Specific Energy Consumption in Convective-microwave Drying of Ashwagandha (withania Somnifera) Roots

Evaluation of specific energy consumption was carried out during convective-microwave and convective drying of Ashwagandha root in a developed laboratory scale microwave dryer.The specific energy consumption in convective drying at 60ºC of air temperature and 1.0 m/s air velocity was estimated as 2.27 ± 0.12) MJ/kg of water evaporated.The increase in air velocity increased the energy consumption.The specific energy consumption at 6 W/g of microwave power level, 60ºC air temperature and 1.0 m/s air velocity was 0.396 ± 0.047) MJ/kg of water evaporated, resulting in about 82% energy saving as compared to convective drying processes.The drying time increased with increase in air velocity in convective -microwave drying process as a reverse trend that was observed in convective drying process of Ashwagandha roots.