The development of rotary dryer for paddy using Hot Air recovery system

Abstract

This research’s objectives were to develop an energy saving rotary dryer for paddy using hot air recovery system and to evaluate the energy using. Rotary dryer divided rotating cylinder made of 304 stainless steel 2 mm of thickness, 39 cm and 200 cm of diameter and length. The inverter was used to control speed of gear motor of 0.5 HP and rotating speeds of 1-3 rpm. The inside of cylinder composed screw and capture flights. The cyclone system was used to dust separating from the system. The moisture trap contained silica gel, the outlet hot air was reduced moisture and recovered using. The fiber glass insulator was applied for reducing energy loss. The heating box composed 3 set of 1600 W heaters and blower motor power was 0.5 HP. In the experiment, the drying temperature was varied of 50, 60, 70 and 80oC and cylinder speed was varied of 1, 2 and 3rpm (15.66, 10.66 and 5.66min of drying time). The initial moisture content of 10 kg paddy was 29.7?0.6 %wb. The result show that, the optimum conditions, drying temperature and cylinder speed were 70-80oC and 1 rpm (15.66 min) and final moisture content was 9.2-11.8 %wb. From the save energy testing found that the reducing of SEC was 0.4-0.6 MJ/kg water per drying cycle. There for, this developed dryer can save energy using