Skip to main content
SpringerLink
Log in

Experimental Study and CFD-PBM Simulation of the Unsteady Gas-Liquid Flow in an Airlift External Loop Reactor

  • Published:
Flow, Turbulence and Combustion Aims and scope Submit manuscript

Abstract

The performance of external loop airlift reactor (ELALR) strongly depends on local prevailing hydrodynamics. In this work, the hydrodynamics characterization of the gas-liquid flow is performed in a laboratory scale ELALR. The bubbles plume and the velocity field of the riser are captured using Particle Image Velocimetry (PIV) technique and a three-dimensional CFD-PBM simulation is implemented to provide a full description of the flow structure. The effects of superficial gas velocity on the flow structure and the time-averaged liquid velocity are quantitatively investigated and the numerical results are in reasonable agreement with the PIV measurement. The results show that the gas-liquid two-phases flow in the riser is always unsteady, and the bubble plume meandering behavior is observed clearly. Gas holdup increases with the increase of superficial gas velocity, while the liquid axial velocity shows a trend of first increase and then decrease and the maximum is observed at superficial gas velocity of 30 mm/s. With the increase of superficial gas velocity, the probability density function curve becomes flatter, and changes from unimodal to bimodal. This work helps to gain in-depth understanding of the complex fluid hydrodynamics behavior inside an ELALR.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15

Similar content being viewed by others

Abbreviations

CD:

Effective drag coefficient, dimensionless

CL:

Lift coefficient, dimensionless

CV:

Virtual mass coefficient, dimensionless

d:

Diameter of the orifice, m

db:

Bubble diameter, m

D:

Diffusivity, m2/s

Eo:

Eotvos number, dimensionless

F:

Force (N/m3)

fBV:

Breakage ratio of daughter droplet to its parent droplet

g:

Acceleration of gravity, m/s2

k:

Turbulence kinetic energy, m2/s2

P:

Pressure, Pa

PDF:

Probability density function

Re:

Reynolds number, dimensionless

Vsup:

Superficial velocities of gas phase, m/s

V:

Bubble volume (m3)

αr:

Volume fraction of the riser, dimensionless

ε:

Turbulent kinetic energy dissipation rate, m2/s3

μg,μl:

Viscosity of gas and liquid phase, Pa s

ρl:

Density of liquid phase, kg/m3

σ:

Surface tension, N/m

τ:

Shear stress, N/m2

References

  1. Liu, M., Zhang, T., Wang, T., Yu, W., Wang, J.: Experimental study and modeling on liquid dispersion in external-loop airlift slurry reactors. Chem. Eng. J. 139(3), 523–531 (2008)

    Article  Google Scholar 

  2. Sarkar, S., Mohanty, K., Meikap, B.C.: Hydrodynamic modeling of a novel multi-stage gas–liquid external loop airlift reactor. Chem. Eng. J. 145(1), 69–77 (2008)

    Article  Google Scholar 

  3. Fakhari, M.E., Moraveji, M.K., Davarnejad, R.: Hydrodynamics and mass transfer of oily micro-emulsions in an external loop airlift reactor. Chin. J. Chem. Eng. 22(3), 267–273 (2014)

    Article  Google Scholar 

  4. Choi, K.H., Lee, W.K.: Circulation liquid velocity, gas holdup and volumetric oxygen transfer coefficient in external-loop airlift reactors. J. Chem. Technol. Biotechnol. 56(1), 51–58 (1993)

    Article  Google Scholar 

  5. Snape, J.B., Zahradník, J., Fialová, M., Thomas, N.H.: Liquid-phase properties and sparger design effects in an external-loop airlift reactor. Chem. Eng. Sci. 50(20), 3175–3186 (1995)

    Article  Google Scholar 

  6. Gavrilescu, M., Tudose, R.Z.: Effects of geometry on hydrodynamics in external-loop airlift reactors. Chem. Eng. Commun. 156(1), 89–113 (2010)

    Article  Google Scholar 

  7. Essadki, A.H., Gourich, B., Vial, C., Delmas, H.: Residence time distribution measurements in an external-loop airlift reactor: study of the hydrodynamics of the liquid circulation induced by the hydrogen bubbles. Chem. Eng. Sci. 66(14), 3125–3132 (2011)

