Evaluation of axial dispersion and mixing performance in oscillatory baffled reactors using CFD

Mikko Manninen, Elena Gorshkova, Kirsi Immonen, X.-W. Ni (Corresponding Author)

Research output: Contribution to journalArticleScientificpeer-review

18 Citations (Scopus)

Abstract

Background: The paper reports extensive CFD work and analyses of an oscillatory baffled reactor (OBR) planned to be used for the production of polyaniline continuously. In the polyaniline process, viscosity changes during the course of the reaction. Two non‐Newtonian fluids were used to represent the stages of fluids during the reaction in a simulation, in addition to water as the reference fluid. Two quantitative measures derived from the CFD results are employed to evaluate OBR reactor performance: the axial dispersion coefficient and the ratio of axial and transverse velocities. Results: The CFD data showed that the dispersion coefficient as a function of viscosity exhibits a maximum for given oscillation parameters. In the turbulent regime, the axial dispersion is often correlated with the oscillatory Reynolds number in OBR or equivalent Reynolds numbers in other reactor devices. In the high viscosity regime, such a general correlation is not valid for different operational parameters. The results of the CFD simulations in the moving baffle‐OBR indicate, for the first time, that the axial dispersion coefficients in the moving baffle arrangement is 10–17% higher than that in the moving fluid type, due to enhanced shear rate in the former device. This quantitative information is valuable for the design and smooth transition from batch to continuous reactors. Conclusion: The established dependence of axial dispersion and the ratio of axial to transverse velocities on both viscosity and the operational parameters enhanced the understanding of mixing and dispersion characteristics of the OBR. The CFD analysis supplied the information needed to determine the design parameters for the reactor used in continuous production of polyaniline.
Original languageEnglish
Pages (from-to)553-562
Number of pages10
JournalJournal of Chemical Technology and Biotechnology
Volume88
Issue number4
DOIs
Publication statusPublished - 2013
MoE publication typeA1 Journal article-refereed

Fingerprint

Viscosity
Computational fluid dynamics
Polyaniline
Fluids
viscosity
Equipment and Supplies
Reynolds number
fluid
non-Newtonian fluid
Shear deformation
evaluation
reactor
Water
simulation
polyaniline
oscillation
parameter

Keywords

  • Axial dispersion coefficient
  • axial to radial velocity ratio
  • computational fluid dynamics
  • moving baffles
  • moving fluids
  • oscillatory baffled reactor
  • polyaniline

Cite this

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title = "Evaluation of axial dispersion and mixing performance in oscillatory baffled reactors using CFD",
abstract = "Background: The paper reports extensive CFD work and analyses of an oscillatory baffled reactor (OBR) planned to be used for the production of polyaniline continuously. In the polyaniline process, viscosity changes during the course of the reaction. Two non‐Newtonian fluids were used to represent the stages of fluids during the reaction in a simulation, in addition to water as the reference fluid. Two quantitative measures derived from the CFD results are employed to evaluate OBR reactor performance: the axial dispersion coefficient and the ratio of axial and transverse velocities. Results: The CFD data showed that the dispersion coefficient as a function of viscosity exhibits a maximum for given oscillation parameters. In the turbulent regime, the axial dispersion is often correlated with the oscillatory Reynolds number in OBR or equivalent Reynolds numbers in other reactor devices. In the high viscosity regime, such a general correlation is not valid for different operational parameters. The results of the CFD simulations in the moving baffle‐OBR indicate, for the first time, that the axial dispersion coefficients in the moving baffle arrangement is 10–17{\%} higher than that in the moving fluid type, due to enhanced shear rate in the former device. This quantitative information is valuable for the design and smooth transition from batch to continuous reactors. Conclusion: The established dependence of axial dispersion and the ratio of axial to transverse velocities on both viscosity and the operational parameters enhanced the understanding of mixing and dispersion characteristics of the OBR. The CFD analysis supplied the information needed to determine the design parameters for the reactor used in continuous production of polyaniline.",
keywords = "Axial dispersion coefficient, axial to radial velocity ratio, computational fluid dynamics, moving baffles, moving fluids, oscillatory baffled reactor, polyaniline",
author = "Mikko Manninen and Elena Gorshkova and Kirsi Immonen and X.-W. Ni",
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Evaluation of axial dispersion and mixing performance in oscillatory baffled reactors using CFD. / Manninen, Mikko; Gorshkova, Elena; Immonen, Kirsi; Ni, X.-W. (Corresponding Author).

