Numerical Simulation of Low-Pressure Drop Static Mixers for Mixing Enhancement

Document Type : Research Article


1 Chemical Engineering Department, NED University of Engineering & Technology, Karachi, Sindh, PAKISTAN

2 Polymer and Petrochemical Engineering Department, NED University of Engineering & Technology, Karachi, Sindh, PAKISTAN


Static Mixers (SM), also generally known as inline mixers, form a newly developing industry trend. They have no moving parts, hence have lower energy consumption, lower installation cost, and very low maintenance cost, and are thus an attractive alternative to conventional agitators. Modifications were made to the design to reduce pressure drop and increase the mixing intensity across the mixer and increase the application of inline mixers in the industries. Three hybrid geometries (different combinations of Kenics and LPD) of static mixers were constructed and simulated using Computational Fluid Dynamics (CFD) tools. Kenics is an excellent radial mixing device, and Low-Pressure Drop (LPD) is an excellent axial mixing device. The key design parameter to modify LPD was the slope angle of elliptical plates which affects the mixer performance. Different slope angles from 90º to 120º were simulated. Kenics was modified for different aspect ratios, and the edge of Kenics was curved. Pressure drop, thermal, and Discrete Phase Model (DPM) analysis were performed on these three different classifications of hybrid geometries. The most promising geometry to emerge based on the low-pressure drop and good mixing efficiency was the curved edge Kenics. Keen-sighted these results, further analysis was performed on curved edge Kenics after the modification of the blend radius. It was concluded that for a lower Reynold number, the curved edge with a higher blend radius dominates all other mixers. Result validation was done by comparing the trends and sensitivity
of process variables with the established results and standards.


