1.The screening efficiency
The screening efficiency are closely related with material nature,the size of the sieve material distribution,particle size, moisture content and silt content .
Construction waste particle size distribution on the screen has a great influence on screening efficiency.The more easy-sieved particles contain in the waste, the higher the screening efficiency is.Close to the screen hole size and particle size of the more "difficult to sieve grain", the screening efficiency is lower.
The particle shape of construction waste also has an effect on screening efficiency, relatively sphere, cube, polygon particles have high screening efficiency.When usingsquare or circular sieve to sieve flat or oblong particles, the screening efficiency is low.
The moisture content of construction garbage and silt content on the sieving efficiency has a certain influence.When screen hole hydraulic, slight moisture can also result in fine particle cluster.
2. Screening Equipment Performance
The screening efficiency of the equipment is relevant to the area of the screen mesh. The most common screen meshes are bar screen mesh, steel plate punching sieve mesh and steel wire woven mesh. The smaller of the mesh area, the lower the screening efficiency is. Woven screening mesh has the largest screening area so as to its screening efficiency. While the punching sieve mesh’s performance goes between them.
Movement methods of the screening mesh also has influence on the screening performance. Different screening equipment has different movement methods and so it is with its working efficiency. The same solid waste adapted different screening methods may have different screening efficiency, which is demonstrated in chart 2-1.
Screen surface width is also affect the ability of the screening equipment to deal with an important factor, the length of the screen surface is affected, screening efficiency too narrow screen surface to make waste layer thickening and unfavorable to fine grained close to the screen surface.Too wide of the sieve sieve surface and make waste time too short.
On the screen surface inclination determines the size of the screen product discharge speed, Angle is too small for oversize product discharge;Angle is too large, it waste too fast, sieving time is short, low screening efficiency.Generally more appropriate screening Angle of 15 a 25 degrees.
3. Operation Conditions of Screening
Enough attentions should be paid to the screening process, the material should be fed evenly to make sure the material is spread out along with the width of the screen mesh. By making full use of screening mesh, it not only improve the screening efficiency of material with small granularities, but also rise the screening capacity of the screen. The maintenance and the repair of the screen mesh also plays a important role in making sure the screening efficiency.
When the screening equipment encounters inadequate vibration, the material will unevenly layered that makes it difficult for screening process. However,. If the screen received excessive vibration, the material will goes into another round of vibration without screening. Then lots of waste objects will move to the end of the mesh and be discharged afterwards, hence, reducing the screening efficiency. Consequently, the vibrating frequency of the screen should match with its amplitude. As for the roller screen, the most important factor is the adjustment of the rotating speed, making sure the vibration is within a reasonable arrange.