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Turbulence Structure and Isotropy in Stirred Vessels

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Abstract

The turbulence structure of the impeller stream of a Rushton turbine was investigated in a vessel of diameter (T) 100 mm using 1° angle-resolved laser-Doppler anemometry (LDA) measurement techniques. The turbine was of diameter D = T/3. Measurements are presented for a region close to the impeller blades for both single and double impeller configurations. Comparisons of the three turbulence levels showed that the turbulence in the impeller stream is mostly anisotropic close to the blades. It is shown that the expressions ׀u’ − v’׀/V tip and ׀w’ − v’׀/V tip can provide a more meaningful and appropriate assessment of the degree of isotropy in the vessel than simple comparisons of the three components of the r.m.s. velocity u’, v’ and w’.

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References

  • Ali, A.M., Yuan H.H.S., Dickey D.S. and Tatterson G.B. (1981). Liquid dispersion mechanisms in agitated tanks: Part I. Pitched blade turbine, Chem. Eng. Commun., 10: 205.

    Article  CAS  Google Scholar 

  • Bakker A. (1992). Hydrodynamics of stirred gas-liquid dispersions. Ph.D. Thesis, Delft University of Technology, The Netherlands.

    Google Scholar 

  • Cutter, L.A., (1966). Flow and turbulence in a stirred tank, Journal of the American Institute of Chemical Engineers, 12 (1): 35.

    Article  CAS  Google Scholar 

  • Hockey, R.M. and Nouri J.M. (1996). Turbulent flow in a baffled vessel stirred by a 60° pitched blade impeller, Chem. Eng. Sci., 51: 4405.

    Article  CAS  Google Scholar 

  • Kresta, S.M. and Wood P.E. (1993). The flow field produced by a pitched blade turbine: characterisation of the turbulence and estimation of the dissipation rate, Chem. Eng. Sci., 48: 1761.

    Article  CAS  Google Scholar 

  • Lee, K.C. (1995). An experimental investigation of the trailing vortex structure and mixing characteristics of stirred vessels. Ph.D. Thesis, University of London.

    Google Scholar 

  • Mahouast, M., Cognet G. and David R. (1989). Two-component LDV measurements in a stirred tank, Journal of the American Institute of Chemical Engineers, 35 (11): 1770.

    Article  CAS  Google Scholar 

  • Ng, K., Fentiman, N.J., Lee, K.C. and Yianneskis, M. (1997). Assessment of sliding mesh CFD predictions and LDA measurements of the flow stirred by a Rushton impeller. Trans. I.Chem.E. Part A, Chemical Engineering Research and Design, 76: 737.

    Article  Google Scholar 

  • Nouri M. and Whitelaw J. H., (1990). Effect of size and confinement on the flow characteristics in stirred reactors. Proc. 5th Int. Symp. on App. Laser Tech. Fluid Mech., Lisbon, Portugal, Paper 23. 2.

    Google Scholar 

  • Rutherford, K., Lee, K.C., Mahmoudi, S.M.S. and Yianneskis, M. (1996). Aspects of the hydrodynamic characteristics of dual impeller stirred reactors. Journal of the American Institute of Chemical Engineers, 42: 332.

    Article  CAS  Google Scholar 

  • Schaefer, M., Yianneskis, M., Waechter, P. and Durst, F. (1997). On the trailing vortices around a 45° pitched blade impeller. Journal of the American Institute of Chemical Engineers, 44: 1233.

    Article  Google Scholar 

  • Sheu, Y.-H.E., Chang T.P.K., Tatterson G.B. and Dickey D.S. (1982). A three-dimensional measurement technique for turbulent flows, Chem. Eng. Commun., 17: 67.

    Article  CAS  Google Scholar 

  • Stoots C.M. & Calabrese R.V. (1995). The mean velocity field relative to a Rushton turbine blade. Journal of the American Institute of Chemical Engineers, 41: 1.

    Article  CAS  Google Scholar 

  • Van’t Riet, K. and Smith J.M. (1975). The trailing vortex system produced by Rushton turbine agitators, Chem. Eng. Sci., 30: 1093.

    Article  Google Scholar 

  • Van’t Riet K., Bruijn W. & Smith J. M., (1976). Real and pseudo-turbulence in the discharge stream from a Rushton turbine, Chem. Eng. Sci., 31: 407.

    Article  Google Scholar 

  • Wu, H. and Patterson G.K. (1989). Laser-Doppler measurements of turbulent-flow parameters in a stirred mixer, Chem. Eng. Sci., 44 (10): 2207.

    Article  CAS  Google Scholar 

  • Yianneskis M., Popiolek Z. and Whitelaw J. H. (1987). An experimental study of the steady and unsteady flow characteristics of stirred reactors, J. Fluid Mech., 175: 537.

    Article  CAS  Google Scholar 

  • Yianneskis M. & Whitelaw J. H. (1993). On the structure of the trailing vortices around Rushton turbine blades. Trans. I.Chem.E. Part A, 71: 543.

    CAS  Google Scholar 

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© 2000 Springer Science+Business Media Dordrecht

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Lee, K.C., Borrett, N.A., Yianneskis, M. (2000). Turbulence Structure and Isotropy in Stirred Vessels. In: Gupta, B.S., Ibrahim, S. (eds) Mixing and Crystallization. Springer, Dordrecht. https://doi.org/10.1007/978-94-017-2290-2_3

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  • DOI: https://doi.org/10.1007/978-94-017-2290-2_3

  • Publisher Name: Springer, Dordrecht

  • Print ISBN: 978-90-481-5410-4

  • Online ISBN: 978-94-017-2290-2

  • eBook Packages: Springer Book Archive

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