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Abstract

Complex rheological properties of yield-stress materials may lead to the generation of an intensive mixing zone near a rotating impeller. From the practical point of view, the zone should cover most of the stirred liquid. According to the literature review, several parameters may affect the size of the mixing zone, in particular forces exerted on the liquid. This paper presents both experimental and numerical investigation of axial and tangential forces generated during mechanical mixing of yield-stress fluids in a stirred tank. The tested fluids were aqueous solutions of Carbopol Ultrez 30 of concentration either 0.2 or 0.6 wt% and pH = 5:0. The study was performed for three types of impeller, pitched blade turbine, Prochem Maxflo T and Rushton turbine, in a broad range of their rotational speed, N = 60 - 900 rpm. The axial and tangential forces were calculated from the apparent mass of the stirred tank and torque, respectively. The experimental results were compared with CFD predictions, revealing their good agreement. Analysis of the generated forces showed that they are dependent on the rheological characteristic of liquid and the impeller type. It was also found that although axial force was smaller than tangential force, it significantly increased the resultant force.
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Bibliography

Adams L. W., Barigou M., 2007. CFD analysis of caverns and pseudo-caverns developed during mixing of non- Newtonian fluids. Chem. Eng. Res. Des., 85, 598–604. DOI: 10.1205/cherd06170.

Amanullah A., Hjorth S.A., Nienow A.W., 1997. Cavern sizes generated in highly shear thinning viscous fluids by SCABA 3SHP1 impellers. Food Bioprod. Process., 75, 232–238. DOI: 10.1205/096030897531630.

Amanullah A., Hjorth S.A., Nienow A.W., 1998. A new mathematical model to predict cavern diameters in highly shear thinning, power law liquids using axial flow impellers. Chem. Eng. Sci., 53, 455–469. DOI: 10.1016/S0009-2509(97)00200-5.

Ameur H., 2016. Agitation of yield stress fluids in different vessel shapes. Eng. Sci. Technol., 19, 189–196. DOI: 10.1016/j.jestch.2015.06.007.

Ameur H., 2017. Mixing of a viscoplastic fluid in cylindrical vessels equipped with paddle impellers. Chemistry Select, 2, 11492–11496. DOI: 10.1002/slct.201702459.

Ameur H., 2019. Some modifications in the Scaba 6SRGT impeller to enhance the mixing characteristics of Hershel-Bulkley fluids. Food Bioprod. Process., 117, 302–309. DOI: 10.1016/j.fbp.2019.08.007.

Ameur H., Bouzit M., Helmaoui M., 2011. Numerical study of fluid flow and power consumption in a stirred vessel with a Scaba 6SRGT impeller. Chem. Process Eng., 32, 351–366. DOI: 10.2478/v10176-011-0028-0.

Arratia P.E., Kukura J., Lacombe J., Muzzio F.J., 2006. Mixing of shear-thinning fluids with yield stress in stirred tanks. AIChE J., 52, 2310–2322. DOI: 10.1002/aic.10847.

Bakker C.W., Meyer C.J., Deglon D.A., 2009. Numerical modelling of non-Newtonian slurry in a mechanical flotation cell. Miner. Eng., 22, 944–950. DOI: 10.1016/j.mineng.2009.03.016.

Bakker C.W., Meyer C.J., Deglon D.A., 2010. The development of a cavern model for mechanical flotation cells. Miner. Eng., 23, 968–972. DOI: 10.1016/j.mineng.2010.03.016.

Bhole M.R., Bennington C.P.J., 2010. Performance of four axial flow impellers for agitation of pulp suspensions in a laboratory-scale cylindrical stock chest. Ind. Eng. Chem. Res., 49, 4444-4451. DOI: 10.1021/ie901854d.

Bhole M.R., Hui L.K., Gomez C., Bennington C.P.J., Dumont G.A., 2011. The effect of off-wall clearance of a side-entering impeller on the mixing of pulp suspensions in a cylindrical stock chest. Can. J. Chem. Eng., 89, 985–995. DOI: 10.1002/cjce.20503.

