In the organic waste gas treatment system, the use of circulating air method in the spray room can reduce the exhaust air volume of the spray room, thereby reducing the operation energy consumption of the organic waste gas treatment system. In addition, the use of RTO equipment or TNV equipment for the heat recovery and utilization of the flash drying room and the waste gas incineration treatment equipment, and the heat recovery and utilization of organic waste gas can reduce the energy consumption of organic waste gas treatment and achieve the purpose of environmental protection and energy saving.

Auto painting production line paint booth

1. The spraying room adopts the circulating air method

In my country's traditional spraying production workshops, wet spray booths (Venturi or water cyclone) + new upgraded exhaust methods are mostly used, that is, the air source selected for the spray booth is clean and fresh air, the central air-conditioning ventilation is one-time, and the exhaust has been exhausted. It is not recycled. For 3C1B and its B1B2 processing technology, the spray booth is long, and the exhaust air volume to be solved is large, so the operation consumes a lot of energy.

When the spraying workshop is under construction, the spraying room can choose the circulating system air supply air. In the industrial workshop with manual hand repair and painting stations, a part of the circulating system air can be used for air supply, and the manual painting section and hand repair section will be exhausted. To the intelligent robot painting section, and its varnish (finish) leveling section, reduce the air supply of the fresh air system; if it is fully automatic robot electrostatic powder spraying, all the air supply methods of the circulating system can be used, that is, the intelligent robot painting section. In addition to the circulating system air returned from the leveling, paint-finishing section and air-sealing section, the exhaust air also includes the exhaust system of the spraying section. Among them, the exhaust system circulation solution includes two methods: dry test cycle solution and wet test cycle solution. The moisture content of the gas discharged from the pre-painting preparation section, air curtain, drying room, etc. is not high, and it can be circulated only by filtration. The system application, or the exhaust system of the spray booth solved by the dry test paint mist collection equipment, because its cleanliness level (0.3Mg/m3) has been qualified, it can be directly recycled, which is called dry cycle;

Auto painting production line paint booth

However, the moisture content of the spray booth solved by the wet test (hand-washing) paint mist collection equipment is enlarged, and it can be recycled after dehumidification and temperature control, which is called the wet test cycle; whether it is a dry test cycle or a wet test cycle, Both can only remove paint mist and fine particles in the exhaust system, and VOC can hardly be removed. Therefore, it is necessary to strictly control the VOC components in the spraying work fixtures, that is, in manual service spraying fixtures, VOC components should be controlled in national defense and security. Within the scope of the sanitation permit specification, in the automatic spraying area (unmanned area), it should be controlled below the fire safety concentration value (that is, below 25% of the lower limit concentration value of flammable gas explosion).

2. Application of organic waste gas in flash drying room

For the production workshop of water-based paint spraying, the color paint is generally water-based paint. After spraying, it needs to enter the water vapor drying furnace for baking. The general temperature will be around 80 °C. Gas is used as mechanical energy to heat the gas. The organic waste gas is generally discharged directly into the air. With the improvement of laws and regulations management system at the level of ecological and environmental protection in my country, clear requirements have been made for VOC components in industrial waste gas. Therefore, the organic waste gas caused by water vapor drying furnace also needs to be incinerated in a centralized manner. If the organic waste gas is immediately sent to the organic waste gas incineration treatment system software for ignition, the VOC concentration value included in the organic waste gas is low, the exhaust air volume to be solved is large, and the gas consumption is large; The exhaust gas is closely combined, and the temperature of the organic exhaust gas after mixing is high, which can easily lead to the loss of the efficiency of the extraction drum. In order to avoid reducing the normal service life of the runner, the heat generated by the organic waste gas discharged from the flash drying room is generally used for the heating solution of the fresh air system.

Auto painting production line paint booth

Under normal circumstances, the temperature of the industrial waste gas in the flash drying room is around 80°C, and it conducts heat transfer with the flash drying fresh air system according to the plate heat exchanger, which promotes the specific temperature of the fresh air system to rise by around 25°C, thereby maintaining the energy consumption. Acquisition and Reasonable Use. In the whole process here, the temperature of the industrial waste gas that has been replaced and tempered is about 50 °C, and it is mixed with the organic waste gas of the paint spraying room, which always promotes the temperature of the organic waste gas to obtain a small temperature rise, which is not easy. Hazardous drum solution is highly efficient. This kind of method can not only cause the temperature of the flash-dried organic waste gas to drop sharply, but also reasonably reduce the composition of water vapor, so as to avoid the adverse effects of the organic waste gas on the normal service life of the drum under the condition of high ambient humidity.

3. Application of heat generation of organic waste gas after incineration

The more common organic waste gas incineration treatment equipment has two kinds of RTO and TAR, all of which are based on high temperature to ignite and dissolve the VOC in the organic waste gas, and then generate carbon dioxide and water, and finally produce clean gas and then discharge it out. However, due to the difference in the structure types of RT O and TA R machines, the temperature of the sewage at the entrance and exit of the two is different. The TAR temperature reaches around 560°C. It must be emphasized that TA R is a very important part of T N V machinery and equipment. It is composed of engine combustion chamber, heat exchanger, burner and main exhaust flue regulating valve. The smoke and dust discharged from sewage can be incinerated. The organic waste gas in the room is heated and heated, and the fresh air system entering the air drying room is also heated.

Picture car painting production line spray booth

On the basis of the official use of organic waste gas treatment equipment, the high-temperature gas of 110 ° C ~ 130 ° C that is discharged by RT O, in most of the production workshops, the gas pollution is carried out according to a very immediate method. If this type of gas is used The heat exchanger is used to carry out the heating solution, and the heat exchanger will also generate organic matter for a long time, which will cause certain harm to the overall operation efficiency of the heat exchanger. For this matter, this kind of gas is generally sent to the paint slag solution area according to the pipeline, and the paint slag is air-dried according to the waste heat recovery, and the water content of the paint slag is reduced to the minimum level as much as possible, so that the paint slag can be removed. Solve the cost control in very few cases.