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Oxygen Transfer and Hydraulic Characteristics in Bubble Column Bioreactor Applied Fine Bubble Air Diffusing System

미세기포 산기장치를 적용한 타워형 생물반응기의 산소전달 및 수력학적 특성

  • Received : 2010.11.18
  • Accepted : 2012.11.28
  • Published : 2012.11.30

Abstract

For improving performance of conical air diffuser generating fine bubble, both experimental and numerical simulation method were used. After adapting diffusers inner real scale bubble column, suitable for various diffuser submergence, the effect of diffuser submergence on oxygen transfer performance such as Oxygen Transfer Coefficient ($K_{L}a_{20}$) and Standard Oxygen Transfer Efficiency (SOTE) was investigated empirically. As flow patterns for various diffuser number and submergence were revealed throughout hydrodynamic simulation for 2-phase fluid flow of air-water, the cause of the change for oxygen transfer performance was cleared up. As results of experimental performance, $K_{L}a_{20}$ was increased slightly by 7% and SOTE was increased drastically by 39~72%, 5.6% per meter. As results of numerical analysis, air volume fraction, air and water velocity in bioreactor were increased with analogous flow tendency by increasing diffuser number. As diffuser submergence increased, air volume fraction, air and water velocity were decreased slightly. Because circulative co-flow is determinant factor for bubble diffusion and rising velocity, excessive circulation intensity can result to worsen oxygen transfer by shortening bubble retention time and amount.

Acknowledgement

Supported by : 한국환경산업기술원

References

  1. R. P. Chhabra and D. Ee Kees, "Transport Processes in Bubbles, Drops, and Particles," Hemisphere Publishing Corp., ISBN 0-89116-999-7 (1992).
  2. George Martin Brown, "Heat or Mass Transfer in a Fluid in Laminar Flow in a Circular or Flat Conduit," AIChE, 6, 2 (1960).
  3. W. G. Burns, "Suppression by Dissolved Hydrogen of Radiolysis of Water by Mixed Radition Fields," AERE-M2702 (1975).
  4. P. Legile, G. Menard, C. Laurent, D. Thomas, and A. Bernis, "Contribution to the Study of an Inverse Three-phase Fluidized Bed Operating Countercurrently," Int. Chem. Eng., pp. 32-41(1992).
  5. D. Garcia-Calderon, P. Buffiere, R. Moletta, and S. Elmaleh, "Anaerobic Digestion of Wine Distillery Wastewater in Down- Flow Fluidized Bed," Water Res., 32, 3593(1998). https://doi.org/10.1016/S0043-1354(98)00134-1
  6. D. G. Karamanev and L. N. Nikolov, "Bed Expansion of Liquid-Solid Inverse Fluidization," AIChE. J., 38, 1916(1992). https://doi.org/10.1002/aic.690381208
  7. Boon, A. G. and Houck, D. H., "Survey and Evaluation of Fine Bubble Dome Diffuser Aeration Equipment," EPA-600/ S2-81-222, U. S. EPA(1981).
  8. Akita, K. and F. Yoshida, "Bubble Size, Interfacial Area, and Liquid Phase Mass Transfer Coefficient in Bubble Columns," Ind. Enc. Chem., Proc. Des. Devel., 13(1), 84-91(1974) https://doi.org/10.1021/i260049a016
  9. "Measurement of Oxygen Transfer in Clean Water," ANSI/ASCE 2-92, 2nd Ed, American Society of Civil Engineers (1992).
  10. Ippen, A. T. and Carver, C. E., Jr., "Basic Factors of Oxygen Transfer in Aeration Systems," Sewage Works J., 26, 813- 827(1954).
  11. Garner, F. H. and D. Hammerton, "Circulation inside Gas Bubbles," Chem. Eng. Sci., 3(1), 1-11(1954).
  12. Dold, P. and Fairlamb, M., "Estimating Oxygen Transfer KLa, SOTE and Air Flow Requirements in Fine Bubble Diffused Air Systems," WEFTEC 2001: Session 31-40, pp. 780-791(2001).
  13. Johnson, T. L. and McKinney, R. E., "Modeling Full-scale Diffused Aeration System," Proc. ASCE Environ. Eng. Conference(1994).

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