Pulp screening is the process that cleaning the pulp with one or more screen. In a word, the pulp screening is used to clean the pulp and remove the impurities from pulp, improve the pulp quality, save the bleaching agent and protect the screening equipment.
Why the pulp screening process is necessary? After the pulp cooking process, the pulp contains some impurities that are mainly from the raw materials or pulp processing. These impurities of coarse pulp will have the bad influence on the pulping process, including equipment broken, low-quality paper pulp, and etc.
How to screen the pulp? Firstly, set the size and shape of hole of the screen according to the difference between impurities and fibers. Then the screen can separate impurities and good pulp successfully.
As for the pulp screening equipment, the screen can be divided into three types by the way to separate impurities, such as pressure screen, centrifugal screen, and vibrating screen. Besides, there is some related equipment in the pulp screening process like knotter and filter.