How Does a Vibrating Screen Work?

The vibrating screen uses the excitation force generated by the shaker to make the screen body move periodically along the direction of the excitation force. The material bounces around the screen surface. The screen surface is collected and conveyed to a designated area for grading or de-intermediation purposes. The amplitude can be adjusted by adjusting the weight of the eccentric block. It is generally divided into circular vibrating screen and linear vibrating screen.

Vibrating screens have been widely used in mining, metallurgy, coal, water conservancy, transportation, chemical and other industries to complete various processes such as screening, classification, washing, demineralization and dewatering of materials. As an intermediate link between mining and smelting, the efficiency of mineral processing not only directly affects the productivity of mineral processing, but also has a profound impact on the rational use of national resources.

The working principle of vibrating screen is to use the double rotating vibration produced by the vibrator. The rotating weight on the upper part of the vibrator makes the screen surface plane vibrate, and the rotating weight on the lower part makes the screen surface cone vibrate. The combined effect is to make the screen surface produce double rotating vibration. Its vibration trajectory is a complex spatial curve. The curve is projected as a circle in the horizontal plane and an ellipse in the vertical plane. By adjusting the excitation force of the upper and lower rotating weights, the amplitude can be changed. Adjusting the spatial phase angle of the upper and lower counterweights can change the curve shape of the trajectory of the screen surface and change the trajectory of the material on the screen surface.

When the vibrating screen is working, the two motors reverse synchronous rotation, so that the exciter produces reverse excitation force, forcing the screen body to drive the screen body for longitudinal movement, so that the material above is periodically thrown forward for a distance. For the excitation force. Thus, the screening operation of the material is completed.

The working part of the vibrating screen is fixed, and the material slides along the working surface for screening. Fixed grizzly screen is the most widely used one in mineral processing equipment, generally used for pre-screening before coarse or medium crushing. It is simple in structure and convenient in manufacture. It does not consume electricity and can unload the ore directly on the screen surface.

In order to complete the screening process of materials successfully, the conditions of relative movement of materials and screen surface must be satisfied. Therefore, the screen box of the vibrating screen should have suitable motion characteristics, which can make the material on the screen surface become loose on the one hand, and make the coarse particles blocked on the screen hole escape on the other hand, and keep the fine-grained material pass through the screen hole smoothly. In the actual production process, the actual screening process is." A large number of different particle sizes and coarse and fine mixed crushing materials into the screen surface, only part of the material in contact with the screen surface. In this part of the material in contact with the screen surface, it is not exactly the fine-grained material smaller than the screen size.

The remaining fine particles smaller than the screen size are mostly distributed in the whole material layer.

Through the movement of the screen box, the material layer on the screen surface is loosened, so that the gap existing between the large particles is further expanded, and the small particles take the opportunity to enter the lower layer through the gap. At the same time, because the gap between small particles of material is very small, large particles cannot pass through. Therefore, the position of large particles keeps increasing during the movement. As a result, the original disorderly group of material particles is separated, that is, stratified by particle size, forming the arrangement law of small particles in the lower layer and coarse particles in the upper layer.

Reach the sieve surface of the fine particles of material, because its size is smaller than the size of the screen hole, can smoothly penetrate the screen, and finally achieve the separation of coarse and fine particles of material, to complete the screening process". However, complete separation is not possible. In the separation process, there is usually a part of fine particles remaining in the coarse particles on the sieve, which cannot penetrate the sieve. Studies have shown that although the size of the fine particles is smaller than the sieve hole, they do not penetrate with the same difficulty. The smaller the particle size compared to the sieve hole, the easier it is to penetrate the sieve hole and vice versa.

For more information, please contact us.