Effect of Temperature on Fine Particle Drying in a Draft-Tube Conical Spouted Bed

The performance of a draft-tube conical spouted bed for drying fine particles under batch operating conditions has been assessed at several temperatures using nonporous and open-sided draft tubes, and the results have been compared with those obtained when operating without a draft tube. In order to ascertain the influence of temperature on drying, experimental runs have been carried out in the 25-300 degrees C temperature range. The open-sided draft tube provides the best performance due to the excellent gas-solid contact attained with this device, which enables shorter drying times. A maximum air temperature of 200 degrees C is recommended for energy optimization. An open-sided tube protruding above the stagnant bed by at least 2/3 of the latter's height produces much lower and denser fountains than a tube flush with the upper surface of the bed.