Abstract: Plant to precipitate suspended matter out of water, such as surface run-off water, industrial waste water, biologically treated waste water and landfill leachates with in-pipe flocculation, a filter filled with granular filter material situated above the sedimentation tank of the plant the direction of flow through which is from top to bottom and a backwash tank and whose subsequent sedimentation and filtration stages comprise the following features: that the backwash tank for filtered water is situated above the filter; that a float seals off an aperture with an enlargened cross-section connecting the filter with the backwash tank in a position raised by buoyancy; that a bypass directs the treated filtered water past the float to the backwash tank if the said aperture is closed off; and that the sludge outflow pipe in the floor of the sedimentation tank and the sludge valve in the sludge outflow pipe are directed against gravity to such an extent that when the sludge valve in the sludge outflow pipe is opene

Abstract: Method and apparatus for treating raw water by introducing the raw water and a flocculating agent into a cylindrical container, preferably in a tangential manner of flow between the cylindrical container wall and a baffle spaced radially inward from the container wall, flowing the fluid radially inward towards the center of the container to a central conduit extending axially upward in the container and opening at the internal bore of the conduit through the bottom of the container, the central conduit being surrounded by a coaxial pipe having a plurality of circumferentially defined, spaced openings therein to induce a radial, i.e., from the wall of the container to the central conduit, flow of water with minimal axial flow components in order to facilitate settling of the flocculated particles from the treated water.

Abstract: A process and apparatus for the treatment of untreated water. The untreated water mixed with a flocculating agent is introduced tangentially into the circumferential area of a tank through a feed connection directed at the tank wall. The tank includes a perforated partition circumferentially spaced from the wall of the tank and a conduit in the center of the tank which passes axially through the tank bottom and whose upper end carries a circular overflow disc located below the water level of the tank. Alternately, the partition comprises upper and lower rings, between which there are disposed guide plates which form openings distributed over the circumference of the partition. The circumferential speed of the water flowing through the partition is reduced by braking such that the occurrence of upwardly directed, secondary flows is prevented and clean water is led downward through the center of the tank.