Particle suspension and mixing characteristics in a solid-liquid stirred tank with high solid content
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摘要: 對高固含體系下Intermig槳攪拌槽內的槳葉攪拌性能以及顆粒的混合與懸浮特性進行實驗研究.采用光導纖維技術對不同槳徑、攪拌轉速和槳葉離底距離下攪拌槽內底部以及軸向顆粒密度進行測量,同時對臨界懸浮轉速和攪拌功率進行測定.實驗結果表明:對高固含液-固攪拌體系,所采用的Intermig攪拌槳具有很好的軸向混合特性,該槳適合在較大的槳徑和較低的槳葉離底距離下應用,可在促進顆粒懸浮與均勻分布的同時,大大降低功率消耗.通過對實驗結果的分析和擬合得出底部均勻度與攪拌槽內弗勞德數有關,Q=0.58Fr-0.35,Intermig攪拌槳功率準數在0.2~0.3之間,且與雷諾數關系為NP=2.1Re-0.2.Abstract: The suspension and mixing characteristics of high-content solid particles were experimentally studied in a tank stirred with an Intermig impeller.An optical fiber technology was adopted to measure the bottom and axial solid concentration under different conditions of impeller diameter,rotational speed and impeller-bottom distance,and the critical suspension speed and power consumption were also investigated at the same time.The results show that the Intermig impeller has good axial mixing performance in the solid-liquid stirred system with high solid content.High impeller diameter and low impeller-bottom distance could improve the solid suspension and uniform distribution with low power consumption.By analyzing and fitting the experimental results,the bottom solid uniformity is calculated by Froude number with the equation of Q=0.58Fr-0.35 and the power number is calculated by Reynolds number with the equation of NP=2.1Re-0.2.
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Key words:
- stirred tank reactor /
- particles /
- mixing characteristics /
- suspension
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參考文獻
[4] Bujalski W, Takenaka K, Paoleni S, et al. Suspension and liquid homogenization in high solids concentration stirred chemical reactors. Chem Eng Res Des, 1999, 77(3):241 [5] Ibrahim S, Nienow A W. Comparing impeller performance for solid-suspension in the transitional flow regime with Newtonian fluids. Chem Eng Res Des, 1999, 77(8):721 [6] Ibrahim S, Nienow A W. Particle suspension in the turbulent regime:the effect of impeller type and impeller/vessel configuration. Chem Eng Res Des, 1996, 74(6):679 [7] Aubin J, Xuereb C. Design of multiple impeller stirred tanks for the mixing of highly viscous fluids using CFD. Chem Eng Sci, 2006, 61(9):2913 [9] Lin L, Bao Y P, Yue F, et al. Physical model of fluid flow characteristics in RH-TOP vacuum refining process. Int J Miner Metall Mater, 2012, 19(6):483 [11] Jiang J, Li J S, Wu H J, et al. Water modeling of molten steel flow in a multi-strand tundish with gas blowing. Int J Miner Metall Mater, 2010, 17(2):143 [12] Shan X G, Yu G Z, Yang C, et al. Numerical simulation of liquid-solid flow in an unbaffled stirred tank with a pitched-blade turbine downflow. Ind Eng Chem Res, 2008, 47(9):2926 [13] Zwietering T N. Suspending of solid particles in liquid by agitators. Chem Eng Sci, 1958, 8(3):244 [14] Wu J, Wang S, Nguyen B, et al. Improved mixing in magnetite iron ore tank via swirl flow:lab-scale and full-scale studies. Chem Eng Technol, 2015, 39(3):505 [15] Ayranci I, Machado M B, Madej A M, et al. Effect of geometry on the mechanisms for off-bottom solids suspension in a stirred tank. Chem Eng Sci, 2012, 79:163 -

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