Powder Technology, Vol.83, No.2, 139-148, 1995
Pneumatic Drying - The Use of Large-Scale Experimental-Data in a Design Procedure
A pneumatic powder-dryer can be used for flash evaporation of surface moisture, where heat transfer dominates the drying phenomenon. Experimental data obtained in several industrial dryers were analyzed and fitted by the correlation Nu=0.15Re(p). The design of pneumatic dryers was thereafter determined by following a strategy using basic powder/gas characteristics, drying thermodynamics and hydrodynamics. A stepwise calculation using the predicted heat transfer coefficient of the above equation predicts moisture and temperature profiles in the pneumatic dryer. The shape of the data fitting is very good. The calculation procedure moreover enables calculation of the required length of the drying path.