Abstract

A batch type fluidised bed drier of smaller capacity was developed for drying cardamom. Experiments were conducted to determine the drying characteristics of cardamom with three heated air temperatures viz. 40, 50 and 60°C and three air velocities viz. 35, 40 and 45 m/s. The results of the study showed that better quality dried product could be obtained from cardamom capsules. The drying of cardamom capsules was followed in falling rate period and drying behaviour found was exponential in nature. The drying time varied between 7.5 and 12.5 h for all the treatments. The drying rate of cardamom was higher during initial stages with all the combinations of air velocities and heated air temperatures and decreased as equilibrium moisture content of cardamom capsules approached. The quality of the dried product was found to be very good at an air velocity of 40 m/s at a drying temperature of 50°C, whereas product from all other treatments were found good.

Keywords: Fluidised bed drier, Air temperature, Air velocity, Drying rate.