bubble columns; non-Newtonian fluids; gas disengagement; flow patterns; electrical tomography
Abstract :
[en] This paper presents an experimental analysis of the influence of the liquid rheology on the gas flow pattern in a bubble column reactor. Aqueous solutions of xanthan are selected as an example of non-Newtonian shear thinning fluid. Averaged gas holdup is determined by two experimental techniques: parietal pressure probes and electrical resistance tomography (ERT). ERT is also used to provide 2D images of the gas phase distribution in a column cross-section. Bubble size distributions are evaluated by a gas disengagement technique using the parietal pressure probes. All these techniques clearly show the gas flow pattern is different in Newtonian and non-Newtonian fluids. Gas holdup values decrease when increasing the liquid viscosity and reach a minimum or a plateau. Homogeneous flow regime, observed in water at low gas velocities, tends to disappear when viscosity increases. This evolution is visualized by a much less isotropic distribution of the gas phase within cross-section of the column and by the appearance of much larger bubbles due to an increased coalescence phenomenon. (c) 2005 Elsevier Ltd. All rights reserved.
Disciplines :
Chemical engineering
Author, co-author :
Fransolet, E.
Crine, A.
Marchot, Pierre ; Université de Liège - ULiège > Département de chimie appliquée > Génie chimique - Systèmes polyphasiques
Toye, Dominique ; Université de Liège - ULiège > Département de chimie appliquée > Génie de la réaction et des réacteurs chimiques
Language :
English
Title :
Analysis of gas holdup in bubble columns with non-Newtonian fluid using electrical resistance tomography and dynamic gas disengagement technique
Publication date :
November 2005
Journal title :
Chemical Engineering Science
ISSN :
0009-2509
eISSN :
1873-4405
Publisher :
Pergamon-Elsevier Science Ltd, Oxford, United Kingdom
Volume :
60
Issue :
22 Sp. Iss. SI
Pages :
6118-6123
Peer reviewed :
Peer Reviewed verified by ORBi
Name of the research project :
MESURES HYDRODYNAMIQUES ET MODÉLISATION STOCHASTIQUE DANS LES SYSTÈMES POLYPHASIQUES DU GÉNIE DES PROCÉDÉS
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