Abstract: A device treats a fiber stock suspension with at least one additive, the fiber stock suspension being used for production of at least one of paper and cardboard. The fiber stock suspension includes a suspension medium and a fiber material. The fiber material has fiber surfaces, the fiber surfaces being moistened by the suspension medium. The device includes a fluffer having an inlet for receiving at least one of the fiber stock suspension and the at least one additive. The fluffer is coupled to the inlet, the fluffer being configured for separating the fiber material and enlarging a specific surface of the fiber surfaces.

Abstract: A method of processing recycled waste paper includes pulping waste paper in a first drum pulper. White fibers are separated from the waste paper in a first screen drum. The white fibers are then processed by screening, cleaning, deinking and bleaching. The remaining waste paper is pulped within a second drum pulper. The brown fibers are separated from the waste paper in a second screen drum. The brown fibers are processed by screening, cleaning and bleaching.

Abstract: An apparatus providing process water used for making or processing a fiber suspension includes a multi-compartment tank with a top, a bottom wall, and a plurality of exterior sidewalls. Each compartment has an inlet positioned near the top, an outlet positioned near the bottom wall, and at least one intervening wall common with an adjacent compartment. Each intervening wall has a height defining an overflow weir whereby the compartments are arranged with sequentially decreasing maximum fluid levels. Each intervening wall also has a backflow device positioned near the bottom wall. The backflow device is selectively openable to allow flow from one compartment to an adjacent compartment in a direction opposite to a flow direction over the corresponding overflow weir.

Abstract: A waste paper processing system in which a fibrous suspension of waste paper is cleaned and sorted. The fine cleaning of the suspension is carried out by means of one or more conical centrifuges in a subsidiary stream which branches off from the mainstream and is later recombined therewith. The portion containing the largest content of coarse substances is introduced from a vertical sorter located in the mainstream into the subsidiary stream in which it is sorted and cleaned. There is practically no need to process the waste from the conical centrifuges and the conical centrifuge unit can be designed to be substantially smaller and thus more economical in terms of energy because of the smaller flow of material therethrough.