Global and local hydrodynamics of bubble columns: effect of gas distributor

Global (level swell) and local (WMS – Wire Mesh Sensor) measurements were made on waters of different purities and air, in a cylindrical laboratory bubble column (2 m tall, 0.127 m dia) using two different gas distributors: a perforated plate (to produce homogeneous flow) and a spider sparger (to pr...

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Main Authors: Sharaf, Safa, Zednikova, Maria, Ruzicka, Marek C., Azzopardi, Barry J.
Format: Article
Published: Elsevier 2016
Subjects:
Online Access:https://eprints.nottingham.ac.uk/35892/
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author Sharaf, Safa
Zednikova, Maria
Ruzicka, Marek C.
Azzopardi, Barry J.
author_facet Sharaf, Safa
Zednikova, Maria
Ruzicka, Marek C.
Azzopardi, Barry J.
author_sort Sharaf, Safa
building Nottingham Research Data Repository
collection Online Access
description Global (level swell) and local (WMS – Wire Mesh Sensor) measurements were made on waters of different purities and air, in a cylindrical laboratory bubble column (2 m tall, 0.127 m dia) using two different gas distributors: a perforated plate (to produce homogeneous flow) and a spider sparger (to produce heterogeneous flow). The level swell method provided the steady space-averaged gas holdup/gas flow rate data. The WMS method provided the actual gas holdups and bubble sizes resolved in time and space at one cross-sectional horizontal plane (1 m above distributor), whose integration yields the timeaveraged data. The following results were obtained: The global and local data agree relatively well; there are distinct differences between the radial profiles and bubble size distributions between the two main flow regimes; the local information identifies why the predictions of published models, which account for the smaller and larger bubbles in the flow, may not perform well; the modelling approaches based on the hindrance and enhancement concepts prove to be suitable for the flow regime identification and description, including the transition range between the homogeneous and heterogeneous flows; based on the hydrodynamics, the specific interfacial area is obtained, together with the mass transfer coefficient.
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spelling nottingham-358922020-05-04T17:41:57Z https://eprints.nottingham.ac.uk/35892/ Global and local hydrodynamics of bubble columns: effect of gas distributor Sharaf, Safa Zednikova, Maria Ruzicka, Marek C. Azzopardi, Barry J. Global (level swell) and local (WMS – Wire Mesh Sensor) measurements were made on waters of different purities and air, in a cylindrical laboratory bubble column (2 m tall, 0.127 m dia) using two different gas distributors: a perforated plate (to produce homogeneous flow) and a spider sparger (to produce heterogeneous flow). The level swell method provided the steady space-averaged gas holdup/gas flow rate data. The WMS method provided the actual gas holdups and bubble sizes resolved in time and space at one cross-sectional horizontal plane (1 m above distributor), whose integration yields the timeaveraged data. The following results were obtained: The global and local data agree relatively well; there are distinct differences between the radial profiles and bubble size distributions between the two main flow regimes; the local information identifies why the predictions of published models, which account for the smaller and larger bubbles in the flow, may not perform well; the modelling approaches based on the hindrance and enhancement concepts prove to be suitable for the flow regime identification and description, including the transition range between the homogeneous and heterogeneous flows; based on the hydrodynamics, the specific interfacial area is obtained, together with the mass transfer coefficient. Elsevier 2016-03-15 Article PeerReviewed Sharaf, Safa, Zednikova, Maria, Ruzicka, Marek C. and Azzopardi, Barry J. (2016) Global and local hydrodynamics of bubble columns: effect of gas distributor. Chemical Engineering Journal, 288 . pp. 489-504. ISSN 1385-8947 Bubble columns; Wire mesh sensor; Gas holdup; Bubble size; Flow regimes; Modelling http://www.sciencedirect.com/science/article/pii/S1385894715016708 doi:10.1016/j.cej.2015.11.106 doi:10.1016/j.cej.2015.11.106
spellingShingle Bubble columns; Wire mesh sensor; Gas holdup; Bubble size; Flow regimes; Modelling
Sharaf, Safa
Zednikova, Maria
Ruzicka, Marek C.
Azzopardi, Barry J.
Global and local hydrodynamics of bubble columns: effect of gas distributor
title Global and local hydrodynamics of bubble columns: effect of gas distributor
title_full Global and local hydrodynamics of bubble columns: effect of gas distributor
title_fullStr Global and local hydrodynamics of bubble columns: effect of gas distributor
title_full_unstemmed Global and local hydrodynamics of bubble columns: effect of gas distributor
title_short Global and local hydrodynamics of bubble columns: effect of gas distributor
title_sort global and local hydrodynamics of bubble columns: effect of gas distributor
topic Bubble columns; Wire mesh sensor; Gas holdup; Bubble size; Flow regimes; Modelling
url https://eprints.nottingham.ac.uk/35892/
https://eprints.nottingham.ac.uk/35892/
https://eprints.nottingham.ac.uk/35892/