The air filter is related to the engine's power, economy, intake noise, and diesel engine smoke. According to statistics, 70% of the early wear and tear of motor vehicles and construction machinery engines is related to the air filter. The filtration efficiency of the air filter plays a decisive role in the wear and life of the engine.

The particles suspended in the air are dust, with a size range of approximately 1-1000+μm. If the wind is low, dust particles with a size greater than 200+μm and less than 1μm will have little effect on engine wear, because dust particles larger than 200μm The child does not float easily in the air and sinks quickly. Dust particles larger than 200+μm and smaller than 1μm have little effect on the abrasion of the engine. The main reason is that particles larger than 200+μm are difficult to enter the friction pair, and dust particles smaller than 1μm are in the oil film of the friction pair. The objects processed by automobile air filters are mainly 1-200μm particles in the air. From the perspective of air filter, dust particles are divided into three levels: (A), 1-5+μm+, (B), 5-30+μm, (C), 30-200+μm, (A) ) Type particles are too small and difficult to filter out with ordinary inertial oil bath or cyclone tube. (B) type particles are easy to filter out with high efficiency air filter. (C) Type particles, generally can be separated by coarse filters. The composition of air dust, particle distribution, physical and chemical properties, dust concentration, geography, climate and other factors are different. According to our country’s situation, the Three Norths area is vast, with heavy wind, sand and dust, and the strong wind season spans a long period of time. The air dust concentration is 0.001-1.0g/+m3. The main component of air dust is hard abrasive, followed by organic matter and oxides such as calcium, aluminum, iron, and others.

Calculations show: When the air filter is not installed and the dust content is 2.5g/+m3 and the engine speed is 1800r/min, the dust sucked into the cylinder by the tank engine is as high as 4kg/h, causing the engine to wear out quickly. The test results show that a tank equipped with a diesel engine only needs to travel for 15+-20h on a dirt road with a dust content of 3g/+m3, and the engine will be damaged due to wear.

Therefore, in order to improve the degree of purification of the engine intake, reduce mechanical wear and extend the service life of the engine, a reliable and effective air filter must be installed in the engine's intake system.