    Article  Google Scholar 

  8. Wu, Q., Wang, X., Wang, T., Han, M., Sha, Z., Wang, J.: Effect of liquid viscosity on hydrodynamics and bubble behaviour of an external-loop airlift reactor. Can. J. Chem. Eng. 91(12), 1957–1963 (2013)

    Article  Google Scholar 

  9. Darmana, D., Deen, N.G., Kuipers, J.A.M.: Detailed modelling of hydrodynamics, mass transfer and chemical reactions in a bubble column using a discrete bubble model. Chem. Eng. Sci. 60(12), 3383–3404 (2005)

    Article  Google Scholar 

  10. Besbes, S., El Hajem, M., Ben Aissia, H., Champagne, J.Y., Jay, J.: PIV Measurements and Eulerian–Lagrangian simulations of the unsteady gas–liquid flow in a needle sparger rectangular bubble column. Chem. Eng. Sci. 126, 560–572 (2015)

    Article  Google Scholar 

  11. van den Hengel, E.I.V., Darmana, D., Deen, N.G., Kuipers, J.A.M.: Large Eddy Simulation of a Bubble Column Reactor Using the Euler-Lagrange Approach Computational FluidDynamics in Chemical Reaction Engineering III. Davos, Switzerland (2003)

    Google Scholar 

  12. Buwa, V.V., Deo, D.S., Ranade, V.V.: Eulerian-lagrangian simulations of unsteady gas-liquid flows in bubble columns. Int. J. Multiphase Flow 32, 864–885 (2006)

    Article  MATH  Google Scholar 

  13. Ebadi Amooghin, A., Jafari, S., Sanaeepur, H., Kargari, A.: Computational fluid dynamics simulation of bubble coalescence and breakup in an internal airlift reactor: analysis of effects of a draft tube on hydrodynamics and mass transfer. Appl. Math. Model. 39(5–6), 1616–1642 (2015)

    Article  MathSciNet  Google Scholar 

  14. Baltussen, M.W., Kuipers, J.A.M., Deen, N.G.: Direct numerical simulation of effective drag in dense gas–liquid–solid three-phase flows. Chem. Eng. Sci. 158, 561–568 (2017)

    Article  Google Scholar 

  15. Carlos Varas, A.E., Peters, E.A.J.F., Kuipers, J.A.M.: Experimental study of full field riser hydrodynamics by PIV/DIA coupling. Powder Technol. 313, 402–416 (2017)

    Article  Google Scholar 

  16. Yang, N., Xiao, Q.: A mesoscale approach for population balance modeling of bubble size distribution in bubble column reactors. Chem. Eng. Sci. 170, 241–250 (2017)

    Article  Google Scholar 

  17. Yang, N., Chen, J., Zhao, H., Ge, W., Li, J.: Explorations on the multi-scale flow structure and stability condition in bubble columns. Chem. Eng. Sci. 62(24), 6978–6991 (2007)

    Article  Google Scholar 

  18. Yang, N., Wu, Z., Chen, J., Wang, Y., Li, J.: Multi-scale analysis of gas–liquid interaction and CFD simulation of gas–liquid flow in bubble columns. Chem. Eng. Sci. 66(14), 3212–3222 (2011)

    Article  Google Scholar 

  19. Jiang, X., Yang, N., Yang, B.: Computational fluid dynamics simulation of hydrodynamics in the riser of an external loop airlift reactor. Particuology 27, 95–101 (2016)

    Article  Google Scholar 

  20. Zahradnik, J., Fialova, M., Ruzicka, M., Drahos, J., Kastanek, F., Thomas, N.H.: Duality of the gas-liquid flow regimes in bubble column reactors. Chem. Eng. Sci. 52(21-22), 3811–3826 (1997)

    Article  Google Scholar 

  21. Loubiere, K., Pruvost, J., Aloui, F., Legrand, J.: Investigations in an external-loop airlift photobioreactor with annular light chambers and swirling flow. Chem. Eng. Res. Des. 89(2), 164–171 (2011)

