Effect of N2 and CO2 bubbles on gas volume fraction and flow pattern in a quasi-2D bubble column by shadow imaging

Title

Effect of N2 and CO2 bubbles on gas volume fraction and flow pattern in a quasi-2D bubble column by shadow imaging

 Author

Sarker, D. (TU Delft ChemE/Transport Phenomena; International University of Business Agriculture and Technology)
Schinkel, C.V. (TU Delft ChemE/O&O groep)
Portela, L. (TU Delft ChemE/Transport Phenomena)

Date

2023

 Abstract

This study reports the effect of N2 and CO2 bubbles on dilute to dense gas-liquid two-phase bubbly flow. A shadowgraph imaging technique captured bubble images at a high spatiotemporal resolution. The recordings of bubble images allow us to compute gas fraction distribution. It requires challenging segmentation and gas-liquid interface detection approaches in image processing. Hence a novel gas contour characterization technique has been introduced in this study that analyses light intensity per pixel for quantifying the effect of local gas volume fraction. The dominant gas structure and repetitive gas pattern have also been determined here using Fourier transform-based power spectral density and 2D cross-correlation functions, respectively. Gas-liquid flow regimes of dissolved CO2 bubbles are found quite different than that of N2 bubbles. The plausible reasons are that gas fraction distribution at the sparger region may inhibit bubble coalescence and the positive surface charge of CO2 bubbles acts as a barrier to the interface deformation.


 Subject

Bubbly flow
CO bubble-bubble interaction
Cross-correlation
Light intensity
Power spectral density
Visual imaging

 To reference this document use:

http://resolver.tudelft.nl/uuid:c2be668f-9276-49eb-8959-73f258dd83c7

 DOI

https://doi.org/10.1016/j.cherd.2022.11.032

 Embargo date

2023-07-01

 ISSN

0263-8762

 Source

Chemical Engineering Research & Design, 189, 500-515

 Bibliographical note

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

 Part of collection

Institutional Repository

 Document type

journal article

 Rights

© 2023 D. Sarker, C.V. Schinkel, L. Portela
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