The crankcase ventilation air breather filter is also the oil-air separator. When the diesel engine is working, a small amount of high-pressure air in the cylinder will always leak into the crankcase (caused by the leakage of high-pressure gas and oil around the piston ring), and there will always be a small amount of oil, water and pollutants in the air. If the engine oil enters the combustion system directly without treatment, it will cause combustion and emission deterioration. In order to ensure the combustion quality, economy and improve the emission, it is necessary to separate the oil vapors in the blowby and oil-air mixture, and return the separated oil to the oil pan through the oil guide pipe. Clean air flows to the intake pipe and enters the engine for combustion.

Crankcase breather filter is used to remove oil contamination before engine bypass gas damages critical engine components and surrounding equipment. It is generally installed in the crankcase ventilation system near the air filter. At present, the breather filter is also gradually applied to automobiles. The more functions are:

l Balance pressure: when the engine is working, some gas will inevitably leak into the crankcase. The reciprocating motion of the piston will change the volume of the crankcase, resulting in the pressure imbalance in the crankcase. This air intake must be removed from the engine, which is known as positive crankcase ventilation (PCV) system. Through the crankcase ventilation pipe and PCV valve which is installed between the engine valve cover and the intake manifold behind the throttle valve, the space in the crankcase is connected with the external atmosphere, and the pressure is adjusted by the external atmospheric pressure to achieve pressure balance.

l Cleaning function: the water and gas in the engine are discharged through the crankcase filter element to realize the cleaning function, prevent the increase of carbon deposition in the engine, keep the engine compartment and components clean, and prevent the engine intake, turbocharger and intercooler from blocking.

l Prevent oil deterioration. The waste gas contains water vapor and sulfur dioxide. Water vapor condenses into foam in oil and destroys the supply of oil. This phenomenon is especially serious in winter. Sulfur dioxide meets water to form sulfuric acid, and sulfuric acid meets oxygen in the air to form sulfuric acid. These acids will not only deteriorate the engine oil, but also corrode the parts.

l Prevent the leakage of crankshaft oil seal and crankcase gasket, and prevent the oil from the air splashing on the filter surface, causing oil accumulation and blocking the ventilation device. 

l Crankcase Breather Filter can completely separate the oil and save oil. When the engine is working, there is always a part of combustible mixture and exhaust air flowing into the crankcase through the piston ring. After the gasoline vapor entering the crankcase condenses, the engine oil becomes thinner and the performance becomes worse.

l Prevent excessive accumulation of crankcase oil and gas and air pollution. Also Recovering oil lost in the environment in history.

l The utility model has the advantages of simple structure, convenient use and maintenance, reduced operation cost and improved the safety of the closed area. In an enclosed area, the oil-bearing gas generated by the engine may cover and damage the surrounding equipment, resulting in hazardous conditions and expensive maintenance.