After the chamber, the waste falls into the screening drum. The screening drum is perforated with technological openings of a rectangular shape through which the small fraction of compost is screened.

A spiral is placed inside the drum, which, based on the principle of a screw conveyor, transports the compost towards the exit end of the drum.

For additional spreading of the compost, and thus better screening, steel paddles are placed around the perimeter of the drum, between the spirals.

The fine fraction falls on the longitudinal belt conveyor, which is located below the sieve, while the coarse fractions that did not pass through the sieve perforation fall after the sieve onto the transverse conveyor.

The drum is easily replaceable, which enables the screening of fractions of different sizes with the same machine.