Patent ID: 7862493

Claim:
A screw centrifuge for continuous separation of flowable substances of different densities, comprising: a rotor drum having discharge openings for a heavy phase that are arranged in a conical portion of the rotor drum, the rotor drum further having weir openings for a light phase that are provided on an end wall closing off the rotor drum; a conveyor screw, rotatable inside the rotor drum, having a screw blade mounted on a hollow shaft for transport of the heavy phase to the discharge openings; a mixture inflow tube arranged coaxially inside the hollow shaft, the mixture inflow tube leading to a feed chamber configured in the hollow shaft, from which feed openings lead to the screw blade, and a protective tube within which the inflow tube extends, the protective tube delimiting the annular space from a cavity within the hollow shaft, wherein an air extraction member is provided before the feed chamber in the delivery direction of the inflow tube, and wherein the air extraction member generates, in an annular space enclosing the inflow tube, a suction flow co-directional with the delivery direction in the inflow tube.