A new, high-efficiency drying oven enables Troldtekt to dry its acoustic panels considerably faster and with a significantly lower energy consumption than previously. This benefits both the environment and the company’s bottom line.
Every single one of the several million acoustic panels which Troldtekt produces each year has passed through the drying oven before leaving the factory. The drying oven accounts for a significant part of the company’s energy consumption. Therefore, Troldtekt paid a lot of attention to lifespan, capacity and energy efficiency when the old drying oven needed replacing.
– The old oven was unable to keep up with demand, and had become a bottleneck. Because of the financial and environmental benefits, it made sense for us to consider energy optimisations as soon as it became clear that we had to invest in a new oven, says Orla Jepsen, factory manager.
Effective drying air
Troldtekt contacted several potential suppliers to find the best possible solution for the new oven. Via Nicholaisen A/S, Troldtekt was put in touch with the German oven manufacturer Venjakob, who thought that a new drying method could realise significant benefits in relation to both drying time and energy consumption.
– In the old oven, the panels were conveyed past a row of nozzles which blew hot air down onto the panel surface. Venjakob suggested that instead of heating the surface, it would be more effective to instead blow air across and through the panels, and in that way remove more moisture. Their calculations indicated that a panel could dry far faster while at the same time only using half the energy per panel, says Orla Jepsen.
Troldtekt and Venjakob decided to jointly test whether the new method worked as assumed. First a mini-oven was built in Germany, which showed promising results. Then a full-scale oven was built at the supplier in order to test the method.
– The complete drying oven consists of ten individual units, which each cost more than DKK 1 million. So we had to be absolutely sure that the oven lived up to our requirements specification before we ordered the other nine. We were in close dialogue with the supplier throughout the whole process. And their technicians paid regular visits to Troldhede. DONG Energy was also involved as a climate partner, and they provided advice and produced calculations of energy subsidies, says Orla Jepsen.