CIESC Journal

• Volume 6 • 上一篇    下一篇

Experimental Determination and Modeling of Bubble Size Distributions in Bubble Columns

H.F.Svendsen1; 罗和安2; K.W.Hjarbo3; H.A.Jakobsen4   

  1. 1 Department of Chemical Engineering, Norwegian University of Science and Technology, NTNU, N-7034 Trondheim, Norway
    2 Department of Chemical Engineering, Xiangtan University,Xiangtan 411105, China
    3 SINTEF Applied Chemistry, N-7034 Trondheim, Norway
    4 DNMI, P.O.Box 43, Blindern, N-0313 Oslo, Norway
  • 收稿日期:1996-07-16 修回日期:1900-01-01 出版日期:1998-03-28 发布日期:1998-03-28
  • 通讯作者: H.F.Svendsen

Experimental Determination and Modeling of Bubble Size Distributions in Bubble Columns

H.F.Svendsen1; Luo He an2; K.W.Hjarbo3; H.A.Jakobsen4   

  1. 1 Department of Chemical Engineering, Norwegian University of Science and Technology, NTNU, N-7034 Trondheim, Norway
    2 Department of Chemical Engineering, Xiangtan University,Xiangtan 411105, China
    3 SINTEF Applied Chemistry, N-7034 Trondheim, Norway
    4 DNMI, P.O.Box 43, Blindern, N-0313 Oslo, Norway
  • Received:1996-07-16 Revised:1900-01-01 Online:1998-03-28 Published:1998-03-28
  • Contact: H.F.Svendsen

摘要: Using a five point conductivity technique local values of bubble size, bubble velocity and gas fraction have been experimentally determined in a 288 mmID and 4.3 m high bubble column as a function of axial and radial position for the air/
water and CO2/N2/aqueous MDEA systems.The experimental results are compared with predictions from a fundamental two-fluid
model.The implementation of a non-steady lateral drag term in the two-fluid model has beenshown.In addition to improving the
physical realism of the model, it is found to give slight improvements in the predictions of the distributions of local
bubble size. Predictions of bubble sizeare found in reasonable agreement with experimental values in the heterogeous flow
regime, whereas they arestill found to be unreliable at low gas velocities.Local void predictions are found in reasonable
agreementwith experimental values, but deviations occur in thehomogeneous flow regime towards the wall.This is attributed to
deficiencies in the simplified bubble size model, suggesting improvements of that .It is shown how the Sauter mean diameter
as a measure for bubble size is a more sensitive parameter to the radial bubble structure variations in a bubble column than
the number averaged diameter. An equation for the calculation of local volumetric gas flow rates, based on conductivityprobe
data, has been developed and is shown to give improved predictions compared to previous methods in theheterogeneous regime.

关键词: Bubble column;bubble size distribution;volumetric velocity;gas fraction;two-fluid model

Abstract: Using a five point conductivity technique local values of bubble size, bubble velocity and gas fraction have been experimentally determined in a 288 mmID and 4.3 m high bubble column as a function of axial and radial position for the air/
water and CO2/N2/aqueous MDEA systems.The experimental results are compared with predictions from a fundamental two-fluid
model.The implementation of a non-steady lateral drag term in the two-fluid model has beenshown.In addition to improving the
physical realism of the model, it is found to give slight improvements in the predictions of the distributions of local
bubble size. Predictions of bubble sizeare found in reasonable agreement with experimental values in the heterogeous flow
regime, whereas they arestill found to be unreliable at low gas velocities.Local void predictions are found in reasonable
agreementwith experimental values, but deviations occur in thehomogeneous flow regime towards the wall.This is attributed to
deficiencies in the simplified bubble size model, suggesting improvements of that .It is shown how the Sauter mean diameter
as a measure for bubble size is a more sensitive parameter to the radial bubble structure variations in a bubble column than
the number averaged diameter. An equation for the calculation of local volumetric gas flow rates, based on conductivityprobe
data, has been developed and is shown to give improved predictions compared to previous methods in theheterogeneous regime.

Key words: Bubble column, bubble size distribution, volumetric velocity, gas fraction, two-fluid model