Study the drying kinetics, Energy consumption and quality parameters of Echium amoenum in an IR equipped solar dryer

In the present study, an infrared-assisted solar dryer was used to determine the drying kinetics, energy consumption and quality parameters evaluation of Echium amoenum. Experiments were conducted with two levels of drying air flow rate (0.0025 and 0.005 m3s-1) and three levels of IR lamp power (100, 150 and 213 W). Drying time, energy consumption and evaluation of quality properties in different air flow rates and lamp powers were compared to the conventional method (shade drying). Five empirical models were fitted on the experimental data and the goodness of regression models were evaluated using coefficient of determination (R2), root mean square error (RMSE), and Chi square (χ2). Results of drying time in the different experiments showed highly significant differences respect to the conventional method (p-value<0.01). Also results showed that increasing the air flow rate and IR power caused a reduction of 37% and 17% in drying time, respectively. Best empirical model to describe the drying behavior was the Page model. The lowest specific energy consumptions (SEC) was 4.63 MJ kg-1, which was occurred at the air flow rate and IR power of 0.005 m3s-1 and 150 W and the highest SEC was 5.26 MJ kg-1 and occurred at 0.0025 m3s-1 of air flow rate and 213 W of IR lamp, respectively. Finally, the air flow rate of 0.005 m3s-1 and the IR power of 150 W was recommended for Echium amoenum drying in the IR-ASD because of the fair energy consumption and the suitable product color.