Highly Efficient Oil Separation Systems for Crankcase Ventilation 2009-01-0974

As a result of the new exhaust gas legislation the significance of crankcase ventilation systems in combustion engines has drastically increased. Oil mist separation, which is a part of the crankcase ventilation systems, influences numerous engine processes, which directly or indirectly impact the emissions of newly developed combustion engines. The oil mist separator’s task is to retain the liquid oil parts and to return them to the oil sump. Thus, the oil mist separator reduces oil consumption and emissions. By continuously optimizing the oil consumption at different sources, oil separation from the blow-by gas is gaining significant influence on the overall oil carry consumption. In addition to reducing oil consumption, the development of highly efficient oil separation systems in crankcase ventilation it also rising in importance due to additional concerns.

The lifetime of the exhaust gas after treatment systems in Diesel engines is limited due to the deposition of particulates caused by the burning of oil. In Diesel engines and particularly among commercial vehicles, insufficient oil separation can pose the risk of carbon build up in the turbocharger, resulting in loss of power and ultimately, component failure. In modern, direct injection gasoline engines, deposits on the intake valves result in insufficient air flow. These topics increasingly determine the threshold values of permissible oil carry over through the crankcase ventilation.

This article will describe 2 developments in this field, which are represented by the switched impactor with none woven insert as a passive system and the electrical driven cone stack separator as an active system.