Drying of suspensions in the draft tube spouted bed

A draft tube spouted bed dryer with inert particles was used for drying suspensions. The effects of the operating conditions on dryer throughput and product quality were investigated. Experiments were performed in a cylindrical column 215 mm in diameter with a draft tube 70 mm in diameter and 900 mm in length. The bed was made of polyethylene particles, 3.3 mm in diameter with a density of 921 kg/m(3). The fungicide Zineb, calcium carbonate, calcium stearate and pure water were used as feeding materials. A drying model using the continuity and momentum equations for turbulent accelerating two-phase flows and conventional rate equations is proposed and discussed. The work is relevant for estimating dryer performance.