The technical and economic indicators of the screening process are screening efficiency and productivity. The former is a quality indicator and the latter is a quantitative indicator. There is a certain relationship between them, and it is also related to many other factors, which determine the results of the screening. The factors affecting the screening process can be roughly divided into three categories:
The physical properties of the material to be screened: including the particle size composition, humidity, mud content and particle shape of the material itself. When the material content is large, the productivity of the sieve is also large. When the humidity of the material is high, the screening efficiency will generally decrease. However, the larger the sieve size, the smaller the influence of moisture. Therefore, in order to improve the screening process for wet materials with larger moisture content, generally the method of enlarging the sieve hole or adopting wet screening can be adopted.
The influence of the structure parameters of the screen surface: the linear vibrating screen makes the particles and the screen surface move vertically, so the screening efficiency is high and the production capacity is large. The relative movement of particles and the screen surface is mainly parallel-moving bar screens, plane vibrating screens, drum screens, etc., and their screening efficiency and production capacity are low. For a certain material, the productivity and screening efficiency of the sieve are determined by the size of the sieve holes. The productivity depends on the width of the screen surface, and the width of the screen surface is high in productivity. The screening efficiency depends on the length of the screen surface, and the long screen surface has a high screening efficiency.
The influence of production conditions: When the load of the sieve is large, the screening efficiency is low. To a large extent, the flat rate of the circular vibrating screen depends on the size of the sieve hole and the total screening efficiency; the larger the sieve hole and the lower the required screening efficiency, the higher the productivity. The uniformity of the feed is of great significance to the screening process. The inclination angle of the sieve should be appropriate, which is generally determined by experiment. Then there is the amplitude and frequency of the sieve, which is related to the physical properties of the sieve. In a certain range, increasing the vibration can improve the screening index.