Heat transfer in a draft tube spouted bed with bottom solids feed

Detailed temperature measurements were obtained for a draft tube spouted bed of 2.6-mm glass beads with bottom solids feed at different air flow rates, air inlet temperatures, solids feed rates and bed heights. The temperature profiles showed that air temperature drops significantly with the axial position in the spout, while air and solids temperatures are uniform in the annulus. The drop in air temperature along the spout decreases with increasing air flow rate and increases with solids feed rate. A model was adapted for use with the spouted bed configuration studied here and its predictions were compared with the experimental data. In general, the model could accurately predict the temperature profiles in the bed, since the largest deviations were observed for the air temperature in the spout and were always less than 5%. Although the model provided for a low deviation in predictions, air temperature in the spout was systematically over-estimated.