In Kumera Drum Dryers using the direct heating principle, heat is transferred to the material almost entirely by convection.
The drum dryer size depends on the amount of water to be evaporated, the amount of the product and its final moisture content. All three depend greatly on the material and drying purpose.
The volume needed for drying different products varies in practice between 10 and 60 m3/t H2O/h. The drum size also depends on the direction of the drying gas flow in relation to the product flow. Both concurrent and countercurrent drum dryers are produced. The countercurrent dryer is more effective and economical because the temperature difference between the drying gas and product stays relatively high throughout the drying process. The use of countercurrent dryers is restricted by the inflammability of the product and its behaviour at high temperatures. A countercurrent dryer is 20 to 30% smaller than a cocurrent dryer used for the same purpose.
KUMERA TECHNOLOGY CENTER (KTC) FI-11100 Riihimäki
Tel: +358 20 755 4200