The filtration principle of the air filter separates the liquid water and liquid oil droplets in the compressed air, and filters out dust and solid impurities in the air, but does not remove the gaseous water and oil.
The airborne particulate removal technology mainly includes mechanical filtration, adsorption, electrostatic dust removal, negative ion and plasma methods, and electrostatic electret filtration.
Mechanical filtration generally captures particles mainly through the following three methods: direct interception, inertial collision, and Brownian diffusion mechanism. The collection effect on fine particles is good but the wind resistance is large. In order to obtain high purification efficiency, the filter element needs to be dense and periodically replaced.
Adsorption is the use of large surface area and porous structure of materials to capture particulate contaminants, which are easy to block and are more effective for gas pollutant removal.