Abstract: A three-phase solid bowl screw centrifuge includes a rotatable drum, a screw arranged in the drum, a solid material discharge located at the fist axial end of the drum, and two liquid outlets are located at a second axial end of the drum. A first of the liquid is for a lighter liquid phase and a second of the liquid outlets is for a heavier liquid phase. One of the liquid outlets includes a skimmer disk arranged in a skimmer chamber and the other of the liquid outlets is formed as an overflow. Two regulating disks are located in the front of the skimmer disk. The regulating disks extend radially from an outside of the drum toward an inside of the drum. A siphon disk extends between the regulating disks and into the skimmer chamber from a interior circumference of the skimmer chamber to an exterior circumference of the skimmer chamber. An annular chamber is formed during an operation and is located between the siphon disk and the skimmer disk.

Abstract: A three-phase solid bowl screw centrifuge has a rotatable drum (1) and a screw (2) arranged in the drum (1). In this case, at least one solid material discharge is arranged at one axial end of the drum (1) and at least two or more liquid outlets for liquid phases of different densities—a lighter liquid phase and a heavier liquid phase—are arranged at its other axial end. The one liquid outlet also has a skimmer disc and the other liquid outlet is formed as an overflow weir, the skimmer disc being preceded by two regulating discs (11, 12) of the same inside diameter, which extend radially from the outside inwards and between which there enters a siphon disc (13), which in the skimming chamber (10) extends from the inner circumference of the latter outwards. This has the effect of forming an annular chamber (14), which is assigned a means for changing the pressure in the annular chamber (14).