Effects of Drying Parameters on the Drying Kinetics of Fermented Ground Cassava Using a Rotary Dryer

Abstract

The effects of drying parameters on the drying kinetics of fermented ground cassava were studied. Fermented ground cassava (TMS 30572) was dried in a bench scale rotary dryer at different inlet air temperature (115-230°C), inlet air velocity (0.83-1.55 m/s), feed drive speed (12-100 rpm), drum drive speed (8-18 rpm), relative humidity of inlet air (50 to 80 percent), and mass of feed (50-500 g). It is shown that inlet air temperature and inlet air velocity have the most significant effects on the drying rate of fermented ground cassava. A model which predicts the drying rate of fermented ground cassava as function of inlet air temperature and inlet air velocity is presented. Predictions of the model are compared with experimental data, and good agreement is obtained. For proper gelatinization of fermented cassava mash, the inlet air temperature should be within the range 140-230°C, low inlet air velocity (< 1.55 m/s), low drum drive speed (8-12 rpm), moderate air humidity (50 to 65 percent), and low feed drive speed of about 12 rpm. For high mass of feed (> 500 g), inlet air temperature in the range 190-230°C is recommended for proper gelatinization of fermented cassava.