Development of a Fluidized Bed Dryer for Drying of a Sago Bagasse

Abstract

Sago is an essential source of starch for some regions in the third and developing world. However, the sago processing industry has been producing a large amount of sago waste, and the untreated waste is usually disposed to the nearest river. It not only leads to the environmental problem, but it is illegal under the Environmental Quality Act 1974. Since the sago waste still has high starch content, which is 58%, it can be converted to high value-added products such as poultry feed. However, before being converted to other products, the sago must be dried to remove the moisture content to prevent any bacteria growth and ensure safety health issues have been observed. Recently, drying of sago bagasse using a fluidized bed dryer (FBD) has gained attention since the dry rate of the material is considerably faster compared to other methods. Due to that reason, the drying of the sago bagasse in the FBD is studied using computational fluid dynamic as it can be executed in a short period of time compared to the experimental approach. The FBD model was developed using ANSYS© Fluent academic version 19.2. The effect of the hot air feed temperature; T=50, 60, 70, and 80°C and velocity of hot air feed; v=1-4 m/s on the sago’s behavior and performance of fluidization profile were studied. The simulation results showed that the high temperature and air feed velocity would result in a rapid drying rate. Besides, the optimum drying rate was at T=60°C with the v=4 m/s as these conditions give a shorter drying time to achieve of final 10% moisture content. It also has the added advantages of reducing the power energy and cost supply. These optimal conditions are very crucial and should be consider as the dried sago bagasse tend to be retrograded when a higher temperature is applied.