The working principle of the air purifier is mainly divided into three types: passive, active, active and passive hybrid.
According to the air purifier for airborne particulate removal technology, there are mainly mechanical filter type, electrostatic electret filter type, high voltage electrostatic dust collection, negative ion and plasma method.
Mechanical filtration
Generally, the particles are captured by the following four methods: direct interception, inertial collision, Brownian diffusion mechanism, screening effect, which has good collection effect on fine particles but large wind resistance. In order to obtain high purification efficiency, the resistance of the filter is large, and the filter is filtered. The net needs to be dense, resulting in a reduced life and needs to be replaced regularly.
High voltage electrostatic dust collection
A dust collecting method for ionizing a gas by using a high-voltage electrostatic field to electrically adsorb dust particles to an electrode, although the wind resistance is small, but the effect of trapping large particles and fibers is poor, causing discharge, and the cleaning is troublesome and time-consuming, and ozone is easily generated. Form secondary pollution.
"High-voltage electrostatic dust collection" is a way to ensure both air volume and fine particles. This is the way in which the particles are charged by a high voltage before the particles pass through the filter core, so that the particles are "easy to adsorb" onto the filter element under the action of electricity.
The high-voltage dust collecting portion originally applies a high voltage to the two electrodes, and when the two electrodes are discharged, the passing dust is charged. Most of the dust is originally neutral or has a weak charge, so the filter can only filter out dust larger than the mesh. However, shrinking the mesh of the filter element can cause blockage. The high-voltage electrostatic dust collecting method can make the dust charged, and it can be adsorbed onto the specially processed and charged filter element under the action of electricity. Therefore, even if the mesh of the filter element is large (thick), the dust can be surely captured.
Electrostatic electret filter
Relative mechanical filtration can only effectively remove particles larger than 10 microns, and when the particle size of the particles is divided into 5 microns, 2 microns or even sub-micron, efficient mechanical filtration systems become more expensive, and Wind resistance will increase significantly. Filtered by electrostatic electret air filter material, it can achieve high capture efficiency with low energy consumption, and has the advantages of electrostatic dust removal and low wind resistance. However, it does not need external voltage of 10,000 volts, so ozone is not generated, and Its composition is made of polypropylene, which is easy to dispose of.
Electrostatic precipitator
It can filter dust, smoke and bacteria smaller than cells, and prevent diseases such as lung diseases and lung cancer. Harmful to the human body in the air is less than 2.5 microns of dust, because it can penetrate cells and enter the blood. The ordinary purifier uses filter paper to filter the dust in the air, which is easy to block the filter hole. The dust not only has no sterilization effect, but also easily causes secondary pollution.
Electrostatic sterilization
Using a high-voltage electrostatic field of about 60 volts, it can instantly kill bacteria and viruses attached to dust and prevent diseases such as colds and infectious diseases. Its sterilization mechanism is to destroy the four polypeptide chains of the bacterial capsid protein and damage the RNA.