Bonn D., Denn M.M., Berthier L., Divoux T., Manneville S., 2017. Yield stress materials in soft condensed matter. Rev. Mod. Phys., 89, 035005, 1–40. DOI: 10.1103/RevModPhys.89.035005.

del Pozo D.F., Line A., Van Geem K.M., Le Men C., Nopens I., 2020. Hydrodynamic analysis of an axial impeller in a non-Newtonian fluid through particle image velocimetry. AIChE J., 66, e16939, 1–16. DOI: 10.1002/aic.16939.

Dylak A., Jaworski Z., 2015. A CFD study of formation of the intensive mixing zone in a highly non-Newtonian fluid. AIP Conference Proceedings, 1648, 030013. DOI: 10.1063/1.4912330.

Ford C., Ein-Mozaffari F., Bennington C.P.J., Taghipour F., 2006. Simulation of mixing dynamics in agitated pulp stock chests using CFD. AIChE J., 52, 3562–3569. DOI: 10.1002/aic.10958.

Fort I., Seichter P., Pešl L., 2013. Axial thrust of axial flow impellers. Chem. Eng. Res. Des., 91, 789–794. DOI: 10.1016/j.cherd.2012.10.001.

Frigaard I. A., Nouar C., 2005. On the usage of viscosity regularisation methods for visco-plastic fluid flow computation. J. Non-Newtonian Fluid Mech., 127, 1-26. DOI: 10.1016/j.jnnfm.2005.01.003.

Galindo E., Arguello M., Velasco D.A., Albiter V., Martinez A., 1996. A comparison of cavern development in mixing a yield stress fluid by Rushton and intermig impellers. Chem. Eng. Technol., 19, 315–323. DOI: 10.1002/ceat.270190405.

Galindo E., NienowA.W., 1992. Mixing of highly viscous simulated Xanthan fermentation broths with the Lightinin A-315-impeller. Biotechnol. Prog., 8, 233–239. DOI: 10.1021/bp00015a009.

Herschel W. H., Bulkley R., 1926. Consistency measurements of rubber-benzol solutions. Kolloid-Zeitschrift, 39, 291–300. DOI: 10.1007/BF01432034.

Hui L.K., Bennington C.P.J., Dumont G.A., 2009. Cavern formation in pulp suspensions using side-entering axial-flow impellers. Chem. Eng. Sci., 64, 509–519. DOI: 10.1016/j.ces.2008.09.021.

Jaworski Z., Nienow A.W., 1994. LDA measurements of flow fields with hydrofoil impellers in fluids with different rheological properties. Eighth European Conference on Mixing, IChemE Symp. Series, 136, 105–112.

Jaworski Z., Spychaj T., Story A., Story G., 2021. Carbomer microgels as model yield-stress fluids. Rev. Chem. Eng., 000010151520200016. DOI: 10.1515/revce-2020-0016.

Kelly W., Gigas B., 2003. Using CFD to predict the behavior of power law fluids near axial-flow impellers operating in the transitional flow regime. Chem. Eng. Sci., 58, 2141–2152. DOI: 10.1016/S0009-2509(03)00060-5.

Nienow A.W., Elson T.P., 1988. Aspects of mixing in rheologically complex fluids. Chem. Eng. Res. Des., 66, 5–15.

Rodriguez B.E., Wolfe M.S., Fryd M., 1994. Nonuniform swelling of alkali swellable microgels. Macromolecules, 27, 6642–6647. DOI: 10.1021/ma00100a058.

Russell A.W., Kahouadji L., Mirpuri K., Quarmby A., Piccione P.M., Matar O.K., Luckham P.F., Markides C.N., 2019. Mixing viscoplastic fluids in stirred vessels over multiple scales: A combined experimental and CFD approach. Chem. Eng. Sci., 208, 115129. DOI: 10.1016/j.ces.2019.07.047.

