Dispersion Parameters and Effect of Impeller Speed, Holdup and Volume Fraction of Dispersed Phase on Separation Efficiency, Mass Transfer Coefficient of Dispersed Phase and Distribution Coefficient on Mixer-Settler Set

Document Type : Research Article

Authors

Faculty of Chemical Engineering, University of Tehran, Tehran, I.R. IRAN

Abstract

An experimental study has been conducted on the hydrodynamics of a stage mixer-settler to obtain an appropriate design. In this paper several tests was performed to investigate full factorial design of experiments. Since each test was repeated seven times, the repeatability of the test was confirmed (P=1 bar and T=25 °C). Sauter diameter was determined by photographing both the mixer and settler in each test. The Sauter diameter was compared with the Calderbank model; finally, a model was suggested. Holdup quantity was measured by a vacuum pump at the end of each test. Another aim of this paper is the evaluation of separation mechanism under different impeller speeds and volume fractions. The effect of impeller speed in constant ratio of phases flow rate, and hold up are evaluated, and the effect of phase flow rate ratios in constant impeller speed on extraction efficiency, mass transfer coefficient and distribution coefficient were determined.

Keywords

Main Subjects


[1] Ali A.M.I., Ahmad I.M., Daoud J.A., CYANEX 272 for the Extraction and Recovery of Zinc from Aqueous Waste Solution Using a Mixer-Settler Unit, Sep. Purif. Technol., 47, p. 135 (2006).
[2] Chakra Borty M., Bhattacharya C., Datt S., Effect of Drop Size Distribution on Mass Transfer Analysis of the Extraction of Nickel (II) by Emulsion Liquid Membrane, Physicochem. Eng. Aspects., 224, p. 65 (2003).
[3] Chouai, M. C., Le Lann M.V., Gourdon C., Casamatta G., Use of Neural Networks for Liquid-Liquid Extraction Column Modeling: an Experimental Study, Chem. Eng. Process., 39, p. 171 (2000).
[4] Dehghani T.R.F., Foster N.R., Current Issues Relating to Anti-Solvent Micronisation Techniques and Their Extension to Industrial Scales, J. Supercrit. Fluid., 21, p. 159 (2001).
[5] Dehkordi M., Application of a Novel-Opposed-Jets Contacting Device in Liquid-Liquid Extraction, Chem. Eng. Process., 41, p. 251 (2002).
[6] Giraldo-Zuniga D.A., Jane Coimbra S.R., Luis Minim A., Edwin Garcia Rojas E., Axial Mixing in a Graesser Liquid-Liquid Contactor Using Aqueous Two-Phase Systems, Chem. Eng. Process., 44, p. 441 (2005).
[7] Giraldo-Zuniga, D., Jane Coimbra S.R., Luis Minim A., Edwin Garcia Rojas E., Current Issues Relating to Anti-Solvent Micronisation Techniques and Their Extension to Industrial Scales, J. Super. Crit. Fluid., 21, p. 159 (2001).
[8] Giraldo-Zuniga D.A., Jane Coimbra S.R., Luis Minim A., Edwin Garcia Rojas E., Dispersed Phase Hold-Up in a Graesser Raining Bucket Contactor Using aqueous Two-Phase Systems, J. Food Eng. , 72, p. 302 (2006).
[9] Gottliebsen K., Grinbaum B., Chen D., Stevens G.W., The Use of Pulsed Perforated Plate Extraction Column for Recovery of Sulphuric Acid from Copper Tank House Electrolyte Bleeds, Hydrometallurgy., 58, p. 203 (2000).
[10] Pinto, G. A., Dura˜ob F.O., Fiu´z A.M.A., Guimara˜es M.B.L., Novais Madureirac C.M., Design Optimisation Study of Solvent Extraction: Chemical Reaction, Mass Transfer and Mixer-Settler Hydrodynamics, Hydrometallurgy., 74, p. 131 (2004).
[11] Rajmane, M.M., Sargar B.M., Mahamuni S.V., Anuse M.A., Solvent Extraction Separation of Zirconium(IV) from Succinate Media with N-n-Octylaniline, J. Serb. Chem. Soc., 71, p. 223 (2006).
[12] Ruivo R., Paiva A., Sim˜oes P.C., Hydrodynamics and Mass Transfer of a Static Mixer at High Pressure Conditions, Chem. Eng. Process., 45, p. 224 (2006).
[13] Ruiz M.C., Lermanda P., Padill R., Drop Size Distribution in a Batch Mixer under Breakage Conditions, Hydrometallurgy, 63, p. 65 (2002).
[14] Saien, J., Ebrahimzadeh Zonouzian S.A., Molaei Dehkordi A., Investigation of a Two Impinging-Jets Contacting Device for Liquid–Liquid Extraction Processes, Chem. Eng. Sci., 61, p. 3942 (2006).
[15] Schloman Jr.W.W. Processing Guayule for Latex and Bulk Rubber, Ind. Crop. Prod., 22, p. 41 (2005).
[16] Schmidt S.A., Simon M., Attarakih M.M., Lagar G. L., Bart H., Droplet Population Balance Modeling-Hydrodynamics and Mass Transfer, Chem. Eng. Sci., 61, p. 246 (2006).
[17] Staszak K., Prochaska K., Adsorption at the Liquid-Liquid Interface in Mixed Systems with Hydrophobic Extractants and Modifiers 2. Dynamic Interfacial Tension at the Hydrocarbon/Water Interface in Binary Mixed Systems, J. Colloid. Interf. Sci., 294, p. 411 (2006).