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Centrifugal separation in tube and disc geometries: experiments and theoretical models

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Abstract

The centrifugal separation of particles or droplets in dispersions is important in a variety of applications, e.g. mineral processing, water and waste water treatment, multistep processing of nanomaterials and biotechnology. Despite numerous studies in the past, separation processes of concentrated dispersions driven by gravity or centrifugal forces are not yet completely understood. Centrifuges can be subdivided into two categories: (1) centrifuges operating with tubes of constant cross section and (2) centrifuges operating with disc or cylinder rotors whose cross-sectional area changes with distance along the axis of rotation. This paper investigates the sedimentation process in centrifuges of these two categories experimentally and theoretically. Based on models for the separation of polydisperse dispersions in centrifugal field numerical calculations were carried out including the conversion of the time dependent concentrations profiles into light transmission profiles. The changes in the dispersion concentration profiles during the sedimentation process were monitored in situ by space- and time-resolved NIR light extinction profiles (STEP-Technology) obtained by multisample analytical centrifugation. Cells having constant and increasing cross sections were used. Results show that the velocity of the boundary between supernatant and dispersion as well as the alteration of the concentration measured radially in the centre of the cells do not depend on the geometry of the cells within the experimental errors. The sediment height in cells with increasing cross section is smaller compared to cells with constant cross section. The simulated sedimentation process is in good agreement with measured data for diluted and concentrated silica suspensions. Based on these results the sedimentation processes in disc or cylinder process centrifuges can be predicted from laboratory tests using analytical centrifugation.

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References

  1. Allen T.: Particle Size Measurement. Kluwer Academic Publishers, Dordrecht (1999)

    Google Scholar 

  2. Anestis, G.: Eine eindimensionale Theorie der Sedimentation in Absetzbehältern veränderlichen Querschnitts und in Zentrifugen. Doctoral Thesis, Technical University of Vienna, Austria (1981)

  3. Anestis G., Schneider W.: Application of theory of kinematic waves to centrifugation of suspensions. Ingenieur Arch. 53, 399–407 (1983)

    Article  Google Scholar 

  4. Babick, F., Stintz, M., Salinas-Salas, G.: Sedimentation of Colloidal particles, experimental study on the influence of the ionic strength on the hindrance function. In: 12th IACIS International Conference on Surface and Colloid Science, Beijing (2006)

  5. Berres S., Bürger R., Karlsen K.H., Tory E.M.: Strongly degenerate parabolic—hyperbolic systems modelling polydisperse sedimentation with compression. SIAM J. Appl. Math. 64, 41–80 (2003)

    Article  MATH  MathSciNet  Google Scholar 

  6. Berres S., Bürger R.: On gravity and centrifugal settling of polydisperse suspensions forming compressible sediments. Int. J. Solids Struct. 40, 4965–4987 (2003)

    Article  MATH  Google Scholar 

  7. Bürger R., Concha F.: Settling velocities of particulate systems: 12. Batch centrifugation of flocculated suspensions. Int. J. Miner. Process 63, 115–145 (2001)

    Article  Google Scholar 

  8. Detloff T., Sobisch T., Lerche D.: Particle size distribution by space or time dependent extinction profiles obtained by analytical centrifugation. Part. Part. Syst. Charact. 23, 184–187 (2006)

    Article  Google Scholar 

  9. Detloff T., Sobisch T., Lerche D.: Particle size distribution by space or time dependent extinction profiles obtained by analytical centrifugation (concentrated systems). Powder Technol. 174, 50–55 (2007)

    Article  Google Scholar 

  10. Frömer D., Lerche D.: An experimental approach to study of the sedimentation of dispersed particles in a centrifugal field. Arch. Appl. Mech. 72, 85–95 (2002)

    MATH  Google Scholar 

  11. van de Hulst H.C.: Light Scattering by Small Particles. Wiley, New York (1957)

    Google Scholar 

  12. ISO 13318, Determination of the particle size distribution by centrifugal liquid sedimentation methods (2001)

  13. Kurganov A., Tadmor E.: New high-resolution central schemes for nonlinear conservation laws and convection–diffusion equations. J. Comput. Phys. 160, 241–282 (2000)

    Article  MATH  MathSciNet  Google Scholar 

  14. Kynch G. J.: A theory of sedimentation. Trans. Faraday Soc. 48, 166–176 (1952)

    Article  Google Scholar 

  15. Leung W.W.F.: Centrifugal Separations in Biotechnology. Academic Press, UK (2007)

    Google Scholar 

  16. Lockett M.J., Bassoon K.S.: Sedimentation of binary particle mixtures. Powder Technol. 24, 1–7 (1979)

    Article  Google Scholar 

  17. Masliyah J.H.: Hindered settling in a multiple-species particle system. Chem. Eng. Sci. 34, 1166–1168 (1979)

    Article  Google Scholar 

  18. Richardson J.F., Zaki W.N.: Sedimentation and fluidization. Trans. Inst. Chem. Eng. 32, 35–53 (1954)

    Google Scholar 

  19. Salinas-Salas G., Ruiz-Tagle-Gutiérrez I., Babick F.: Análisis de la función de corrección de la velocidad de sedimentación para micro partículas Analysis of the correction function for micro-particle sedimentation velocity. Ingeniare. Revista Chilena de Ingeniería 15(3), 283–290 (2007)

    Google Scholar 

  20. Schaflinger U.: Centrifugal separation of a mixture. Fluid Dyn. Res. 6, 213–224 (1990)

    Article  Google Scholar 

  21. Schneider, W.: On the one-dimensional flow approximation in sedimentation process. In: Gyr A., Kinzelbach, Wolfgang (eds.) Proceedings of the Symposium, Sedimentation and Sediment Transport, held in Monte Verità, Switzerland, pp. 127–130, 2 to 6 September 2002

  22. Sobisch, T., Lerche, D., Babick, F., Salinas-Salas, G.: Particle interactions in dispersions of micro and nanoparticles/sedimentation of colloidal particles. In: Proceedings PARTEC 2007 Nuremberg 27th–29th March 2007, International Congress on Particle Technology (eds.) Wolfgang Peukert, Claudia Schregelmann, S18_1.pdf CD-ROM

  23. Ungarish M.: Hydrodynamics of Suspensions. Springer, Berlin (1993)

    Google Scholar 

  24. Ungarish M.: On the separation of a suspension in a tube centrifuge: critical comments on theoretical models and experimental verification. Arch. Appl. Mech. 73, 399–408 (2003)

    Article  MATH  Google Scholar 

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  1. L.U.M. GmbH, Rudower Chaussee 29 (OWZ), 12489, Berlin, Germany

    Torsten Detloff & Dietmar Lerche

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  1. Torsten Detloff
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  2. Dietmar Lerche
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Correspondence to Torsten Detloff.

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Dedicated to Professor Wilhelm Schneider on the occasion of his 70th birthday

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Detloff, T., Lerche, D. Centrifugal separation in tube and disc geometries: experiments and theoretical models. Acta Mech 201, 83–94 (2008). https://doi.org/10.1007/s00707-008-0074-y

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  • DOI: https://doi.org/10.1007/s00707-008-0074-y

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