2000 Volume 62 Issue 4 Pages 89-101
Experimental study on microwave drying of thick layer rough rice with concurrent, counter and cross flow ventilation was carried out and the appropriate conditions for microwave drying of thick layer rough rice with concurrent flow ventilation are discussed. The experimental data showed that during the microwave drying process, ventilation could prevent overheating and the ventilation air flowing direction was important to obtain uniform drying and favorable product quality. Concurrent flow ventilation was the most favorable means to obtain uniform drying. Air velocity significantly affected the drying rate and uniformity. Ventilation air acted as a moisture carrier and an energy conveyer in microwave drying of thick layer rough rice with concurrent flow ventilation. The most appropriate conditions for microwave drying of thick layer rough rice with concurrent flow ventilation are when microwave power is below 0.10W/g, air velocity is about 0.07-0.12m/s and the thickness of grain layer is about 100-120mm.
