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Modelling of coalescence in turbulent liquid/liquid dispersions considering droplet charge

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Warianty tytułu
PL
Wzory koalescencji w turbulentnych dyspersjach między płynami w odniesieniu do ładunku kropelki
Języki publikacji
EN
Abstrakty
EN
Drop size distributions in liquid/liquid systems within a turbulent flow, being an integral part of many technical applications, can be simulated solving population balance equations. Experimental investigations in stirred toluene/water systems at constant ionic strength of 0.1 mol/L showed that with pH values higher than 11, coalescence is hindered considerably due to electrostatic effects. Within this work, two designated models are used to simulate the transient drop size distributions in a stirred tank, showing that the influence of droplet charge due to a change in pH value or ion concentration cannot be predicted satisfactorily by existing models. This finding motivates a new modelling approach implementing the DLVO theory into the population balance framework.
PL
Nierównomierne rozmieszczenie w przepływie turbulentnym w układach między płynami, stanowiących integralną część wielu urządzeń technicznych, można symulować przez rozwiązywanie równań równowagi populacji. Badania doświadczalne w zakresie mieszanych układów toluen/woda przy stałej sile jonowej 0,1 mol/L pokazały, że przy wartościach pH przekraczających 11 koalescencja jest znacznie utrudniona ze względu na efekty elektrostatyczne. W pracy niniejszej wykorzystano dwa przydzielone modele symulujące nierównomierne rozmieszczenie przejściowe w mieszanym zbiorniku. Za pomocą istniejących modeli nie można wiarygodnie prognozować wpływu ładunku kropelki po zmianie wartości pH lub stężenia jonu. Odkrycie to stanowi motywację dla nowej taktyki realizowania teorii DLVO w zakresie równowagi populacji.
Rocznik
Strony
113--124
Opis fizyczny
Bibliogr. 28 poz., wz., tab., wykr.
Twórcy
autor
  • Chair of Chemical and Process Engineering, TU Berlin
  • Chair of Chemical and Process Engineering, TU Berlin
autor
  • Chair of Chemical and Process Engineering, TU Berlin
autor
  • Chair of Chemical and Process Engineering, TU Berlin
Bibliografia
  • [1] Ramkrishna D., Population balance, Academic Press, San Diego 2000.
  • [2] Gomes L.N., Guimaraes M.L., Lopes J.C., Madureira C.N., Stichlmair J., Cruz-Pinto J.J., Reproducibility of the Hydrodynamic Performance and Measurements in a Liquid-Liquid Kühni Extraction Column-Relevance to Theoretical Model Evaluation, Industrial & Engineering Chemistry Research, 43(4), 2004, 1061-1070.
  • [3] Davies G.A., Jeffreys G.V., Smith D.V., Rate of coalescence of the dispersed phase in a laboratory mixer settler unit. II. Analysis of coalescence in a continuous mixer settler system by a differential model, AIChE J., 16, 1970, 827–831.
  • [4] Frising T., Noik C., Dalmazzone C., The liquid-liquid sedimentation process: From droplet coalescence to technologically enhanced water-oil emulsion gravity separators: A review, Journal of Dispersion Science and Technology, 27, 2006, 1035-1057.
  • [5] Gäbler A., Wegener M., Paschedag A., Kraume M., The effect of pH on experimental and simulation results of transient drop size distributions in stirred liquid-liquid dispersions, Chemical Engineering Science, 61(9), 2006, 3018-3024.
  • [6] Rambhau D., Phadke D.S., Dorle A.K., Evaluation of o/w emulsion stability through zeta potential, I, J. Soc. Cosmet. Chem, 28, 1977, 183-196.
  • [7] Watanabe A., Electrochemistry of oil-water interfaces, [in:] Matijevic E.: Surface and Colloid Science, 13, Plenum Press, New York 1984, 1-70.
  • [8] Lyklema J., van Leeuwen H.P., Minor M., DLVO-theory, a dynamic re-interpretation, Advances in Colloid and Interface Science, 83(1-3), 1999, 33-69.
