DEVELOPMENT OF A FULL-SCALE CONDUCTION HEATING ROTARY DRYER FOR ACCELERATED DRYING AND STERILIZATION OF HIGH MOISTURE ROUGH RICE

Document Type : Original Article

Authors

1 Professor of Agricultural Engineering, Faculty of Agriculture, Ain Shams University, Cairo, Egypt

2 Professor of Agricultural Mechanical, Faculty of Agriculture, Mansoura University, Mansoura, Egypt

3 Agricultural Engineering Research Institute, Agricultural Research Center, Dokki, Giza, Egypt

Abstract

A full-scale conduction heating rotary dryer was designed and constructed at the Dep. of Agric. Mech., Fac. of Agric. Mansoura Univ. The dryer was tested, examined and evaluated for accelerated drying and sterilization of high moisture rough rice (Giza 176) at the Rice Mech­anization Center 'experimental farm of the Agric. Eng. Res. Institute, Kafr EI-Shiekh Gov. branch. Dryer performance through field experiments and calculation of parameters proved the applicability of the dryer for rapid drying and sterilization of high moisture rough rice down to 17-18%. Heat treat­ment of rough rice corresponding to 80% led to a significant improve­ment in grain physical quality and milling potential. The heat-treated grain exhibited a marked reduction in grain broken percentage approached 30-35% in comparison with the naturally dried grain . The reduction in grain broken percentage was attributed to the increase in grain hardness and the reduction in grain crack percent­age. The average thermal efficiency of the dryer was determined to be 68.5% and the required heat energy for removing 1 kg of water from rice was about 3681.69 kJ. In general, the dryer showed a good me­chanical and thermal performance and proved to be practical.