Device and method for separating a suspension

A sedimentation device (1) for separating a solid-liquid suspension, comprising

• a settling tank (2) defining an inside;
• a feed well (3) disposed on the inside of the settling tank (2);
• a feed pipe (4) comprising an inlet end (5) and an outlet end (6) communicating with the feed well (3);
• an overflow collector (7) disposed around a periphery of the settling tank (2) configured to collect overflow from the settling tank (2);
• and
• a mixing area (9) to which clarified liquid is fed from an upper part of the settling tank (2), wherein
• the mixing area (9) is disposed around the periphery of the settling tank (2), the inlet end (5) of the feed pipe (4) communicates with the mixing area (9), and overflow from the overflow collector (7) and the solid-liquid suspension to be separated are fed to the mixing area (9),
• a pump (8) is disposed in the overflow collector (7) for feeding overflow from the overflow collector (7) to the mixing area (9),
• a stilling chamber (10) having an overflow weir (11) is disposed between the mixing area (9) and the overflow collector (7),
• the overflow from the overflow collector (7) is fed to the stilling chamber (10),
• the overflow from the stilling chamber (10) is fed over the overflow weir (11) to the mixing area (9) forming a free surface (13), and
• a level measuring device (14) is associated with the stilling chamber (10) for measuring the filling level in the stilling chamber (10), thereby enabling determination of the amount of overflow flowing over the overflow weir (11) into the mixing area (9).