Patent ID: 9085851
Filing Date: 2015-07-21
Classification: B01D,B07B,D21D

Abstract:
1. Pressure filter for filtering pulp, which pressure filter comprises a pulp container defining a substantially cylindrical chamber; comprising a feed opening for the pulp at its upper part, a cylindrical filtering surface located within of the container in which case the pulp, which has penetrated the mentioned filtering surface as an accept fraction, and is removed from the container through at least one removal outlet from the container, the pulp container further comprises a vertical rotor which is rotatably mounted in the container, which rotor is equipped with radial arms extending to outer wings which clean the filtering surface and said filter further comprises a feed pipe for dilution water and for directing the dilution water into the chamber of the container in order to avoid the thickening of the pulp, and that the dilution water is directed between the rotor and the filtering surface to such height that beginning from a lower edge of the filtering surface to at least over 30% of the filtering surface comes within the range of the pulp which has been diluted with the dilution water, the rotor being equipped with an inner substantially cylindrical wall spaced radially inwardly of the outer wings and having a lower opening for receiving pulp to be recirculated from a lower portion of the chamber upwardly to a position above said lower portion of said chamber, said substantially cylindrical wall defining a recirculation chamber and having gaps in said wall above the lower opening and said rotor having pumping wings within said recirculation chamber for pumping said pulp from said lower portion of the chamber through said gaps for pulp recirculation in said chamber.