ROTAMAT® Rotary Drum Fine Screens are completely made of stainless steel and are acid treated in a pickling bath. They are either installed directly into channels or are supplied as tank-mounted units, with an inclination of 35°.
Dependant on the bar spacing (0.5 - 6 mm) or plate perforation (1 - 6 mm) and the drum diameter (up to 3000 mm) any flow rate can be realised.
The wastewater flows into and through the open end of the inclined screen basket with the floating and suspended materials being retained by the screen basket. Blinding of the screen surface generates an additional filtering effect so that suspended materials can be retained that are smaller than the bar or perforation of the screen basket. The basket starts to rotate when a certain upstream water level is exceeded due to screen surface blinding.
The rotating screen drum lifts the screenings and drops them into the centrally arranged trough. Screenings removal is supported by a scraper brush and spray bar. A screw conveyor in the trough rotates and transports the screenings through an inclined pipe.
The conveying screw transports, dewaters and compacts the screenings, without odour nuisance, and discharges them into the customer's container or a subsequent conveying unit.
Integrated Screenings Washing System IRGA
To optimise the treatment process an integrated screenings washing system can be provided. It improves the carbon/nitrogen ratio of the pretreated wastewater. In addition, the IRGA reduces the costs of screenings disposal. The ROTAMAT® principle allows for integration of the screenings washing system directly in the trough and/or the lower end of the rising pipe. As the soluble matter is separated from the inert material, faeces are virtually completely washed out which leads to a significant weight reduction and improved operating and hygienic conditions.