Extractors for treatment appts - for liquids polluted with mud, sand, fibres

摘要

Extraction system for sand, fibres and sludge is applicable to a setling tank hving at least one settling chamber with a cylindro-conical shape. The settling chamber comprises a hydraulic reaction wheel fed by means of a hollow shaft with the portion of the liq. to be treated which contains the coagulating agent. The other portion of the liq. is introduced into the residual turbulent zone of the reaction wheel and it is in this zone that the preliminary mixing with the agent is effected and where flocculation starts. A paddle mixer, driven by the reaction wheel, is arranged below teh latter and near the bottom of the chamber. A conical hopper below the chamber receives the sand which settles out in a pot fitted with a tube and discharge valve; a deflector prevents the sand from blocking the inlet of the discharge tube. A flushing arrangement is also provided with the same object. The sludge passes over teh wall of the concentric conical hopper and settles in a second pot for evacuation through a suitable outlet. The purified water leaves at the top of the chamber.