What factors affect the screening efficiency of mining vibrating screen and how to improve it?
Vibrating Screen is used for the crushing of raw materials in metallurgy, architecture, road construction, chemistry, and silicate industry which can Grind the mid-hard ore and rock. This series Vibrating Screen has a feature of large crushing ratio, uniform product granularity, simple construction, reliable operation, easy maintenance, low operating cost. However,What factors affect the screening efficiency of mining vibrating screen and how to improve it?
1. The characteristics of the materials entering the sieve, different materials have their own unique characteristics, and there are differences in density, hardness, moisture content, etc.
When the particle size of the material is close to the size of the screen hole, the screening efficiency will be significantly reduced. These particles may block the screen hole and reduce the effective screening area. This is a phenomenon that often occurs in the closed-circuit crushing process. This situation can be improved by increasing the vibration，The increase of the amplitude can promote the fine-grained materials to pass through the screen surface and reduce the occurrence of blockage. In addition, the passing rate of the middle part of the screen can be increased, so that the screening effect can be improved, and the screening effect of the vibrating screen can be improved by changing the feeding method.
When the water content of the material is large, the material is prone to sticking, which reduces the screening efficiency. Generally speaking, the wet material with a large water content can improve the screening effect by increasing the screen hole，However, if the mud content of the material is greater than 8%, it should be treated by wet screening or pre-washing.
2. The parameters of the screen surface of the vibrating screen
the screen parameters of the vibrating screen include the shape of the screen hole of the vibrating screen, the opening rate of the screen surface of the vibrating screen, the material of the screen surface and so on.Generally speaking, the longer the screen surface, the longer the residence time of the material, the more opportunities to pass through the screen, and the higher the efficiency, while the wider screen surface has better processing capacity.
The aperture ratio of the screen surface of the vibrating screen here refers to the effective screening area of the vibrating screen, which is the ratio of the screen hole area to the total screen surface area. The larger the effective screen hole area, the higher the productivity per unit screen surface, and the screening efficiency，As for the shape of the sieve hole, it is selected according to the particle shape of the material. Generally, the square sieve hole is better for sieving the material with round particles.
In terms of material, different screen surface materials will also affect the screening effect, which can directly affect the adhesion coefficient between minerals and the screen，For viscous minerals, rubber, polyurethane and other elastic screen surface materials should be used to ensure that the materials on the screen are loose.However, such materials usually have the disadvantage of small open porosity.
3. Motion parameters of vibrating screen
The motion parameters of the vibrating screen include two factors: the vibration frequency of the vibrating screen and the direction angle of the vibrating screen.Vibration enables the materials on the screen surface to be thrown away from the screen surface, so that the coarse-grained materials reach the upper layer of the material layer, and the fine-grained materials reach the lower layer of the material layer, close to the screen surface, the screen layer is evenly distributed, and the passing rate of fine-grained materials increases accordingly.For materials with large particle size, generally the higher the frequency, the higher the number of beatings on the screen surface, the increased chance of contact between the material and the screen surface, and the reduction of the occurrence of clogging of the screen holes. Therefore, appropriately increasing the vibration frequency can effectively improve the screening effect.
The vibration direction angle is the angle between the vibration direction line and the screen surface. The larger the value of this angle, the smaller the horizontal movement distance of the material during the screening process, and the lower the movement speed on the screen.Through practice, it is found that the direction angle should be small when screening easy-to-screen materials, and the direction angle should be large when screening difficult-to-screen materials.In general, the direction angle of the linear vibrating screen is between 30 degrees and 60 degrees, while the direction angle of the circular vibrating screen is 90 degrees.
After the above analysis, we have understood some factors that affect the screening effect of mining vibrating screen and how to improve the efficiency of vibrating screen,All in all, we need to choose the vibrating screen according to the actual needs, choose the appropriate screen surface material as much as possible, improve the motor to adjust the exciting force,And try to ensure the lower water content of the material, and improve the screening effect on the premise of ensuring the processing capacity.
Jiangxi Hengchang Mining Machinery Vibrating screen application scenarios