Evaluation of Thermal Efficiency of a Rotary-Type Paddy Dryer Using an LPG Gas Burner

Abstract

This study aims to analyze the effect of varying drying temperatures on moisture reduction, energy consumption, and energy efficiency in rice drying using an LPG-fueled rotary dryer. The drying temperatures applied were 45°C, 55°C, and 65°C. The results showed that increasing the drying temperature accelerated the reduction of rice moisture content at each time interval. The highest drying rate occurred at 65°C, indicating that it took a shorter time to reach low moisture content compared to 55°C and 45°C. This increase in drying rate was due to a higher thermal gradient and a greater vapor pressure difference between the rice and the drying air, which increased heat and mass transfer. However, higher drying temperatures also resulted in greater total energy consumption, with the highest energy consumption occurring at 65°C. Nevertheless, energy efficiency tended to increase with increasing temperature, from approximately 25% at 45°C to almost 27% at 65°C, indicating more effective utilization of thermal energy for water evaporation.