Why is there too much material accumulation on the vibrating screen?

Why is there too much material accumulation on the vibrating screen?

Excessive material accumulation on the vibrating screen may be caused by the following reasons:

Feeding problem

• Feeding speed is too fast: If the amount of material fed into the vibrating screen in a unit time exceeds its processing capacity, the material cannot pass through the screen in time, which will cause the accumulation of the material on the screen. For example, in some mining production, the speed of the feeder is improperly set, so that a large amount of ore enters the vibrating screen quickly, exceeding its normal processing capacity.
• Uneven feeding: When feeding, the material is unevenly distributed on the screen surface, and there is too much material in a local area, which will cause the accumulation of material on the screen in that area. For example, the position of the feed port is offset, so that the material falls on one side of the screen surface, and material accumulation is easy to occur on this side.

Screen related

• Screen blockage: Fine particles, sticky substances or wet materials in the material are easy to block the screen holes, which reduces the effective screening area of ​​the screen and reduces the material screening rate, resulting in the accumulation of the screen. For example, when processing sand and gravel materials containing soil, the soil is easy to adhere to the screen and block the screen holes.
• Broken screen: If the screen is damaged, some of the materials that should have passed through the screen will not be able to pass through normally, but will remain on the screen, causing accumulation. At the same time, the screen structure around the damaged part may be affected, the screening effect will be worse, and the material accumulation will be further aggravated.
• Improper selection of screen mesh: If the screen mesh is too fine, it will be more difficult for the material to pass through the screen for a given material processing volume, which will cause the material on the screen to accumulate. On the contrary, if the screen mesh is too large, although the material is easy to pass through, it may not achieve the expected screening accuracy.

Vibrating screen operating parameters

• Insufficient vibration amplitude: The vibration amplitude of the vibrating screen is small, and the material jumps and moves slowly on the screen surface, which cannot effectively disperse the material and force it to pass through the screen, resulting in the accumulation of the material on the screen. This may be caused by insufficient excitation force of the vibration motor or aging of the spring.
• Inappropriate vibration frequency: Too high or too low vibration frequency may affect the screening effect. If the frequency is too high, the material will jump too violently on the screen surface, which may cause some materials to be thrown off the screen surface before they can pass through the screen; if the frequency is too low, the material will move too slowly on the screen surface, which may easily cause material accumulation.
• Unreasonable screen surface inclination: If the screen surface inclination is too large, the material will stay on the screen surface for too short a time, and it may slide off before it can be fully screened; if the inclination is too small, the material will move slowly on the screen surface, which may easily cause accumulation.

Other factors

• Changes in material properties: Changes in the humidity, particle size distribution, viscosity and other properties of the material may affect the screening effect. For example, if the humidity of the material increases, fine particles will easily agglomerate, block the screen, and cause the material on the screen to accumulate.
• Equipment failure: Failures in other components of the vibrating screen, such as motor failure, transmission device failure, etc., will cause the vibrating screen to fail to work normally and also cause material accumulation.

To solve the problem of excessive material accumulation on the vibrating screen, it is necessary to adjust and optimize the feed amount, screen, vibration parameters, etc. according to the specific situation, and eliminate equipment failures in time to ensure the normal operation of the vibrating screen and good screening effect.