Mathematical modeling for pulsed microwave convective drying of red gram (Brg-2 variety)

Abstract

The effect of microwave drying experiments on three independent variables i.e., microwave power levels (540, 720 and 900 w), pulsation levels (30, 60 & 90s) and initial moisture contents (14, 16 & 18% w.b) on drying time, drying rate and effective moisture diffusivity of red gram been investigated. By increasing the microwave power (540 to 900w) and Pulsation level (30 to 90s) at a moisture content of 14, 16 & 18% (wet basis), the drying time decreased from 300-690s, 180-360s and 150-330s, respectively. To determine the drying kinetics, the drying data fitted to “n” best thin layer drying various models based on the ratios of the differences between the initial and final moisture contents and equilibrium moisture content versus drying time studied. The Midilli et al. model gave a superior prediction than all other models evaluated and described the drying characteristics of red gram more effectively. The relationship between the drying rate was also estimated and gave a linear relationship.