Process for the breaking and cleaning of contaminant-containing raw paper stocks, in particular of recovered paper

摘要

Process for the disintegration and cleaning of contaminant-containing raw paper stocks. The process includes producing a contaminant-containing suspension, feeding the contaminant-containing suspension to a closed coarse screen, drawing of a cleaned flow fraction from the closed coarse screen, and drawing off an overflow fraction containing an increased amount of contaminants from the coarse screen during at least about 80% of an operating time. The process also includes adjusting a volumetric mass flow of the overflow fraction to at least about 15% and maximally about 50% of a volumetric mass flow of an inflow into the coarse screen, and feeding the overflow fraction to a screening device, in which contaminants collected are sluiced out discontinuously as a further overflow fraction, thereby forming a further cleaned flow fraction.