Drying Paddy Using Fluidized Bed Technique

Abstract

This research revealed the study of a fluidized bed paddy drying system. A hot-air-recycled dryer of SO % was employed. Experimental results illustrated that the air-input velocity of 5.25m/s induced the fluidize bed. The drying system applied 3 levels of air-input temperature, namely 70 , SO and 90°C. For paddy, the bed hight of S.5 cm , with initial moisture content 24.6%, wet basis, the final grain moisture content dropped to 19%, wet basis. The experimental results also yielded that the airinput temperature of drying affected drying time, water evaporation rate and operational cost.· When the temperature of drying air increased from 70 to 90°C at final 19% wet basis moisture content, drying time reduced from 3.7 to 1.9 minutes, water evaporation rate increased from 3.667 to 6.947 kg water evap./h and operational cost reduced from 1.51 to 0.S4 baht/kg water evap. From experimental data, the relation between moisture ratio (MR) versus drying time (t) and air-input temperature (T) were correlated using Page's model.