What is the purification principle of air purifier? What are the air purification technologies available on the market?

What is the purification principle of air purifier? What are the air purification technologies available on the market?

The upcoming eleven is the peak season of electric promotions, under the influence of the haze air purifier market will be reproduced in the buying frenzy, but in the face of a wide range of products, you really know which one you should choose? What are the current mainstream purification technologies, and what is the difference between them?

Purification Principle Analysis: The Truth That Businesses Won't Tell You

To choose a suitable air purification products, we must first understand the types of indoor pollutants, so that we can prescribe the right medicine. Currently, indoor pollution can be divided into eight main sources: dust pollution, adsorbable particulate pollution, nicotine pollution, kitchen fumes pollution, indoor odors, bacteria, viruses and chemical pollution caused by decoration. One of the most common and most serious is the adsorbable particulate matter and chemical pollution.

The main sources of indoor pollution

For different sources of pollution, the choice of purification technology is also very different, when we understand the source of pollution, and then according to their own needs to choose products, you can effectively purify indoor air. Today I will talk to you about the principle of mainstream air purification technology and its advantages and disadvantages.

Activated carbon technology: high adsorption capacity

Activated carbon can be said to be one of the most common purification technologies, and I believe that most people are not unfamiliar with it, and its strong adsorption capacity has been widely used in a variety of technical fields. Domestically, it is mainly used in the industrial fields of medicine, chemical industry and food processing, etc. Since the 70's, it has been applied to industrial wastewater treatment in China and gradually become one of the main methods for secondary or tertiary treatment of industrial wastewater. The super adsorption capacity for impurities or pollutants makes it the first choice for many air purification products.

Activated carbon technology is quite mature

So how does an air purifier based on activated carbon adsorption technology work? Simply put, it releases clean air that has been filtered through activated carbon back out through a powerful fan. As one of the most basic purification technologies available, most air purifiers have applications. Currently, commercially available activated carbon is mainly categorized into three types: coconut shells, fruit shells and coal, with coconut shells having the strongest adsorption capacity.

Advantages: strong adsorption capacity, can effectively adsorb most of the harmful substances in the air

Disadvantages: The adsorption effect of activated carbon is relatively short-lived, once the adsorption amount reaches saturation, the adsorbed pollutants will be released to cause secondary pollution. Therefore, this type of purifier must often replace the filter material to avoid secondary pollution.

Negative Oxygen Ion Technology: purifies second-hand smoke pollution, effectively eliminates odors

Negative ion technology may sound mysterious, but it is actually a relatively common purification technology. Negative ions refer to negatively charged ions in the air. The fact that we feel the air is very fresh after a thunderstorm is actually the result of an increase in the amount of negative ions in the air. At present, the technology of negative air ions generator has been quite mature, most of the air purifiers have applications.

Negative ions in the air increase significantly after thunderstorms

Scientific research shows that negative ions have sedative, hypnotic, analgesic and other effects, but also can restore the pollutants from the atmosphere, nitrogen oxides and cigarette combustion generated by the reactive oxygen, to reduce the harm; and the air with a positively charged particles neutralization and precipitation, so as to achieve the effect of purifying the air.

Advantages: negative oxygen ion purifier on second-hand smoke and other pollution has a fairly significant purification effect, and can effectively improve human health, while releasing trace amounts of ozone flowers have a certain sterilization effect.

Disadvantages: Negative ions in the air does not exist for a long time, need to continue to release; negative ions on formaldehyde and other pollutants in the decoration of the purification effect is not as good as desired, need to be targeted to choose.

Photocatalyst catalytic decomposition technology: there is "light" to catalyze

From the literal meaning, it is not difficult to see that this is a technology that purifies by catalyzing the decomposition of pollutants. Its reaction principle is not complicated: under the irradiation of light, the photocatalyst itself will not react, but will promote chemical reactions. It can use the energy of a specific wavelength light source to produce catalytic effect (redox reaction), so that the surrounding oxygen and water molecules into active free radicals, these free radicals can decompose most of the harmful organic matter and some inorganic substances.

Photocatalyst principle of action

Photocatalytic catalytic decomposition technology is also more common nowadays, mainly used for the purification of formaldehyde and other organic pollutants. However, it should be noted that, although this catalytic reaction can be carried out at room temperature and pressure, but must be irradiated by ultraviolet light can be carried out.

