Patent ID: 6499682
Filing Date: 2002-12-31
Classification: B02C,D21D

Abstract:
Apparatus for refining lignocellulosic material comprising a first refining element including a first refining surface, and a second refining element including a second refining surface facing said first refining surface thereby providing a refining gap therebetween, said first and second refining surfaces being substantially planar and relatively rotatable with respect to each other whereby said lignocellulosic material can be refined while passing through said refining gap, said first refining surface including a first plurality of rows of projecting working pins being substantially cylindrical, having a substantially circular cross-section, having a diameter of from 20 to 30 mm and including a rounded upper surface, and at least one first strip projecting above and extending substantially circumferentially along said first refining surface, and said second refining surface including a second plurality of rows of projecting working pins having a substantially circular cross-section and at least one second strip projecting above and extending substantially circumferentially along said second refining surface, said first and second pluralities of rows of projecting working pins disposed at selected radial positions on said first and second refining surfaces and said at least one first and second strips extending discontinuously across said first and second refining surfaces whereby said first and second pluralities of rows of projecting working pins avoid contact with each other upon said relative rotation of said first and second refining surfaces.