(33e) Magnetic Resonance Imaging and Modeling of Liquid-Solid Fluidization

Christopher M. Boyce^1,2, Alexander Penn^2,3, Klaas P. Pruessmann³, Christoph R. Müller²

¹Department of Chemical Engineering, Columbia University

²Department of Mechanical and Process Engineering, ETH Zürich

³Institute for Biomedical Engineering, University of Zürich and ETH Zürich

Although less studied than gas-solid fluidized beds, liquid-solid fluidized beds have a variety of applications ranging from particle separation to thermal energy storage to bioreactors¹. On a fundamental level, liquid-solid fluidized beds typically exhibit homogeneous fluidization, making them an ideal candidate for studying particle motion in a granular gas². Studies of liquid-solid fluidized beds have been somewhat limited by difficulties in studying particle and liquid motion in the interior of 3D opaque systems.

Here, we use rapid magnetic resonance imaging (MRI) to study both liquid and particle dynamics inside of a 3D liquid-solid fluidized bed. MRI techniques are used to create instantaneous maps of particle and liquid velocity over time³, as well as the distribution of particle and liquid velocities⁴ in the system at the molecular level. The findings are compared with various theories for fluid and particle motions in a granular gas. Additionally, the results are compared with computational fluid dynamics – discrete element method (CFD-DEM)⁵ simulations to understand the abilities and deficiencies of such a model in capturing liquid and solid dynamics in a liquid-solid fluidized bed.

References:

(1) Epstein, N. Applications of Liquid-Solid Fluidization. Int. J. Chem. React. Eng. 2003, 1, 1–16.

(2) Rouyer, F.; Menon, N. Velocity Fluctuations in a Homogeneous 2D Granular Gas in Steady State. Phys. Rev. Lett. 2000, 85 (17), 3676–3679.

(3) Penn, A.; Tsuji, T.; Brunner, D. O.; Boyce, C. M.; Pruessmann, K. P.; Müller, C. R. Real-Time Probing of Granular Dynamics with Magnetic Resonance. Sci. Adv. 2017, Accepted.

(4) Boyce, C. M.; Rice, N. P.; Ozel, A.; Davidson, J. F.; Sederman, A. J.; Gladden, L. F.; Sundaresan, S.; Dennis, J. S.; Holland, D. J. Magnetic Resonance Characterization of Coupled Gas and Particle Dynamics in a Bubbling Fluidized Bed. Phys. Rev. Fluids 2016, 1 (7), 074201.

(5) Tsuji, Y.; Kawaguchi, T.; Tanaka, T. Discrete Particle Simulation of Two-Dimensional Fluidized Bed. Powder Technol. 1993, 77 (1), 79–87.