Analysis of Hydrodynamic Similarity of Pressurized Three-Phase Slurry Bubble Column for its Design and Scale-up

가압 삼상슬러리 기포탑의 설계 및 Scale-up을 위한 수력학적 Similarity 해석

  • Seo, Myung Jae (Department of Chemical Engineering, Chungnam National University) ;
  • Lim, Dae Ho (Department of Chemical Engineering, Chungnam National University) ;
  • Jin, Hae Ryong (Department of Chemical Engineering, Chungnam National University) ;
  • Kang, Yong (Department of Chemical Engineering, Chungnam National University) ;
  • Jung, Heon (Synfuel Research Group, Korea Institute of Energy Research) ;
  • Lee, Ho Tae (Synfuel Research Group, Korea Institute of Energy Research)
  • 서명재 (충남대학교 화학공학과) ;
  • 임대호 (충남대학교 화학공학과) ;
  • 진해룡 (충남대학교 화학공학과) ;
  • 강용 (충남대학교 화학공학과) ;
  • 정헌 (한국에너지기술연구원 청정화석연료연구센터) ;
  • 이호태 (한국에너지기술연구원 청정화석연료연구센터)
  • Received : 2009.08.13
  • Accepted : 2009.09.15
  • Published : 2009.12.31

Abstract

Hydrodynamic similarity was investigated in pressurized three-phase slurry bubble columns by selecting the bubble holdup and pressure drop as objective functions, for the effective design and scale-up of it. In addition, effects of operating variables on the bubble holdup with variation of column diameter were also analyzed. Gas velocity($U_G$), viscosity(${\mu}_{SL,eff}$) and surface tension(${\rho}_{SL}$) of slurry phase, density difference between the slurry and gas phases(${\rho}_{SL}-{\rho}_G$) depending on the operating pressure, pressure drop per unit length(${\Delta}P/L$), column diameter(D) and gravitational acceleration(g) were chosen as governing parameters in determining the bubble holdup and pressure drop in the column. From the dimensional analysis, four kinds of dimensionless groups were derived from the 7 parameters and 4 fundamental dimensions. Effects of dimensionless groups such as Reynolds, Froude and Weber numbers on the bubble holdup in the column were discussed. The pressure drop and bubble holdup could be predicted from the correlation of dimensionless groups effectively, which could be used as useful information for the design and scale-up of pressurized slurry bubble columns.

가압으로 운전되는 삼상슬러리 기포탑에서 기포 체류량과 압력강하를 목적함수로하여 기포탑의 설계 및 scale-up을 위한 수력학적 similarity를 고찰하였다. 또한, 본 연구에서 선택한 각 실험변수가 기포탑의 직경변화에 따라 기포탑 내 기포 체류량에 미치는 영향을 분석하였다. 슬러리 기포탑에서 기체체류량 및 압력강하의 결정에 영향을 미치는 주요 인자로써 기체유속($U_G$), 연속 슬러리 상의 점도(${\mu}_{SL,eff}$) 및 표면장력(${\rho}_{SL}$), 운전압력의 변화에 따라 변화하는 기체상의 밀도(${\rho}_G$)와 슬러리 밀도(${\rho}_{SL}$)의 차($\rho_{SL}$-${\rho}_G$), 기포탑 내부에서 단위길이 당 압력강하(${\Delta}P/L$), 기포탑의 직경(D) 그리고 기포탑에서 다상흐름에 작용하는 중력의 영향을 고려하기 위해 중력가속도(g) 등을 선정하였다. 선정된 7개의 슬러리 기포탑의 수력학적 특성에 영향을 미치는 파라메타들과 3개의 기본차원들로부터 차원해석에 의해 수력학적 특성을 지배하는 4개의 무차원 군을 도출하였다. 도출된 무차원 군인 레이놀즈 수, 프라우드 수 그리고 웨버 수 등이 기포탑에서 기포체류량에 미치는 영향을 검토하였다. 기포탑 내부에서의 압력강하와 기체 체류량 등을 무차원 군의 상관식으로부터 효과적으로 예측할 수 있었다. 본 연구의 결과는 가압슬러리 기포탑의 설계 및 scale-up 등에 매우 유용한 정보를 제공할 수 있을 것으로 사료된다.

Acknowledgement

Supported by : 한국에너지기술연구원

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