Upflow Pressure Screen Enhances Screening Efficiency

The impurities in recycled pulp can be divided into light impurities and heavy impurities. Traditional pressure sieve feeds from the top, discharges slag from the bottom and passes through the whole sieve area. When treating chemical pulp, the proportion and quality of impurities in the pulp are generally larger than that of single fiber. This structure helps to reduce the residence time of impurities in the equipment. But when the recycled pulp contains a large number of light impurities with a small proportion, it will greatly prolong the residence time of light impurities in the equipment, resulting in the decrease of screening efficiency and increase the wear and even damage of the rotor and the sieve drum.

Up-flow pressure screen adopts the structure design of bottom slurry feeding, bottom weight slag discharging and top light slag discharging, which effectively solves the above problems. Light impurities and air in the slurry rise naturally to the top of the slag discharge outlet to discharge, heavy impurities into the body can settle to the bottom of the discharge. In this way, on the one hand, the residence time of impurities in the screen area is effectively shortened, the possibility of impurity circulation is reduced, and the screening efficiency is improved; on the other hand, the damage caused by heavy impurities to the rotor and screen drum is prevented, and the service life of the equipment is prolonged.