How does the air purifier purify the air?

The continuous smog days of the previous period made the air purifier a hot product and a hot topic. Many people are also concerned about how air purifiers clean the air. How much can it be used?

Air purifier, also known as "air cleaner", air freshener, refers to the ability to adsorb, decompose or convert various air pollutants (generally including dust, pollen, odor, bacteria, allergens and formaldehyde, etc.) A product that effectively improves air cleanliness.

Originally originated from firefighting purposes

Air purifiers originated in firefighting applications. In 1823, John and Charles Dean invented a new type of smoke protection device that allowed firefighters to avoid smoke during firefighting. In 1854, a man named Johns Tenghaus made new progress on the basis of his predecessors: through several attempts, he learned that adding charcoal to the air filter can filter out harmful and toxic gases. During World War II, American scientists developed HEPA filters, which were once very popular.

Passive purification and active purification

Air purifiers now come in many different ways of designing. From the mode, there are two methods: passive purification and active purification.

Passive purification is the use of a fan to pump air into the machine, through the built-in filter to filter the air, mainly to filter dust, odor, toxic gases and kill some bacteria. The filter screen also divides the dust filter, the formaldehyde removal filter, the deodorization filter, the HEPA filter and the like. The higher cost is the HEPA filter, which can decompose toxic gases and sterilize, especially to suppress secondary pollution.

Active purification includes silver ion technology, negative ion technology, photocatalytic technology, and the like. For example, our common negative ion technology, the main principle is to use electrostatic discharge of negative ions, adsorption of dust concentrated in the air to reduce dust, while negative ions also ionize the oxygen in the air into ozone, a certain killing effect on bacteria. Photocatalyst technology is a technology that utilizes semiconductors to emit free radicals with strong oxidizing power under the illumination of light.

More means can be effective

The popular air purifiers on the market usually adopt a combination of passive and active purification methods, which circulate indoor air through the motor, and the polluted air passes through the air filter in the machine to remove or adsorb various pollutants, and then pass through. The negative ion generator installed in the air outlet continuously ionizes the air to generate a large amount of negative ions, which are sent by the breeze to form a negative ion airflow, so as to clean and purify the air.

In fact, the so-called active and passive purification is only a general statement. There are five internationally accepted principles of air purification, namely physical, electrostatic, chemical, negative and composite. In general, an air purifier that uses multiple purification methods at the same time will have a better purification effect. For example, large particles such as dust, odor, and pollen can be filtered by physical purification; while harmful substances such as allergens, viruses, and formaldehyde require chemical purification to purify them.