Rotary drum screen
for in-channel or in-tank installation – FSHm

Data Sheet

Technical Specifications

  • Frame in AISI 304/316 stainless steel, depending on requirements
  • Spiral with shaft in high tensile carbon steel or AISI 304/316, depending on requirements
  • Single motor for drum and screw.
  • Flow rate up to 3,308 m³/h (919 l/sec.)
  • Screen aperture 1 to 2 mm (perforated plate)
  • Drum diameter from 600 to 3,000 mm
  • Screenings washing system to reduce organic matter contents
  • Extracted solids collection system: in single bags or continuous liner
  • Starting from standard dimensions, the machine can be supplied in customized lengths in accordance with the screenings transport section


  • At the inlet to the treatment plant with MBR membrane technology
  • As a fine screening stage after coarse screening


  • Screening of industrial wastewater in general
  • Direct installation in the channel with no lifting pump required
  • Minimum risk of jamming and clogging, and separation of up to 80% of suspended solids
  • Drum cleaning with water washes via specific nozzles, with the facility to use recirculated water
  • No moving mechanical parts inside the drum
  • Reduced organic matter contents in the extracted solids and reduced volumes for disposal
  • Solids extracting screw through spiral with shaft
  • No jamming or clogging, even in the case of very long and fibrous products
  • Single motor for drum and screenings lifting screw
  • Extracting screw in line with the screen axis. Easy and flexible installation


Send now your request, you will be contacted as soon as possible!.

Spare Parts

Click below for original spare parts for your machines!

Description and operation

Definitive Ecology’s FSHm screen features a lifting, washing, and dewatering screw for efficient separation of organic matter and screenings volume reduction. The frame is secured and sealed between the walls of the channel or tank to avoid leakage, with consequent efficiency losses. The machine drum is installed in the channel or in the tank at a 35° angle with respect to the influent wastewater. The drum can be supplied exclusively in perforated plate with 1 or 2 mm aperture. The drum is equipped with a washing system composed of medium pressure spray nozzles. A brush, installed on the outside of the rotary drum, provides optimal cleaning action. The screen and screw are arranged in line and driven by the same gearmotor. This screw with shaft avoids possible clogging when handling long and/or fibrous products. The collected screenings are lifted, dewatered and compacted before discharge. The screening zone features a washing system for the solid contents, while an additional system is installed in the compaction zone to wash the compacting basket during the process, thus efficiently separating organic matter and reducing the screenings volume. The washing water flows through the screen and is discharged with the washed soluble components in the wastewater. The screw is composed of three sections:

  • First section to drain the water and wash the screenings
  • Second section to lift the screenings
  • Third section to compact and dewater the screenings after discharge

The lifting screw can be supplied without the compaction zone on request.

The operating principle involves ingress of the wastewater flow in the drum, which, because it is closed on the bottom, forces the water to change direction and flow through the perforated surface of the drum while solids of larger size than the drum apertures are captured inside the drum. This results in a rise in the water level upstream from the screen; when the level reaches a pre-determined value, the drum starts to rotate to convey the solids out of the wastewater. During drum rotation, a nozzles system cleans the screen with pressurised nozzles. The screenings and water are collected in a trough, which discharges them into a shaftless screw conveyor.

Models available

  • FSHm = for in-channel installation at 35°, with lifting screw in-line with the drum
  • FSHm/T = for in-tank installation at 35°, with lifting screw in-line with the drum