Previously, the hood elements had been designed as a riveted structure. Over the years, the 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 replaced the hood elements of the wall and ceiling, using the modular, rivet-free hood elements from the EcoHood dryer section hood. 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 that 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 EUR 725 million, produces more than 500,000 metric tpy of paper, and employs around 1,700 people.
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