Patent ID: 8048298

Claim:
A domestic effluent purification installation, comprising a mixing vessel ( 210 ) which receives effluent, a flocculation tank ( 220 ) comprising an upper, tapered portion extended by a lower portion, which flocculation tank is located inside a clarification vessel and in which sludge flocs form, a descending pipe ( 270 ) which connects the mixing vessel ( 210 ) to the lower portion of the flocculation tank ( 220 ), through which the effluent passes from the bottom to top and is clarified on contact with the sludge flocs, the descending pipe ( 270 ) comprising an upper tube, one end of which is connected to the mixing vessel ( 210 ) and the other end of which opens into a lower tube having a larger diameter than the upper tube, the lower end thereof opening into the lower portion of the flocculation tank, a sludge vessel ( 230 ) which receives the sludge that flows over from the flocculation tank ( 220 ), characterised by A—a first chamber ( 100 ) which forms a homogenisation vessel and is equipped with an agitator ( 120 ) and a pumping unit ( 140 ), B—a connecting pipe ( 300 ) at the outlet from the pumping unit ( 140 ), comprising a reagent injector ( 310 ) and static mixer ( 320 ), C—a second chamber ( 200 ) which forms the clarification vessel surmounted by the mixing vessel ( 210 ) into which the connecting pipe ( 300 , 320 ) opens tangentially, comprising the flocculation tank ( 220 ) in the form of an inverted truncated cone located above the sludge vessel ( 230 ) and surmounted by a filtration chamber ( 240 ), the flocculation tank ( 220 ) having in its upper portion openings ( 223 ) for the passage of the sludge flocs, the descending pipe ( 270 ) descending from the mixing vessel ( 210 ) to the bottom ( 222 ) of the flocculation tank ( 220 ), as well as an outlet ( 241 ) for water from a filtration chamber ( 240 ), and D—a by-pass pipe ( 160 ) connecting the upper portion of the homogenisation vessel ( 100 ), beneath the level of an effluent inlet of the homogenization vessel, directly to the sludge vessel ( 230 ).