The Rotary drum  screen for water treatment is composed of a case made up of stainless steel plate and section bars. The stainless steel filter, whose surface is made up of a stainless steel "v" profile wedge wire type winded up as a spiral, rotates inside the case. The distance between each coil is the same as the desired filtering slot.

The liquids to be filtered flow in the feeding tank through a flanged inlet and are conveyed along with the filter surface through a special distributor equipped with wet seal. The solids separation occurs there: the solids are kept and made to rotate by the external surface of the rotating filter, and, finally, discharged by a brass cleaning blade. The liquid filtered passes through the filtering drum, where it is washed again on the opposite side of the filter, conveyed on the tank bottom and then discharged. The filter rotates thanks to a bath oil gearbox directly connected at the rotating drum filter. Inside the rotating filter there is or a washing system equipped with nozzles (mobile washing system), which work with high-pressure water, or a bar composed of a   set of spray nozzles (fixed washing system), through which the filtering drum can be periodically cleaned.