Main Subjects

[1] Bunkluarb N., Sawangtong W., Khajohnsaksumeth N., Wiwatanapataphee B., Numerical Simulation of Granular Mixing in Static Mixers with Different Geometries, Adv. Diff. Equ.2019: 1-17 (2019).
[2] Ouda M., Al-Ketan O., Sreedhar N., Hasan Ali M.I., Abu Al-Rub R.K., Hong S., Arafat H.A., Novel Static Mixers Based on Triply Periodic Minimal Surface (TPMS) Architectures, J. Environ. Chem. Eng.8: 1-11 (2020).
[3] Soman S.S., Madhuranthakam C.M.R., Effects of Internal Geometry Modifications on the Dispersive and Distributive Mixing in Static Mixers, Chem. Eng. Process., 122: 31-43 (2017).
[4] Jegatheeswaran S., Ein-Mozaffari F., Wu J., Process Intensification in a Chaotic SMX Static Mixer to Achieve an Energy-Efficient Mixing Operation of Non-Newtonian Fluids, Chem. Eng. Process., 124:
1-10 (2018).
[5] Göbel F., Golshan S., Norouzi H.R., Zarghami R., Mostoufi N., Simulation of Granular Mixing in a Static Mixer by the Discrete Element Method, Powder Technol.346: 171-179 (2019).
[6] Jung S.Y., Ahn K.H., Kang T.G., Park G.T., Kim S.U., Chaotic Mixing in a Barrier-Embedded Partitioned Pipe Mixer, AIChE J., 64: 717-729 (2018).
[7] Stec M., Synowiec P.M., Study of Fluid Dynamic Conditions in the Selected Static Mixers Part III—Research of Mixture Homogeneity, Can. J. Chem. Eng.97: 995-1007 (2018).
[8] Gurieff N., Keogh D.F., Timchenko V., Menictas C., Enhanced Reactant Distribution in Redox Flow Cells, Molecules, 24: 1-10 (2019).
[9] Saad M.A.M., Elamari A.A., Alshebani A.E., Elmabrouk E.M., Abukanisha S.I., Static Mixers for Water Ozonation: Applications and Mathematical Modelling - A Review, J. Pure Appl. Sci., 19: 59-72 (2020).
[10] Meng H.-B., Song M.-Y., Yu Y.-F., Jiang X.-H., Wang Z.-Y., Wu J.-H., Enhancement of Laminar Flow and Mixing Performance in a Lightnin Static Mixer, Int. J. Chem. React. Eng., 15: 1-21 (2017).
[11] Gidde R.R., Shinde A.B., Pawar P.M., Ronge B.P., Design Optimization of a Rectangular Wave Micromixer (RWM) Using Taguchi Based Grey Relational Analysis (GRA), Microsyst. Technol., 24: 3651-3666 (2018).
[12] Vasilev M.P., Abiev R.S., Intensity and Efficiency of Droplet Dispersion: Pulsating Flow Type Apparatus vs. Static Mixers, Chem. Eng. Res. Des., 137: 329-349 (2018).
[13] Alekseev K.A., Mukhametzyanova A.G., Classification, Function, and Construction of Modern Static Mixers, Chem. Pet. Eng.55:  934-942 (2020).
[15] Castro A., Helver N.L., Granada G.S., Gonzalez J., Nunhez, Assessment of the Use of Static Mixers for the Dilution of Heavy Oils with The Use of a Computational Fluid Dynamics Model, Braz. J. Chem. Eng.38:  1-19 (2020).
[16] Mukhametzyanova A.G., Alekseev K.A., Galimov F.F., Numerical Simulation of Flow Hydrodynamics in Irregular Packing Layer, Chem. Pet. Eng.52: 90-95 (2016).
[17] Kjær L.S., Poulsen M., Sørensen K., Condra T., Modelling of Hot Air Chamber Designs of a Continuous Flow Grain Dryer, Eng. Sci. Tech. Int. J.21: 1047-1055 (2018).
[18] Vasilev M.P., Abiev R.S., Turbulent droplets Dispersion in a Pulsating Flow Type Apparatus – New Type of Static Disperser, Chem. Eng. J., 349: 646-661 (2018).
[19] Iqbal S., Bibi I., Ata S., Kamal S., Ibrahim S.M., Iqbal M., Gd and Co-Substituted LaNiO3 and their Nanocomposites with r-GO for Photocatalytic Applications, Diamond Relat. Mater., 110: 1-14 (2020).
[20] Dharavath M., Manna P., Sinha P.K., Chakraborty D., Numerical Analysis of a Kerosene-Fueled Scramjet Combustor, J. Therm. Sci. Eng. Appl.8:  1-7 (2016).
[21] Nemati O., Ibarra L.M.C., Fung A.S., Review of Computer Models of Air-Based, Curtainwall-Integrated PV/T Collectors, Renewable Sustainable Energy Rev., 63: 102-117 (2016).
[22] Mahmoodi H., Razzaghi K., Shahraki F., Improving Mixing Performance by Curved‐Blade Static Mixer, AIChE J., 66: 1-13 (2020).
[23] Habchi C., Ghanem A., Lemenand T., Della Valle D., Peerhossaini H., Mixing Performance in Split-And-Recombine Milli-Static Mixers—A numerical Analysis, Chem. Eng. Res. Des., 142: 298-306 (2019).
[24] Mansour M., Zähringer K., Nigam K.D.P., Thévenin D., Janiga G., Multi-Objective Optimization of Liquid-Liquid Mixing in Helical Pipes Using Genetic Algorithms Coupled with Computational Fluid Dynamics, Chem. Eng. J., 391: 1-13 (2020).
[25] Belhout C., Bouzit M., Menacer B., Kamla Y.,
Ameur H., Numerical Study of Viscous Fluid Flows in a Kenics Static Mixer, Mechanics, 26: 206-211 (2020).
[26] Haddadi M.M., Hosseini S.H., Rashtchian D.,
Olazar M., Comparative Analysis of Different Static Mixers Performance by CFD Technique: An Innovative Mixer, Chin. J. Chem. Eng.28: 672-684 (2020).
[27] Hussain Z., Zaman M., Nadeem M., Ullah A., CFD Modeling of the Feed Distribution System of a Gas-Solid Reactor, Iran. J. Chem. Chem. Eng. (IJCCE), 38: 233-242 (2019).
[28] Hassan M., Razzaghi K., Shahraki F., Improving Mixing Performance by Curved‐Blade Static Mixer, AIChE J., 66: 1-13 (2020).