The upflow pressure screen is designed for the characteristics of impurities in recycled pulp. It uses the pressure difference inside and outside the screen drum and the positive pressure of the rotor head as the screening power, and uses the pressure pulse generated by the high-speed rotation of the rotor to clean the screen plate. The unscreened pulp enters the body along the tangent direction from the bottom inlet. Because of the centrifugal force produced by the high-speed rotation, the heavy impurities rotate rapidly along the peripheral wall and flow to the bottom of the heavy slag chamber. The pulp removing heavy impurities rises to the screening area, and the qualified fibers flow out of the sieve drum through the sieve hole (or sieve crack) and discharge through good pulp outlet. Light impurities continue to rise and are discharged by light impurities located at the top.
Because of the upflow structure, the residence time of impurities in the screening zone is shortened, the rings of rotor and screen drum are effectively prevented from being damaged by heavy impurities, and the service life of the equipment is greatly prolonged. Up-flow pressure screen can be widely used in the screening of crude, fine and front pulp of various waste pulps. It has incomparable good performance and reliability. It is a renewal product of various domestic pressure sieves used in the treatment of regenerated pulp.