1.1 Technical Background
The painting process is widely used in machinery, electrical equipment, household appliances, automobiles, ships, furniture and other industries. Spray paint exhaust gas is mainly composed of volatile solvents, thinner molecules and non-volatile paint mist molecules. Paints have complex solvent or thinner mixtures. Due to the small paint mist particles, high viscosity, and easy adhesion to the surface of substances, especially when activated carbon is used to absorb and recover organic solvents, paint mist particles can easily block the pores of activated carbon, which affects the adsorption efficiency and service life of activated carbon. This process adopts multi-channel paint mist filtration, and then performs activated carbon adsorption/desorption to achieve the purpose of organic solvent recovery.

1.2 Process flow


1.3 Process description
The organic waste gas containing paint mist emitted from the painting production line is initially filtered through the organic solvent waste gas pipe connected to the paper filter, and the organic waste gas containing paint mist is separated and captured from the gas by the cyclone dust collector to remove a part Low-viscosity paint powder air-dried in the paper filter at the initial stage; the organic waste gas from the initial paint mist removal enters the bag filter for high-efficiency dust removal, and the paint powder is discharged by opening the bottom plate of the bag filter; the organic solvent waste gas is then discharged by high pressure The centrifugal fan is sent into the adsorption tank, and the organic solvent waste gas enters the activated carbon adsorption layer. The organic solvent content of the purified gas after adsorption meets the emission standard requirements, and is directly discharged into the atmosphere from the exhaust port of the adsorption tank; at least 2 adsorption tanks are used for adsorption. They are all switched from the desorption regeneration tank, so the time for each adsorption tank to absorb organic solvents is different, and there is a time difference in the time to reach saturation. The adsorption tank that reaches saturation first switches to the desorption regeneration tank, and the other desorption regeneration process The tank is then switched to the adsorption tank, which is serially connected and dried, and then adsorbed in parallel with other adsorption tanks. The mutual switching of adsorption and desorption is automatically completed by the control system settings. Such mutual switching ensures the continuity of system operation. The desorption regeneration uses water vapor as the medium, and is carried out by passing water vapor into the desorption regeneration tank; the desorbed organic solvent vapor and water vapor enter the condenser to be cooled into a liquid state, and finally sent to the oil-water separator to utilize the organic solvent and water. The difference in specific gravity carries out the separation of organic solvents and water.

1.4 Product Features
This technology overcomes the shortcomings of the traditional process. It uses a paper filter to pre-dry the paint mist and filter the paint powder, and then uses a cyclone dust collector to pre-dedust and further air-dry the paint mist to form powder particles. Finally, it is processed by a bag filter. Efficiently removes paint powder after air drying. Due to the pre-air-drying of the paper filter, it is avoided that the highly viscous paint mist adheres to the inner wall of the cyclone dust collector, which affects the effect of cyclone dust removal. In addition, the pre-dust removal and further air-drying of the cyclone dust collector reduces the load of bag dust removal. The air-dried paint powder has no stickiness, and the bag filter is easy to remove dust. Therefore, this technology has the characteristics of reasonable and compact process connection and high dust removal efficiency.

1.5 Technical indicators

Product use: recyclable.

1.6 Desorption method
Water vapor desorption, nitrogen desorption, vacuum desorption, nitrogen + vacuum desorption

1.7 Main Patents
201310234348.2 A device and method for recycling organic solvents from spray paint waste gas
201410368655.4 Purification device and method for organic waste gas from container painting
201110311140.7 Waste gas recovery device for spray paint organic solvent and organic solvent recovery method
201220539019.X Activated carbon series adsorption and vacuum desorption recovery organic solvent waste gas device
201320442573.0 Organic solvent recovery device using nitrogen desorption