Skip to main content
SpringerLink
Log in

Study of the liquid circulation velocity in external-loop airlift bioreactors

  • Originals
  • Published:
Bioprocess Engineering Aims and scope Submit manuscript

Abstract

Liquid circulation velocity was studied in externalloop air-lift bioreactors of laboratory and pilot scale, respectively for different gas input rates, downcomer-to-riser cross-sectional area ratio, A D/AR and liquid phase apparent viscosities.

It was found that, up to a gas superficial velocity in the riser v SGR ≈ 0.04 m/s the dependency of v SLR on v SGR is in the following form: v SLR = a v bSGR , with the exponent b being 0.40. Over this value of v SGR, only a small increase in liquid superficial velocity, v SLR is produced by an increase in v SGR.

A D/AR ratio affects the liquid superficial velocity due to the resistance in flow and overall friction.

For non-Newtonian viscous liquids, the circulation liquid velocity in the riser section of the pilot external-loop airlift bioreactor is shown to be dependent mainly on the downcomer-to-riser cross-sectional area ratio, A D/AR, the effective (apparent) liquid viscosity, η eff and the superficial gas velocity, v SGR.

The equation proposed by Popovic and Robinson [11] was fitted well, with an error of ± 20%.

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

Similar content being viewed by others

Abbreviations

A D m2 :

downcomer cross-sectional area

A Rm2 :

riser cross-sectional area

a =:

coefficient in Eq. (7)

b =:

exponent in Eq. (7)

c s m−1 :

Coefficient in Eq. (3)

D D m:

downcomer diameter

D R m:

riser diameter

g m2/s:

gravitational acceleration

H D m:

dispersion height

H L m:

ungassed liquid height

K Pa sn :

consistency index

K B =:

friction factor at the bioreactor bottom

K F =:

friction factor

K T =:

friction factor at the bioreactor top

V L m3 :

liquid volume in the bioreactor

V D m3 :

liquid volume in downcomer

V R m3 :

liquid volume in riser

v LDm/s:

downcomer linear liquid velocity

v LR m/s:

riser linear liquid velocity

v SGR m/s:

riser superficial liquid velocity

v SLR m/s:

riser superficial liquid velocity

\(\dot \gamma \) s−1 :

shear rate

ε GD =:

downcomer gas holdup

ε GR =:

riser gas holdup

η eff Pa s:

effective (apparent) viscosity

τ Pa:

shear stress

References

  1. Blenke, H.: Loop Reactors. In: Ghose, T.K.; Fiechter, A.; Blackebrough, N. (Eds): Advances in biochemical engineering, vol. 13, pp. 121–214. Berlin: Springer Verlag, 1979

    Google Scholar 

  2. Jones, A.G.: Liquid Circulation in a draft-tube bubble column. Chem. Eng. Sci. 15 (1985) 449–462

    Google Scholar 

  3. Kawase, W.; Moo-Young, M.: Liquid circulation time in concentrictube airlift columns with non-newtonian fermentation broths. J. Chem. Tech. Biotechnol. 46 (1989) 267–274

    Google Scholar 

  4. Margaaritis, A.; Sheppard, J.: Mixing time and oxygen transfer characteristics of a double-draft-tube airlift fermentor. Biotechnol. Bioeng. 23 (1981) 2117–2135

    Google Scholar 

  5. Wachi, S.; Jones, A.G.; Elson, T.P.: Flow dynamics in a draft-tube bubble column using various liquids. Chem. Eng. Sci. 46 (1991) 657–663

    Google Scholar 

  6. Orazem, M.E.; Fan, L.T.; Erickson, L.E.: Bubble flow in the downflow section of an airlift tower. Biotechnol. Bioeng. 21 (1979) 1579–1606

    Google Scholar 

  7. Siegel, M.H.; Merchuk, J.C.; Schüger, K.: Air-lift reactor analysis interrelationships between riser, downcomer and gas-liquid separator behaviour, including gas recirculation effects. AIChEJ. 32 (1986) 1585–1596