  • [9] Lyklema J., Fundamentals of Interface and Colloid Science: Liquid-fluid interfaces, Academic Press, London 2000.
  • [10] Derjaguin B.V., Landau E.M., Theory of the stability of strongly charged lyophobic sols and of the adhesion of strongly charged particles in solutions of electrolytes, Acta Physicochitnica U.R.S.S, 14, 1941, 633-662.
  • [11] Verwey E.J.W., Overbeek J.T.G., Theory of the Stability of Lyophobic Colloids, Elsevier 1948.
  • [12] Tobin T., Ramkrishna D., Coalescence of charged droplets in agitated liquid-liquid dispersions, AIChE Journal, 38(8), 1992, 1199-1205.
  • [13] Kraume M., Gäbler A., Schulze K., Influence of physical properties on drop size distributions of stirred liquid-liquid dispersions, Chemical Engineering & Technology, 27(3), 2004, 330-334.
  • [14] Wegener M., Experimentelle Untersuchungen und Modellierung von transienten Tropfengrößenverteilungen in gerührten Flüssig-flüssig-Systemen, Master thesis, Chair of Chemical and process Engineering, TU Berlin, Germany 2004.
  • [15] Liao Y., Lucas D., A literature review of theoretical models for drop and bubble breakup in turbulent dispersions, Chemical Engineering Science, 64(15), 2009, 3389-3406.
  • [16] Liao Y., Lucas D., A literature review on mechanisms and models for the coalescence process of fluid particles, Chemical Engineering Science, 65, 2010, 2851-2864.
  • [17] Coulaloglou C.A., Tavlarides L.L., Description of interaction processes in agitated liquid-liquid dispersions, Chemical Engineering Science, 32, 1977, 1289-1297.
  • [18] Tobin T., Ramkrishna D.: Modeling the effect of drop charge on coalescence in turbulent liquid-liquid dispersions, The Canadian Journal of Chemical Engineering, 77(6), 1999, 1090-1104.
  • [19] Tsouris C., Tavlarides L.L., Breakage and Coalescence Models for Drops in Turbulent Dispersions, AIChE Journal, 40(3), 1994, 395-406.
  • [20] Maaß S., Kraume M.: Determination of breakage rates using single drop experiments, Chemical Engineering Science, 70, 2012, 146-164.
  • [21] Maaß S., Wollny S., Voigt A., Kraume M., Experimental comparison of measurement techniques for drop size distributions in liquid/liquid dispersions, Experiments in Fluids, 50(2), 2011, 259-269.
  • [22] Jon D.I., Rosano H.L., Cummins H.Z., Toluene Water/1-Propanol Interfacial-Tension Measurements by Means of Pendant Drop, Spinning Drop, and Laser Light-Scattering Methods, J. Colloid Interface Science, 114, 1986, 330-341.
  • [23] Arashiro E.Y., Demarquette N.R., Use of the Pendant Drop Method to Measure Interfacial Tension between Molten Polymers, Materials Research, 2, 1999, 23-32.
  • [24] Cupples H.L., Interfacial Tension by the Ring Method - the Benzene-Water Interface, Journal of Physical and Colloid Chemistry, 51, 1947, 1341-1345.
  • [25] Wulkow M., Gerstlauer A., Nieken U., Modeling and simulation of crystallization processes using parsival, Chemical Engineering Science, 56(7), 2001, 2575-2588.
  • [26] Misek T., Berger R., Schröter J., Standard Test Systems for Liquid Extraction, 2nd edn. EFCE Publication Series 46, European Federation of Chemical Engineering, Warwickshire 1985.
  • [27] Maaß S., Paschedag A.R., Kraume M., Influence of Electrolytes and Turbulence Parameters on Drop Breakage and Drop Size Distributions in Stirred Liquid/Liquid Dispersion, Proceedings of 6th International Conference on Multiphase Flow, Leipzig 2007.
  • [28] Pfennig A., Schwerin A., Influence of Electrolytes on Liquid-Liquid Extraction, Industrial & Engineering Chemistry Research, 37(8), 1998, 3180-3188.
Typ dokumentu
Bibliografia
Identyfikator YADDA
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