CIESC Journal ›› 2020, Vol. 71 ›› Issue (10): 4632-4641.doi: 10.11949/0438-1157.20200303

• Fluid dynamics and transport phenomena • Previous Articles     Next Articles

Chaotic mixing performance and mass transfer enhanced by rigid-flexible impeller with pulse jet

Zuohua LIU1,3(),Wei SUN1,3,Xia XIONG1,3,Changyuan TAO1,3,Yundong WANG2,Fangqin CHENG4   

  1. 1.School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
    2.Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
    3.State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China
    4.Institute of Resources and Environment Engineering, Shanxi University, Taiyuan 030006, Shanxi, China
  • Received:2020-03-23 Revised:2020-07-10 Online:2020-10-05 Published:2020-08-15
  • Contact: Zuohua LIU E-mail:liuzuohua@cqu.edu.cn

Abstract:

Conventional stirred reactors generally use rigid impeller for mechanical stirring, which leads to the easy creation of isolation mixing regions in the reactor and reduces the efficiency of fluid mixing. The use of multi-flow field coupling to induce chaos and promote more fluids into a chaotic state is one of the effective ways to improve fluid mixing efficiency. In this work, the largest Lyapunov exponent(LLE) and multi-scale entropy(MSE) are investigated with the Matlab compile pressure pulsation signals. The effects of duty ratio, paddle type, flexible paddle thickness, paddle height from the bottom and pulsed air jet flow rate on the chaotic mixing of fluids in a stirred reactor under different pulse periods are explored. In addition, the effects of different impeller types, jet types and air jet flow rate on the volume oxygen mass transfer coefficient KLa are compared and analyzed. When T=0.4 s and D=80%, the results show that the LLE of the rigid-flexible RT impeller compared with the rigid RT impeller increases 11.58% and the MSE of the rigid-flexible RT impeller is also larger than that of rigid RT impeller. It was showed that the pulsed jet rigid-flexible impeller system can better enhance fluid chaos, increase the fluid mixing efficiency and homogenize the system energy distribution. In addition, pulse jet coupling RF-RT impeller system enhances the turbulent characteristics of the fluid, promotes the reduction of the thickness of the liquid film, strengthens the mass transfer and increases the KLa value of the system. When power consumption per unit volume is 360 W/m3, the KLa of the PJ-RF-RT system compared with the PT-R-RT system increases 13.46%, and the KLa of the PJ-R-RT system compared with the SJ-R-RT system increases 11.86%.

Key words: chaos, pulse jet, rigid-flexible impeller, largest Lyapunov exponent, coefficient of mass transfer

CLC Number: 

  • TQ 028.8

Fig.1

Mixing experimental apparatus"

Fig.2

Jet types"

Fig.3

Impellers used in experiment"

Fig.4

Pulse electric signal waveform"

Fig.5

Effect of pulsed duty ratio on LLE"

Fig.6

Effect of impeller types on LLE"

Fig.7

Effect of thickness of flexible part on LLE"

Fig.8

Effect of impeller off-bottom clearances on LLE"

Fig.9

Effect of pulsed air jet flow rates on LLE"

Fig.10

Effect of impeller types on MSE"

Fig.11

Effect of thickness of flexible impeller on MSE"

Fig.12

Effect of pulsed air jet flow rates on MSE"

Fig.13

Effect of impeller types on KLa"

Fig.14

Effect of pulsed air jet flow rates on KLa"

