The harm caused by painting is very great, especially the exhaust gas of paint wire has the characteristics of large air volume and low concentration, especially for automatic painting wire. The smell of lacquer contains benzene, toluene, xylene and so on. These VOC have a great impact on the surrounding environment. What should we do with waste gases such as painting? We need to treat the waste gas in the paint room. We need to know what kind of substances are contained in this kind of waste gas. Generally speaking, the exhaust gas emitted from the painting process of the painting room contains three main harmful substances:
1. Oil-based paint: water drops carrying paint particles; paint paint: the water droplets of the paint are dissolved;
2. The paint particles in the waste gas are sprayed separately in the air;
3. The odor of the raw material of the paint in the gasification state, the peculiar smell emitted by the diluent (the normal-temperature paint curing agent), And off-flavors released during the reaction and curing process.
It is known that the above three substances produced during the painting process of the paint spraying room can be solved in the waste gas treatment of the paint spraying room, and the three methods for treating the waste gas of the paint spraying room can be provided for reference:
1. The water spraying method for the waste gas treatment method of the paint spraying room is as follows: The invention relates to a pretreatment primary spraying with an indoor waste gas treatment, which is characterized in that the water is sprayed on the waste gas, and a part of the water-soluble or large-particle component in the waste gas of the paint spray room is settled down, so that the purpose of partial pollutant and clean gas separation is achieved. But some of the exhaust gas still has a water-soluble or large particulate component that is discharged from the top floor. The method is economical and applicable, but in the waste gas treatment of the painting room Can not remove all the paint fog, and cannot achieve the effect of removing odour;
2. Direct combustion method of waste gas treatment method in paint room: the mixed gas is heated to a certain temperature (700 ℃) for a certain time by using the heat released by auxiliary fuel combustion such as gas or fuel, so that the flammable harmful gas can be burned. The process is simple, the investment is low, but the energy consumption is large and the operation cost is high. However, this method is suitable for the treatment of high concentration and small air volume paint room waste gas, but it is not suitable for most of the multi-volume low concentration and large air volume paint room waste gas treatment.
3. the uv lamp tube + plasma tube method of the waste gas treatment method of the paint spraying room: the waste gas in the paint spray room in the workshop is pumped by the fan and then enters the washing tower, the waste gas is sprayed and washed by the washing tower, and the main function is to remove the dust and the large paint mist particles, And has certain physical dissolution and masking effect. The circulating water in the spray tower is communicated with the circulating water tank, and the paint on the surface of the water surface can be periodically removed. After the waste gas is treated by the spraying and washing tower, the waste gas enters into the uv photolysis equipment, and the uv photolysis equipment is provided with a photolysis lamp tube and a plasma tube. the uv photolysis tube and the plasma tube are used for the treatment of the waste gas and the treatment of the organic waste gas, and the VOC The treatment of S-gas is an effective treatment, and the effect is very good.Uv photolysis lamp mainly uses special low voltage ultraviolet lamp to emit the bispectral characteristics of 185nm ultraviolet and 254nm ultraviolet at the same time. The 185nm ultraviolet light emitted by the lamp can trigger O _ 2 (oxygen) in the air and convert it into O _ 3 (ozone). Ozone has a strong oxidation ability. After it is fully mixed with hydrocarbons (such as benzene, hydrocarbons, alcohols, lipids, etc.) in the waste gas of paint room, these harmful pollutants can be directly oxidized and decomposed into water and carbon dioxide under the condition of ultraviolet radiation catalysis of 254nm emitted by lamp.