Abstract:
This thesis aimed to investigate the simulation of paddy drying in a tangentialhorizontal impinging stream system by computational fluid dynamics. The model was used to simulate
the effects of various parameters including inlet air velocity of 20 and 25 m/s, inlet drying air temperatures of 70, 90 and 110 ºC, paddy feed rate of 25, 35 and 56 kgdry solid/h, volume of drying chamber of 50 liters on the paddy moisture content, volumetric evaporation rate and volumetric heat transfer coefficient. The research also explored the effect from the increasing size of drying chamber. The results showed that the model could predict the paddy moisture content, the volumetric evaporation rate and the volumetric heat transfer coefficient were close to the experimental results within ±10%. In addition, the decreasing size of drying chamber resulted in the increasing volumetric water evaporation rate and the volumetric heat transfer coefficient rate. The maximum volumetric water evaporation rate was 62.72 kgwater/m3h at the inlet air velocity of 25 m/s, inlet drying air temperatures of 110 ºC, the paddy feed rate of 56 kgdry solid/h and the volume of drying chamber of 50 liters. The maximum volumetric heat transfer coefficient rate was 112.63 W/m3K at the inlet air velocity of 25 m/s, the inlet drying air temperatures of 110 ºC, the paddy feed rate of 56 kgdry solid/h and the volume of drying chamber of 50 liters.