What is the working principle of the vibrating screen?

The working principle of the vibrating screen is mainly based on the reciprocating vibration generated by the vibrator excitation, and the material is screened through this vibration. The following is a detailed analysis of its working principle.

‌1. Vibrator excitation and vibration mode‌

The core driving force of the vibrating screen comes from the vibrator excitation, which is usually achieved through an eccentric block vibration motor or an electromagnetic exciter. The upper rotating hammer of the vibrator causes the screen surface to produce a plane gyration vibration, while the lower rotating hammer causes the screen surface to produce a conical gyration vibration. The combined action of the two causes the screen surface to produce a complex gyration vibration. This vibration trajectory is projected as a circle on the horizontal plane and an ellipse on the vertical plane.

‌2. Material movement and screening process‌

Under the action of vibration, the material presents a parabolic motion trajectory on the screen surface, including three stages of throwing, free falling and collision with the screen. Smaller particles are more likely to pass through the screen holes due to the combined effects of gravity, vibration force and friction, while larger particles remain on the screen surface, thereby achieving material separation.

‌3. Vibration parameter adjustment‌

By adjusting the excitation force and spatial phase angle of the upper and lower rotating hammers, the curve shape of the screen surface motion trajectory and the material motion trajectory can be changed, thereby optimizing the screening efficiency.

‌4. Screening mechanism‌

The screening process is essentially a combination of geometric screening and probability screening. The probability of fine particles passing through the sieve hole is closely related to the size ratio of the particles to the sieve hole, the thickness of the material layer and the vibration intensity parameters. The introduction of secondary vibration technology can further improve the screening accuracy and solve the problem of particle blocking.

5‌. Advantages in practical applications‌

The vibrating screen has the advantages of high screening efficiency, simple structure, convenient operation and large processing capacity. It is widely used in mining, chemical industry, building materials, food and other industries.

Through the above principles, the vibrating screen can efficiently complete the material screening task and is an indispensable key equipment in modern industrial production.