Thermal Investigation of Dehydration of Jaggery

Abstract

Thin-layer drying kinetics of Jaggery was experimentally investigated in tray and vacuum tray drying on tray and vacuum tray convective dryers. Experiments were performed at drying temperatures 60, 70 and 80 °C, at three vacuum pressures 300, 400 and 500 mm of Hg and thickness are 0.5, 1 and 2.54 cm. The various factors of the sample that were investigated were drying time, drying rate, kinetics of drying curve, effective moisture diffusivity, activation energy and empirical mathematical model. It was observed that the drying rate was increased with increased in vacuum pressure and temperature and drying time decreased with increasing in temperature and vacuum pressure. Various 10 different thin layer drying model were used for evaluation of parameters of drying kinetics, out of which empirical Polynomial (Gamli) model presented the best fit for all drying conditions. For the plot of best fitting drying curve was use MATLAB (R2015a). Give a highest value of R2 and low values of RSS and RMSE. The Fick’s diffusion law was also used to estimate the effective moisture diffusivity and values were found to be in range 1.57 10-8 m2/s to 4.79 10-9 m2/s at the drying conditions. The Arrhenius type equation was used to calculate the activation energy and resulting range was 22.77 to 39.48 kJ/mol K for constant thickness of the Jaggery samples and developed the empirical mathematical correlation in MINITAB 17.1.0.