During the actual operation period of mechanical production enterprises, that is, in the daily production process, most of them will produce paint exhaust gas such as polishing dust, silane waste gas, electrophoresis waste gas, drying waste gas, and strong cold waste gas. How is it governed? It should be implemented according to the specific assessment of the EIA unit and the actual and EIA requirements.
The specific requirements need to be based on the "Chengdu 2023 Air Pollution Prevention and Control Work Action Plan", and the construction unit should meet the "Technical Guidelines for the Formulation of Emergency Emission Reduction Measures for Key Industries in Heavy Pollution Hot Spot Engine Plan (2020 Revised Edition)".
Ten. 9. Industrial coating "B-level enterprise performance grading index. 
Let's give an example of the exhaust gas generation and specific treatment measures of general machinery manufacturers.
VOCs Pollution Control Facility Requirements:
1. Spraying exhaust gas is provided with dry limestone, carton or wet venturi and other high-efficiency paint mist treatment devices;
2. When using solvent-based coatings, the VOCs-containing waste gas in the processes of paint mixing, painting, leveling, drying, and cleaning adopts adsorption concentration + combustion, combustion and other treatment technologies, with a treatment efficiency of 85%;
3. When using water-based coatings (water-containing UV), when the initial emission rate of NMHC in the exhaust of the workshop or production facility is 2 kg h, the terminal pollution control facility will be constructed. Note: Powder coating or VOCs content is used.
Waste gas generation and treatment measures:
1) Welding fume and polishing dust - Generally, a gas collection hood is set up at the station to collect polishing dust, and the welding fume generated by the corresponding welding line enters the filter cartridge dust collector for treatment and is discharged from the exhaust cylinder.
2) Silane exhaust gas - the silane process of the electrophoresis line produces hydrogen fluoride, the silane station of each electrophoresis line is set up with a gas collection hood, and the exhaust gas is collected by the gas collection hood and discharged from the exhaust cylinder after being treated by a set of water spray devices.
3) Electrophoresis exhaust gas, drying exhaust gas, strong cold waste gas - the exhaust gas generated by electrophoresis and drying is generally discharged through the exhaust cylinder after being treated by the "spray + secondary active carbon" device.
4) Waste gas of sewage treatment station - most of the sewage treatment facilities are sealed with a cover plate, and the air inlet and outlet are reserved on the cover plate, and the foul odor generated by the biochemical treatment tank can be collected through the exhaust pipe and entered the alkali absorption device for treatment, and then discharged from the exhaust cylinder.
The above are the common waste gases and treatment measures generated by machinery manufacturers in the production process. For example, electrophoresis uses water-based paint, and the electrophoresis exhaust gas and drying exhaust gas generated are basically collected through the exhaust system and sent to the "spray + secondary activated carbon" device for treatment, which can meet the requirements of the EIA.
For the later exhaust gas detection, according to the "Technical Specifications for the Application and Issuance of Pollutant Discharge Permits for Automobile Manufacturing Industry" (HJ 971-2018), the "Technical Guidelines for Self-monitoring of Pollutant Discharge Units" (HJ 1086-2020), and the "General Principles of Technical Guidelines for Self-monitoring of Pollutant Discharge Units" (HJ819-2017), the monitoring plan for exhaust gas pollution sources in the production and operation stage of the project is proposed.