Engine crankcase ventilation system

A crankcase ventilation system for separating oil particles from crankcase blow-by gases of an internal combustion engine, ICE, comprising

• a housing;
• a disc stack separator arranged within the housing comprising
• a chamber;
• a rotor comprising
• an oil separating element arranged within the chamber and spaced from one or more walls of the chamber;
• and
• a shaft configured to rotatably mount the oil separating element;
• a first gas inlet for supplying the crankcase blow-by gases to the oil separating element along the shaft;
• and
• a first gas outlet for discharging the at least partially oil-separated gases;
• a filter element comprising a second gas inlet, a second gas outlet, and a filter arranged between the second gas inlet and the second gas outlet, wherein the filter is composed of a layer of arranged fibers;
• and
• wherein the first gas inlet is configured to be connected to a crankcase blow-by outlet of the ICE,
• wherein the first gas outlet is connected to the second gas inlet, and
• wherein the filter element is not connected to the shaft.