Comparative Assessment of Closed Loop Heat Pump Dryer and Direct Solar Dryer System for Banana Drying

Abstract

The comparative assessment of direct solar dryer system (DSDS) and closed loop heat pump dryer (CLHPD) for drying of banana has been investigated. This study was carried out with 3 drying methods including DSDS, CLHPD without preheating and CLHPD with preheating for 30 minutes to determine the performance and drying characteristics of banana dryer from the initial mass of 8 kg to evaporate of moisture content of 3.2 kg. The results showed that the drying time of banana using CLHPD with preheating (30 minutes), CLHPD without preheating and DSDS are 255 minutes, 305 minutes and 720 minutes, respectively. The CLHPD drying time with pre-heating was faster than CLHPD without pre-heating and it was the fastest compare to DSDS. The higher value of Specific Moisture Extraction Rate (SMER) of banana using CLHPD with preheating (30 minutes), CLHPD without preheating and DSDS were 1.29 kg/kWh, 1.18 kg/kWh and 0.35 kg/kWh, respectively. The SMER of CLHPD with pre-heating was higher than that CLHPD without pre-heating and it was the highest compared to DSDS. The CLHPD with preheating showed a better performance in comparison with CLHPD without preheating and it was the best performance compared to DSDS.