3 杨锋苓, 周慎杰, 张翠勋, 等. 偏心搅拌槽固液悬浮特性[J]. 过程工程学报, 2008, 8(6): 1064-1069.
Yang F L, Zhou S J, Zhang C X. et al. Investigation on solid-liquid suspension performance in an eccentrically stirred tank [J]. The Chinese Journal of Process Engineering, 2008, 8(6): 1064-1069.
4 Yao W G, Sato H, Takahashi K, et al. Mixing performance experiments in impeller stirred tanks subjected to unsteady rotational speeds[J]. Chemical Engineering Science, 1998, 53(17): 3031-3040.
5 Kordas M, Story G, Konopacki M, et al. Study of mixing time in a liquid vessel with rotating and reciprocating agitator[J]. Industrial & Engineering Chemistry Research, 2013, 52(38): 13818-13828.
6 Paglianti A, Liu Z H, Montante G, et al. Effect of macroinstabilities in single- and multiple-impeller stirred tanks[J]. Industrial & Engineering Chemistry Research, 2008, 47(14): 4944-4952.
7 Sadhan C, Tjahjadi M, Ottino J M, et al. Chaotic mixing of viscous fluids by periodic changes in geometry: baffled cavity flow[J]. AIChE Journal, 1994, 40(11): 1769-1781.
8 Hwu T Y. Chaotic stirring in a new type of mixer with rotating rigid blades[J]. European Journal of Mechanics-B/Fluids, 2008, 27(3): 239-250.
9 Chien W L, Rising H, Ottino J M. Laminar mixing and chaotic mixing in several cavity flows[J]. Journal of Fluid Mechanics, 1986, 170: 355-377.
10 Hwu T Y. Fluid stirrings in a circular cavity with various driven boundaries[J]. European Journal of Mechanics-B/Fluids, 2006, 25(2): 192-203.
11 Bulnes‐Abundis D, Alvarez M M. The simplest stirred tank for laminar mixing: mixing in a vessel agitated by an off‐centered angled disc[J]. AIChE Journal, 2013, 59(8): 3092-3108.
12 Parekh D E, Kibens V, Glezer A, et al. Innovative jet flow control-mixing enhancement experiments[C]//34th Aerospace Sciences Meeting and Exhibit. Reno, 1996.
13 Freund J B, Moin P. Jet mixing enhancement by high-amplitude fluidic actuation[J]. AIAA Journal, 2000, 38(10): 1863-1870.
14 Kong B, Li T, Eri Q. Large eddy simulation of turbulent jet controlled by two pulsed jets: effect of forcing frequency[J]. Aerospace Science and Technology, 2019, 89: 356-369.
15 Fan J H, Wang Y D, Fei W Y. Large eddy simulations of flow instabilities in a stirred tank generated by a Rushton turbine[J]. Chinese Journal of Chemical Engineering, 2007, 15(2): 200-208.
16 刘作华, 宁伟征, 孙瑞祥, 等. 偏心空气射流双层桨搅拌反应器流场结构的分形特征[J]. 化工学报, 2011, 62(3): 628-635.
1 刘宝庆, 张义堃, 刘景亮, 等. 新型同心双轴搅拌器功率与混合特性的数值模拟[J]. 化工学报, 2013, 64(4): 1135-1144.
Liu B Q, Zhang Y K, Liu J L, et al. Numerical simulation of power consumption and mixing characteristic in stirred vessel with novel coaxial mixer[J]. CIESC Journal, 2013, 64(4): 1135-1144.
2 胡银玉, 刘喆, 杨基础, 等. 偏心搅拌反应器内的液相混合行为[J]. 化工学报, 2010, 61(10): 2517-2522.
Hu Y Y, Liu Z, Yang J C, et al. Liquid mixing in eccentric stirred tank [J]. CIESC Journal, 2010, 61(10): 2517-2522.
16 Liu Z H, Ning W Z, Sun R X, et al. Fractal flow structure in eccentric air jet-stirred reactor with double impeller [J]. CIESC Journal, 2011, 62(3): 628-635.
17 王海楠, 朱金波, 费之奎, 等. 射流-搅拌耦合式煤泥浮选装置的能量转化研究[J]. 选煤技术, 2018, 270(5):24-27.
Wang H N, Zhu J B, Fei Z K, et al. Study on energy conversion mechanism of jet-stirring integrated fine coal flotation device [J]. Coal Preparation Technology, 2018, 270(5): 24-27.
18 刘作华, 许传林, 何木川, 等. 穿流式刚-柔组合搅拌桨强化混合澄清槽内油-水两相混沌混合[J]. 化工学报, 2017, 68(2): 637-642.
Liu Z H, Xu C L, He M C, et al. Oil-water biphase chaotic mixing enhanced by punched rigid-flexible combination impeller in mixer-settler[J]. CIESC Journal, 2017, 68(2): 637-642.
19 熊黠, 刘作华, 谷德银, 等. 刚柔组合桨强化粉煤灰酸浸搅拌槽内固液混沌混合[J]. 化工学报, 2019, 70(5): 1693-1701.
