Patent ID: 8337707

Claim:
A device for dewatering dredged material with a dry substance rate below 15%, comprising: a tank arranged with at least one inlet conduit for dredged material; a first outlet for cleaned water; and a second outlet for sludge; the tank further comprises a mixing chamber, to which the at least one inlet for dredged material leads, and a sedimentation chamber in which the first and the second outlets are arranged, where the mixing chamber and the sedimentation chamber are in fluid communication, the at least one inlet conduit having one end on the outside of the tank for connection with an extern tube and an outlet opening in the mixing chamber, at least one of the inlet conduit(s) including a connection for injection of at least one flocculation chemical to the inlet; a turbulence means for creating a turbulent flow in the mixing chamber for mixing incoming dredged material with the at least one flocculation chemical; and an evacuation means for removing stones and gravel from the bottom of the mixing chamber via a third outlet of the tank, wherein the evacuation means is at least one screw at the bottom of the mixing chamber.