摘要 |
<p>The present invention relates to a method and apparatus for keeping a screen surface or a filter surface clear. The method and apparatus according to the invention is especially suitable in connection with thickeners, screens and filters intended for treating the fiber suspensions in the pulp and paper industry. The greatest disadvantage of all above-mentioned equipment is the tendency of perforated screen/filter surfaces to become gradually clogged as fibers of pulp suspensions adhere to the openings in the screen/filter surface. In the method of the invention, pressure fluid is introduced from a conduit (5) to the secondary side (10) of the screen/filter drum (6), which fluid flows, during the underpressurized stage caused by the blades (9) of the rotor (7) rotating on the primary side of the screen/filter drum (6), through the screen/filter drum (6) from the secondary side to the primary side thereby rinsing the openings of the drum (6) and making them clear.</p> |