Analysis of energy and specific energy requirements in various drying process of mint leaves

摘要

Various drying techniques have been operated to determine the energy requirements for drying mint leaves. The investigates were approved with different air-drying temperature of 30, 40 and 50°C at different air velocity of 1.0, 1.5 and 2.5 m/s in hot-air dryer. The infrared and hybrid dryers were performed at different infrared intensity 1000, 2000 and 4000 W/m2 with same conditions of air velocity and temperature of convection drying. Under hot air convection, the energy consumption reduced significantly by increasing the air temperature while increases with rise in velocity. While the energy consummation decreased by increasing the infrared intensity using hybrid and infrared dryer but rise air velocity increased the energy. The minimum SEC was verified 2.6 MJ/kg with air temperature of 50 °C and at intensity 4000 W/m2, while maximum SEC 19.7 MJ/kg was observed at 30°C and 1000 W/m2 under air velocity 1 m/s. The lower SEC of 2.6 MJ/kg was noted applying the hybrid dryer, which was 92.1 and 49.4% lesser than infrared and hot-air dryers, respectively. The optimum condition was conducted to 1.0 m/s, 50°C, and 4000 W/m2 under hybrid dryer for efficient drying of mint.