Treatment Method of Asphalt Flue Gas in Asphalt Mixing Station

In asphalt flue gas, the main component is volatile organic pollutants (VOCs), which is a fine tar mist. The treatment method of asphalt flue gas in asphalt mixing station is mainly to treat these tar fine fog particles, avoid their discharge into the air, and minimize the impact on the environment. At present, the technologies for the treatment of asphalt flue gas from batch type plant  in the market are complex and diverse, such as thermal combustion technology and plasma photocatalysis technology.

Thermal Combustion Technology

According to relevant calculations, when the temperature exceeds 760°C, the asphalt flue gas will quickly decompose, and if the concentration of its own exhaust gas cannot support continuous combustion, it can be burned with the help of thermal combustion technology.

Thermal combustion technology is mainly used to purify waste gas with low concentration of organic matter that can be burned. In the thermal combustion, if the oxygen content of the low-concentration exhaust gas is sufficient, it can be used as an auxiliary fuel combustion gas. When the auxiliary fuel is burned to the thermal combustion temperature, the gaseous pollutants in the exhaust gas will be instantly oxidized and decomposed into C02 and H2O. Among them, the temperature of the burner flame is usually set at 1300-1800 ° C, so if the asphalt smoke is mixed with the fuel, it will be instantly burned and burned thoroughly at high temperatures.

Plasma Photocatalysis Technology

Plasma photocatalysis technology is mainly composed of spray swirl tower, electrostatic precipitator, centrifugal defogging machine, plasma photocatalysis integrated machine and so on. The process flow of applying plasma photocatalysis technology to treat asphalt flue gas is mainly asphalt waste gas – swirl tower washing – centrifugal defogging electrostatic dust removal equipment – plasma photocatalysis equipment – centrifugal fan – standard discharge.

The effect of the spray swirl tower is that when the exhaust gas enters the tower from the side, and rotates upward in the tower, the smoke is spun onto the wall by centrifugal action, and at the same time, the smoke is soaked by water spray, using gravity to knock it down. This process can effectively remove most of the larger particles of soot.

The centrifugal defogging machine is to remove the water mist released by the spray swirl tower and remove the dust left behind. With the help of the centrifugal turntable, the water mist and the dust left behind can be removed through multiple centrifugal forces.

The electrostatic precipitator is to ensure that the subsequent equipment removes odor, and the dust is treated to 95% or more, and then install the electrostatic precipitator after the centrifugal defogging machine. Through the effect of discharge, the dust is charged, and then adsorbed by the electrode, and finally removed.

The plasma photocatalytic machine is that the irritating taste of asphalt is mainly due to the secondary chemical taste of various organic compounds, and the structure of organic compounds must be destroyed if you want to remove these irritating tastes.

Photocatalysis is mainly the use of ultraviolet light, direct irradiation on the catalyst, the formation of active free radicals, when the waste gas through the photocatalytic equipment, it will be strong ultraviolet light to decompose, at the same time, by the active free radical oxidation, and cut off the chemical bond in the waste gas, and then be decomposed.

Through photocatalytic treatment, various organic compounds in the exhaust gas are not completely decomposed, and directly enter the plasma process. The electric field generated by the plasma through the high voltage discharge has huge energy and strong free radical oxidation. When the exhaust gas passes through the plasma equipment, various organic compounds in the exhaust gas will be completely broken down and decomposed into odorless and harmless substances, which are discharged to the standard. The plasma photocatalysis technology has a processing flow rate of up to 25,000 m3/h per hour.

When purchasing asphalt mixing station, you would better choose a strong and experienced manufacturer whose station is equipped with environmentally equipment to minimize air pollution. 

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