Clever modernization of an RTO system
New from old: Modernization of air pollution control system for coating industry doubles the exhaust air capacity
As air pollution control systems age, the question arises of whether to replace them or modernize them. For a particularly well-thought-out solution, one of Europe’s leading beverage can manufacturers turned to plant engineering company Dürr. Ball Beverage Packaging has extended the air pollution control capacity of its plant in Gelsenkirchen, Germany, by relocating an existing system from another site where it was no longer required and scaling it up with just a few new components.
A move is always challenging, and even more so when the item in question is a complete regenerative thermal oxidizer (→ RTO) air pollution control system with three towers rated for 75,000 m³/h of exhaust air and a weight of 60 metric tons. However, it was all worth it: by reusing the existing components, Ball Beverage Packaging ended up with a modern five-tower system for a total of 110,000 m³/h of exhaust air. The costs are much lower than for an equivalent new system. And on top of this, the beverage can manufacturer still has a capacity buffer for the future.
As in many industrial processes, the manufacture of beverage cans produces solvent-laden exhaust air. The cans made from metal are coated on the inside and the outside. The majority of the solvents contained in the coatings are emitted with the exhaust air when the coatings are cured in the hot air dryer. Ball operated regenerative thermal oxidizers (RTO) at its two sites in Gelsenkirchen and Recklinghausen, both in Germany. This highly sustainable technology oxidizes the organic pollutants almost completely. What’s more, RTO systems require much less primary energy than other air pollution control methods since over 95% of the energy consumed is recovered in the internal heat exchange media and the energy contained in the hot exhaust gases is used to preheat the exhaust air. The systems work autothermally above a pollutant concentration of approx. 1.5 g/Nm3, in other words no external fuel is required to operate the system.
A system modernization of this kind really pays off for clients. They can save up to a third of the costs they would otherwise have to pay for a new system.
Rolf Schäfer, Project Manager, Dürr Systems AG
The air pollution control system in the Recklinghausen plant had only been in operation for four years when Ball decided to vacate the site and instead significantly expand the Gelsenkirchen site. However, the system used there for air pollution control was a very old RTO system that was not energy efficient. Dürr was assigned to develop a concept for extending the existing three-tower system by another two towers, and to act as general contractor for the project. This included dismantling the existing system in Recklinghausen, organizing the transport, assembling the old parts and new components for the expansion, installing a new control system with adapted safety technology, putting the modernized RTO into operation at the new site in Gelsenkirchen, and setting it up as required for production there.
The concept realized at Ball Beverage Packaging includes a lot of detailed engineering aimed at ensuring that the two new tower elements, including associated combustion chamber parts, fit seamlessly into the existing system.
“Any system expansion starts with the existing system, and everything needs to be oriented towards it. Let’s look at the example of the inflow to the pipelines: the existing diameters were too small for the new capacity requirements, and structurally could not be enlarged either. So we designed an alternative and now have inflow coming from two ends,” explains Rolf Schäfer.
A particular challenge was the tight schedule as well as an extremely short manufacturing shutdown of just two days for the necessary reconnection, where the RTO at the new site in Gelsenkirchen was connected to the existing pipeline system. Ball Beverage Packaging is pleased with the new air pollution control system, which has been in use in Gelsenkirchen since May 2019.
The system went into operation without any complications, and has been running very reliably since then.
Ilja Hober, Project Manager, Ball Beverage Packaging
Assembly of the Ecopure® RTO with a combination of existing and new components.