Theoretically, the fine particles having a particle size smaller than the size of the mesh can pass through the mesh to form the undersize product, and the coarse particles larger than the mesh size should be left on the sieve to become the product on the sieve. However, in the actual operation of the waste treatment equipment company, due to many factors in the screening process, there will always be some fine particles smaller than the sieve hole left on the sieve to become the product on the sieve, and the fine mesh in the sieve is not transparent. The more grains, the worse the screening effect. Screening efficiency is an indicator for assessing the separation efficiency of screening equipment.
(2) Factors affecting screening efficiency
1 Screening material properties The screening efficiency of materials is closely related to the size distribution of the screening materials, particle shape, water content and mud content.
2 Screening equipment performance The screening efficiency of the screening equipment is closely related to the effective area of the screen surface. The common screen surface has three kinds of screen surface, steel plate punching screen and steel wire mesh. The effective surface area of the bar screen surface is small, the screening efficiency is low, the effective area of the woven screen mesh is large, the screening efficiency is high, and the punching screen surface is between the two.
3 Screening operation conditions In the screening operation, attention should be paid to continuous and uniform feeding, so that the waste is paved into a thin layer along the entire width of the screen surface, which not only makes full use of the screen surface, but also facilitates the fine grain screening, which can improve the processing capacity of the sieve and the sieve. Efficiency. Timely cleaning and maintenance of the screen surface is also an important condition to ensure the efficiency of screening.