Development of long pepper drying system using a combined rotary dryer and infrared radiation

Abstract

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.