Abstract: A sludge removal apparatus for a clarifier/thickener tank includes a central rotatable or stationary sealed sludge collection box submerged in the tank and surrounding a vertical, central influent column or support shaft. The collection box is positioned at any elevation between the tank bottom to a position just below the liquid/air level in the tank. At least one rotatable rake arm, preferably one or two pairs of spaced rake arms each having a spiral blade, is affixed to and rotates with the box and a driving cage, to inwardly push or pick-up sludge at the tank bottom for transport to the collection box. A substantially controlled flow of sludge may be provided into the collection box by valved or adjustable gate control through a sidewall opening in the collection box.

Abstract: A sludge removal apparatus for a clarifier tank includes a rotatable or stationary sealed sludge collection box submerged in the tank and surrounding a vertical, central influent column. The collection box is positioned at any elevation between the tank bottom to a position just below the liquid/solids level in the tank. A rotatable rake arm or pick-up pipe or sludge collection duct may be affixed to and rotates with the box and a driving cage to push or pick-up sludge at the tank bottom for transport to the collection box. A substantially constant flow of sludge may be provided in the collection box by valved or adjustable orifice control over the flow of sludge from the pick-up pipe(s) or duct(s) or center tank cone. A fixed flanged manifold spool with spaced branches is positioned between flanged vertical sections of the center column and sludge is transported from the collection box through the branches to a concentric sludge withdrawal pipe extending downwardly within the center column.

Abstract: Apparatus for backwashing the filter media of a liquid filtering machine while at the same time enabling the machine to filter liquid. The machine is of the type having a tank and a continuous bed of granular filter media in the tank through which liquid having suspended solids therein for removing the solids. The apparatus comprises a partitioning chamber and a carriage for selectively supporting and conveying the chamber above the media bed, with the chamber being insertable into the bed to isolate a portion thereof from the remainder of the bed. The apparatus further comprises a mechanism to selectively allow insertion of the chamber into the bed and to remove it, and a pump to draw liquid through the isolated portion of the bed to backwash it, while filtration may proceed in the remainder of the bed. Apparatus for removing the media from the chamber and replacing it with new, cleaned or regenerated media is also disclosed.

Abstract: An improved filtering machine of the down-flow type is disclosed wherein a particular section of a granular media filtration bed is isolated for backwashing while allowing filtration to proceed in the remainder of the bed. The filter machine includes a liquid-holding tank containing a bed of granular media, structure permitting passage of filtrate through the bed from below, a flume for distributing influent liquid containing suspended solids across the bed for downward percolation therethrough, and a partitioning chamber mounted on a carriage mechanism which selectively conveys the partitioning chamber across the surface of the bed. The partitioning chamber is reciprocatably insertable into the bed to isolate selected sections from the remainder of the bed. A pump is in communication with the partitioning chamber to draw liquid upward through the bed within the isolated section.