What is the principle of air purifier?

Physical purification method

1. Adsorption filtration-activated carbon

Activated carbon is a porous carbonaceous substance with a highly developed pore structure. The porous structure of activated carbon provides it with a large surface area, which can fully contact with gas (impurities), thus giving it unique adsorption performance, making it very easy to adsorb and collect impurities. Just like magnetic force, all molecules attract each other.

Disadvantages: Ordinary activated carbon can't absorb all toxic gases, which is inefficient and easy to desorb.

2. Mechanical filtration -—HEPA net

HEPA (High Efficiency Particulate Air Filter), which means high efficiency air filter in Chinese, has an efficiency of 99.998% at 0.3 micron. The characteristic of HEPA is that air can pass through, but fine particles can't. HEPA filter screen consists of a stack of sub-glass fiber films folded back and forth continuously, forming a wavy gasket for placing and supporting the filter screen boundary.

Electrostatic purification mode

Working principle: the working principle of high voltage electrostatic adsorption dust removal is adopted. Electrostatic type is the working principle of high voltage electrostatic adsorption dust removal. Under the action of high-voltage static electricity, the cathode wire in the electrostatic field produces corona discharge, and the corona layer produces a large number of negative ions, which constantly move to the anode under the action of electrostatic field. When the dust in the air passes through the electric field, the dust is charged by the collision of negative ions, and the charged dust is also affected by the electrostatic field, moving to the anode (collecting electrode) and releasing the charge after reaching the anode.

Disadvantages: it can remove floating dust (toxic gas can not be removed), the efficiency is lower than that of mechanical type, the speed is slow, and ozone is easily generated. This model is rated as the worst purifier in the American market.

Chemical purification mode

1 photocatalytic method

Working principle: When the air passes through the photocatalytic air purification device, the photocatalyst itself does not change under the irradiation of light, but harmful substances such as formaldehyde and benzene in the air that can promote chemical reactions are degraded under the action of photocatalysis to generate non-toxic and harmless substances, and bacteria in the air are also removed by ultraviolet light, thus purifying the air.

Disadvantages: wide spectrum, low air volume, slow purification speed, and certain radiation to human body, which is a purification method eliminated in Europe and America.

2. Formaldehyde scavenger

Working principle: Using chemical substances to react with formaldehyde to achieve the purpose of removing formaldehyde.

1, chemical reaction: chemical reaction with formaldehyde to generate carbon dioxide and water, such as ammonia water;

2. Biology: It is made of biological agents that can react with formaldehyde, such as urea, soybean protein, amino acids, etc.

3. Plants: made of plant extracts, such as aloe vera and tea extract;

4. Closed type: made of film-forming substances, which form a film to prevent formaldehyde from releasing, such as chitosan and liquid paraffin.

Disadvantages: First, the substances generated after chemical reaction are easy to cause secondary pollution. In practice, the phenomenon of secondary detection exceeding the standard occurs from time to time. Second, the absorption of formaldehyde does not change the chemical composition, reducing the formaldehyde content in the air. However, in this way, the symptoms are not cured, and formaldehyde is easily released again.

3. Medicine and catalysis-cold catalyst essence

Working principle: Cold catalyst, also known as natural catalyst, is a new type of air purification material after photocatalyst deodorizes air purification material. It can catalyze a reaction at room temperature, decompose various harmful malodorous gases into harmless and odorless substances at room temperature and pressure, from simple physical adsorption to chemical adsorption, and decompose and remove harmful gases such as formaldehyde, benzene, xylene, toluene and TVOV at the same time of adsorption to generate water and carbon dioxide. During the catalytic reaction, it is cold. The cold catalyst itself is non-toxic, non-corrosive and non-combustible, and the reaction products are water and carbon dioxide, which does not produce secondary pollution and greatly prolongs the service life of adsorption materials.

Other purification methods

1. water washing method

Based on the siphon and centrifugal principles, the purifying agent mixed with water is sucked into the suction pipe at the lower part of the coaxial centrifugal turbine on the motor base by the siphon principle, and the purifying agent mixed with water is sprayed into the bottle liner by the centrifugal principle to form a water film, so that dust and bacteria in the air are sucked into the water, and the purified air is blown into the room at the same time, so that toxic organic substances, dust, smoke smell, peculiar smell, viruses and the like in the room can be quickly and effectively removed, and a large amount is generated.

2. Negative ion method

When hydroxyl negative ions come into contact with harmful gases floating in the air, it can reduce pollutants, nitrogen oxides and active oxygen (oxygen free radicals) produced by cigarettes in the air, and reduce the harm of excessive active oxygen to human body. Neutralize the positively charged air dust, settle without charge and purify the air.