Modeling of power characteristics for multistage rotor-stator mixers of shear-thinning fluids
文献类型：期刊论文
| 作者 | Wu, Huashuai1,2; Shu, Shuli2,3; Yang, Ning2; Lian, Guoping4; Zhu, Shiping4; Liu, Mingyan1 |
| 刊名 | CHEMICAL ENGINEERING SCIENCE
 |
| 出版日期 | 2014-09-27 |
| 卷号 | 117期号:SEP页码:173-182 |
| 关键词 | Rotor-stator mixers Multistage CFD Shear-thinning fluids Metzner-Otto concept |
| ISSN号 | 0009-2509 |
| 其他题名 | Chem. Eng. Sci. |
| 中文摘要 | Multistage rotor-stator (RS) mixers are widely utilized to generate high shear rate in dispersion processes such as foam generation and emulsification, featuring narrow gaps between rotors and stators in the axial direction and close clearance between rotors and vessel wall in the radial direction. In this study, CM simulation of the multistage RS mixers is carried out for Newtonian and shear-thinning power-law fluids to investigate the strain rate distribution and power characteristics, both of which are critical for bubble or droplet size distribution and process optimization. The simulation indicates that the shear-thinning power-law fluids lead to large fluid dead zones in the laminar regime compared to the Newtonian fluids, whereas such dead zone disappears in turbulent regime. But the area of higher strain rate of the power-law fluid near the tip of rotors is greater than that of Newtonian fluid. The average strain rate in turbulent flow is much higher than that in laminar flow, and the tails of strain rate distribution become longer as the flow index n decreases. The radial clearance ratio is found to have a non-negligible effect on the proportionality constant K-p between the power number and Reynolds number. For non-Newtonian fluids, CFD simulation indicates that the shear rate proportionality K-s nearly keeps constant in the laminar regime and is insensitive to the flow index n, showing that the Metzner-Otto concept is still suitable for the multistage RS systems. However K-s is strongly dependent on the radial clearance ratio and the axial gap, and hence new correlations are proposed for K-p and Ks to consider this effect. Then a new correlation for the power number is established and can serve as a unified correlation for Newtonian and shear-thinning power-law fluids in the laminar regime in multistage RS systems. (C) 2014 Elsevier Ltd. All rights reserved |
| 英文摘要 | Multistage rotor-stator (RS) mixers are widely utilized to generate high shear rate in dispersion processes such as foam generation and emulsification, featuring narrow gaps between rotors and stators in the axial direction and close clearance between rotors and vessel wall in the radial direction. In this study, CM simulation of the multistage RS mixers is carried out for Newtonian and shear-thinning power-law fluids to investigate the strain rate distribution and power characteristics, both of which are critical for bubble or droplet size distribution and process optimization. The simulation indicates that the shear-thinning power-law fluids lead to large fluid dead zones in the laminar regime compared to the Newtonian fluids, whereas such dead zone disappears in turbulent regime. But the area of higher strain rate of the power-law fluid near the tip of rotors is greater than that of Newtonian fluid. The average strain rate in turbulent flow is much higher than that in laminar flow, and the tails of strain rate distribution become longer as the flow index n decreases. The radial clearance ratio is found to have a non-negligible effect on the proportionality constant K-p between the power number and Reynolds number. For non-Newtonian fluids, CFD simulation indicates that the shear rate proportionality K-s nearly keeps constant in the laminar regime and is insensitive to the flow index n, showing that the Metzner-Otto concept is still suitable for the multistage RS systems. However K-s is strongly dependent on the radial clearance ratio and the axial gap, and hence new correlations are proposed for K-p and Ks to consider this effect. Then a new correlation for the power number is established and can serve as a unified correlation for Newtonian and shear-thinning power-law fluids in the laminar regime in multistage RS systems. (C) 2014 Elsevier Ltd. All rights reserved |
| WOS标题词 | Science & Technology ; Technology |
| 类目[WOS] | Engineering, Chemical |
| 研究领域[WOS] | Engineering |
| 关键词[WOS] | NON-NEWTONIAN FLUIDS ; IMPELLERS CONFIGURATION ; ENERGY-DISSIPATION ; GAS DISPERSION ; CONSUMPTION ; BEHAVIOR ; GEOMETRY ; LIQUIDS ; FLOW |
| 收录类别 | SCI |
| 原文出处 | |
| 语种 | 英语 |
| WOS记录号 | WOS:000340931800018 |
| 公开日期 | 2014-09-30 |
| 版本 | 出版稿 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/11554]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 作者单位 | 1.Tianjin Univ, Sch Chem Engn & Technol, Tianjin 300072, Peoples R China 2.Chinese Acad Sci, Inst Proc Engn, State Key Lab Multiphase Complex Syst, Beijing 100190, Peoples R China 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 4.Unilever Res Colworth, Sharnbrook MK44 1LQ, Beds, England |
| 推荐引用方式 GB/T 7714 | Wu, Huashuai,Shu, Shuli,Yang, Ning,et al. Modeling of power characteristics for multistage rotor-stator mixers of shear-thinning fluids[J]. CHEMICAL ENGINEERING SCIENCE,2014,117(SEP):173-182. |
| APA | Wu, Huashuai,Shu, Shuli,Yang, Ning,Lian, Guoping,Zhu, Shiping,&Liu, Mingyan.(2014).Modeling of power characteristics for multistage rotor-stator mixers of shear-thinning fluids.CHEMICAL ENGINEERING SCIENCE,117(SEP),173-182. |
| MLA | Wu, Huashuai,et al."Modeling of power characteristics for multistage rotor-stator mixers of shear-thinning fluids".CHEMICAL ENGINEERING SCIENCE 117.SEP(2014):173-182. |
入库方式： OAI收割
来源：过程工程研究所
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