Abstract:

Mixing is a critical process in modern industry, and efficient mixing serves as the core of the phosphoric acid extraction and purification process in wet-process phosphoric acid manufacturing. This paper conducted a preliminary investigation into the mixing characteristics of micro-vortex mixers and explored the feasibility of enhancing the wet-process phosphoric acid extraction process through micro-vortex mixers. Using the Eulerian-Eulerian multiphase flow model, simulations were performed on Kenics mixers, single tangential-inlet micro-vortex mixers, and two tangential-inlets micro-vortex mixers under different inlet Reynolds numbers. A comprehensive comparison was made of the mixing performance, vorticity, turbulent kinetic energy, and pressure drop among the three mixers. The results indicated that micro-vortex mixers exhibit higher vorticity and turbulent kinetic energy, which were more conducive to mixing. The coefficient of variation (COV) at the outlet of the single tangential-inlet micro-vortex mixer was on average 0.15 lower than that of the other two mixers, demonstrating the best mixing uniformity. As the inlet Reynolds number increases, the pressure drop correspondingly rises. At an inlet Reynolds number of 7400, the dual tangential-inlet micro-vortex mixer exhibits the maximum pressure drop of approximately 12782.5Pa, representing 14.7% higher than that of the other two mixers. Considering the two key indicators of mixing uniformity and pressure drop, the single tangential-inlet micro-vortex mixer demonstrates superior performance.

Key words: mixing, static mixer, cyclone mixing, computational fluid dynamics, numerical simulation

摘要：

混合是现代工业的关键过程，在湿法磷酸制造工艺中，高效地混合是磷酸萃取提纯过程的核心。本文对微旋流混合器的混合特性进行初步探究，研究微旋流混合器强化湿法磷酸萃取过程的可行性。采用Eulerian-Eulerian多相流模型模拟了不同入口雷诺数下的Kenics混合器、单切向进口微旋流混合器、双切向进口微旋流混合器，对三种混合器的混合性能、涡量与湍流动能、压降进行对比分析。结果表明微旋流混合器的涡量与湍流动能更大，更有利于混合；单个切向进口微旋流混合器出口变异系数COV比另外两个混合器平均小0.15，混合均匀程度最好；随着入口雷诺数增大，压降相应增大，在入口雷诺数为7400时，双切向进口微旋流混合器的压降最大约12782.5Pa，比其他两种混合器大14.7%。综合混合均匀程度与压降两个关键指标，单切向进口微旋流混合器性能更佳。

关键词: 混合, 静态混合器, 旋流混合, 计算流体力学, 数值模拟