关键词: 双行星搅拌器, 混合特性, 桨叶结构, 数值模拟

Abstract: During the preparation of lithium battery slurry, poor uniformity and powder agglomeration significantly impact battery performance. This study investigates the effects of rotation speed, stirring direction, ratios of impeller diameter to tank diameter, and screw pitch on the flow field distribution, circulation characteristics, shear properties, concentration distribution, and specific mixing energy using computational fluid dynamics (CFD). The results indicate that in counter-rotational stirring mode, the vortex center is notably higher, demonstrating stronger fluid circulation characteristics. The complex vortex structures and cross-flows effectively enhance shear stress. Although specific mixing energy exhibits a positive correlation with impeller speed, counter-rotational stirring exhibits advantages in reducing energy dissipation. Compared to co-rotational stirring, counter-rotational stirring achieves an energy saving rate of 21.7% to 60.7% within the range of 100 to 400 r/min. Regarding mixing uniformity, low-speed co-rotational stirring performs better, while high-speed counter-rotational stirring achieves superior mixing uniformity. Increasing the impeller diameter ratio can effectively boost axial and radial velocities and enhance shear stress, but it also increases specific mixing energy, thereby decreasing mixing efficiency. Increasing pitch enhances axial and radial velocities, improves mixing uniformity, reduces flow resistance, and boosts mixing efficiency. However, excessively large ratios of impeller diameter to tank diameter and impeller pitches can lead to uneven flow and affect the uniform distribution of solid particles.

Key words: double planetary mixer, mixing characteristics, blade structure, numerical simulation