Hydrodynamic study and drying of grains in a tapered fluidized bed

Abstract

Cereal grain and food drying are done as an aid to warrant minimization of grain damage, on one side and economic feasibility on another side.Proper drying procedures can eliminate the potential of spoilage during subsequent storage and improve the quality of grain. Appropriate dryer should be designed for reducing the damage to grain and for economically feasibility. The drying method and conditions effectively determine type and characteristics of the final product. The drying performance of a tapered fluidized bed dryer on wheat grains and mustard seeds are studied. An investigation is undertaken to study the effects of temperature, time, moisture content and gas velocity on the drying performance in a tapered fluidized bed. Furthermore, the hydrodynamic aspects e.g. pressure drop and minimum fluidization velocity are also studied. The results show that the efficiency increases with increase in temperature and time of drying. This clearly indicates that the moisture transfer from the material depends strongly on the air temperature. The drying rate decreases with increase in particle size. A good agreement is obtained between the predicted hydrodynamics and the obtained results.