    Google Scholar 

  8. Siegel, M.H.; Merchuk, J.C.: Mass transfer in a rectangular airlift reactor: effects of geometry and gas recirculation. Biotechnol. Bioeng. 32 (1988) 1128–1137

    Google Scholar 

  9. Hsu, Y.C.; Dudukovic, M.P.: Gas-holdup and liquid recirculation in gas-lift reactors. Chem. Eng. Sci. 35 (1980) 135–141

    Google Scholar 

  10. Weiland, P.: Untersuchung eines Airliftreaktors mit aüsserem Umlauf in Himblich auf seine Anwendung as Bioreaktor. PhD Thesis Dortmund University, Dortmund, 1978

    Google Scholar 

  11. Popovic, M.; Robinson, C.W.: External-circulation-loop airlift bioreactors: study of the liquid circulating velocity in highly viscous non-newtonian liquids. Biotechnol. Bioeng. 32 (1988) 301–312

    Google Scholar 

  12. Bello, R.A.; Robinson, C.W.; Moo-Young, M.: Mass transfer and liquid mixing in external-circulation-loop contactors. In: Moo-Young, M.; Robinson, C.W.; Vezina, C. (Eds): Advances in Biotechnology, Vol. 1. p. 547–552. Toronto: Pergamon Press, 1984

    Google Scholar 

  13. Bello, R.A.; Robinson, C.W.; Moo-Young, M.: Liquid circulation and mixing characteristics of airlift contactors. Can. J. Chem. Eng. 62 (1984) 573–577

    Google Scholar 

  14. Onken, U.; Weiland, P.: Airlift fermenters. Construction, behaviour and uses. In: Advances in Biotechnological Processes. vol. 1. pp. 67–95. New York: Alan R. Liss, Inc., 1983

    Google Scholar 

  15. Popovic, M.; Robinson, C.W.: Mixing characteristics of external-loop airlifts: non-newtonian systems. Chem. Eng. Sci. 48 (1993) 1405–1413

    Google Scholar 

  16. Verlaan, P.; Modelling and characterization of an airlift-loop bioreactor. PhD thesis, University of Wageningen, 1987

  17. Merchuk, J.C.: Why use airlift bioreactors?. TIBTECH. 8 (1990) 66–71

    Google Scholar 

  18. Merchuk, J.C.; Stein, F.: Local holdup and liquid velocity in airlift reactors. AIChEJ 27 (1981) 377–388

    Google Scholar 

  19. Merchuk, J.C.; Stein, Y.; Mateles, R.I.: A distributed parameter model of an airlift fermenter, Biotechnol. Bioeng. 22 (1980) 1189–1211

    Google Scholar 

  20. Allen, D.G.; Robinson, C.W.: Measurement of rheological properties of filamentors fermentation broths. Chem. Eng. Sci. 45 (1990) 37–48

    Google Scholar 

  21. Gavrilescu, M.; Roman, R.V.; Efimov, V.: Rheological behaviour of some antibiotic biosynthesis liquids. Acta Biotechnol. 12 (1992) 383–396

    Google Scholar 

  22. Schumpe, A.; Deckwer, W-D.: Viscous media in tower bioreactors: hydrodynamic characteristics and mass transfer properties. Bioprocess Eng. 2 (1987) 79–84

    Google Scholar 

  23. Zaidi, A.; Bourziza, H.; Echihabi, L.: Wärmeübergang und effektives Schergefäle in Blasensäulen-Bioreaktoren mit Xanthan-Lösungen. Chem. Eng. Tech. 59 (1987) 748–749

    Google Scholar 

  24. Nishikawa, M.; Kato, H.; Hashimoto, K.; Heat transfer in aerated tower filled with non-newtonian liquid. Ind.Eng. Process Dev. 16 (1977) 133–137

