explain how many types of range hoods are used in China?

Answer:

1) Electrostatic lampblack treatment:

Electrostatic lampblack treatment means that under the action of high-voltage electric field, the oil mist gas is ionized, and tiny oil particles move to the electric field dust collecting electrode and accumulate on the dust collecting electrode, and the oil is finally collected in the oil storage tank after being deposited, so that the gas is purified;

2) Wet oil fume treatment technology:

Wet oil fume treatment technology is a kind of mature technology, which is to form a liquid film or mist by absorbing and purifying liquid (water and chemicals) through a special device, and make the oil fume fully contact with it to complete the transfer from gas phase to liquid phase to wash and absorb oil fume pollutants;

3) Control technology of filtration and adsorption method:

The principle of this method is to remove particulate matter and volatile organic gases through interception, collision and screening when the oil fume passes through the filter material;

4) Mechanical control technology:

The principle of this method is to make the movement direction of oil fume flow turn strongly through mechanical coercion, so that the particles in oil fume can reach the deposition surface under the inertia and be separated from the gas;

5) Catalytic control technology:

The principle of this method is to use various catalysts with self-purification function, and at the cooking temperature, the oil droplets in the cooking process are converted into CO2 and water vapor by catalytic oxidation combustion, thus eliminating pollution and odor.

6) plasma fume purification equipment:

plasma fume purification equipment has been put into use, which is the most advanced fume treatment technology in China at present. Its principle is to set a plasma field at the front end of the electrostatic field while using the high-voltage electrostatic method, and use a large number of active free radicals excited by its high energy to degrade the oil mist particles, so as to reduce their viscosity, so that the oil collected by the polar plate can be settled into the oil sump to the greatest extent; At the same time, in the process of generating plasma, the instantaneous high energy generated by high-frequency discharge can open the chemical bonds of some harmful gas molecules and decompose them into simple atoms or harmless molecules;

7) compound technology:

The mechanical treatment is used as pretreatment unit, followed by electrostatic treatment unit or wet treatment unit to form a purification system. Sensitive discharge areas with odor removal requirements can also add an activated carbon adsorption unit after the electrostatic or wet treatment unit as a post-treatment unit. Composite technology combines different technologies into a system, and gives full play to their respective technical expertise to form an economical and reasonable optimization system with high purification efficiency. Composite technology is the most promising practical technology in the future.