HIGH-INTENSITY INFRARED DRYING STUDY .1. CASE OF CAPILLARY-POROUS MATERIAL

Experiments involving the drying of a thin horizontal unconsolidated w et sand layer under intensive infrared radiation (IR) have been perfor med in a laboratory-scale dryer. The drying rates and solid temperatur e data were much higher than in conventional convective processes. Cou pled heat and mass-transfer phenomena have also been analyzed. It was observed that medium-infrared radiation (medium-IR) was more efficient than near-infrared radiation (near-IR) and that the analogy between h eat and mass transfer is still valid in the case of high mass fluxes. A simple receding model based on the assumption that IR radiation is a bsorbed at the surface of the product could predict the drying rates a nd the temperature profiles up to the zero moisture content. The exper imentally determined parameters of the main model were the mass transf er and infrared absorption coefficients.