Grit and Sand Classifier

Grit Classifier SC

Description and Working Principle

The SC Grit Classifier is a stand alone unit designed to remove small particulate solids, grit, sand and fines from waste water elevating and de-watering the solids prior to disposal. It is fed either by an air lift pump, pump or pump and cyclone washer/concentrator.

Grit laden water is fed via the flanged inlet of the integral decanting hopper where the solids are allowed to settle out. Special baffle plates and inlet/outlet arrangements can be used to remove any remaining floating matter. The settled solids are removed from the hopper by a low speed conveying screw. Once elevated above the unit’s water level, the solids are further de-watered and transferred to a convenient discharge height.



Performance and Technical Features


Liquid throughput

  • min. 8 l/s 
  • max. 360 l/s

Solids output: 0.08 dm³/s

Efficiency: 90 % separation of sand with grain size as small as 200 micron


– Municipal waste water treatment plants for separation and de-watering grit coming from the sedimentation basin
– Industrial plants in which sand or grit has to be de-watered


Water to be conditioned passes through the charging inlet P and is let into the decantation hopper, where the sedimentation of solid particles takes place. The low speed of screw rotation allows Sedimentation and discharge at C of dewatered material. Treated water comes out of the discharge spout Q.


Hopper: Made from stainless steel and designed to avoid material blockages.

Flight: Made from heavy duty sections of wear resistant carbon steel.

Trough: Made from stainless steel, lined inside with low friction, wear resistant material. The design of the liner allows for easy replacement.


  • Baffle box
  • Discharge chute
  • Additional material removal screw at discharge level
  • Variable speed drive
  • Steel support structure
  • The unit can be manufactured from stainless steel on request

Advantages and Innovative Features

  • Shaftless spiral 
  • Absence of bearings 
  • Low speed 
  • Low installation cost