Method of and apparatus for purifying waste water

摘要

An improved technique for reprocessing, through a reaction zone, a portion of an agitated flow of waste water that is coupled into a wedge-shaped or frusto-conical separating zone via such reaction zone is described. A recirculation conduit, independent of an inlet aperture at the bottom of the separating zone for admitting an upward flow of water from the separating zone, has an inlet end communicating with the separating zone at an upper region thereof, the outlet of the recirculation zone emptying into the agitated water stream in the reaction zone. The inlet aperture at the bottom of the separating zone has a cross-sectional area which is small relative to the cross-sectional area of the separating zone and small relative to the cross-sectional area of the reaction zone. The resulting pressure drop between the inlet aperture at the bottom of the separating zone and the outlet of the recirculation conduit prevents impurities in the separation zone from returning to the reaction zone through the inlet opening.