Magnetic resonance imaging of a stream of bubbles injected into liquid suspensions

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-08, Vol.494, p.153282, Article 153282
• Main Authors: Bordbar, Alireza, Zia, Wasif, Birnbaum, Janine, Omidi, Javad, Lee, Ray F., Lev, Einat, Boyce, Christopher M.
• Format: Article
• Language: English
• Subjects: Bubbles; Dense suspensions; Magnetic resonance imaging
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.153282

•Fully 3D magnetic resonance imaging (MRI) of bubble rise in dense suspensions.•Non-axisymmetric bubble dynamics are observed.•Timed bubble injection can create periodic bubble coalescence. Magnetic resonance imaging (MRI) is a powerful tool for characterizing opaque multiphase flows non-invasively. However, MRI has often (i) had low temporal resolution and thus not captured transient dynamics, (ii) only provided 2D slice images of 3D flows and (iii) been limited to flows in narrow (∼30 mm) tubes with significant wall effects. Here, we apply multi-band echo planar imaging (MB-EPI) with a custom-built radiofrequency coil in a full-body MRI scanner to provide fully 3D images of the dynamics of a stream of bubbles rising through a dense suspension with 151 ms resolution in a 178 mm diameter system. Image processing demonstrates that bubble rise and coalescence dynamics vary significantly with (a) initial spacing between bubbles and (b) particle volume fraction. The ability to image bubble dynamics in dense suspensions as well as in full 3D provides future opportunities to characterize complex, non-axisymmetric, multiphase flows.