What Affects The Screening Efficiency Of Vibrating Screen?

The three most important factors affecting the screening performance of mining vibrating screens are the material properties, the screen surface parameters, and the vibrating screen motion parameters. The following article analyzes these three factors and explores how to improve the performance of mining vibrating screens by changing them.

What affects the screening efficiency of vibrating screen?

1. Material Properties

Material properties include particle size composition, moisture content, mud content, and shape. A high fines content results in a higher vibrating screen productivity. High moisture content reduces screening efficiency. However, larger mesh sizes minimize the impact of moisture. Therefore, for wet materials with high moisture content, increasing mesh size or wet screening can improve the screening process. Materials with high mud content (greater than 8%) should be wet screened or pre-washed.

2. Vibrating Screen Surface Parameters

Vertical motion between the material and the vibrating screen surface results in high screening efficiency and high production capacity. However, relative motion between the material and the screen surface is primarily parallel, resulting in planar vibration, which reduces screening efficiency and production capacity. For a given material, the productivity and screening efficiency of a vibrating screen are determined by the mesh size. Wider mesh widths yield higher productivity, while screening efficiency depends on the mesh length, with longer meshes yielding higher screening efficiency. A typical aspect ratio is 2. The larger the effective vibrating screen area, the higher the productivity and screening efficiency per unit area. Larger mesh size increases the productivity per unit area and the higher the screening efficiency.

3. Vibrating Screen Motion Parameters

Vibrating screen motion parameters include the vibration frequency and azimuth angle. For materials with larger particle sizes, higher frequency increases the number of bounces on the screen surface, increasing the chance of material contact and reducing screen blockage. Therefore, appropriately increasing the vibration frequency can effectively improve screening efficiency. The vibration azimuth angle is the angle between the vibration direction and the screen surface. The larger this angle, the smaller the horizontal distance the material moves during screening and the relatively lower the speed on the screen. Practice has shown that for materials that are easy to screen, the azimuth angle should be smaller; for materials that are difficult to screen, the azimuth angle should be larger. Generally, the azimuth angle for linear vibrating screens is between 30 and 60 degrees, while for circular vibrating screens, the azimuth angle is 90 degrees.