Screening operations are mainly divided into two types: pre-screening and screening.
Pre-screening is the screening operation before the ore enters the crusher . The sieve is installed in front of the crusher, and the fine-grained material in the ore is pre-screened to prevent over-grinding of the ore, reduce the amount of ore entering the crusher, increase the fluidity of the ore in the crushing chamber, and improve the production capacity of the crusher. . Especially in the middle and fine crushing, in order to avoid the clogging of the crusher by fine-grained materials, pre-screening is often used.
Inspection screening is a screening operation after the ore has been crushed by a crusher. The purpose is to screen out the crushed product larger than a certain size, and then return to the crusher for re-crushing to control the final particle size of the crushed product and fully utilize the crusher's production capacity. For example, when the short-head cone crusher breaks the medium - breakable ore, the content of the particles in the product larger than the discharge port accounts for 60%, and the maximum particle size is 2.2 to 2.7 times that of the discharge port, so the short-head cone crusher often consists of inspection and screening. Closed road broken.
In production, sometimes a sieve is used for both pre-screening and double-checking the screening, called pre- and inspection screening.

Agricultural Machinery Piston Pin including:Harvester Piston Pin , planter piston pin , tractor piston pin and grader piston pin etc.