Magnetic reduction of gas back-mixing in bubbling fluidized beds with Geldart-B magnetizable particles

This study investigated the performance of magnetic fields in reducing gas back-mixing in bubbling fluidized beds with Geldart-B magnetizable particles. The Peclet number (Pe) and axial dispersion coefficient (D-a,D-g) were determined using the one-dimensional dispersion model. A weak magnetic field reduced gas back-mixing to a certain extent, while a moderate field resulted in minimal decrease. The performance of a strong magnetic field varied significantly depending on the operation mode. Under the magnetization-FIRST operation mode, gas back-mixing was significantly reduced. The corresponding Pe and D-a,D-g were calculated as -76 and -3.6 x 10(-4) m(2)/s, indicating that the gas flow approached the ideal plug-flow manner. However, when the magnetization-LAST operation mode was used, the strong magnetic field failed to mitigate gas back-mixing. Therefore, the performance of magnetic fields in reducing gas back-mixing depended not only on their intensity but also on their application sequence to the gas flow field. (c) 2024 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.