The sorting process is based on falling of the sorted material through the gaps between the rotating shafts with the stars (undersized fraction). The material which does not fall through, is transported by the stars to the end of the screen where it is dumped as waste (oversize fraction). The shafts are fitted with fully covered bearings and are driven by covered chain drive units. Geared motors are mounted on the side of the machine’s frame. The screening area consists of several sections with independent drives controlled by frequency converters. Each section is adjusted separately upon the operation conditions on-site, including precise fraction setting during machine’s operation by step-less setting of stars’ revolutions. Each section can be fitted with different star type or size. Feeding of materials onto a star screen must be even across the entire width of the working area in the direction of the material flow, crushed, and thoroughly loosened. The oversize fraction must be continuously discharged from the screening area and must not accumulate on the discharge end of the screen, e.g. due to a narrow discharge chute.
Manufacturer recommends equipping the star screen with feeding hopper (buffer) with agitator and discharge conveyors for undersized and oversize fractions to avoid material clogging. The screen is fitted with rotation speed sensors and centralized lubrication system, or with other safety devices.
The stars can be made of rubber, anti-static rubber, carbon steel, hard metal (HARDOX), stainless steel, plastic or other materials as required by the customer.
The surface is treated by heavy-duty resistant coating, hot-dip galvanizing, or by using stainless steel as primary construction material.
The screens can be arranged into sets to separate multiple fractions. They can also be made as mobile or with own power generator.
Star screens are designed according to the specific needs of the customer and configuration of the following basic parameters:
1) fraction (in mm)
2) required performance in m3/hour (or by nominal weight of processed material in t/hour)
3) working area width in mm
4) working area length in mm