ENVIROSAND sand classifiers fulfill the function of sand separation coming from the sand trap of pretreatment of sewage treatment plants.

The settled sand, still wet, are pumped back or air-lifted to be transferred by piping to the settling tank of the ENVIROSAND sand classifier.

The tank volumes of each model are sized for predefined maximum flow rates. This is done in order to respect the residence times and the decantation speeds, guaranteeing the separation of more than 90% of the particles greater than 200 microns.

›SETTLING

The connection to the tank is by flange. A siphoid partition inscribes the course to be carried out by the effluent in order to match, with respect to the volume of the tank, the hydraulic decanting rules.

An internal overflow collects treated water and directs it to the outlet flange.

›SAND EXTRACTION

The extraction of the sand is carried out by a shaftless screw made of special hardened steel.

The screw lays on bars spaced apart.

Beyond the guiding effect that these bars performed, they also ensure the drainage of the water during sand lifting in the emerged area of the screw. The sands thus drained can be discharged into a container.