Xiong X, Liu Z H, Gu D Y, et al. Chaotic mixing process of fly ash in acid leaching tank intensified by rigid-flexible impeller [J]. CIESC Journal, 2019, 70(5): 1693-1701.
20 邱发成, 刘作华, 刘仁龙, 等. 偏心射流-刚柔组合桨搅拌器内混沌混合行为研究[J]. 化工学报, 2018, 69(2): 618-624.
Qiu F C, Liu Z H, Liu R L, et al. Chaotic mixing performance in rigid-flexible impeller stirred tank with eccentric air jet [J]. CIESC Journal, 2018, 69(2): 618-624.
21 Garcia-Ochoa F, Gomez E. Bioreactor scale-up and oxygen transfer rate in microbial processes: an overview[J]. Biotechnology Advances, 2009, 27(2): 153-176.
22 Drandev S, Penev K I, Karamanev D. Study of the hydrodynamics and mass transfer in a rectangular air-lift bioreactor[J]. Chemical Engineering Science, 2016, 146(2): 180-188.
23 Aref H, Balachandar S. Chaotic advection in a Stokes flow[J]. Physics of Fluids, 1986, 29(11):3515-3521.
24 刘作华, 王运东, 陶长元. 流体混沌混合及搅拌过程强化方法[M]. 重庆: 重庆大学出版社, 2016: 24-30.
Liu Z H, Wang Y D, Tao C Y. Method for Strengthening Chaotic Mixing and Stirring of Fluid [M]. Chongqing: Chongqing University Press, 2016: 24-30.
25 Hewakandamby B N. A numerical study of heat transfer performance of oscillatory impinging jets[J]. International Journal of Heat and Mass Transfer, 2009, 52(1/2): 396-406.
26 Amiri T Y, Moghaddas J S, Moghaddas Y. A jet mixing study in two phase gas–liquid systems[J]. Chemical Engineering Research and Design, 2011, 89(3): 352-366.
27 Costa M, Goldberger A L, Peng C K. Multiscale entropy analysis of complex physiologic time series[J]. Physical Review Letters, 2002, 89(6): 1-4.
28 Prasad K Y, Ramanujam T K. Gas holdup and overall volumetric mass transfer coefficient in a modified reversed flow jet loop reactor[J]. The Canadian Journal of Chemical Engineering, 1995, 73(2): 190-195.
29 Jamshidi A M, Sohrabi M, Vahabzadeh F, et al. Studies on the hydrodynamic behavior and mass transfer in a down-flow jet loop reactor with a coaxial draft tube[J]. Journal of Chemical Technology & Biotechnology: International Research in Process, Environmental & Clean Technology, 2001, 76(1): 39-46.
[1] Baiping XU, Biao LIU, Yao LIU, Shouzai TAN, Yaoxue DU, Chuntai LIU. Numerical simulation of distributive mixing under a pair of triangular cams [J]. CIESC Journal, 2020, 71(8): 3545-3555.
[2] Zuohua LIU,Hongjun WEI,Xia XIONG,Changyuan TAO,Yundong WANG,Fangqin CHENG. Experiment and numerical simulation of chaotic mixing performance enhanced by perturbed rigid-flexible impeller in stirred tank [J]. CIESC Journal, 2020, 71(10): 4621-4631.
[3] Yubing LI, Mo YANG, Tingkang LU, Zhenghua DAI. Study on heat and mass transfer and nonlinear characteristics with heat and mass source in cavity [J]. CIESC Journal, 2019, 70(S2): 130-137.
[4] Li ZHANG, Gang YOU, Xiaofeng QIAO, Guangwen XU, Guozhen LIU, Yunyi LIU. Chaotic analysis of pressure fluctuation and identification of flow regime in chlor-alkali electrolyzer [J]. CIESC Journal, 2019, 70(S1): 35-44.
[5] Xia XIONG, Zuohua LIU, Deyin GU, Facheng QIU, Liang WANG, Changyuan TAO, Yundong WANG. Chaotic mixing process of fly ash in acid leaching tank intensified by rigid-flexible impeller [J]. CIESC Journal, 2019, 70(5): 1693-1701.
[6] Bing LI, Yi YANG, Zuohua LIU, Changyuan TAO, Deyin GU, Chuanlin XU, Yundong WANG. Solid-liquid chaotic mixing and leaching enhancement performance in phosphoric acid leaching process [J]. CIESC Journal, 2019, 70(5): 1742-1749.
[7] Zhaoming XIE, Rongrui DENG, Zuohua LIU, Li DENG, Qianwen LI, Zhu ZHANG, Zhaoqian YIN, Changyuan TAO. Evolution behavior of fractal growth of sodium roasting converter vanadium slag powder [J]. CIESC Journal, 2019, 70(5): 1904-1912.