Advantages: Photocatalytic technology has a spectral practical effect and high purification efficiency.

Disadvantage: The photocatalytic reaction must be exposed to UV light. In order to fulfill this condition, most manufacturers choose to add UV emitting lamps inside the machine. Users should pay attention to avoiding the exposure of UV emitting lamps when using these purifiers.

Fractionation Complexing Technology: Effective for Decoration Pollution

Fractional complexation technology is currently the most effective technology for formaldehyde and other decoration chemical pollution. The basic principle of this technology is to collect and capture indoor formaldehyde, benzene, ammonia and other pollutants, and then through the formaldehyde capture agent and water complex decomposition system, respectively, formaldehyde and ammonia and other gaseous short molecular chain material quickly complexed into irreversible long molecular chain solid material, and decomposition of ammonia salts, and ultimately converted into precipitates.

This technology utilizes the water-soluble properties of formaldehyde and ammonia to pass the indoor polluted gases into the complex decomposition system composed of molecular complexing agent and water, and ultimately the pollutants in the indoor air are irreversibly transformed into solid substances, so as to achieve the purpose of purification.

Advantage: The technology is a special application for formaldehyde and other decoration pollutants, and has a good purification effect on organic pollutants such as formaldehyde, benzene and TVOC.

Disadvantages: Solutions containing complex ions or related components need to be replaced regularly, especially for newly renovated homes with high levels of formaldehyde, where filter media are replaced more frequently.

Electrostatic dust collection technology: efficiently removes dust, odors, etc.

Electrostatic dust collection technology utilizes the principle of high-voltage electrostatic adsorption to remove airborne particulate pollutants such as dust and pollen. By forming a high-voltage electric field locally, the airborne particles are separated from the airflow under the action of the electric field. Compared with other technologies, it has the advantages of low energy consumption, high dust removal efficiency, etc., and is able to effectively remove airborne particles of 0.01-50μm.

Principle of Electrostatic Dust Collection

At present, this technology has also been widely used in the field of air purification, air purifier understanding of the user may find that most of the high-end imported products are using electrostatic dust collection technology, this is because foreign air purifiers are mainly used to remove pollen and other particles, this technology for particles purification effect advantage is quite obvious.

Advantages: Highly efficient filtration of particulate pollutants and partial adsorption of bacteria and other pathogenic microorganisms. Compared with other purification technologies, electrostatic adsorption technology has low energy consumption, good adsorption effect, and the filter material can be reused, lower purification costs.

Cons: Ozone is produced during operation, and these air purifiers have little effect on formaldehyde and other decorative chemical pollutants.

HEPA filtration technology: good filtration efficiency

HEPA filter can be said to be currently recognized as the best filtration effect of high-efficiency filter material, we say that the HEPA filter is actually composed of a continuous folded before and after the sub-glass fiber membrane to form a wavy gasket used to place and support the filter media. HEPA filter purification effect is directly proportional to its surface area, and its unfolding area up to the original area of the filter several times or even dozens of times, the filtering effect is very impressive.

The HEPA filter has a large spread area

Like electrostatic adsorption technology, HEPA filtration technology is favored by most foreign brands for its superb filtration effect on particles, and has become one of the most common purification technologies abroad. However, the domestic HEPA filter air purifier is still in a relatively embarrassing situation. Due to the late start of China's air purification industry, the relevant technology is not mature enough; and the domestic pollution situation is more serious, the service life of the HEPA filter will be shortened, the high cost of replacement of the filter material has become the main reason why many users shy away.

Benefits: HEPA filters have an unrivaled filtration effect on particulate pollutants, with superb particle capture, extremely small pore sizes and greater adsorption capacity giving it a higher purification efficiency.

Disadvantages: At present, China's pollution is more serious, the air PM2.5 and other particulate pollutants in the high content, the user to use HEPA filter type purifiers, you need to face the frequent replacement of the filter media and expensive post use costs.

Summarize: Through the previous introduction we can see that each purification technology and material purification is targeted, all pollutants have the effect of purification technology does not exist. We choose to purify the product before the first to figure out the existence of the main types of pollutants at home, and then targeted selection, in order to achieve the best purification results.