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Real-time magnetic resonance imaging and numerical modelling of gas-solid hydrodynamics in vibrated bubbling fluidized beds
Publikationstyp
Conference Presentation
Date Issued
2025
Sprache
English
Author(s)
Citation
Quantitative NMR Methods for Reaction and Process Monitoring, NMRPM 2025
Contribution to Conference
Gas-solid fluidized beds are used in a variety of chemical engineering applications, such as food processing, or energy conversion. Vibrating the beds helps to further enhance process efficiency [1]. Studying the hydrodynamics of fluidized beds is
challenging due to their opaque nature. Therefore, three-dimensional (3D) tomographic techniques, such as Magnetic Resonance Imaging (MRI) [2], are necessary to study the hydrodynamics within these systems.
This work investigates the gas-solid hydrodynamics of 3D vibrated fluidized beds using real-time MRI with a world-wide unique vertical 3T MRI scanner. In contrast to conventional clinical systems, this MRI features an open radiofrequency (RF) shielding, allowing to place the electrodynamic shaker and other RF-noise emitting peripherals in axis with the fluidized bed. A tailored RF receiver array for signal detection is used allowing real-time imaging with high temporal resolution enabling the observation of dynamics such as bubble growth and coalescence. The size distribution and rise velocity of gas bubbles in the bed are investigated for Geldart group A, B, and C particles. Additionally, MRI data is compared with CFD-DEM numerical simulations to validate drag force models and
coarse-graining approaches. The project is financially supported by the German Research Foundation (DFG) under project number 471615686. References: [1] Guo, Q. et al., Current Opinion in Chemical Engineering, (2023), 22113398, 100977 [2] Penn, A. et al., Science Advances, (2017), 117-123
challenging due to their opaque nature. Therefore, three-dimensional (3D) tomographic techniques, such as Magnetic Resonance Imaging (MRI) [2], are necessary to study the hydrodynamics within these systems.
This work investigates the gas-solid hydrodynamics of 3D vibrated fluidized beds using real-time MRI with a world-wide unique vertical 3T MRI scanner. In contrast to conventional clinical systems, this MRI features an open radiofrequency (RF) shielding, allowing to place the electrodynamic shaker and other RF-noise emitting peripherals in axis with the fluidized bed. A tailored RF receiver array for signal detection is used allowing real-time imaging with high temporal resolution enabling the observation of dynamics such as bubble growth and coalescence. The size distribution and rise velocity of gas bubbles in the bed are investigated for Geldart group A, B, and C particles. Additionally, MRI data is compared with CFD-DEM numerical simulations to validate drag force models and
coarse-graining approaches. The project is financially supported by the German Research Foundation (DFG) under project number 471615686. References: [1] Guo, Q. et al., Current Opinion in Chemical Engineering, (2023), 22113398, 100977 [2] Penn, A. et al., Science Advances, (2017), 117-123
Subjects
Magnetic Resonance Imaging
VIbrated gas-solid fluidized beds
Numerical modelling
DDC Class
620: Engineering