How does an air purifier purify the air?

How does an air purifier purify air? 
      The continuous haze days before, made the air purifier a hot topic and hot topic. Many people are also concerned about how the air purifier cleans the air. How useful can it be?
      Air purifiers, also known as “air cleaners” or air cleaners, refer to the ability to absorb, decompose, or convert various air pollutants (generally including decoration dust such as dust, pollen, odor, bacteria, allergens, and formaldehyde, etc.) , Effectively improve the air cleanliness of the product. 
The earliest air purifiers originating from fire fighting originated as fire-fighting uses. In 1823, John and Charles Dean invented a new type of smoke protection device that would allow firefighters to avoid smoke during fire extinguishing. In 1854, a man named Johns Tenghouse made new progress based on the invention of his predecessors: Through several attempts, he learned that adding charcoal to air filters can filter out harmful and toxic gases. During World War II, American scientists developed HEPA filters, which were very popular. 
      Passive purification and active purification Air purifiers now have a variety of different ways of designing and manufacturing. In terms of mode, it is nothing more than passive purification and active purification. 
      Passive purification is the use of fans to pump air into the machine, filtering the air through the built-in filter, which can mainly play the role of filtering dust, odor, toxic gases and kill some bacteria. The filter also divides dust filters, de-formaldehyde filters, deodorizing filters, HEPA filters, and the like. Among the relatively high cost is the HEPA filter, which can play a role in the decomposition of toxic gases and bactericidal effects, especially the suppression of secondary pollution. 
       Active purification includes silver ion technology, negative ion technology, and photocatalyst technology. For example, our common negative ion technology, the main principle is the use of electrostatic discharge negative ions, adsorption of dust concentrated in the air play a role in dust reduction, while the negative ion of oxygen in the air is also ionized into ozone, a certain degree of bacteria killing effect. Photocatalyst technology is a technology that uses semiconductors to release strong oxidizing free radicals under the irradiation of light. 
      Many methods can be effective The popular air purifier on the market usually adopts a combination of passive and active purification methods. It uses the motor to make the indoor air circulate. The contaminated air passes through the air filter in the machine and removes various pollutants. Or adsorption, and then through the negative ion generator installed in the outlet, the air is continuously ionized, resulting in a large number of negative ions, was sent by the breeze, the formation of negative ion flow, to achieve the purpose of cleaning and purifying the air. 
      In fact, the so-called active and passive purification is only a general statement. There are five principles of international air purification, namely, physical, electrostatic, chemical, anion, and compound. In general, an air purifier that uses multiple purification methods at the same time will have a better purification effect. For example, dust, odor, pollen, and other large particles can be filtered by physical purification; harmful substances such as allergens, viruses, and formaldehyde require chemical purification. ((South China Jianzhong was engaged in the development and production of air purifier filters for 11 years. It is known that the air purifier purifies the basic principles of air. Therefore, there are many technical pitfalls in the filters sold on the market. Everybody must pay more attention to air when purchasing.