Crankcase ventilation is essential to keep engines running cleanly and efficiently. They ensure separation of blow-by gases that are inevitably generated during the compression process of the fuel-oxygen mixture in the engine. This prevents release of unfiltered blow-by gases contaminated with oil mist into the environment. The separated oil is returned to the oil circuit, and the combustion gases return to the intake tract (crankcase ventilation).

In the impactor type oil mist separator, the oil in the blow-by gases is separated through a fleece layer and returned to the crankcase. The filtered gases are then supplied to the intake tract. This reduces the load on engine components such as the intercooler or turbocharger. Other benefits are lower oil consumption and improved combustion.

Generation of blow-by gases

Blow-by gases are generated during the fuel combustion process in combustion engines when gases escape through the piston rings into the crankcase area of the engine. The gases consist of unburned fuel, water, nitrogen oxides and hydrocarbons. They can be caused by insufficient sealing of the piston rings or increased pressure in the cylinders.