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Study on optimum structure of air-lift bio-reactor using numerical analysis of two-phase flow

이상 유동 수치해석을 이용한 기포 구동 생물 반응기 내부 최적 구조에 관한 연구

  • Kim, San (School of Mechanical Engineering, Sungkyunkwan University) ;
  • Chung, Ji Hong (School of Mechanical Engineering, Sungkyunkwan University) ;
  • Lee, Jae Won (School of Mechanical Engineering, Sungkyunkwan University) ;
  • Sohn, Dong Kee (School of Mechanical Engineering, Sungkyunkwan University) ;
  • Ko, Han Seo (School of Mechanical Engineering, Sungkyunkwan University)
  • Received : 2019.12.04
  • Accepted : 2019.12.15
  • Published : 2019.12.31

Abstract

Recently, an air-lift bio-reactor operated by micro bubbles has been utilized to product hydrogen fuel. To enhance the performance, characteristics of hydrodynamics inside the bio-reactor were analyzed using a numerical simulation for two-phase flow. An Eulerian model was employed for both of liquid and gas phases. The standard k-ε model was used for turbulence induced by micro bubbles. A Population Balance Model was employed to consider size distribution of bubbles. A hollow cylinder was introduced at the center of the reactor to reduce a dead area which disturbs circulation of CO bubbles. An appropriate diameter of the draft tube and hollow cylinder were optimized for better performance of the bio-reactor. The optimum model could be obtained when the cross-sectional area ratio of the hollow cylinder to the reactor, and the width ratio of the riser to the downcomer approached 0.4 and 3.5, respectively. Consequently, it is expected that the optimum model could enhance the performance of the bio-reactor with the homogeneous distribution and higher density of CO, and more effective mixing.

Keywords

References

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