Mathematical modeling of drying kinetics of black pepper in a spouted bed dryer with and without non porous draft tubes

Abstract

A conventional spouted bed dryer and a spouted bed dryer fitted with a non porous draft tube were used to analyze the drying kinetics of black pepper. Minimum air velocities required for black pepper spouting were determined for both bed configurations and drying experiments were conducted at minimum spouting conditions. The minimum air flow rate required for spouting of non porous draft tube fitted spouted bed is 45% lower than that of the conventional bed. The highest drying rate was achieved when black pepper was dried without draft tube at highest drying temperature. A new thin layer drying model is proposed and experimentally determined drying kinetic data were fitted to the proposed model and compared with five commonly used models. Goodness of fit was evaluated using statistical parameters reduced chi square, root mean square error and coefficient of determination. Statistical analysis showed that drying behavior of black pepper in spouted bed dryer is best fitted to the Verma et al. model and the proposed model. Model parameters were calculated and presented.