    Article  Google Scholar 

  22. Su, Y., Wang, Y., Zeng, Q., Li, J., Yu, G., Gong, X., Yu, Z.: Influence of liquid properties on flow regime and backmixing in a special bubble column. Chem. Eng. Process. Process. Intesif. 47(12), 2296–2302 (2008)

    Article  Google Scholar 

  23. Nedeltchev, S.: New methods for flow regime identification in bubble columns and fluidized beds. Chem. Eng. Sci. 137, 436–446 (2015)

    Article  Google Scholar 

  24. Chen, R.C., Reese, J., Fan, L.S.: Flow structure in a three - dimensional bubble column and three - phase fluidized bed. AlChE J. 40(7), 1093–1104 (2010)

    Article  Google Scholar 

  25. Jo, D., Revankar, T.S.: Effect of coalescence and breakup on bubble size distributions in a two-dimensional packed bed. Chem. Eng. Sci. 65(14), 4231–4238 (2010)

    Article  Google Scholar 

  26. Jo, D., Revankar, S.T.: Investigation of bubble breakup and coalescence in a packed-bed reactor – Part 1: A comparative study of bubble breakup and coalescence models. Int. J. Multiphase Flow 37(9), 995–1002 (2011)

    Article  Google Scholar 

  27. Sattar, M.A., Naser, J., Brooks, G.: Numerical simulation of two-phase flow with bubble break-up and coalescence coupled with population balance modeling. Chem. Eng. Process. Process. Intensif. 70, 66–76 (2013)

    Article  Google Scholar 

  28. Liu, Y., Hinrichsen, O.: Study on CFD–PBM turbulence closures based on k–ε and Reynolds stress models for heterogeneous bubble column flows. Comput. Fluids 105, 91–100 (2014)

    Article  MathSciNet  MATH  Google Scholar 

  29. Hlawitschka, M.W., Jaradat, M., Chen, F., Attarakih, M.M., Kuhnert, J., Bart, H.-J.: A CFD-population balance model for the simulation of kühni extraction column. In: Pistikopoulos, E.N., M.C.G., Kokossis, A.C. (eds.) Computer Aided Chemical Engineering, vol. 29, pp. 66–70. Elsevier (2011)

  30. Xing, C., Wang, T., Wang, J.: Experimental study and numerical simulation with a coupled CFD–PBM model of the effect of liquid viscosity in a bubble column. Chem. Eng. Sci. 95, 313–322 (2013)

    Article  Google Scholar 

  31. Yan, W., Li, J., Luo, Z.: A CFD–PBM coupled model with polymerization kinetics for multizone circulating polymerization reactors. Powder Technol. 231, 77–87 (2012)

    Article  Google Scholar 

  32. Che, Y., Tian, Z., Liu, Z., Zhang, R., Gao, Y., Zou, E., Wang, S., Liu, B.: A CFD–PBM model considering ethylene polymerization for the flow behaviors and particle size distribution of polyethylene in a pilot-plant fluidized bed reactor. Powder Technol. 286, 107–123 (2015)

    Article  Google Scholar 

  33. Long, B., Yang, H., Ding, Y.: Impact of seedloading ratio on the growth kinetics of mono-ammonium phosphate underisothermal batch crystallization. Korean J. Chem. Eng. 33, 623–628 (2016)

    Article  Google Scholar 

  34. Akbari, V., Nejad Ghaffar Borhani, T., Shamiri, A., Kamaruddin Abd. Hamid, M.: A CFD–PBM coupled model of hydrodynamics and mixing/segregation in an industrial gas-phase polymerization reactor. Chem. Eng. Res. Des. 96, 103–120 (2015)

    Article  Google Scholar 

  35. Jain, D., Kuipers, J.A.M., Deen, N.G.: Numerical study of coalescence and breakup in a bubble column using a hybrid volume of fluid and discrete bubble model approach. Chem. Eng. Sci. 119, 134–146 (2014)

    Article  Google Scholar 

  36. Hu, L., Li, D., Tang, X., Zhang, Z.: Study on the hydrodynamics characteristics of external-loop airlift slurry reactors. Pet. Process. Petrochem. 43(6), 1–5 (2012)

