新型多叶轮潜水搅拌机流场特性
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摘要
为提高搅拌机搅拌效果,针对各种形状的污水处理池,设计出系列新型多叶轮潜水搅拌机.文中基于ANSYS Fluent 15.0,对2种新型多叶轮潜水搅拌机搅拌流体进行计算,展开深入研究.结果表明:新型双向潜水搅拌机和新型双层潜水搅拌机搅拌水池内流体有效轴向推进距离分别是同叶轮的传统潜水搅拌机的2. 0倍和1. 8倍,池内流体平均流速分别为0. 194 m/s和0.215 m/s,与传统潜水搅拌机搅拌流体平均速度0.203 m/s接近.新型双向潜水搅拌机池内最大速度沿轴向呈现马鞍形分布,且流体速度差较大,仅有73.2%流体的流速大于0.050 m/s,且低速区存在于水池中上部,其更适用于狭长且不深的水池.新型双层潜水搅拌机搅拌水池内流体最大速度分布沿轴向呈现双曲线递减分布,78.71%流体的流速在0.100～0.300 m/s,池内低速流体仅占1.55%.故新型双层潜水搅拌机和新型双向潜水搅拌机搅拌性能明显优于同叶轮的传统潜水搅拌机.研究结果可为潜水搅拌机的实际工程应用提供参考.
To improve the mixing effect of a submersible mixer,a series of new-type multi-impeller mixers were designed for sewage treatment pools in various shapes. Based on computational fluid dynamics software ANSYS Fluent 15.0,the flow fields of two new-type multi-impeller submersible mixers were studied. The results show that the effective axial propulsion distances in the new-type two-way submersible mixer and the new-type two-impeller submersible mixer are 2 times and 1.8 times that of the traditional mixer,and the average velocities of the fluid in the pool are 0.194 m/s and 0.215 m/s,respectively,which are close to the average velocity of 0.203 m/s in the traditional mixer. The maximum velocity curve induced by the new two-way submersible mixer is saddle-shaped,and the velocity difference is greater,only 73. 2% fluid velocity in the pool is higher than 0. 050 m/s,and the lowvelocity zone is in the middle and upper part of the pool. The maximum velocity curve generated by the new-type two-impeller submersible mixer is in a hyperbolic decreasing shape. 78.71% fluid velocity in the pool is between 0.100 and 0.300 m/s,and the low-velocity zone accounts for 1.55% of the water body in the pool. Thus,two new-type mixers designed are obviously better than the traditional mixer in performance. The results can provide a reference for practical engineering application of submersible mixers.
To improve the mixing effect of a submersible mixer,a series of new-type multi-impeller mixers were designed for sewage treatment pools in various shapes. Based on computational fluid dynamics software ANSYS Fluent 15.0,the flow fields of two new-type multi-impeller submersible mixers were studied. The results show that the effective axial propulsion distances in the new-type two-way submersible mixer and the new-type two-impeller submersible mixer are 2 times and 1.8 times that of the traditional mixer,and the average velocities of the fluid in the pool are 0.194 m/s and 0.215 m/s,respectively,which are close to the average velocity of 0.203 m/s in the traditional mixer. The maximum velocity curve induced by the new two-way submersible mixer is saddle-shaped,and the velocity difference is greater,only 73. 2% fluid velocity in the pool is higher than 0. 050 m/s,and the lowvelocity zone is in the middle and upper part of the pool. The maximum velocity curve generated by the new-type two-impeller submersible mixer is in a hyperbolic decreasing shape. 78.71% fluid velocity in the pool is between 0.100 and 0.300 m/s,and the low-velocity zone accounts for 1.55% of the water body in the pool. Thus,two new-type mixers designed are obviously better than the traditional mixer in performance. The results can provide a reference for practical engineering application of submersible mixers.
引文
[1]田飞,施卫东,张德胜.潜水搅拌机理论、设计及工程应用[M].北京:科学出版社,2016.
