مقايسه ترك خوردگي دانه و زمان خشك شدن شلتوك در شرايط بسترهاي ثابت و سيال آزمايشگاهي

Traditional paddy dryer systems in Iran cause considerable losses in rice production due to non-uniform drying. In order to decrease the amount of kernel fissuring and to increase the drying rate, fluidized bed method was applied in this study for rough rice drying at temperatures higher than normal. An experimental dryer was used for drying the samples. The drying experiments were set up to find kernel fissuring percentage and the drying times under three conditions: fixed, minimum, and full fluidized bed conditions at temperatures of 40, 60 and 80°C. Results showed that the amount of kernel fissuring, at minimum fluidization compared to fixed bed condition, decreased 57%, 68% and 75% at temperatures of 40, 60 and 80°C, respectively. This reduction at full fluidization compared to fixed bed condition, at the above temperatures, was 40%, 54% and 65%. The minimum fluidization method took the lowest and the fixed bed method took the highest drying time. It was concluded that the minimum fluidization drying method had the lowest fissuring and drying times at all experimental temperatures.