The Application Of Different Screening Machine

2025-01-13

Working Principle And Application Of Screening Machinery

The screening machinery is mechanical equipment that uses rotation, vibration, reciprocation, shaking, and other actions to screen various raw materials and primary products into several grades according to the particle size of the materials, or to remove moisture, impurities, etc., and then carry out the next step of processing and improve product quality.

1. Fixed screen

The working part is fixed, and the material is screened by sliding along the working surface. Fixed grid screen is a kind of screen that is widely used in ore dressing plants, and is generally used for pre-screening before coarse or medium crushing. It has a simple structure and is easy to manufacture. It does not consume power and can directly unload the ore onto the screen surface. The main disadvantages are low productivity and low screening efficiency, generally only 50%~60%.

2. Roller screen

The working surface is composed of a series of rolling shafts arranged horizontally, with plates on the shafts, and fine particles pass through the gaps between the rollers or plates. Large pieces of material are driven by the rollers to move to one end and discharged from the end. Ore dressing plants generally rarely use this type of screen.

3. Cylinder screen

The working part is a cylindrical shape, and the entire screen rotates around the axis of the cylinder. The axis is generally installed at a small inclination angle. The material is fed from one end of the cylinder, the fine-grade material passes through the sieve holes on the cylindrical working surface, and the coarse-grained material is discharged from the other end of the cylinder.

The circular screen has a low speed, stable operation, and good power balance. However, its screen holes are easy to clog, the screening efficiency is low, the working area is small and the productivity is low. It is rarely used as screening equipment in ore dressing plants.

4. Plane motion screen

The body swings or vibrates in a plane. According to its plane motion trajectory, it is divided into linear motion, circular motion, elliptical motion, and complex motion. Shaking screens and vibrating screens belong to this category. The shaking screen uses a crank connecting rod mechanism as a transmission component. The motor drives the eccentric shaft to rotate through a belt and a pulley, and the connecting rod makes the body reciprocate in a certain direction. The direction of movement of the body is perpendicular to the center line of the support rod or the suspension rod. Due to the swinging motion of the body, the material on the screen surface moves to the discharge end at a certain speed, and the material is screened at the same time.

Compared with the above-mentioned sieves, the shaking screen has higher productivity and screening efficiency. Its disadvantage is poor power balance. It is rarely used in ore dressing plants now, and has been replaced by a more reasonable structure of vibrating screens.