Types of Air Filters

According to the filtration principle, air filters can be divided into filter type, centrifugal type, oil bath type and compound type.

The air filters commonly used in engines mainly include inertial oil bath air filters, paper dry air filters, and polyurethane filter air filters. 

The inertial oil bath air filter has three stages of filtration: inertial filtration, oil bath filtration, and filter filtration. 

The latter two types of air filters are mainly filtered through the filter element. The inertial oil bath air filter has the advantages of small air

 intake resistance, can adapt to dusty and sandy working environment, and has a long service life. It was used in various types of automobile

 and tractor engines before. However, this kind of air filter has low filtration efficiency, heavy weight, high cost and inconvenient maintenance,

 so it has been gradually eliminated in automobile engines. The filter element of the paper dry air filter is made of resin-treated microporous filter

 paper. The filter paper is porous, loose, and folded. It has certain mechanical strength and water resistance. It has high filtration efficiency,

simple structure, light weight, and low cost. Low cost, easy maintenance and other advantages, is currently the most widely used automotive air 

filter. Polyurethane filter The filter element of the air filter is made of soft, porous and spongy polyurethane with strong adsorption capacity. 

This air filter has the advantages of paper dry air filter, but its mechanical strength is low. It is used in car engines. used more widely. 

The disadvantages of the latter two types of air filters are their short service life and unreliable operation under harsh environmental conditions.

Advantages and disadvantages

Various air filters have their own advantages and disadvantages, but inevitably there is a contradiction between the intake air volume and

 the filtration efficiency. With the in-depth research on air filters, the requirements for air filters are getting higher and higher. 

Some new air filters have appeared, such as fiber filter element air filters, composite filter material air filters, muffler air filters, 

constant temperature air filters, etc., to meet the needs of engine work.