In: Journal of Chemical Technology and Biotechnology, Vol. 88, No. 4, 2013, p. 553-562.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Evaluation of axial dispersion and mixing performance in oscillatory baffled reactors using CFD

AU - Manninen, Mikko

AU - Gorshkova, Elena

AU - Immonen, Kirsi

AU - Ni, X.-W.

N1 - Project code: 31359

PY - 2013

Y1 - 2013

N2 - Background: The paper reports extensive CFD work and analyses of an oscillatory baffled reactor (OBR) planned to be used for the production of polyaniline continuously. In the polyaniline process, viscosity changes during the course of the reaction. Two non‐Newtonian fluids were used to represent the stages of fluids during the reaction in a simulation, in addition to water as the reference fluid. Two quantitative measures derived from the CFD results are employed to evaluate OBR reactor performance: the axial dispersion coefficient and the ratio of axial and transverse velocities. Results: The CFD data showed that the dispersion coefficient as a function of viscosity exhibits a maximum for given oscillation parameters. In the turbulent regime, the axial dispersion is often correlated with the oscillatory Reynolds number in OBR or equivalent Reynolds numbers in other reactor devices. In the high viscosity regime, such a general correlation is not valid for different operational parameters. The results of the CFD simulations in the moving baffle‐OBR indicate, for the first time, that the axial dispersion coefficients in the moving baffle arrangement is 10–17% higher than that in the moving fluid type, due to enhanced shear rate in the former device. This quantitative information is valuable for the design and smooth transition from batch to continuous reactors. Conclusion: The established dependence of axial dispersion and the ratio of axial to transverse velocities on both viscosity and the operational parameters enhanced the understanding of mixing and dispersion characteristics of the OBR. The CFD analysis supplied the information needed to determine the design parameters for the reactor used in continuous production of polyaniline.

AB - Background: The paper reports extensive CFD work and analyses of an oscillatory baffled reactor (OBR) planned to be used for the production of polyaniline continuously. In the polyaniline process, viscosity changes during the course of the reaction. Two non‐Newtonian fluids were used to represent the stages of fluids during the reaction in a simulation, in addition to water as the reference fluid. Two quantitative measures derived from the CFD results are employed to evaluate OBR reactor performance: the axial dispersion coefficient and the ratio of axial and transverse velocities. Results: The CFD data showed that the dispersion coefficient as a function of viscosity exhibits a maximum for given oscillation parameters. In the turbulent regime, the axial dispersion is often correlated with the oscillatory Reynolds number in OBR or equivalent Reynolds numbers in other reactor devices. In the high viscosity regime, such a general correlation is not valid for different operational parameters. The results of the CFD simulations in the moving baffle‐OBR indicate, for the first time, that the axial dispersion coefficients in the moving baffle arrangement is 10–17% higher than that in the moving fluid type, due to enhanced shear rate in the former device. This quantitative information is valuable for the design and smooth transition from batch to continuous reactors. Conclusion: The established dependence of axial dispersion and the ratio of axial to transverse velocities on both viscosity and the operational parameters enhanced the understanding of mixing and dispersion characteristics of the OBR. The CFD analysis supplied the information needed to determine the design parameters for the reactor used in continuous production of polyaniline.

KW - Axial dispersion coefficient

KW - axial to radial velocity ratio

KW - computational fluid dynamics

KW - moving baffles

KW - moving fluids

KW - oscillatory baffled reactor

KW - polyaniline

U2 - 10.1002/jctb.3979

DO - 10.1002/jctb.3979

M3 - Article

VL - 88

SP - 553

EP - 562

JO - Journal of Chemical Technology and Biotechnology

JF - Journal of Chemical Technology and Biotechnology

SN - 0268-2575

IS - 4

ER -