Savreux F., Jay P., Magnin A., 2007. Viscoplastic fluid mixing in a rotating tank. Chem. Eng. Sci., 62, 2290–2301. DOI: 10.1016/j.ces.2007.01.020.

Simmons M.J.H., Edwards I., Hall J.F., Fan X., Parker D.J., Stitt E.H., 2009. Techniques for visualization of cavern boundaries in opaque industrial mixing systems. AIChE J., 55, 2765–2772. DOI: 10.1002/aic.11889.

Sossa-Echeverria J., Taghipour F., 2014. Effect of mixer geometry and operating conditions on flow mixing of shear thinning fluids with yield stress. AIChE J., 60, 1156–1167. DOI: 10.1002/aic.14309.

Sossa-Echeverria J., Taghipour F., 2015. Computational simulation of mixing flow of shear thinning non-Newtonian fluids with various impellers in a stirred tank. Chem. Eng. Process., 93, 66–78. DOI: 10.1016/j.cep.2015.04.009.

Story A., Jaworski Z., 2017. A new model of cavern diameter based on a validated CFD study on stirring of a highly shear-thinning fluid. Chem. Pap., 71, 1255–1269. DOI: 10.1007/s11696-016-0119-y.

Story A., Jaworski Z., Major-Godlewska M., Story G., 2018. Influence of rheological properties of stirred liquids on the axial and tangential forces in a vessel with a PMT impeller. Chem. Eng. Res. Des., 138, 398–404. DOI: 10.1016/j.cherd.2018.09.006.

Story A., Story G., Jaworski Z., 2020. Effect of carbomer microgel pH and concentration on the Herschel–Bulkley parameters. Chem. Process Eng., 41, 173–182. DOI: 10.24425/cpe.2020.132540.

Stręk F., 1981. Mieszanie i mieszalniki. Wydawnictwa Naukowo-Techniczne, Warszawa.

Wichterle K., Wein O., 1975. Agitation of concentrated suspensions. CHISA ’75, Paper B.4.6. Prague, Czechoslovakia.

Wu J., Pullum L., 2000. Performance analysis of axial-flowmixing impellers. AIChE J., 46, 489–498. DOI: 10.1002/aic.690460307.

Xiao Q., Yang N., Zhu J. H., Guo L.J., 2014. Modeling of cavern formation in yield stress fluids in stirred tanks. AIChE J., 60, 3057–3070. DOI: 10.1002/aic.14470.
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Authors and Affiliations

Anna Story
1
Grzegorz Story
1
Zdzisław Jaworski
1

  1. West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical and Process Engineering, al. Piastów 42,71-065 Szczecin, Poland
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Abstract

We demonstrate in this study that a rotating magnetic field (RMF) and spinning magnetic particles using this kind of magnetic field give rise to a motion mechanism capable of triggering mixing effect in liquids. In this experimental work two mixing mechanisms were used, magnetohydrodynamics due to the Lorentz force and mixing due to magnetic particles under the action of RMF, acted upon by the Kelvin force. To evidence these mechanisms,we report mixing time measured during the neutralization process (weak acid-strong base) under the action of RMF with and without magnetic particles. The efficiency of the mixing process was enhanced by a maximum of 6.5% and 12.8% owing to the application of RMF and the synergistic effect of magnetic field and magnetic particles, respectively.
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Bibliography

Baldyga J., Bourne J.R., 1988. Calculation of micromixing in inhomogenous stirred tank reactors. Chem. Eng. Res. Des., 66(1), 33–38.

Baldyga J., Bourne J.R., 1992. Interactions between mixing on various scales in stirred tank reactors. Chem. Eng. Sci., 47, 1839–1848. DOI: 10.1016/0009-2509(92)80302-S.

Bałdyga J., Pohorecki R., 2013. Editorial. 14th European Conference on Mixing. Chem. Eng. Res. Des., 91(11), 2071–2072). DOI: 10.1016/j.cherd.2013.10.021.

