Segregation in magnetized fluidized bed with Geldart-B magnetizable and nonmagnetizable particles

Abstract

For magnetized fluidized beds with Geldart-B magnetizable and nonmagnetizable particles operated under the magnetization-LAST mode, segregation occurs and deepens as the magnetic field intensity increases. This work aimed to explore the effects of particle size and density difference on such segregation. The field intensities (His and Hcs) for the segregation to initiate and complete increased as the gas velocity (Ug) increased. Moreover, their increases were steeper at higher gas velocities. The increase of Ug raised not only the collision to the magnetic chains but also their mixing tendency with the nonmagnetizable particles. For the given nonmagnetizable particles and Ug, His and Hcs increased as the size or density of the magnetizable particles decreased, indicating that it was more difficult for the segregation to occur and complete. Additionally, the smaller/lighter the magnetizable particles, the steeper the variations of His and Hcs with Ug. A much stronger magnetic field was required for more of such magnetizable particles to form the desired magnetic chains and keep the desired size. Segregation could only be postponed but completely prevented under the magnetization-LAST operation mode however the two types of particles were matched.