At present, all the filtering efficiency of the filter, and refers to the unit of time by air cleaner dust filter, dust amount and percentage ratio of air into the air cleaner with the concept. This tradition is to measure the filtering efficiency by weight method. In essence, the engine into the particle size and quantity directly affect the engine service life. Small particles of dust particles into the engine will not cause engine damage, only the dust reaches a certain size, will cause engine damage.

Therefore, efficiency concept must change the original traditional reference, a new concept that is suitable for filtering efficiency. The suitable filtering efficiency is to ensure the lowest efficiency reliability of the engine. The suitable filtering efficiency by particle diameter and the number of air filter , and dust particle diameter size and number into the air cleaner with the ratio of the air. Suitable filtering efficiency of the air filter filtration ability and the level of protection of the engine air filter can be unified. Special control influence the service life of the engine large dust particles, the small dust particles not filtering. Thus, to reduce the air resistance, air filter size, reduce the cost of all good.

2.Engine requirements for air filters

In order to give full play to the potential of the engine, the engine manufacturers put forward many requirements for air filter, including air resistance, filtering efficiency, service life, maintenance, size, weight and cost. An air cleaner whether application of how are inevitably a series of compromises and concessions to each other, but the core is the filtering efficiency of the engine. Manufacturers tend to make excessive demands on the air filter, filter manufacturers are difficult to achieve.

According to the concept of suitable filtering efficiency is determined, a pressing matter of the moment of different engine suitable filter efficiency value of air filter, namely how much the number of dust particles and can provide reliable protection to the engine.

3.Wear and particulates in internal combustion engines

Engine wear is a very complex problem. An internal combustion engine intake system, lubricating system and fuel system are respectively provided with an air filter, oil filter, fuel filter, air filter without filter. The abrasion of various dust particles and combustion products mainly to gas ring and the upper part of the cylinder. The oil filter filter without metal scraps, through a lot of air the crankcase vent into the dust and debris from the combustion chamber into the oil pan, it is mainly to wear oil ring and the lower part of the cylinder.