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Recent Innovations in Chemical Engineering

Editor-in-Chief

ISSN (Print): 2405-5204
ISSN (Online): 2405-5212

Research Article

Analysis of Performance in Homogenous Mixing Systems Using Ansys

Author(s): M. Aslam Abdullah*, Ambuj Gupta, Rithul Roy* and Aseel A.

Volume 16, Issue 2, 2023

Published on: 07 July, 2023

Page: [135 - 146] Pages: 12

DOI: 10.2174/2405520416666230525095959

Price: $65

Open Access Journals Promotions 2
Abstract

Objective: This study aims to understand the mixing phenomenon and the mass transfer occurring simultaneously by simulating the system using Ansys Fluent.

Methods: Taking liquid-liquid mixing into account, a simple agitated mixing system can be compared to a CSTR, utilizing the impeller to provide forced convection mixing conditions. The same forced convection can be achieved using high flow rates in smooth vessels instead of mechanical impellers to produce the convection current. The systems are then stimulated using Ansys Fluent software to calculate the mass transfer coefficient and several dimensionless numbers, such as the Reynolds number, Sherwood number, and Schmidt number, in order to understand the underlying mechanism of mass transfer in mixing systems.

Results: It has been observed that a 90° pitch impeller tends to have a higher NP value as compared to a 45° pitch impeller. Overall performance can be compared by the time taken to achieve homogeneity at the same angular rotational speed of 100 rpm. Thus, in terms of performance, it can be concluded that 45° pitch is (inclined) > 90° pitch is (in-centre) > 45° pitch (in-centre) is > 90° pitch (inclined).

Conclusion: The simulation model used in this study is useful for a combination of CFD model predictions using the sliding mesh approach and the VOF model. It can be applied to study the effect of different designs on the flow pattern and mixing time for a set of axial flow impellers.

Keywords: Agitated, mixing system, Ansys, impellers, power, number, VOF Model, CFD, CSTR.

Graphical Abstract
[1]
Arratia PE, Lacombe JP, Shinbrot T, Muzzio FJ. Segregated regions in continuous laminar stirred tank reactors. Chem Eng Sci 2004; 59(7): 1481-90.
[http://dx.doi.org/10.1016/j.ces.2003.06.003]
[2]
Burghardt A, Lipowska L. Mixing phenomena in a continuous flow stirred tank reactor. Chem Eng Sci 1972; 27(10): 1783-95.
[http://dx.doi.org/10.1016/0009-2509(72)85040-1]
[3]
Hadjeb A, Bouzit M, Kamla Y, Ameur H. A new geometrical model for mixing of highly viscous fluids by combining two-blade and helical screw agitators. Pol J Chem Technol 2017; 19(3): 83-91.
[http://dx.doi.org/10.1515/pjct-2017-0053]
[4]
Patil SS, Deshmukh NA, Joshi JB. Mass transfer characteristics of surface aerators and gas inducing impellers. Ind Eng Chem Res 2004; 43(11): 2765-74.
[http://dx.doi.org/10.1021/ie030428h]
[5]
Hassanzadeh M, Tayebi L, Dezfouli H. Investigation of factors affecting on viscosity reduction of sludge from Iranian crude oil storage tanks. Petrol Sci 2018; 15(3): 634-43.
[http://dx.doi.org/10.1007/s12182-018-0247-9]
[6]
Rajavathsavai D, Khapre A, Munshi B. Study of mixing behavior of cstr using CFD. Braz J Chem Eng 2014; 31(1): 119-29.
[http://dx.doi.org/10.1590/S0104-66322014000100012]
[7]
Rakoczy R, Masiuk S. Forced convection masstransfer enhancement in mixing systems. In: Advanced Topics in Mass Trans. UK: Intech open 2011; pp. 113.
[8]
Santos-Moreau V, Brunet-Errard L, Rolland M. Numerical CFD simulation of a batch stirred tank reactor with stationary catalytic basket. Chem Eng J 2012; 207: 596-606.
[http://dx.doi.org/10.1016/j.cej.2012.07.020]
[9]
Lipowska L. The influence of geometric parameters on the ideal mixing range of liquid in a continuous flow stirred tank reactor. Chem Eng Sci 1974; 29(9): 1901-8.
[http://dx.doi.org/10.1016/0009-2509(74)85007-4]
[10]
Medek J, Fort I. Mixing in vessel with eccentrical mixer. Proceedings of the Fifth European Conference on Mixing. Wurzburg, Germany. 1985; pp. 263-71.
[11]
Moucha T, Linek V, Prokopová E. Gas hold-up, mixing time and gas–liquid volumetric mass transfer coefficient of various multiple-impeller configurations: Rushton turbine, pitched blade and techmix impeller and their combinations. Chem Eng Sci 2003; 58(9): 1839-46.
[http://dx.doi.org/10.1016/S0009-2509(02)00682-6]
[12]
Bugay S, Escudié R, Liné A. Experimental analysis of hydrodynamics in axially agitated tank. AIChE J 2002; 48(3): 463-75.
[http://dx.doi.org/10.1002/aic.690480306]
[13]
Lu WM, Wu HZ, Chou CY. Effect of impeller blade number on KlA in mechanically agitated vessels. Korean J Chem Eng 1999; 16(5): 703-8.
[http://dx.doi.org/10.1007/BF02708156]
[14]
Mavros P, Xuereb C, Bertrand J. Determination of 3-D flow fields in agitated vessels by laser Doppler velocimetry: Use and interpretation of RMS velocities. Chem Eng Res Des 1998; 76(2): 223-33.
[http://dx.doi.org/10.1205/026387698524640]
[15]
Zhou G, Kresta SM. Distribution of energy between convective and turbulent flow for three frequently used impellers. Chem Eng Res Des 1996; 74: 379-89.
[16]
Fentiman NJ, Hill NST, Lee KC, et al. A novel profiled blade impeller for homogenization of miscible liquids in stirred vessels. Chem Eng Res Des 1998; 76: 835-42.
[http://dx.doi.org/10.1205/026387698525586]
[17]
Huang W, Li K. CFD simulation of flows in stirred tank reactors through prediction of momentum source. In: Nuclear Reactor Thermal Hydraulics and Other Application. UK: Intech open 2013.
[18]
Escudié R, Bouyer D, Liné A. Characterization of trailing vortices generated by a Rushton turbine. AIChE J 2004; 50(1): 75-86.
[http://dx.doi.org/10.1002/aic.10007]
[19]
Bohlav J, Fort I, Maca K, Placek J. Turbulent characteristics of discharge flow from the turbine impeller. Collect Czech Chem Commun 2004; 43: 2765-74.
[20]
Jaworski Z, Nienow AW, Dyster KN. An LDA study of the turbulent flow field in a baffled vessel agitated by an axial, down-pumping hydrofoil impeller. Cancer J Chem Eng 1996; 74(1): 3-15.
[http://dx.doi.org/10.1002/cjce.5450740103]

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