In this work possible energy savings were investigated by introducing a new layout of a 2-zone progressive kiln. The layout consisted of installing a door between the first and second zone, thereby allowing the two zones to be run at different temperature levels -making internal heat recovery possible. An Optimized Two Stage continuous kiln is dimensioned for drying sideboard of Norway spruce (Picea abies L. Karst) with the aid of a commercial simulation program. Temperature levels of 75/55°C (dry bulb/wet bulb) were chosen at the pressure side of zone 1 and 45/25°C (dry bulb/wet bulb) at the pressure side of zone 2. The capacity of the heat exchanger was assumed to be sufficient to make the suggested design functional and no consideration was given to the increased air flow resistance the introduction of the heat exchanger would cause. The results indicated that roughly 30% of the heat is possible to recover in comparison to a traditional kiln. It was finally concluded that the influence of ingoing process parameters needs to be implemented in the kiln control system to fully utilize the kilns potential.
Validerad; 2016; Nivå 1; 20151214 (tomvik)