Hood refurbishing provides for energy-efficient operation
Voith replaced the hood roof and the hood side walls of the PM 4 at the August Koehler SE paper mill in Oberkirch, Germany, and thus facilitated an energy-efficient operation of dryer section and heat recovery.
Previously, the hood elements had still been designed as a riveted structure. Over the years, these rivets loosened due to the heating and cooling of the hood. Moisture thus penetrated into the insulation. The insulation effect of the elements weakened, causing condensation during operation of the dryer section with a high exhaust air dew point. However, a high exhaust air dew point is a precondition for energy-efficient operation of the dryer section and for a high level of performance for heat recovery from the dryer section exhaust air.
Voith therefore replaced the hood elements of the wall and ceiling. The proven modular rivet-free hood elements from the EcoHood dryer section hood were used. They were mounted on the existing steel substructure together with new seals. The hood can thus be operated condensation-free with a high exhaust air dew point. The August Koehler paper mill confirms: the dryer section and heat recovery are again working in an energy-efficient manner.
The Koehler Group produces paper and board at four locations in Germany. The company generates sales of 725 million euros, produces more than 500,000 metric tons of paper annually and employs around 1,700 people.