Performance Testing and Evaluation of On-Farm Mobile Paddy Dryer

Abstract

Efficient drying from any mobile paddy dryer would result in the superior quality of the product within a desirable time. Dryer was evaluated using 5332.5 kg of freshly harvested paddy at 21.01% moisture content (w.b). The air velocity at top layer was found to vary from 0.50 to 0.33 m/s at loading condition and 1.7 to 0.6 m/s at no-load condition. The moisture content, the coefficient of uniformity (Cu) and moisture ratio at bottom of the drying chamber were observed to vary from 21.03 to 13.44% (w.b), 91.47 to 98.32%, and 0.928 to 0.085 respectively during the start to the end of the drying. The temperature of the drying chamber at bottom and top layers were found to vary from 35.57 to 32.47°C and 40.63 to 32.47°C, respectively. The relative humidity values at the bottom and top layers were 95.87 to 94.27% and 72.40 to 93.43%, respectively during drying. At the end of drying after 4.5 h, the final moisture was estimated to be 15.23% (w.b). The thermal efficiency, heat utilization factor and effective heat efficiency were calculated to be about 58.5%, 0.99 and 0.89, respectively. The total power requirement was assumed to be 15 kW. The cost of drying was found to be Rs. 943 /h and Rs. 0.79 /kg of paddy.