Abstract: An arrangement for cleaning gas includes a centrifugal separator and pre-separation unit. The centrifugal separator includes a stationary casing, enclosing a separation space through which a gas flow is permitted, a gas inlet extending through the stationary casing and permitting supply of the gas from the pre-separation unit, a rotating stack of separation disks, a gas outlet and a drainage outlet for discharging separated liquid impurities. The pre-separation unit is arranged upstream of said inlet of said centrifugal separator, and it comprises a pre-separation inlet having a cross-sectional area A2 and permitting supply of the gas to be cleaned. A2 is larger than the cross-sectional area A1 of the inlet to the separation space of the centrifugal separator. A pre-separation outlet permits supply of gas from the pre-separation unit to the gas inlet of the centrifugal separator.

Abstract: A centrifugal separator structure is configured for cleaning of crankcase gases from an internal combustion engine. The centrifugal separator structure includes a separator rotor configured for rotation about a centre axis arranged inside a stationary housing. The separator rotor includes an axle member configured for connection to a shaft of a driving device. A stack of separation discs is supported on the axle member. The axle member is un-journaled inside the stationary housing when the centrifugal separator structure is separate from the driving device. Further, an assembly includes the centrifugal separator structure and a driving device.

Abstract: A centrifugal separator for separating a liquid phase from crankcase gases of an internal combustion engine includes a separation chamber, a rotor shaft, a rotor inside the separation chamber, an inlet for crankcase gases, a gas outlet, and a liquid outlet for separated liquid phase. The centrifugal separator also includes a liquid outlet chamber, a check valve, and a rotating member. The liquid outlet chamber forms an individual chamber and is arranged in fluid communication with the separation chamber via a liquid passage. The rotating member is connected to the rotor shaft and is arranged inside the liquid outlet chamber. The liquid outlet forms an outlet of the liquid outlet chamber. The check valve is arranged in the liquid outlet.