In actual working conditions, it is often impossible to achieve emission requirements by adopting a single treatment facility. Therefore, two or more types of treatment facilities need to be combined to achieve higher and better governance effects. In addition, the exhaust gas generated in the actual working conditions, except for VOCs, may also containing "impurities" such as dust, water vapor, oil, etc., and even some of the exhaust gas also contains physical factors such as high temperature, so in the process of treating exhaust gas, it is necessary to know the nature of the exhaust gas. After clear understanding, the pretreatment process is selected to reduce the processing load of subsequent governance facilities, thus improving the governance efficiency.

Common pretreatment methods:

Washing tower includes water washing tower, chemical washing tower, chemical oxidation tower, etc.;

Dust collector includes bag filter, electrostatic precipitator, Shakron (ie cyclone dust collector), junior, middle and high-grade filter, etc.;

Fume purifier includes electrostatic fume purifiers and high efficiency filters, etc.;

Cooling facilities includes heat exchangers, air conditioning, and so on.