An experimental study of the drying of granular materials in a packed bed passed by hot air. The local humidity of the material

With the purpose of establishing the mechanism responsible for the drying of granular materials in a packed bed passed by a gaseous thermic agent, experimental kinetic study was performed. In a pilot plant, the axial and radial distributions of the local humidity were determined in the non-steady regime. The results show that it is possible for three zones, each at a different state of dryness, to exist in the bed: one zone with initial humidity, one zone with variable humidity and one zone with dried material.