The acid mist purification system adopts exhaust ventilation method to control the diffusion of air pollutants in the production plant. The system usually consists of local gas collecting hood, purification device, air duct, ventilator and chimney. The purification device adopts different treatment methods and devices according to different treatment objects (such as dusty gas, harmful gas in the sea,} warm flue gas, flammable and explosive gas, etc.): at present, the commonly used gas purification methods include condensation method, combustion method, adsorption method, absorption method, etc. There is no gas at local pollution sources, It is the most effective and commonly used method to control air pollution during production after purification treatment and then discharged to the outside or high altitude