Introduction
A trommel screen is a rotary screen that is used to separate materials on the basis of size. It is mainly used in the solid waste processing industries and mineral processing. The oversize material is separated from the undersized material.
The trommel screen consists of a long cylindrical drum that has many holes of the size of separation required. The holes help in the classification of material and when the drum rotates it only allows the material that is smaller than the size of the holes to fall through while the oversized materials flow out through the other side of the trommel.
Working principle
Trommel screen consists a few parts, typically screening drum, frame, hopper, transmission part.
After materials enter the drum, on the one hand, materials are screened along with the rotation of drum, on the other hand, the bigger materials flow forward along the direction of slope and be separated by the screen with different numbers of meshes.
The different materials fall into different hopper and then are sent to different finished product stacks by manpower or belt conveyor.
According to different sizing specification, the numbers of hierarchical level could be from one to four. Materials whose size is larger than the screen mesh of the last part will be discharged from the outlet.
Features
● Short set-up time
● Low feeding height
● Robust steel construction
● Variable speed for screening drum
● Optimal transport dimensions
● Aggressive drum RPM for better results
● Self-cleaning drum
Advantages of Trommel Screen
● Efficient, generally cheaper and easy to maintain
● Handle a wide range of material and can easily break compacted material
● Less noise and are mechanically more robust
● Trommel system can be easily set up near the source of solid waste material
● Wide process capacity range
Applications
Trommel screen has a wide range of applications, municipal waste, gold washing, glass, coal, sand and gravel, wood chips, compost, slags, recycling, topsoil, construction waste, crushed stones, etc.
Two major applications
1. Municipal and industrial waste
Trommel screens are used by the municipal waste industry in the screening process to classify sizes of solid waste.
This is done by removing inorganic materials such as moisture and ash from the air-classified light fraction segregated from shredded solid waste, thereby increasing the quality of the product fuel.
2. Mineral processing
Trommel screens are also used for the grading of raw materials to recover valuable minerals.
The screen will segregate minuscule materials which are not in the suitable range of size to be used in the crushing stage.
