Abstract: A washer drum is provided with unique cross bracing which prevents twisting, reduces vortex formation in radial inflow ports, and further provides support for the decking between closely spaced intermediate heads.

Abstract: A method and apparatus for filtering pulp fibers from a pulp slurry, using a combination of vacuum, hydrodynamic and hydrostatic forces in order to achieve a more effective deposition of pulp fibers onto the filter surface and enhanced flow of filtrate through the cylinder. The apparatus is in the form of an improved vacuum filtration system, in which the filtrate outlet tube is disposed along the axis of rotation of the rotary cylinder and the filtrate inlet and outlet ports of each filtrate conduct are radially offset from one another in the direction of intended rotation of the cylinder. During various phases of filter operation, vacuum forces generated by the vacuum source cooperate with either hydrodynamically or hydrostatically generated forces, which together act upon columns of filtrate in the filtrate conduits as the cylinder rotates.

Abstract: A method and apparatus for forming on the outside of a permeable, rotatable drum by feeding a pulp slurry through a mat forming and pressing zone, followed by a mat washing zone. In the mat washing zone, the mat is washed with liquid from the first source and then washed with liquid from a second source.A Washing baffle has a first portion extending from its upstream end partially along the outside surface of the drum and slightly spaced from the outside surface of the drum. This first portion is followed by a second portion extending partially along the outside surface of the drum and spaced further from the outside surface of the drum than the first portion. A valve is provided for controlling the velocity of liquid through a slot into a circumferential space separating the washing baffle from the drum.

Abstract: A pulp mat is formed on the outside of a permeable, rotatable drum by feeding a pulp slurry through a mat forming and pressing zone, followed by a mat washing zone. In the mat washing zone, the mat is washed with liquid from a first source and then washed with liquid from a second source.A washing baffle has a first portion extending from its upstream end partially along the outside surface of the drum and slightly spaced from the outside surface of the drum. This first portion is followed by a second portion extending partially along the outside surface of the drum and spaced further from the outside surface of the drum than the first portion.