AirwashTM exhaust air purification systemEcoplants
Meet AirwashTM, our brand-new system for cleaning the exhaust air from aluminum cold rolling mills. It helps you protect the atmosphere and reduce operating costs by recovering rolling oil for recycling.
During aluminum cold rolling, some of the rolling oil evaporates. Most of it escapes in gaseous form, although droplets also occur. Unlike mechanical filters, which only trap droplets, our AirwashTM filters also separate gaseous particles out of the air.
This is how it works: first, the exhaust air purification system sucks in the exhaust air containing rolling oil. Then it channels the air into the absorption column. Next, the waste air flows from the bottom to the top through separation packings. Here, a washing oil such as AirwashTM Oil 300 from SMS Lubrication trickles downwards in a countercurrent. That ensures the washing oil absorbs the rolling oil. Now purified, the exhaust air escapes into the atmosphere through the stack. Meanwhile, the particle- laden washing oil is collected and treated in the downstream rectifying column. There the oil, which has a low boiling point, evaporates. Finally, it’s condensed, captured in distillate form, and fed back into the oil circulation system.
AirwashTM is proving so effective and successful that already 24 customers worldwide use the system. One of them is Yunnan Aluminum, based in China. We supplied an aluminum cold rolling plant to this customer in 2010. The integrated AirwashTM system handles an exhaust volume of 120,000 m3/h.
It also meets high environmental protection requirements. The result is clean air, recovered rolling oil for the rolling process, and treated washing oil. Plus: the washing oil is used again to clean more exhaust air. This state-of-the-art technology filters between 150 and 400 kg of rolling oil per hour from the exhaust air, depending on the plant type.
Moreover, AirwashTM is easy to retrofit, so the solution is ideal for upgrading existing rolling mills. Best of all: you can expect a return on investment within just a few years.