OFM series of internally-fed rotary screens are designed for the high flow rate/low solids content of municipal sewage. They are compact units and fully enclosed to contain vapours. The housing is a unitary body of plate and structural members that provides a stable platform for mounting of the screen cylinder. The OFM can use screen media of wire mesh, wedgewire of perforated plate or combinations. Selection of screen filament is based on requirements of the downstream treatment process. Wire mesh(200—1000microns) is used for the fine screenings, coarser applications (2mm-10mm) typically utilize perforated plate. Wedgewire can be used for a wide range of slot openings.
- 304 stainless steel construction
- TEFC motor and gear drive
- UHMW polyethylene trunnions shaft-mounted
- Internal flights
- External spray bar
Method of Operation
The influent enters a headbox, where the energy is dissipated and the flow is evenly distributed onto the interior sidewalls of the drum. Solids are retained on the screen surface and the liquid flows radially through the screen openings. Splash guards direct the liquid filtrate to a central drainage area and the solids are transported axially, by lights, to the open end of the drum. The rotation of the drum allows the entire screening surface to be continuously or intermittently washed by a fixed , external, spray bar fitted with a blank of spray nozzles.