In order to optimize the structure and technology parameters of rotary drying, mathematical models of effective residence time and mass of loading were established based on the motion of solid particles in rotary dryer. Uniform design was applied in experimental design with material of rapeseed. Four independent variables such as structural parameter (cylinder inclination angle) and operating parameters (the rotation speed of rotary dryer, solids feed speed and airflow speed) were investigated. Prediction models of effective residence time and mass of loading were established by using software DPS7.05 to optimize the experimental design. The experiment results showed that under experimental conditions, the effects of airflow speed, rotation speed, the interaction of rotation speed with airflow speed and the interaction of rotation speed with solids feed speed on effective residence time were significant. Rotation speed, airflow speed, the interaction of cylinder inclination angle with solids feed speed and the interaction of feed speed with airflow speed had significant influences on mass of loading. By optimizing with multiple objective programming, the optimal parameters were obtained as follow: cylinder inclination angle of 1.8°, rotation speed of rotary dryer of 4 r/min, solids feed speed of 2.5 kg/s and airflow speed of 2.4 m/s. The research has important significance to well improve structure and technology parameters of rotary drying technology in solids drying.
A Computational Approach to Determine the Residence Time Distribution of Biomass Particles in Rotary Drum Dryers
