Generally, the spray painting operation in the auto repair industry is discontinuous. Due to the characteristics of the industry, the spray painting is generally used to repair parts of the vehicle, and spray painting and drying are mostly integrated. This determines that the exhaust emissions of spray paint spraying in the auto repair industry have the following characteristics:
、油性漆和水性漆混合使用，按照环保部门源头治理的要求以及漆的种类不断丰富，水性漆被应用到越来越多的环节，传统的油漆逐步被替代。 1. Mixed use of oil-based paints and water-based paints, in accordance with the requirements of the source control of the environmental protection department and the variety of paints, water-based paints are applied to more and more links, and traditional paints are gradually replaced. However, because water-based paint is not mature enough, it can only be partially applied in the short term, and it is increasing year by year, and it cannot completely replace oil-based paint. Therefore, in this context, it is more a mixture of two paints. Consideration must be given when considering VOCs governance processes.
、风量大、浓度低，汽车喷漆作业的特点对漆层表面气体流速要求较高，因此虽然喷漆量不大，但风量设置并不小，一般的喷漆房分为两种风量，一种是15000m3/h，另外的是25000m3/h。 2. The air volume is large and the concentration is low. The characteristics of automobile spray painting require high gas flow velocity on the surface of the paint layer. Therefore, although the spray volume is not large, the air volume setting is not small. The general spray booth is divided into two types of air volume. One is 15000m3 / h, the other is 25000m3 / h. The concentration is basically between 100-300mg / m3. According to the requirements of Beijing's emission standards, the concentration of non-methane total hydrocarbons should be <20mg / m3, which requires that the purification efficiency cannot be lower than 80%.
、场地有限、供电量不足，老的喷漆房的安装位置是固定的，随着时间的推移，车间的管路、物品和工具会把空间占满，很难有大的空间去布置和安装新设备；且电负荷一般在建厂之初就定了，后续扩容很麻烦。 3. The site is limited and the power supply is insufficient. The installation position of the old spray paint room is fixed. Over time, the pipes, articles and tools in the workshop will fill up the space, and it is difficult to arrange and install a large space. New equipment; and the electrical load is generally set at the beginning of the plant, and subsequent expansion is cumbersome. Therefore, when considering the installation of VOCs paint spraying exhaust gas treatment equipment, these factors should be considered as much as possible. It is an ideal and practical choice to replace the old equipment in the original location, and the energy consumption of the new equipment is as low as possible.
、需要良好的预处理，漆雾的处理是喷漆废气处理的重点和难点，漆雾去除效率如何直接关系到后续净化设备的效果和使用寿命。 4. Good pretreatment is required. The treatment of paint mist is the focus and difficulty of paint spray waste gas treatment. How the paint mist removal efficiency directly affects the effectiveness and service life of subsequent purification equipment. For the auto repair industry, because the amount of paint used is not large, three-stage filtration can be used.
、间歇式作业：通常是一辆车喷烤结束再换下一辆，底漆和面漆作业之间有时间间隔，换车空隙有时间间隔等，这些特征决定了废气排放的非连续性，表现在对净化设备的要求是即开即用。 5. Intermittent operation: usually one vehicle is spray-baked and then replaced with another. There is a time interval between the primer and topcoat operations, and there is a time interval between the car change intervals. These characteristics determine the discontinuity of exhaust emissions. , Expressed in the requirements for purification equipment is out of the box.
Benzene in spray paint and baking paint exhaust gas: Benzene, with the chemical formula of C6H6, is a colorless, slightly sweet, transparent liquid at ordinary temperature, and has a relatively strong aromatic taste. Benzene is flammable and toxic, a substance that can cause cancer. Benzene is also a type of hydrocarbon. It is the simplest type of aromatic hydrocarbon. It is difficult to dissolve in water, but it is easy to dissolve in some organic solvents, and it can also be regarded as an organic solvent. Benzene is a basic raw material of the petrochemical industry. Its production quantity and production skill level are important indicators of the development level of a country's petrochemical industry. The ring system that benzene has is called the benzene ring, and it is also the simplest of the aromatic rings.
Toluene in the exhaust of paint spraying and baking: Toluene is a colorless, very clear liquid with a bit of odor like benzene, has relatively strong refractive properties, and can be used with ethanol, ether, acetone, chloroform, carbon disulfide, and glacial acetic acid. Mixing and dissolving with each other, the characteristics of dissolving in water are very small. Toluene is an easily flammable liquid. Steam can produce explosive mixtures with air with a little irritation.
The components in spray paint and baking paint exhaust gas have certain complex characteristics, certain toxicity, and easy combustion and explosion. When treating, it is necessary to use high pressure fans to pump the spray exhaust gas into the swirl tower for treatment.
The deodorant uses plant extraction technology to extract effective ingredients from the roots, stems, leaves and flowers and fruits of various plants. It generates forces under the action of rays, improves the activity of plant liquids, and can rapidly polymerize with various harmful and odorous molecules. , Chemical reaction such as substitution, replacement, adsorption, etc., the product is neutral, and it is an environmentally friendly product that effectively removes exhaust gas, odor and odor. Put the deodorant into the circulating water of the spray tower. During the cycle, the deodorant reacts with the malodorous molecules to generate substances that are not harmful to the air. The waste gas treatment of the spray paint company is as simple as that.