Abstract: A screen plate (1) for screening of pulp suspensions, comprises a number of elongated at least partially curved screen slots (3). According to the invention every screen slot has a width which is maximally 0.8 mm, and the screen slots bend in such a way that a straight rod, which has a breadth which is less than the width of the screen slot and the length which is 5 mm, is prevented from passing through the screen slot, when the rod extends along the screen plate, independently of how this rod is oriented in relation to the screen slot. At that elongated stiff shives may be separated more efficiently by means of the screen plate. This screen plate may also be used for separating a pulp suspension into a first fraction comprising comparatively stiff fibers and a second fraction comprising comparatively flexible fibers.
Abstract: A separation device for separating contaminants from fiber pulp suspensions, preferably produced from waste paper, comprises a cylindrical screen number (4) and a rotor (7) arranged therein. An annular inlet passage (14) for incoming suspension surrounds a tubular wall (11), which extends from the screen member (4) coaxially with the rotor (7). According to the invention, a flow deflecting wall member (16) extends toward the rotor (7) to a position in which the wall member is axially in front of an open end (12) of the tubular wall (11) and radially inside the tubular wall. Furthermore, the wall member (16) with a cross-sectional area which is substantially less than the cross-sectional area of the annular inlet passage (14).