On the whole, the organic waste gas treatment method should be based on the following factors: the types of organic pollutants, the concentration level of organic pollutants, the exhaust temperature of the organic waste gas, the discharge flow of organic waste gas, the level of particulate emission, and the control level of the pollutants to be reached.
1.Waste gas treatment of spray paint at normal temperature
From the introduction of the "source and characteristics of spraying waste gas" above, we can see that the exhaust gases from the paint room, the airing room, the lacquer room, the surface paint sewage treatment are low concentration and large discharge at normal temperature, and the concentration of these exhaust gases is generally within the limit of discharge. The way to remove the high altitude. Although this method can meet current emission standards, the waste gas is in essence untreated dilution, and the total amount of gas pollutants discharged by a large body spray line per year may be as high as hundreds of tons, and the harm to the atmosphere is very serious. It In order to reduce the emission of exhaust pollutants in essence, especially for the exhaust gas at normal temperature, which is not up to the standard itself, it can be combined with several waste gas treatment methods, but the cost of waste gas treatment is very high. At present, the more mature methods are as follows: the organic waste gas is concentrated to reduce the total amount of organic waste gas to be treated. The total amount is 15 times concentrated by adsorption and desorption wheel, and then the concentrated waste gas is treated by destructive treatment. There are similar methods in China. First, adsorption method (active carbon or zeolite as adsorbent) is used to adsorb low concentration ambient temperature spray exhaust gas, and high temperature gas is desorbed. The concentrated exhaust gas is treated by catalytic combustion or heat storage thermal combustion.
2.Drying waste gas treatment
The exhaust gas from drying is a medium high concentration high temperature exhaust gas, which is suitable for combustion. Combustion reaction has three important parameters: time, temperature and disturbance, that is, combustion 3T condition. The efficiency of waste gas treatment is essentially the degree of combustion reaction, which depends on the 3T condition control of combustion reaction. RTO can control the combustion temperature from 820 to 900, stay (1 to 1.2) seconds, and ensure the necessary disturbance (full mixing of air and organic matter), the treatment efficiency of the organic waste gas can reach 99%, and the waste heat recovery rate is high and the energy consumption is low. Most Japanese automobile factories in Japan and China usually use RTO to concentrate on drying (primer, middle coat and top coat). For example, Dongfeng Nissan Passenger Vehicle Co Huadu spray line, using RTO centralized treatment spray drying exhaust gas, the effect is very good, can fully meet the emission regulation requirements. However, due to the high disposable investment of RTO waste gas treatment equipment, it is not economical to treat waste gas with less exhaust gas flow.