Technical and economic index in the process of screening is screening efficiency and productivity.The former is quality index, the latter is a quantitative index. There is a certain relationship between them.These factors determined the screening results.
一, Physical properties of the material
Including the grain size composition of the material, humidity, silt content and particle shape etc. When the material content of fine particle is larger, the productivity is also big, when the material humidity is bigger, generally screening efficiency will reduce. But the mesh size is bigger, the moisture influence is smaller. So, for a large wet material containing water, in order to improve the screening process, generally way is increasing the mesh or use wet sieving. When the silt content is more than 8%, you need to adopt wet sieving, or cleaning silt in advance.
二,The influence of screen surface properties and structure parameters
Vibrating screen makes the particles and the surface screen surface do vertical movement, so screening efficiency is high, production capacity is large. Particles and screen surface relative motion is mainly parallel motion bar screen, flat vibrating screen, drum sieve, etc., its screening efficiency and production capacity is low.
For material, sieve productivity and screening efficiency are depended by mesh size, productivity is depended by the screen surface width, screen surface is wide, then productivity is high. Screening efficiency is depended by the length of screen surface, screen surface is long, then screening efficiency is high. General length-width ratio is 2.
Effective sieve area(mesh area compare to whole screen surface area) is bigger, sieve surface productivity for per unit area and screening efficiency is higher.
Surface screen mesh size is larger, the unit productivity, the greater the screening efficiency is higher.
三,The influence of production condition
When the sieve load is big, the screening efficiency is low.
The feeding uniformity means a lot to screening process.
Generally taking a test to determine sieve angle. Or vibration amplitude and vibration time, this is associated with the structure property of sieve, in a certain range, increasing vibration can improve the screening index.
For material, sieve productivity and screening efficiency are depended by mesh size, productivity is depended by the screen surface width, screen surface is wide, then productivity is high. Screening efficiency is depended by the length of screen surface, screen surface is long, then screening efficiency is high. General length-width ratio is 2.
Effective sieve area(mesh area compare to whole screen surface area) is bigger, sieve surface productivity for per unit area and screening efficiency is higher.
Surface screen mesh size is larger, the unit productivity, the greater the screening efficiency is higher.
三,The influence of production condition
When the sieve load is big, the screening efficiency is low.
The feeding uniformity means a lot to screening process.
Generally taking a test to determine sieve angle. Or vibration amplitude and vibration time, this is associated with the structure property of sieve, in a certain range, increasing vibration can improve the screening index.
