Chaotic mixing properties under rotation plus revolution revealed by purification experiments and numerical simulations

Background: The purification process of Zn-containing solid waste causes severe pollution, and energy and ma-terial consumption because of its low mechanical stirring efficiency. Thus, a new effective stirring method called rotation plus revolution (RPR) has been proposed.Methods: The enhanced mixing performance of eccentric rotation (ER), orbital rotation (OR), and RPR were investigated through purification experiments and numerical simulations. Combined with chaotic mixing theory, the influence of momentum transfer on the reaction rate controlled by diffusion is analyzed.Significant findings: Compared with ER and OR, RPR induces a specific chaotic attractor state in the fluid, which destabilizes the flow field, thereby realizing chaotic mixing and destroying the isolated mixing region. RPR promotes sufficient momentum diffusion, and the trajectory of folding and stretching increases the effective collision probability per unit time, greatly improving the reaction rate. At 60 min, the purification rate of RPR reached 96.9%, which was 37.8 and 35.1% higher than those of ER and OR, respectively. RPR also had a higher energy utilization rate, and its unit ion purification energy decreased by 2.3% and 20.4% compared with ER and OR, respectively. Overall, RPR improved the purification efficiency with low energy consumption, thereby saving energy and reducing emissions.

Automated summary

The rotation plus revolution (RPR) stirring method achieves chaotic mixing by inducing a specific chaotic state in the fluid, which disrupts isolated mixing regions. RPR significantly improves reaction rates by increasing effective collision probabilities. Compared to eccentric rotation (ER) and orbital rotation (OR), RPR achieved a purification rate of 96.9% in 60 minutes, which was 37.8% and 35.1% higher, respectively. RPR also had higher energy utilization and lower unit ion purification energy compared to ER and OR, resulting in improved purification efficiency with reduced energy consumption.