The objective of this research was to study of rotary drying of high-moisture long pepper by using a combined hot air and infrared radiation. The experiment was carried out at the drying temperatures of 80 90 and 100 °C infrared power level of 500 W hot air velocity of 2.5 m/s and rotary revolution of 3 6 and 9 rpm. In this study two patterns were examined by the different drying conditions namely 1) hot air drying and 2) combined hot air and infrared radiation drying. The effects of above drying parameters on the change in moisture content of long pepper and specific energy consumption (SEC) of the drying system were investigated. The results showed that the combined hot air and infrared radiation drying was shorter drying time than hot air drying. The lowest total SEC during drying process of 26.77 MJ/kg water when the drying temperatures of 80 °C infrared power level of 500 W hot air velocity of 2.5 m/s and rotary revolution of 3 rpm were used.

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