Automotive Paint Room Exhaust Gas Treatment Method

Automotive paint room exhaust gas treatment method

The harmful gases in the painting process of automotive paint booths are mainly organic compounds such as benzene series and non-methane total hydrocarbons. Their chemical compositions are complex, and the raw materials of the products are different. The composition and concentration are different. The processing methods are numerous and have different characteristics. Commonly used adsorption method water spray method, condensation recovery method, absorption method, combustion method, catalytic method and so on.

Adsorption method: (1) Direct adsorption method: The organic gas directly passes through activated carbon particles or activated carbon filter cotton, and can achieve a purification rate of 95%. The equipment is simple, the investment is small, and the operation is convenient, but the activated carbon needs to be frequently replaced for low concentration and pollution. (2) Adsorption recovery method: The organic gas is adsorbed on activated carbon, and after activated carbon is saturated, it is desorption and regeneration with hot air.

Water spray method: The water spray process has a wide range of applications in air pollution treatment and has also been used in the spraying process. For example, a water curtain cabinet is one example. The principle is to spray water on the exhaust gas to make the water soluble in the exhaust gas or The large particle components settle down to achieve the purpose of separation of pollutants and clean gas. Its advantages are that water resources are readily available, and that it can be reused after filtration and precipitation to minimize the waste of water resources. Water spray is used to treat large particles. Has a very high efficiency, often as a pretreatment of exhaust gas treatment.

Condensate recovery method: Directly condenses or condenses after condensing the exhaust gas. The condensate is separated to recover valuable organic matter. This method is used for high concentration, low temperature, and small amount of exhaust gas treatment. However, this method has large investment and high energy consumption. Operating costs are large, so there is no special need, and this method is generally not used.

Absorption: can be divided into chemical absorption and physical absorption, but "triphenyl" exhaust gas has low chemical activity and generally does not use chemical absorption. Physical absorption is to use a liquid absorbent with a small volatility, and it has a High affinity, after absorption saturated, heated and analyzed, cooled and reused. This method is used for exhaust gas with low atmospheric temperature, low temperature, and low concentration. The device is complex, the investment is large, the selection of absorption liquid is difficult, and there is secondary pollution.

Direct combustion method: Heat the gas mixture to a certain temperature (700-800°C) by using the heat released from combustion of auxiliary fuel such as gas or fuel, and stay for a certain time to burn flammable harmful gases. This method is simple and the equipment investment is low. , but it has high energy consumption and high operating costs.

Catalytic combustion method: The exhaust gas is heated to 200~300°C and then burned through a catalytic bed to achieve the purpose of purification. The method has low energy consumption, high purification rate, no secondary pollution, simple and easy operation, and is suitable for the treatment of high-temperature and high-concentration organic waste gas. Does not apply to low concentration, high volume of organic waste gas treatment.