Prediction of mass transfer coefficients in an asymmetric rotating disk contactor using effective diffusivity

doi:10.1016/j.cjche.2016.08.021

Abstract

Abstract: Mass transfer characteristics have been investigated in a 113 mm diameter asymmetric rotating disk contactor of the pilot plant scale for two different liquid-liquid systems. The effects of operating parameters including rotor speed and continuous and dispersed phase velocities on the volumetric overall mass transfer coefficients are investigated. The results show that the mass transfer performance is strongly dependent on agitation rate and interfacial tension, but only slightly dependent on phase flow rates. In this study, effective diffusivity is used instead of molecular diffusivity in the Gröber equation for estimation of dispersed phase overall mass transfer coefficient. The enhancement factor is determined experimentally and there from an empirical expression is derived for prediction of the enhancement factor as a function of Reynolds number. The predicted results compared to the experimental data show that the proposed correlation can efficiently predict the overall mass transfer coefficients in asymmetric rotating disk contactors.

Key words: Asymmetric rotating disk contactor, Mass transfer coefficient, Enhancement factor, Interfacial area, Dispersed phase holdup

摘要： Mass transfer characteristics have been investigated in a 113 mm diameter asymmetric rotating disk contactor of the pilot plant scale for two different liquid-liquid systems. The effects of operating parameters including rotor speed and continuous and dispersed phase velocities on the volumetric overall mass transfer coefficients are investigated. The results show that the mass transfer performance is strongly dependent on agitation rate and interfacial tension, but only slightly dependent on phase flow rates. In this study, effective diffusivity is used instead of molecular diffusivity in the Gröber equation for estimation of dispersed phase overall mass transfer coefficient. The enhancement factor is determined experimentally and there from an empirical expression is derived for prediction of the enhancement factor as a function of Reynolds number. The predicted results compared to the experimental data show that the proposed correlation can efficiently predict the overall mass transfer coefficients in asymmetric rotating disk contactors.

关键词: Asymmetric rotating disk contactor, Mass transfer coefficient, Enhancement factor, Interfacial area, Dispersed phase holdup

Meisam Torab-Mostaedi, Mehdi Asadollahzadeh, Jaber Safdari. Prediction of mass transfer coefficients in an asymmetric rotating disk contactor using effective diffusivity[J]. , 2017, 25(3): 288-293.

