Design and Study of a Conduction Type High Temperature Short Time Rotary Drum Dryer

In order to decrease the mildew losses of grain, a conduction type high temperature short time continuous flow rotary drum dryer was developed in the light of present economic and technical conditions of the vast countryside. On the basis of single-factor tests and guadratic orthogonal rotary combination tests, the relations between main technical parameters and the performance of the dryer was studied. The regression equations were established, and the drying effect of various combinations of the main technical parameters were forecasted.Optimal combinations of the main parameters for paddy with different initial moisture contents were obtained by means of multiple objective nonlinear programming method.The influence of the number of drying passes and the method of final drying on grain qualities was investigated by analyzing the qualities of milled rice from the dried batches. The qualities of the grains dried by the dryer was found comparable with that of sundried paddy. Moreover, the percentage of head rice was raised slightly. Therefore, it was concluded that quick drying of high moisture paddy to a level of moisture content that would arrest deterioration immediately after harvest was a viable technique for grain quality preservation. These results have profound significance for solving the perennial problem of grain deterioration due to delayed drying, especially during the wet season.