HUBER Coanda Grit Washing Plant RoSF4

Sand separation, washing, and dewatering in one system.

  • Reduced disposal costs
  • Utilizes the Coanda effect for high efficiency sand removal.
  • Less than 3% organic content
  • High solids flow rate
  • Over 2,000 installations worldwide

The HUBER Coanda Grit Washing Plant combines grit classification and grit washing in one compact unit. By utilizing the Coanda effect, the classification process can be combined with the sorting process to ensure continuous high separation efficiency and exceptional washing performance.

Solid materials in the flow (sand particles, organic material) are then separated due to flow redirection and reduced flow velocity, depending on the settling velocity of the particles, settling to the bottom of the tank. Excellent flow scheme in the Coanda Grit Washer leads to > 95% separation of grain particles with a diameter of 0.20 – 0.25 mm.

The degree of separation depends on the settling velocity of the separated solid materials (due to density and particle size), so organic material will also be separated.

The separated grit is then rinsed, and the attached organic material is separated from the grain particles.

After the removal of organic material, the clean sand is discharged through a screw classifier, statically dewatered, and discharged into a container. The organic material remaining in the Coanda Grit Washing Plant is also automatically but discontinuously removed from the plant, depending on the overall process, ensuring a consistently available separation capacity.


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HUBER Grit Washer RoSF4 T

Grit Washer for treatment of partially dewatered sand from wastewater treatment plants

  • Less than 3% organic content
  • Very high solids content of > 90%
  • Easily retrofitted after existing grit classifiers
  • Reduced disposal costs

Conventional grit separation

Conventional sand classifiers practically separate all solid materials contained in the grit chamber effluent. This classified and partially dewatered sand is usually more or less contaminated with organic particles.

Subsequent sand washing

The classified sand is therefore further processed in a sand washing plant where the organic matter is separated from the mineral particles.

By introducing upward-directed wash water, the sand in the lower part of the RoSF4 T Grit Washer will be fluidized in the water stream, creating a fluidized layer of sand/gravel. Within this fluidized layer, lighter organic particles are separated from the denser particles, regardless of particle size.

This process is supported by a central mixer that keeps the particles in motion. After the removal of organic material, the clean sand is discharged through a screw classifier, statically dewatered, and discharged into a container.

The removed organic material is automatically discharged with the introduced wash water.


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HUBER Grit Washer RoSF G4E

Sand separation, washing, and dewatering in one system

  • Reduced disposal costs
  • Low investment costs
  • Over 90% separation efficiency for grain size > 0.2 mm
  • Reduction of organic content to < 5%

Also suitable for classified materials for sand capture from biogas plants The Grit Washer RoSF G4E combines continuous separation and washing of contaminated material from the grit chamber in one plant.


Special design for biogas plants.


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