References

[1] M. Asadollahzadeh, Sh. Shahhosseini, M. Torab-Mostaedi, A. Ghaemi, Mass transfer performance in an Oldshue-Rushton column extractor, Chem. Eng. Res. Des. 100(2015) 104-112.
[2] M. Asadollahzadeh, Sh. Shahhosseini, M. Torab-Mostaedi, Ghaemi, The effects of operating parameters on stage efficiency in an Oldshue-Rushton column, Chem. Ind. Chem. Eng. Q. 22(1) (2016) 75-83.
[3] M. Asadollahzadeh, M. Torab-Mostaedi, Sh. Shahhosseini, A. Ghaemi, Holdup, characteristic velocity and slip velocity between two phases in a multi-impeller column for high/medium/low interfacial tension systems, Chem. Eng. Process. 100(2016) 65-78.
[4] M. Asadollahzadeh, M. Torab-Mostaedi, Sh. Shahhosseini, A. Ghaemi, Experimental investigation of dispersed phase holdup and flooding characteristics in a multistage column extractor, Chem. Eng. Res. Des. 105(2016) 177-187.
[5] A. Kumar, S. Hartland, Prediction of dispersed phase hold-up in rotating disc extractors, Chem. Eng. Commun. 106(1987) 56-87.
[6] É. Moreira, L.M. Pimenta, L.L. Caneiro, P.C.L. Faria, M.B. Mansur, C.P. Pibeiro, Hydrodynamic behavior of a rotating disc contactor under low agitation conditions, Chem. Eng. Commun. 192(2005) 1017-1035.
[7] Y.D.Wang, W.Y. Fei, J.H. Sun, Y.K. Wan, Hydrodynamics and mass transfer performance of a modified rotating disc contactor (MRDC), Chem. Eng. Res. Des. 80(2002) 392-400.
[8] M. Asadollahzadeh, A. Ghaemi, M. Torab-Mostaedi, Sh. Shahhosseini, Experimental mass transfer coefficients in a pilot plant multistage column extractor, Chin. J. Chem. Eng. 24(8) (2016) 989-999.
[9] Y. Kawase, Dispersed-phase holdup and mass transfer in a rotating disc contactor with perforated skirts, J. Chem. Technol. Biotechnol. 48(1990) 247-260.
[10] S. Soltanali, Y. Ziaie-Shirkolaee, G. Amoabediny,H. Rashedi, A. Sheikhi, P. Chamanrokh, Hydrodynamics and mass transfer of rotating sieved disc contactors used for reversed micellar extraction of protein, Chem. Eng. Sci. 64(2009) 2301-2306.
[11] B.D. Kadam, J.B. Joshi, R.N. Patil, Hydrodynamic and mass transfer characteristics of asymmetric rotating disc extractors, Chem. Eng. Res. Des. 87(2009) 756-769.
[12] N. Outili, A.-.H. Meniai, G. Gneist, H.-.J. Bart, Model assessment for the prediction of mass transfer coefficients in liquid-liquid extraction columns, Chem. Eng. Technol. 30(2007) 758-763.
[13] H. Gröber, Die Erwärmung and abkühlung einfacher geometrischer körper, Z. Var. Dtsch. Ing. 69(1925) 705-711.
[14] R. Kronig, J.C. Brink, On the theory of extraction from falling drops, Appl. Sci. Res. A2(1950) 142-154.
[15] A.E. Handlos, T. Baron,Mass and heat transfer fromdrops in liquid-liquid extraction, AIChE J. 3(1957) 127-136.
[16] A.I. Johnson, A.E. Hamielec, Mass transfer inside drops, AIChE J. 6(1960) 145-149.
[17] L. Steiner, Mass transfer rates from single drops and drop swarms, Chem. Eng. Sci. 41(1986) 1979-1986.
[18] H. Bahmanyar, L. Nazari, A. Sadr, Prediction of effective diffusivity and using of it in designing pulsed sieve extraction columns, Chem. Eng. Process. 47(2008) 57-65.
[19] M. Amanabadi, H. Bahmanyar, Z. Zarkeshan, M.A. Mousavian, Prediction of effective diffusion coefficient in rotating disc columns and application in design, Chin. J. Chem. Eng. 17(2009) 366-372.
[20] M. Torab-Mostaedi, J. Safdari, M. Ghannadi-Maragheh, M.A. Moosavian, Prediction of overallmass transfer coefficient in a Hanson mixer-settler using effective diffusivity, J. Chem. Eng. Jpn. 42(2009) 78-85.
[21] M.Torab-Mostaedi, J. Safdari, Predictionofmass transfer coefficients in a pulsed packed extraction column using effective diffusivity, Braz. J. Chem. Eng. 26(2009) 685-694.
[22] M. Torab-Mostaedi, A. Ghaemi, M. Asadollahzadeh, Prediction ofmass transfer coefficients in a pulsed disc and doughnut extraction column, Can. J. Chem. Eng. 90(2012) 1569-1577.
[23] A. Hemmati, M. Torab-Mostaedi, M. Asadollahzadeh, Mass transfer coefficients in a Kühni extraction column, Chem. Eng. Res. Des. 93(2015) 747-754.
[24] T. Míšek, R. Berger, J. Schröter, Standard Test Systems for Liquid Extraction Studies, EFCE Publ. Ser. 46(1985) 1.
[25] H.R.C. Pratt, G.W. Stevens, Axial dispersion, in:J.D. Thornton (Ed.), Science and Practice in Liquid-Liquid Extraction, Oxford University Press, UK, 1992, pp. 461-492.
[26] A. Kumar, S. Hartland, Prediction of axial mixing coefficients in rotating disc and asymmetric rotating disc extraction columns, Can. J. Chem. Eng. 70(1992) 77-87.