Four Common Types of Screening Machines

The screening machine is a vibrating screening mechanical equipment that uses the relative movement of the bulk material and the screen surface to make some particles pass through the screen holes, and divide the sand, gravel, crushed stone and other materials into different levels according to the particle size. According to the different screen surfaces, there are many types of screening machines. Today, we mainly introduce four common ones for you.

Fixed sieve

Fixed screen is the simplest and oldest screening machinery. The screen surface is composed of many screen bars arranged in parallel, and the direction of the arrangement is generally the same as the direction of the material flow on the screen. The sieve surface is inclined and installed, and it is fixed during operation. The material slides along the sieve surface by its weight and is screened. The inclination angle can be 35°~45°. According to the size of the screen gap, the screen surface can be made of round steel, square steel, rail or T-shaped section steel.

The fixed screen has a simple structure, does not consume power, has no moving parts, and has low equipment and use costs. Therefore, this sieve is generally only used for sieving when the classification particle size is ≥ 100mm.

Roller screen

The screen surface of the roller sieve is formed by several vertical rollers with the material flow on the screen. Each roller is driven by a motor through a chain drive or gear drive to rotate in the same direction. Conveying, production capacity and screening efficiency are higher than fixed screen.

To strengthen the conveying effect of materials, the screen surface is installed at an inclination of 12°~15°. The roller screen has a solid structure, reliable operation and stable operation, but the structure is complex and heavy, and the production capacity and screening efficiency are low. Roller screen is suitable for the pre-screening of raw coal when the incoming particle size is relatively large.

Trommel screen

The structure of the trommel screen. The screen surface of the trommel screen is a cylindrical or conical screen cylinder, and a rotating shaft is installed along the symmetrical axis of the screen cylinder. When the transmission device drives the rotating shaft to rotate, the screen cylinder also rotates.

The conical sieve drum is installed horizontally, the material is fed from the small end of the sieve drum, and is carried up with the rotation of the sieve drum. When it reaches a certain height, it will fall down by itself due to the action of gravity, so the continuous ups and downs make the fine particles pass through the screen and coarse particles. The particles are gradually transported to the big end of the sieve drum for discharge.

For the cylindrical screen drum, to make the material move axially in the drum, its rotating shaft must be installed at an inclination of 3° to 5°.

The trommel runs smoothly and reliably, but the production capacity is low, the screen holes are easily blocked, and the screening efficiency is low. It can be used for the screening of coarse and medium-sized materials.

Shake the sieve

The screening face is a rectangular screen box with a flat surface. The screen box is reciprocating oscillated by the eccentric link mechanism. To enable the particles on the screen surface to move forward, the screen surface is often installed inclined. When the screen surface moves forward, the screen box will be slightly raised upwards, and the material will also move forward and rise. forward position on, that is, jump forward once.

The screen box keeps shaking, and the material keeps jumping forward. During this movement, fine particles are leaked from the sieve holes, and coarse particles are removed from the end to complete the screening work.

The advantage of the shaking screen is that the shaking amplitude (stroke) of the screen box does not change due to the change in the feeding amount, that is, the movement is stable. The disadvantage is that the productivity and efficiency are lower, so the newly designed coal preparation plant is no longer an option.

Conclusion

We have screening machine for sale, for more information, please kindly contact us at any time. We are glad to answer for you.