Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Gas holdup

Fluid Dynamic in Bubble Columns with Heat Exchanger Internals

Burhan Sadeq Abdulrazzaq

Engineering and Technology Journal, 2014, Volume 32, Issue 11, Pages 2815-2829

The effects of vertical cooling internals on the gas hydrodynamics was studied in gas-liquid system (bubble columns) for column diameters, 15 and 30 cm in the absence and presence of internals (the % occluded area by internals 5, 10, and 20%). The superficial gas velocity was varied in the range 0.8-30 and 0.8-7.6 cm/s for 15 and 30 cm column diameters respectively. The effect of internals on the bubble dynamics in columns was assessed using the electroresistivity probe technique. The overall gas holdup is measured experimentally by bed expansion technique. The experimental results show that the increased in percentage coverage of cross sectional area by internals causes an increase in the overall gas holdup values, gas holdup radial profiles, bubble rise velocity, bubble frequency and reduce average bubble diameters. Correlations have been used for the estimation of the gas holdup in gas-liquid system bubble column. The overall gas holdup can be easily predicted from .Comparison of the model predictions with the experimental data shows agreement with error 0.017 which ensure the reliability and confidentiality of the adopted the correlations to be used in further designation and scale-up purposes.

CFD Modeling and Gas Holdup Measurement in Three-Phase Slurry Bubble Column

Ali H. Jawad; Raheek I. Ibrahim; Amer A. AbdulRahman

Engineering and Technology Journal, 2009, Volume 27, Issue 16, Pages 3012-3022

Gas-Liquid-Solid system as slurry in a reactor have a wide range of applications in industry, a slurry reactor is a vessel containing the catalyst suspended in a liquid phase. In this study, we develop a CFD model to predict the gas holdup at different gas superficial velocities.
The experiments were done in a gas-liquid-solid slurry bubble column to find the gas holdup (eG). The experimental data showed a good agreement with CFD results. An empirical correlation has been developed to predict the gas holdup for three-phase slurry with a correlation co-efficient of 0.994; this correlation shows that the gas holdup predicted was in good agreement with experimental values.