    Google Scholar 

  25. Mercer, D.G.: Flow characteristics of a pilot-scale airlift fermentor. Biotechnol. Bioeng. 23 (1981) 2421–2431

    Google Scholar 

  26. Fields, P.R.; Slater, N.K.H.: Trancer dispersion in a laboratory air-lift reactor. Chem. Eng. Sci. 38 (1983) 647–653

    Google Scholar 

  27. Fan, L-S.; Hwang, S-J.; Matsuura, A.: Hydrodynamic behaviour of a draft-tube gas-liquid-solid spouted bed. Chem. Eng. Sci. 39 (1984) 1677–1688

    Google Scholar 

  28. Kawase, Yi; Moo-Young, M.: Liquid circulation time in concentrictube airlift columns with non-newtonian fermentation broths. J. Chem. Technol. Biotechnol. 46 (1989) 267–274

    Google Scholar 

  29. Chakrawarty, M.; Begum, S.; Singh, H.H.; Baruah, J.N.; Yengar, M.:gas holdup distribution in a gas-lift column. Biotechnol. Bioeng. Symp. 4 (1973) 363–378

    Google Scholar 

  30. Saxena, S.C.; Rao, N.S.; Thimmapuram, P.R.: Gas phase holdup in slurry bubble columns for two- and three- phase systems. The Chem. Eng. J. 49 (1992) 1551–1559

    Google Scholar 

  31. Weiland, P.; Onken, U.: Fluid dynamics and mass transfer in an air-lift fermentor with external-loop. Ger. Chem. Eng. 4 (1981) 42–48

    Google Scholar 

  32. Onken, U.; Weiland, P.: Hydrodynamics and mass transfer in an airlift loop fermentor. Eur. J. Appl. Microbiol. Biotechnol. 10 (1980) 31–40

    Google Scholar 

  33. Merchuk, J.C.; Stein, Y.: A distributed parameter model for an airlift fermentor. Effects of pressure. Biotechnol. Bioeng. 23 (1981) 1309–1324

    Google Scholar 

  34. Weiland, P.: Influence of draft-tube diameter on operation behaviour of airlift loop reactors. Ger. Chem. Eng. 7 (1984) 374–385

    Google Scholar 

  35. Lans, R.C.J.M. van der: Hydrodynamics of a bubble column loops reactor. PhD thesis, Delft University of Technology, Delft, 1985

    Google Scholar 

  36. Wallis, G.B.: One dimensional two-phase flow. New York, McGrawHill, 1969

    Google Scholar 

  37. Chisty, Y.: Airlift bioreactors. London-New-York: Elsevier Appl. Science, 1989

    Google Scholar 

  38. Hatch, R.T.: Experimental and theoretical studies of oxygen transfer in an airlift fermenter. PhD thesis, Massachussets Institute of Technology, Cambridge, 1973

    Google Scholar 

  39. Nicklin, D.J.; Wilkes, J.O.; Davidson, J.F.: Two-phase flow in vertical tubes. Trans. Inst. Chem. Eng. 40 (1962) 61–68

    Google Scholar 

Download references

Author information

Author notes

  1. R. Z. Tudose

    Present address: Faculty of Industrial Chemistry Department of Transfer Phenomena and Chemical Engineering Technical University of Iasi, 6600, IASI, Romania

Authors and Affiliations

  1. Research Center for Antibiotics, Chemical Pharmaceutical Research Institute, Valea Lupului no. 1, 6647, IASI, Romania

    M. Gavrilescu & R. Z. Tudose

Authors
  1. M. Gavrilescu
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. R. Z. Tudose
    View author publications

    You can also search for this author in PubMed Google Scholar

Additional information

The authors wish to thank Mrs. Rodica Roman for the help in experimental data collection and to Dr. Stefanluca for the financial support.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Gavrilescu, M., Tudose, R.Z. Study of the liquid circulation velocity in external-loop airlift bioreactors. Bioprocess Engineering 14, 33–39 (1995). https://doi.org/10.1007/BF00369850

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00369850

Keywords

Search

Navigation