Effect of blade configuration on the mixing process of particles in an intensive mixer

Abstract

DEM simulations of particle mixing process in the intensive mixer were conducted to study the influence of blade configuration and impeller speed on the particle dynamics and mixing performance. Two tagged particles at different locations were used to discuss the influence of blade configuration on the particle trajectory and residence time in the intensive mixing region. The average magnitude velocity in the intensive mixing region, time-averaged velocity fluctuation, coordination number, impeller torque and relative standard deviation (RSD) were adopted to quantify the mixing performance during the mixing process. It was found that the blade configuration plays a vital role in the mixing process as it affects the residence time, particle velocity and mixing performance. The magnitude velocity of particles agitated by the thread blades is lower than that agitated by the arc and straight blades. The residence time for the thread blade mixer is longer than that for the arc and straight blade mixers. The mixing performance of particles in the thread blade mixer is better than that in the arc and straight blade mixers. Results obtained show that a proper impeller speed is very important for the mixing of particles, and the optimal impeller speed for granular mixing in the intensive mixer is 150 rpm.