Step screens are used to retain coarse dispersed impurities from wastewater with subsequent extraction. Screens are used in treatment plants as part of a mechanical treatment assembly after preliminary rough mechanical treatment, which protects the screen from large debris (logs, stones, etc.) entering it.
The main working unit of the step screen is a filter screen consisting of a set of plates (movable and fixed) of stepped stainless steel installed in a rectangular frame. Coarse impurities from the wastewater are retained by the filter screen and then the moving lamellas are driven by the drive, and due to the rotational movement of the movable lamellas, a gradual upward movement of the detained waste from the passing wastewaters occurs for each revolution.
After the screen, the waste is fed into a conveyor, a container or a waste treatment device, for example a screw press.
Step screens operate in automatic mode without the participation of maintenance personnel and are fully integrated with the automated control system of any complexity.