Multi-sided materials are not suitable for the use of roller screens!
The trommel screen mainly relies on the gravity and friction of the material itself in screening multi-sided materials. When the material is about to slide down while rotating along the trommel screen, the gravity component of the material along the tangent at this critical point is greater than When the friction force component, the material and the drum roll relatively, through this principle, the material can pass through the sieve and achieve the purpose of classification.
Multi-sided materials are not suitable for the use of roller screens! The running speed of the material itself is much lower than the running speed of the material in the linear screening machine, and it has a better chance to pass through the screen holes to achieve the purpose of classification. In the linear vibrating screen, the material running speed is ≥0.2m/s, and the running speed is fast, which reduces the ability of the material to pass through the screen. The polygonal shape of the material itself is easy to block the screen holes, so the screening ability is not good, and the efficiency is reduced.
Polygonal materials are sieved with a trommel, which slides on the trommel screen by the gravity of the material itself. The running speed is slow and the probability of passing through the sieve is high. Therefore, the screening efficiency is appropriately improved.
After the comparison between the above drum screen and the linear screen, it is not difficult to find that the shape of the material screened by the drum can be irregular, which can solve the problem of the working condition that the linear vibrating screen cannot be screened.
When the trommel screen is working, various forms of blockage will occur according to the nature of the material. What are the main reasons for the blockage of the trommel screen?
1. Contain a lot of particles close to the separation point;
2. The material has high water content;
3. Spherical particles or materials with multiple contact points to the mesh;
4. Static electricity will occur;
5. Materials with fibrous materials;
6. There are more flaky particles;
7. The woven screen wire is thick;
8. Thicker screens, such as rubber screens, have unreasonable hole shape design, which does not reach the upper and lower sides, causing the particles to get stuck.
When the material particle size is finer, the mud content is more, and the sieving particle size is smaller, the water will play a decisive role in the blockage of the screen. When the moisture in the material is greater than 5%, if the material is dried unconditionally, the screen surface and the screen hole should be selected. When the moisture is greater than 8%, wet screening should be used. For materials with more flake particles, it is necessary to change the material crushing method and the particle size matching of different crushing methods.
Reasonable adjustment of the screen tension is an effective way to reduce the hole blocking of the screen. The reasonable tension causes the screen to produce a slight secondary vibration with the supporting beam, thereby effectively reducing the occurrence of blocking. The specific method is to make the tension hook into a constant tension mechanism, that is, install a spring on the tension bolt.
Because most of the material particles that need to be screened are irregular, the reasons for blockage are also diverse. In order to effectively prevent the screen from clogging, corresponding measures should be taken for the reasons of the above-mentioned screen hole clogging.