The wastewater grit washer classifier receives the liquid with grit into the inlet hopper where it is first washed by means of a rotating agitator that causes the liquid to form a rotating vortex, which in turn causes the grit particles to rub against each other, thus removing organic matter that is sticking to the surface of the grit particles. The grit then settles in the bottom of the inlet hopper from where it is removed and transported by means of the inclined screw to the elevated discharge chute into a receiving bin. The dewatering of the grit takes place by gravity in the inclined transport zone before being discharged.


  • Separation of grit from liquid flows with additional organics washing
  • Receives settle-able grit in liquids from upstream process
  • Solids settle in inlet hopper by gravity and vortex movement created by rotating agitator
  • Organic material is removed by vortex movement in the inlet hopper
  • Inclined shaft-less or shafted screw transports settled grit to discharge end
  • Grit dewaters by gravity in the transport zone
  • Dry grit is discharged vertically into receiver bin or conveyor
  • Trough wear protected by metal or HDPE liner

Technical specifications:

Material 304ss, 316ss
Screw 304ss, 316ss, micro alloy steel
Trough protection 304ss, 316ss wear bars
Screw diameter 240 – 280mm
Screw type shaft-less or shafted
Transport length 4210 – 5260mm
Inclination 40 deg
Discharge height 2300 – 3000 from ground level
Flow rate  30 – 90 m3/h wet solids 2 – 5% DS
Grit separation 95%  of particles >200 micron
Organics removal 95% with additional washing
Grit extraction 2000 kg/h at 90% DS