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[3]石磊,张德胜,陈健,等.基于PANS模型的轴流泵叶顶空化特性[J].排灌机械工程学报,2016,34(7):590-596.SHI Lei,ZHANG Desheng,CHEN Jian,et al.Analysis on characteristics of tip cavitation in an axial-flow pump based on PANS model[J].Journal of drainage and irrigation machinery engineering,2016,34(7):590-596.(in Chinese)
[4]TERASHIMA M,GOEL R,KOMATSU K,et al.CFDsimulation of mixing in anaerobic digesters[J].Bioresource technology,2009,100(7):2228-2233.
[5]TIANF,SHI W D,He X H,et al.Study on installation of the submersible mixer[C]//Proceedings of the 6th International Conference on Pumps and Fans with Compressors and Wind Turbines,2013.
[6]谭林伟,施卫东,张德胜,等.叶片出口安放角对单叶片泵性能的影响[J].排灌机械工程学报,2017,35(10):835-841.TAN Linwei,SHI Weidong,ZHANG Desheng,et al.Effects of blade outlet angle on the performance for single blade pumps[J].Journal of drainage and irrigation machinery engineering,2017,35(10):835-841.(in Chinese)
[7]TIAN Fei,SHI Weidong,JIANG Hua,et al.A study on two-phase flow of multiple submersible mixers based on rigid-lid assumption[J].Advances in mechanical engineering,2014(5):1-7.
[8]YOSHIDA M,EBINA H,ISHIOKA K,et al.Hydraulic design and power characterization of closed turbine-type agitator[J].International journal of chemical reactor engineering,2017,15(4):20160198.
[9]SHI WD,TIAN F,LU X N,et al.Strength analysis of the submersible mixer[J].Applied mechanics and materials,2012,197:18-23.
[10]OCHIENG A,ONYANGO M S,KUMAR A,et al.Mixing in a tank stirred by a Rushton turbine at a low clearance[J].Chemical engineering&processing process intensification,2008,47(5):842-851.
[2]中华人民共和国国家质量监督检验检疫总局、中国国家标准化管理委员会.CJ/T109-2007潜水搅拌机[S].北京:中国标准出版社,2007.
[3]石磊,张德胜,陈健,等.基于PANS模型的轴流泵叶顶空化特性[J].排灌机械工程学报,2016,34(7):590-596.SHI Lei,ZHANG Desheng,CHEN Jian,et al.Analysis on characteristics of tip cavitation in an axial-flow pump based on PANS model[J].Journal of drainage and irrigation machinery engineering,2016,34(7):590-596.(in Chinese)
[4]TERASHIMA M,GOEL R,KOMATSU K,et al.CFDsimulation of mixing in anaerobic digesters[J].Bioresource technology,2009,100(7):2228-2233.
[5]TIANF,SHI W D,He X H,et al.Study on installation of the submersible mixer[C]//Proceedings of the 6th International Conference on Pumps and Fans with Compressors and Wind Turbines,2013.
[6]谭林伟,施卫东,张德胜,等.叶片出口安放角对单叶片泵性能的影响[J].排灌机械工程学报,2017,35(10):835-841.TAN Linwei,SHI Weidong,ZHANG Desheng,et al.Effects of blade outlet angle on the performance for single blade pumps[J].Journal of drainage and irrigation machinery engineering,2017,35(10):835-841.(in Chinese)
[7]TIAN Fei,SHI Weidong,JIANG Hua,et al.A study on two-phase flow of multiple submersible mixers based on rigid-lid assumption[J].Advances in mechanical engineering,2014(5):1-7.
[8]YOSHIDA M,EBINA H,ISHIOKA K,et al.Hydraulic design and power characterization of closed turbine-type agitator[J].International journal of chemical reactor engineering,2017,15(4):20160198.
[9]SHI WD,TIAN F,LU X N,et al.Strength analysis of the submersible mixer[J].Applied mechanics and materials,2012,197:18-23.
[10]OCHIENG A,ONYANGO M S,KUMAR A,et al.Mixing in a tank stirred by a Rushton turbine at a low clearance[J].Chemical engineering&processing process intensification,2008,47(5):842-851.