Liquid treatment apparatus

Liquid treatment apparatus comprising:

• a tank for containing a body of liquid and having a bottom wall;
• an inlet for liquid to be clarified disposed generally centrally of said bottom wall and extending about a generally vertical axis, said inlet being arranged to direct influent liquid generally vertically upwards in said tank;
• a generally conical partition member extending about said axis and disposed in said liquid above said inlet so that a liquid circulation zone is defined below said member;
• a tubular eductor member disposed generally vertically below said generally conical member on said vertical axis and arranged so that liquid entering the tank from said inlet flows upwardly in said member, said member having an open upper end from which liquid enters said liquid circulation zone, and an open lower end disposed relative to said liquid inlet so that liquid entering the eductor member from the inlet entrains surrounding liquid and establishes a recirculation of liquid below said partition member;
• deflector means disposed above said open upper end of the eductor member and arranged to outwardly deflect liquid leaving said member;
• liquid outlet means disposed generally at the level of the surface of said body of liquid and through which clarified liquid can leave the tank;
• sludge outlet means disposed generally centrally of the bottom wall of said tank and through which settled particles can be removed as a sludge;
• and
• a sludge scraper assembly which is rotatable in the tank about said generally vertical axis and which is rotationally located with respect to said axis, said assembly including:
• said tubular eductor member;
• scraper means adapted to move over said bottom wall of the tank as said assembly rotates and to convey settled particles towards said sludge outlet;
• drive means supported above the level of said body of liquid for rotating said scraper means;
• a driving member drivably coupled to said drive means, said driving member extending down into the tank generally along said axis and being rotatable about said axis when said drive means is operated;
• said tubular eductor member being coupled to said scraper means and to said driving member so as to transmit rotational movement of said driving member to said scraper means and cause the latter to convey settled particles to said sludge outlet.