关键词: 回转式烘干机, 干燥, 传递过程, 状态方程, 数值分析, 停留时间

Abstract: At present,the research method of material movement in the cylinder of a rotary dryer is mainly to set up the held and thrown material models of a lifting plate and the residence time model of materials in the cylinder body. But the most formulas depend too much on the empirical constants,and the physical meaning is not clear. Based on the thrown movement law of materials,the space model of the particle transportation in a rotary dryer is established. First,the motion rule was studied for the solids in the flight rotary dryer. The paths of fall of the particles in the drum were drawn by Matlab drawing toolbox and showed on the three-dimensional image. Then,the analytic mathematical models of the motion were proposed for the space particle. The equations of residence times were deduced. The proposed estimation models were determined by considering the air drag on the solids in the drum,as well as the inclined angle,the rotation speed and the filling rate of a drum. The calculation formula of residence times was with a clear and definite physical meaning. The residence time calculated by using the proposed equation was compared to the average experimental values from the engineering example and the results obtained by calculations using equations proposed in the literature. The equation proposed for predicting residence time generated accurate estimations.

Key words: rotary dryer, drying, transport processes, equation of state, numerical analysis, residence times