    Google Scholar 

  37. Wang, T., Wang, J., Jin, Y.: Theoretical prediction of flow regime transition in bubble columns by the population balance model. Chem. Eng. Sci. 60(22), 6199–6209 (2005)

    Article  Google Scholar 

  38. Wang, T., Wang, J., Jin, Y.: Slurry reactors for gas-to-liquid processes: a review. Ind. Eng. Chem. Res. 46(18), 5824–5847 (2007)

    Article  Google Scholar 

  39. Vial, C, Poncin, S., Wild, G., Midoux, M.: Experimental and theoretical analysis of the hydrodynamics in the riser of an external loop airlift reactor. Chem. Eng. Sci. 57(22), 4745–4762 (2002)

    Article  Google Scholar 

  40. Kumar, S., Ramkrishna, D.: On the solution of population balance equations by discretization—I. A fixed pivot technique. Chem. Eng. Sci. 51(8), 1311–1332 (1996)

    Article  Google Scholar 

  41. Sato, Y., Sadatomi, M., Sekoguchi, K.: Momentum and heat transfer in two-phase bubble flow—I. Theory. Int. J. Multiphase Flow 7(2), 167–177 (1981)

    Article  MATH  Google Scholar 

  42. Sato, Y., Sadatomi, M., Sekoguchi, K.: Momentum and heat transfer in two-phase bubble flow—II. A comparison between experimental data and theoretical calculations. Int. J. Multiphase Flow 7(2), 179–190 (1981)

    Article  MATH  Google Scholar 

  43. Tomiyama, A., žun, I., Higaki, H., Makino, Y., Sakaguchi, T.: A three-dimensional particle tracking method for bubbly flow simulation. Nucl. Eng. Des. 175(1–2), 77–86 (1997)

    Article  Google Scholar 

  44. Tomiyama, A., Tamai, H., Zun, I., Hosokawa, S.: Transverse migration of single bubbles in simple shear flows. Chem. Eng. Sci. 57(11), 1849–1858 (2002)

    Article  Google Scholar 

  45. Luo, H., Svendsen, H.F.: Theoretical model for drop and bubble breakup in turbulent dispersions. AlChE J. 42, 1225–1233 (1996)

    Article  Google Scholar 

  46. Wang, T., Wang, J., Jin, Y.: A CFD–PBM coupled model for gas–liquid flows. AIChE J 52(1), 125–140 (2006)

    Article  Google Scholar 

  47. Deen, N.G., Solberg, T., Hjertager, B.H.: Large eddy simulation of the gas-liquid flow in a square cross-sectioned bubble column. Chem. Eng. Sci. 56, 6341–6349 (2001)

    Article  Google Scholar 

Download references

Funding

This work is financially supported by the Science and Technology Major Project of Hubei Province (grant number 2016ACA179), Scientific research plan projects of Hubei Education Department (grant number B2016490) and Natural Sciences Foundation of Hubei Province (grant number 2014CFB768).

Author information

Authors and Affiliations

  1. School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan, 430074, China

    Xia Lu, Bingwen Long, Yigang Ding & Fuli Deng

  2. The College of Post and Telecommunication of Wuhan Institute of Technology, Wuhan, 430074, China

    Xia Lu

  3. Hubei Key Lab of Novel Reactor & Green Chemical Technology, Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan Institute of Technology, Wuhan, 430074, China

    Bingwen Long, Yigang Ding & Fuli Deng

Authors
  1. Xia Lu
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Bingwen Long
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Yigang Ding
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Fuli Deng
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Bingwen Long.

Ethics declarations

Conflict of interests

The authors declare that they have no conflict of interest.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Electronic supplementary material

Below is the link to the electronic supplementary material.

(DOCX 175 KB)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Lu, X., Long, B., Ding, Y. et al. Experimental Study and CFD-PBM Simulation of the Unsteady Gas-Liquid Flow in an Airlift External Loop Reactor. Flow Turbulence Combust 102, 1053–1073 (2019). https://doi.org/10.1007/s10494-018-9992-5

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10494-018-9992-5

Keywords

Search

Navigation