Ansys fluent; CFD; PCRD; simulation; sago starch

Abstract

The mini-scale pneumatic conveying ring dryer (PCRD) type sago starch dryer with a capacity of 80 kg / day has been applied to the processing of sago starch to produce dry sago starch. To increase the production capacity of the PCRD dryer, a recirculation pipe was modified. The modified pipe section is the venturi pipe diameter and the upriser vertical pipe increased. The diameter of the vertical upriser pipe is 2.5 times larger than that of the ubend pipe and the downcomer vertical pipe so that a buffer is formed. In addition, the difference in the diameter of the recirculation pipe can increase the residence time of the material. The purpose of this study was to simulate using ansys fluent to determine the temperature profile, air flow velocity, and pressure in the pneumatic conveying ring dryer (PCRD) type sago starch dryer pipe with a capacity of 1 ton per day. Simulations were carried out using the Computational Fluid Dynamics (CFD) technique using ansys fluent software package. The simulation results show that the temperature along the pipe has decreased by about 2oC at various variations of the input air velocity and variations in the outlet at the boundary conditions. Likewise, the air velocity at the end of the outlet pipe (vertical downcomer pipe) increases due to the difference in diameter with the inlet pipe. The pressure on the vertical upriser pipe is higher than the pressure on the ubend pipe and downcomer vertical pipe. The simulation results show that the recirculation pipe design is very well used so that it can be continued for the manufacture of PCRD-type sago starch dryer on a scale of 1 ton per day.