(153f) Comparison of Power Consumption and Mixing Time of a Stirred Tank with Different Impellers

The impeller in a stirred tank plays a core role, which directly determines the power consumption and mixing efficiency of the whole system, and influences the economic benefits of industrial processes. Therefore, the development and design of novel high efficient impellers are always highly concerned. In this work, a novel zigzag punched impeller is developed in order to decrease the power consumption and improve the mixing efficiency in stirred tanks. Experiments on power consumption and mixing time of the stirred tank agitated by different impellers such as Rushton impeller, three pitched blade impeller, centripetal impeller, punched blade impeller and our novel zigzag punched impeller are systematically studied. The results show that at the same impeller speed, the power consumption of the Rushton impeller is the highest, and the three pitched blade impeller is the lowest. The power consumptions of the centripetal impeller, punched impeller and zigzag punched impeller are almost the same, and are only a little higher than that of the three pitched blade impeller. Among the five impellers, the mixing time of the novel zigzag punched impeller is the lowest, and the overall evaluation of the mixing efficiency of the novel zigzag punched impeller is the best. Moreover, the importance of the factors affecting the mixing efficiency is impeller speed > impeller type > impeller off-bottom clearance.

References

1. Chao Yang, Qinghua Zhang, Zai-Sha Mao, Xiangyang Li, Jingcai Cheng, Xin Feng, Xiaoxia Duan. High efficiency punched impeller. CN201810116769.8, 2018-2-6.
2. Juan Yang, Qinghua Zhang, Zai-Sha Mao, Chao Yang. Enhanced micro-mixing of non-Newtonian fluids by a novel zigzag punched impeller. Industrial & Engineering Chemistry Research, 2019, in press, DOI: 10.1021/acs.iecr.9b00465.

Acknowledgements

The National Key Research and Development Program (2016YFB0301701), the Major National Scientific Instrument Development Project (21427814), the National Natural Science Foundation of China (21776282, 21490584), and the Key Research Program of Frontier Sciences, CAS (QYZDJ-SSW-JSC030) are gratefully acknowledged.