The role of drum screen in the food processing industry

Drum screen produced by PK machinery is widely used in coal, mining, power industry, but nowdays it is more used in grain processing and act as an immense role.

The pore diameter is a bit larger than the biggest particles in grain purification processing, its role is to let the food particles and smaller impurities go through sieve pores and down, while the large size particles as oversized things was discharged, feed the grain into the sieve, it will move with little impurity through the pore, the large impurity like paper, hessian cloth, fag end, masonry plaster, wood and long straw as oversized things discharged, the small impurities such as dust and sand will be filtered out by the sieve on the exit.the grain is discharged with strong suction process, the major part of the drum screen is perforated screen which is the horizontal drum, outside is a brush fixed to clean the pore, beside this there is a suction equipment to removal the dust.

The drum screen is acting as a cleaning equipment before grain flow in silo, large capacity and easy conduct will increase the work processing 

Solution to trommel screen mesh blockage of Kazakhstan customer

Our Kazakhstan customer told us that the trommel screen he purchased two months ago occurred blockage during the operation process which makes the screening efficiency very poor. After communication,we found out the blockage was caused by the high humidity material, here engineers gives some solutions accordingly to prevent blockage:

1.Add an automatic cleaning brush on screen which can achieve automatic cleaning during operation. 

2.Add an air compressors, since sand is slightly damp, so cleaning purpose can be achieved by air force.

3. Add an anti blocking device, due to the high frequency and small force of vibration impact, it can clean up the blockage efficiently.

In addition, textile screen mesh made of 16Mn can also adopted to ensure material pass through the mesh smoothly.

Hope above methods is helpful,further information please click: www.pkmachinery.com 

Application and Difference of Shaft and Shaftless Trommel Screen

There are 2 kinds structure of trommel screen. One is trommel screen with shaft, the other is shaftless trommel screen. Generally both of them can be applied in some common bulk material, however, for material with special property, we must pay more attention to select a more suitable model according to the application working condition.
Trommel screen with shaft: 
The drum is installed aslope on the main frame. The motor and gearbox connect the drum through a coupling and rotates around an axis. After the material fed into the drum, the material can move forward and rotate due to the inclination and rotation of drum. The qualified material will be discharged from the bottom hopper, and the unqualified material will be discharged from the end outlet. As the material rotates in the drum, which make the blocked material bounced out of the aperture to prevent the mesh blocking.
Trommel screen with shaft is generally used for screening granular material with large density, such as: sand, coal, limestone, fertilizer, compost and mineral, etc.

Shaftless trommel screen: 
The shaftless trommel screen is installed horizontally. The drum is rotated driven by motor wheel gear or motor chain. Generally the rotate speed is very slow and the drum length can be designed longer, which can increase the screening efficiency. In the drum internal wall, there is a delivery plate ( sometimes screw type) to make the material move forward. The material which is larger than mesh size will be discharged at the end outlet, and the material which is smaller than mesh size will be discharged at the bottom discharge hopper. If the material is household garbage, we can also add a cutting tool, which can rive some plactis bags, etc. 
Shaftless tromme screen is generally used for screeninig material with small density, such as: waste, wooden chips, activated carbon, fertilizer, construction material, chemical material, etc.