Experimental Evaluation of the Thermal Performance of Dryer Airflow Configuration

This work focuses on the comparative study of energy efficiency of a dryer according to the drying principle. The experimental study of the mango drying was carried out in an electric dryer at 40 °C, 50 °C and 60 °C, 0.6 m/s with two configurations (vertical airflow batch drying and vertical countercurrent airflow drying). For each configuration, the evolution of drying kinetics and energy efficiency were highlighted at different temperatures. The analysis of results showed that the higher hot air temperature led to the faster drying rate and the shorter drying time. At 40 °C, the time to reach an equilibrium moisture ratio of 30% is 10 h and 12 h respectively for vertical airflow batch drying and vertical countercurrent airflow drying. The vertical countercurrent airflow drying permits us to obtain best quality of products in terms of moisture ration. Dryer efficiency decreases with increase in the drying temperature. For vertical airflow batch drying, efficiency is 17%, 18% and 22 % respectively at 40°C, 50°C and 60°C. In the case of vertical countercurrent airflow drying those efficiency are 34%, 25% and 22%.