New CNIE Paper: Bubble Self-Organization in Pulsed Annular Gas-Solid Fluidized Beds

Our latest paper on dynamically structured flow in pulsed fluidised beds, titled “Bubble Self-Organization in Pulsed Annular Gas-Solid Fluidized Beds”, has been published in a Special Issue of Powder Technology, in memory of Professor John Grace (University of British Columbia), who recently passed away.

This work is a collaborative effort, co-first authored by former NICE/CNIE PhD student, Dr Kaiqiao Wu, and current PhD student Shuxian Jiang, in collaboration with Dr Victor Francia, a former NICE/CNIE postdoctoral researcher and Assistant Professor at Heriot-Watt University, along with Prof Marc-Olivier Coppens (NICE/CNIE).

Pulsating the gas flow in rectangular, quasi-2D fluidized beds can turn the chaotic bubble flow into a regular bubble pattern. Bubbles form a rising triangular lattice, leading to a scalable flow structure with controllable properties, such as narrow bubble size distribution, distance between bubbles, and residence time. This overcomes challenges encountered in conventional units, like flow maldistribution and non-uniform contact. In this work, we reproduced a similar, dynamically structured flow in a cylindrical annular geometry. Regular bubble patterns emerge along the circumference of the cylinder, despite the absence of lateral walls and strongly curved boundaries, which could cause instabilities.

This study presents an operating window for creating spatiotemporally structured flows and compares the flow properties in quasi-2D rectangular and annular systems, quantifying the impact of curvature and, effectively, lateral walls on flow behaviour. These insights offer new opportunities for modularization of fluidized bed operations.

This work was recently presented at the AIChE Annual Meeting in Orlando, Florida, in a session in honour of Dr Ray Cocco (Particles in Motion LLC, former president of PSRI, Chicago, and long-time CNIE Advisory Board Member), who received the AIChE PTF Lifetime Achievement Award, sponsored by Elsevier.

Reference: K. Wu, S. Jiang, V. Francía, M.-O. Coppens, 2023, Bubble self-organization in pulsed annular gas-solid fluidized beds, Powder Tech. 431, 119096. DOI:10.1016/j.powtec.2023.119096.