Patent ID: 6029825
Filing Date: 2000-02-29
Classification: D21D,Y10T

Abstract:
Screen for sorting fiber suspensions, said screen having a screen wall being rotationally symmetric to a screen axis and having an inflow side for the fiber suspension to be sorted and an outflow side located opposite thereto for pressure sorters comprising a rotor mounted for rotation about the screen axis and having profiled elements arranged for rotation adjacent to the inflow side of said screen wall for generating positive and negative pressure pulses in the fiber suspension to be sorted, wherein said screen wall has at its inflow side grooves approximately V-shaped in cross section, said grooves extending approximately parallel to the screen axis and following one another in circumferential direction of the screen wall, wherein the screen wall comprises through-channels for communicating said inflow side with said outflow side, said through-channels opening into said grooves, wherein each of the grooves is limited--when seen in the direction of rotation of the profiled elements--by a front groove side wall and a rear groove side wall and has a groove base, said front groove side wall and said rear groove side wall defining a width of each of said grooves at said inflow side of the screen wall, wherein said through-channels open at least approximately into said groove bases and said front groove side wall is inclined to a greater extent in relation to the circumferential direction of the screen wall than said rear groove side wall, and wherein a surface area essentially smooth and at least approximately parallel to said circumferential direction is provided at the inflow side of the screen wall in its circumferential direction between each two consecutive grooves, said surface area having a predetermined width measured in said circumferential direction, and wherein(a) in cross section at right angles to the screen axis said front groove side wall forms with the circumferential direction of the screen wall an angle of approximately 40.degree. to approximately 70.degree.;(b) in cross section at right angles to the screen axis said front and rear groove side walls form with one another an angle of approximately 80.degree. to approximately 110.degree.;(c)--when seen in circumferential direction of the screen wall--said predetermined width of each of said surface areas is approximately 20% to approximately 30% of said width of said grooves.