The previous literature reports that using a hydrocyclone as an extractor intensifies the mass transfer and largely reduces the consumption of extractant from 1800–2000 kg h−1 to 30–90 kg h−1. However, the intensification mechanism has not been clear. This paper presents experimental and numerical methods to study the multi-scale motion of particles in hydrocyclones. In addition to the usually considered translational behavior, the high-speed rotation of dispersed micro-spheres caused by the anisotropic swirling shear flow is determined. The rotation speeds of the tested micro-spheres are above 1000 rad s−1, which are much larger than the instantaneous rotation speed in isotropic turbulence. Due to the conical structure of a hydrocyclone, the rotation speed maintains stability along the axial direction. Numerical results show that the particle Reynolds number of micro-droplets in a hydrocyclone is equal to that in conventional extractors, but the particles have high rotation speeds of up to 10,000 rad s−1 and long mixing lengths of more than 1000 mm. Both the rotation of micro-droplets along the spiral trajectories and the intense eddy diffusion in a hydrocyclone contribute to the extraction intensification.
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机译：以前的文献报道，使用水力旋流器作为萃取器，可以增强传质，并将萃取剂的消耗从1800–2000 kg h -1 降低到30–90 kg h -1 sup>。但是，强化机制还不清楚。本文提出了实验和数值方法来研究水力旋流器中粒子的多尺度运动。除了通常考虑的平移行为外，还确定了由各向异性旋流剪切流引起的分散微球的高速旋转。所测试的微球的旋转速度高于1000 rad s -1 ，远大于各向同性湍流中的瞬时旋转速度。由于水力旋流器的锥形结构，转速保持了沿轴向的稳定性。数值结果表明，水力旋流器中微滴的雷诺数与常规抽提器相同，但具有高达10,000 rad s -1 的高旋转速度和较长的混合长度。大于1000 mm微小液滴沿螺旋形轨迹的旋转以及旋流器中强烈的涡流扩散都有助于提取强度的提高。
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