Bao S.R., Zhang R.P., Rong Y., Zhi X.Q., Qiu L.M., 2019. Interferometric study of the heat and mass transfer during the mixing and evaporation of liquid oxygen and nitrogen under non-uniform magnetic field. Int. J. Heat Mass Transfer, 136, 10–19. DOI: 10.1016/j.ijheatmasstransfer.2019.02.044.

Boroun S., Larachi F., 2016. Role of magnetic nanoparticles in mixing, transport phenomena and reaction engineering – challenges and opportunities. Curr. Opin. Chem. Eng., 13, 91–99. DOI: 10.1016/j.coche.2016.08.011.

Boulware J.C., Ban H., Jensen, S., Wassom S., 2010. Influence of geometry on liquid oxygen magnetohydrodynamics. Exp. Therm Fluid Sci., 34, 1182–1193. DOI: 10.1016/j.expthermflusci.2010.04.007.

Chen X., Zhang L., 2019. A review on micromicers acuated with magnetic nanomaterials. Microchim Acta, 184, 3639–3649. DOI: 10.1007/s00604-017-2462-2.

Davidson P.A., 1999. Magnetohydrodynamics in materials processing. Annu. Rev. Fluid Mech., 31, 273–300. DOI: 10.1146/annurev.fluid.31.1.273.

Davidson P.A., 2001. An introduction to magnetohydrodynamics. Cambridge Uniwversity Press. DOI: 10.1017/CBO9780511626333.

Ergin F.G.,Watz B.B., Erglis K., Cebers A., 2015. Time-resolved velocity measurements in a magnetic micromixer. Exp. Therm Fluid Sci., 67. DOI: 10.1016/j.expthermflusci.2015.02.019.

Gao Y., 2013. Active mixing and catching using magnetic particles. Phd Thesis. Technische Universiteit Eindhoven. DOI: 10.6100/IR759475.

Gopalakrishnan S., Thess A., 2010. Chaotic mixing in electromagnetically controlled thermal convection of glass melt. Chem. Eng. Sci., 65, 5309–5319. DOI: 10.1016/j.ces.2010.07.008.

Hajiani P., Larachi F., 2014. Magnetic-field assisted mixing of liquids using magnetic nanoparticles. Chem. Eng. Process., 84, 31–37. DOI: 10.1016/j.cep.2014.03.012.

Hajiani P, Larachi F., 2013. Remotely excited magnetic nanoparticles and gas–liquid mass transfer in Taylor flow regime. Chem. Eng. Sci., 93, 257–265. DOI: 10.1016/j.ces.2013.01.052.

Hao Z., Zhu Q., Jiang Z., Li H., 2008. Fluidization characteristics of aerogel Co/Al2O3 catalyst in a magnetic fluidized bed and its application to CH4-CO2 reforming. Powder Technol., 183, 46–52. DOI: 10.1016/j.powtec.2007.11.015.

Harnby N., Edwards M.F., Nienow A.W., 1985. Mixing in the process industries. Butterworth-Heinemann. DOI: 10.1016/b978-0-7506-3760-2.x5020-3.

Hausmann R., Reichert C., Franzreb M., HöllW.H., 2004. Liquid-phase mass transfer of magnetic ion exchangers in magnetically influenced fluidized beds: II. AC fields. React. Funct. Polym., 60, 17–26. DOI: 10.1016/j.reactfunct polym.2004.02.007.

Hristov J., 2002. Magnetic field assisted fluidization – a unified aproach Part 1. Fundamentals and relevant hydrodynamics of gas-fluidized beds (batch solids mode). Rev. Chem. Eng., 18, 295–512. DOI: 10.1515/REVCE.2002.18.4-5.295.

Hristov J., 2007. Magnetic field assisted fluidization-Dimensional analysis addressing the physical basis. China Particuology, 5, 103–110. DOI: 10.1016/j.cpart.2007.03.002.

