Patent ID: 6649068
Filing Date: 2003-11-18
Classification: B01D,D21D

Abstract:
A process for removing solid particles from a liquid stream in a pulp or paper mill having a filtering device having an inlet for liquid having at least some particulate materials, an outlet for treated liquid having reduced concentration of the particulate material, an outlet for the particulate material, and a perforated screen element, comprising:(a) introducing a first liquid having a first concentration of particulate materials to the inlet, wherein the particulate materials have an average size smaller than an aperture size of perforations in the screen element; (b) introducing a second liquid having at least some comminuted fibrous material to the inlet to form a mixture of the first and second liquids, wherein said fibrous material has an average fiber length greater than the aperture size of the perforations in the screen element; (c) passing the mixture of the first and second liquids through the screen element to produce a third liquid having a reduced amount of the particulate material; (d) discharging the third liquid from the filtering device; and (e) practicing steps (a)-(d) so that at least some of the comminuted cellulosic fibrous material introduced with the second liquid is retained on the screen element to form a permeable mat of cellulose material which acts as a filtering medium for the undesirable material in the first liquid.