Paintshop will make a big amount of waste air during operation. Based the current paint spraying technologies, the maximum paint application rate is about 60%. That means at least 40% paint will be extracted. If the paint booth provides up to 90% filtration capacity and save the solid particles inside booth tank, rest 10% is still hazard if we blow into atmosphere directly. Especially when the factory is close to a residential area, there’re very strict extraction standards. Thus a proper treatmen solution is required for any paint shop construction.
Waste paint air treatment or filtration is a complex system based the construction standards. Generally there’re following stages for a complete clean filtration: water filtration – carbon filtration – VOC treatment – flame treatment.
Water filtration – The primary and basic filtration device which happens at the very first stage for paint spraying. When the paint booth is water curtain production, it provides primary filtration then the rest air will flow to secondary filtration device which is also water based. Here the solid paint particles will be greatly collected under votex air flow and PP ball vibration. In early ages, it is already good enough as the hazard extraction already very low.
Carbon filtration – It’s connected directly after water filtration device. The purpose is to reduce the air humidity grade and solvent smell absorption. Inside this filtration unit, there’re multi layers of active carbon. When the exhaust fan blowing, air flow will pass through each carbon layer for proper filtration.
VOC treatment – VOC is short of “volatile organic compounds“. Under the action of high-energy ultraviolet rays in the wavelength range of 170nm-184.9nm (704kJ/mol-647kJ/mol), oxygen in the air is cracked and converted to ozone; on the other hand, the chemical bonds of the malodorous gas are broken to form a free state at atom level. At the same time, the generated ozone participates in the reaction process, so that the malodorous gas is finally cracked and oxidized to form simple and stable compounds, such as CO2, H2O, SO2, NO, etc.
Flame treatment – As the name tells, it’s direct burning over the waste air. It’s normally set at the last stage of treatment system. The unit has a combustion furnace and a fume exhaust furnace, a waste gas introduction mechanism and a heat exchange mechanism.
This burning device is normally constructed by tower like platform which is followed by strict standards. As there’re natural gas piping and ignition, it’s also a high temperature operation, so the safety protection must be high to avoid any potential injury.
Above is the list of existing solutions of paintshop waste air treatment. Generally, we need at least one or two above solutions for a basic paint shop construction and reduce the hazard extraction to atmosphere as much as possible.
