zone and for forming a mat of the pulp on the drum within the divergent formation zone. The means for defining and forming comprises a first arcuate portion of the housing with the formation zone being divergent between upstream and downstream ends thereof. The upstream end of the divergent formation zone communicates with the means for receiving the flow of the pulp. The press further includes a means for washing the pulp mat within a displacement zone disposed downstream of the extraction zone.