Dewatering plant for sludges leaving waste water treatment plant, receives batch feed in accordance with filter press demand and includes drainage, constriction, cyclonic mixing and additive dosing stages

摘要

Sludge is extracted intermittently from the waste water treatment plant (1), effecting thickening in batches, in response to filter press (9) demand. In the thickening section, drainage (11) achieves solids concentration of some 50 g/l. The sludge is mixed through a constriction (16) followed by a cyclonic static mixer (14). Preferred features: The constriction is a venturi or orifice plate. Drainage is carried out on a flat, fixed grid with continuous sludge feed and scraping by flexible blades. The grid comprises bars, their clearance varying along their length. The venturi or orifice plate equipment, includes de-watering agent injection (13). The static cyclonic mixer(s) provide for reagent injection (15). Reagents are organic and/or mineral.