混合澄清槽数值模拟与实验研究进展

Advances in numerical simulation and experimental investigation on mixer-settler extractor

稀土是不可再生的重要战略资源,在高新技术材料中具有不可替代的战略作用。混合澄清槽具有操作稳定性好、级效率高、结构简单、易放大等优点,是稀土分离工业中使用最为广泛的萃取设备。本文概述并分析了应用于混合澄清槽模拟的数值模型,结果表明Eulerian-Eulerian多相流模型、k-?湍流模型和多参考系模型因使用简便、精度可靠、对计算机性能要求不高而被当前的研究者们大量采用。此外,针对混合澄清槽抽吸性能、混合特性和澄清特性三大重要性能指标,分别总结了影响各性能的主要参数和调控方法,分析表明在抽吸性能和混合时间方面的研究较为成熟,在液滴聚并破碎数值研究、澄清方式和改进等方面的研究相对薄弱,构建高精度网格、采用更细致分析流场时空发展趋势的大涡模拟和引入种群平衡模型等方法将是下一步深入研究混合澄清槽的重要方向。

Rare earths are important non-renewable strategic resources. They play an irreplaceable part in high-tech materials. Mixer-settler is one of the most widely used extraction facilities in the rare earth industry with the advantages such as stable operation, high stage-efficiency, simple structure and easy scale-up. In this paper, numerical models used in the simulation of mixer-settler are summarized and analyzed. Eulerian-Eulerian multiphase model, k-ε turbulent model and multiple reference frame model are widely used by researchers because of convenience, reliable accuracy and low performance requirements for computers. Pumping capacity, mixing performance, and clarifying characteristics of mixer-settler are considered, and the main factors influencing these performance parameters are summarized. Analyses show that researches on pumping capacity and mixing time are mature, but numerical studies on droplet coalescence and breakup, as well as clarifying method and improvements, are relatively weak. Creating high precision grids, adopting large eddy simulation method to provide a more detailed time-space information and introducing population balance model will be the next important research direction of mixer settler.