Enhancing fluidization quality of nanoparticle agglomerates by combining vibration, stirring and jet assistances

Gas fluidization is an efficient method to process nanoparticles. In this study, we employ 3D printing to fabricate a hollow stirring structure of blades with jet holes and position it in a vibrating fluidized bed to realize an integration of vibration, stirring and jetting assistance methods, without increasing structural complexity. The fluidization of SiO2, Al2O3 and TiO2 nanoparticle agglomerates with different primary particle sizes and surface properties are investigated. The combination of vibration and stirring improves the bed expansion obviously, while a further addition of the gas jets at a velocity of a few meters per second allows a further small improvement of bed expansion. The jets slightly reduce the agglomerate size in the dense bed, the agglomerate size at the bed outlet, and the elutriation rate. By combining vibration, stirring and jets, the fluidization is enhanced while the elutriation is kept low during fluidization lasting for a few hours.