Hristov J., 2010. Magnetic field assisted fluidization – A unified approach. Part 8. Mass transfer: Magnetically assisted bioprocesses. Rev. Chem. Eng., 26, 55–128. DOI: 10.1515/REVCE.2010.006.

Hristov J.Y., 1998. Fluidization of ferromagnetic particles in a magnetic field Part 2: Field effects on preliminarily gas fluidized bed. Powder Technol., 97, 35–44. DOI: 10.1016/S0032-5910(97)03392-5.

Krakov M.S., 2020. Mixing of miscible magnetic and non-magnetic fluids with a rotating magnetic field. J. Magn. Magn. Mater., 498. DOI: 10.1016/j.jmmm.2019.166186.

Lange A., 2002.Kelvin force in a layer of magnetic fluid. J. Magn. Magn. Mater., 241, 327–329. DOI: 10.1016/S0304 -8853(01)01368-3.

Lu X., Li H., 2000. Fluidization of CaCO3 and Fe2O3 particle mixtures in a transverse rotating magnetic field. Powder Technol., 107, 66–78. DOI: 10.1016/S0032-5910(99)00092-3.

Moffatt H.K., 1965. On fluid flow induced by a rotating magnetic field. J. Fluid Mech., 22, 521–528. DOI: 10.1017/S0022112065000940.

Moffatt H.K., 1990. On the behaviour of a suspension of conducting particles subjected to a time-periodic magnetic field. J. Fluid Mech., 218, 509–529. DOI: 10.1017/S0022112090001094.

Moffatt H.K., 1991. Electromagnetic stirring. Phys. Fluids A, 3, 1336–1343. DOI: 10.1063/1.858062.

Molokov S., Moreau R., Moffat H.K., 2007. Magnetohydrodynamics. Historical evolution and trends. Springer Science+Business Media B.V. DOI: 10.1007/978-1-4020-4833-3.

Nouri D., Zabihi-Hesari A., Passandideh-Fard M., 2017. Rapid mixing in micromixers using magnetic field. Sens. Actuators, A, 255, 79–86. DOI: 10.1016/j.sna.2017.01.005.

Olivier G., Pouya H., Fadçal L., 2014. Magnetically induced agitation in liquid–liquid–magnetic nanoparticle emulsions: Potential for process intensification. AIChE J., 60, 1176–1181. DOI: 10.1002/AIC.14331.

Penchev I.P., Hristov J.Y., 1990. Fluidization of beds of ferromagnetic particles in a transverse magnetic field. Powder Technol., 62, 1–11. DOI: 10.1016/0032-5910(90)80016-R.

Poulsen B.R., Iversen J.J.L., 1997. Mixing determinations in reactor vessels using linear buffers. Chem. Eng. Sci., 52, 979–984. DOI: 10.1016/S0009-2509(96)00466-6.
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Authors and Affiliations

Rafał Rakoczy
1
ORCID: ORCID
Marian Kordas
1
ORCID: ORCID
Agata Markowska-Szczupak
1
ORCID: ORCID
Maciej Konopacki
1
ORCID: ORCID
Adrian Augustyniak
1
ORCID: ORCID
Joanna Jabłońska
1
Oliwia Paszkiewicz
1
ORCID: ORCID
Kamila Dubrowska
1
Grzegorz Story
1
Anna Story
1
Katarzyna Ziętarska
1
Dawid Sołoducha
1
Tomasz Borowski
1
Marta Roszak
2
Bartłomiej Grygorcewicz
2
ORCID: ORCID
Barbara Dołęgowska
2
ORCID: ORCID

  1. West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical and Process Engineering, al. Piastów 42,71-065 Szczecin, Poland
  2. Pomeranian Medical University in Szczecin, Chair of Microbiology, Immunology and Laboratory Medicine, Department of Laboratory Medicine, al. Powstańców Wielkopolskich 72, 70-111 Szczecin, Poland

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