关键词: 离散单元法, 强力混合机, 混匀效果, 转速, 填充率

Abstract: The mixing effect of raw materials is an important factor affecting the quality and production efficiency of pellets. The forcing mixer is the core mixing equipment, and the appropriate operating parameters can make the mixed materials achieve the best mixing effect. In industry, the basic performance indicators of pellets are generally used to replace the mixing effect of materials, such as falling strength and compressive strength, resulting in long detection process, large error, and inability to visually obtain material trajectory and dispersion effect. In this study, SOLIDWORKS software is used to establish a forcing mixer model, and EDEM discrete element software is used to simulate the movement behavior of materials in the reactor. The effects of the rotating motion of the rotor, the bottom and the wall of the mixer and the filling rate of the materials on the mixing effect are studied. The results show that increasing the rotor speed can significantly improve the mixing effect, but when the rotation speed reaches ±48 r/min, the improvement of the mixing effect is not obvious. The rotation of the bottom can break through the speed threshold of the double rotor rotation, and the bottom can greatly improve the mixing effect at a lower rotation speed of +30 r/min. On the contrary, the rotation of the wall produces a stacking effect, which inhibits the dispersion of the particles, thereby reducing the mixing effect. The high filling rate is not conducive to the dispersion of materials above the rotor blade position, and the mixing effect is the best when the filling rate is 60%. Considering the enterprise pellet production and mixing equipment running performance requirements, the reasonable operating parameters are rotor rotation speed of ±30 r/min, the bottom rotation speed of +30 r/min, the wall rotation speed of 0 r/min, and filling rate of 60%.

Key words: discrete element method, forcing mixer, blending effectiveness, rotational speed, filling rate