[8] XIA Dahai, SONG Shizhe, WANG Jihui. Chaos analysis of electrochemical noise and its application in localized corrosion detection [J]. CIESC Journal, 2018, 69(4): 1569-1577.
[9] GU Deyin, LIU Zuohua, ZHANG Jiyizhe, QIU Facheng, LI Jun, TAO Changyuan, WANG Yundong. Chaotic mixing and dispersing characteristics of gas-liquid two phases in stirred tank [J]. CIESC Journal, 2018, 69(2): 625-632.
[10] QIU Facheng, LIU Zuohua, LIU Renlong, QUAN Xuejun, CHEN Jiaxing, GU Deyin, LI Bing, WANG Yundong. Chaotic mixing performance in rigid-flexible impeller stirred tank with eccentric air jet [J]. CIESC Journal, 2018, 69(2): 618-624.
[11] XIAO Qingtai, HUANG Junwei, PAN Jianxin, LIU Yun, XU Jianxin, WANG Hua. Assessing mixing uniformity of bubbles in direct-contact boiling heat transfer process [J]. CIESC Journal, 2017, 68(8): 3049-3055.
[12] LIU Zuohua, XU Chuanlin, HE Muchuan, GU Deyin, XU Huiqin, HE Haixian, TAO Changyuan, WANG Yundong. Oil-water biphase chaotic mixing enhanced by punched rigid-flexible combination impeller in mixer-settler [J]. CIESC Journal, 2017, 68(2): 637-642.
[13] LIU Zuohua, XU Huiqin, GU Deyin, XU Chuanlin, XIE Zhaoming, TAO Changyuan, WANG Yundong. Chaotic mixing performance enhanced by single-wire flexible impeller in stirred vessel [J]. CIESC Journal, 2017, 68(12): 4592-4599.
[14] FANG Haizhou, YANG Honghai, WANG Jun, LI Jianhua, ZOU Jing. Fractal characteristics of temperature oscillation in pulsating heat pipe under medium-low load [J]. CIESC Journal, 2016, 67(4): 1251-1257.
[15] ZHU Jun, LIU Zuohua, ZHENG Xiongpan, CHEN Chao, WANG Yundong. Macro-instability regulated by double rigid-flexible combination impeller [J]. CIESC Journal, 2015, 66(3): 896-904.
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
[1] LI Shaojun, HUANG Dingwei. Simulation and Analysis on Multiple Steady States of an Industrial Acetic Acid Dehydration System[J]. , 2011, 19(6): 983 -989 .
[2] HAN Jin, ZHU Tong, IMAI Tsuyoshi, XIE Liyang, XU Chenghai, NOZAKI Tsutomu. Solubilization of excess sludge by high speed rotary disk[J]. CIESC Journal, 2008, 59(2): 478 -483 .
[3] FAN Yiqun, QI Hong, XU Nanping. Advance in preparation techniques of porous ceramic membranes[J]. CIESC Journal, 2013, 64(1): 107 -115 .
[4] SUN Dongliang, XU Jinliang, CHEN Qicheng, CAO Zhen. Influence of gravity on flow pattern modulation in vertical phase separation condenser tube[J]. CIESC Journal, 2013, 64(9): 3189 -3197 .
[5] WU Meirong, ZHANG Rui, ZHOU Jun, XIE Xinxin, YONG Xiaoyu, YAN Zhiying, GE Mingmin, ZHENG Tao. Effect of temperature on methanogens metabolic pathway and structures of predominant bacteria[J]. CIESC Journal, 2014, 65(5): 1602 -1606 .
[6] LIU Dong, YU Haitong, YANG Zhen, DUAN Yuanyuan. Ultrathin film absorber for solar water splitting[J]. CIESC Journal, 2015, 66(S1): 297 -301 .
[7] LIU Changjun, GUO Qiuting, YE Jingyun, SUN Kaihang, FAN Zhigang, GE Qingfeng. Perspective on catalyst investigation for CO2 conversion and related issues[J]. CIESC Journal, 2016, 67(1): 6 -13 .
[8] WANG Ruirui, ZHAO Youjing, SHAO Mingfei, XIANG Xu, DUAN Xue. Recent progresses in water oxidation over layered double hydroxide catalysts[J]. CIESC Journal, 2016, 67(1): 54 -72 .
[9] DONG Jian, ZHANG Shenglu, SUN Weizhen, XU Zhimei, ZHAO Ling. Liquid-phase oxidation kinetics of sec-butylbenzene[J]. CIESC Journal, 2018, 69(11): 4737 -4745 .
[10] XIAO Junyin, YU Xiaochen, TANG Weiqiang, TAO Jiabo, ZHAO Shuangliang, LIU Honglai. DFT study on effect of hydrophilic modification of catalyst on oxidation efficiency of hydrogen gas[J]. CIESC Journal, 2018, 69(11): 4683 -4692 .