Fluidization of nanoparticle agglomerates assisted by combining vibration and stirring methods

Fluidization of nanoparticle agglomerates is a promising technology to process nanoparticles, where the nanoparticles always exist in complex agglomerates due to strong interparticle forces. In this study, we propose an assisted method by combing vibration and stirring to improve the fluidization quality of nanoparticle agglomerates. The fluidization behaviors are evaluated in terms of minimum fluidization velocity, bed expansion ratio, and the size distribution of agglomerates, for three kinds nanoparticles of SiO2, Al2O3 and TiO2. The results show that, both vibration and stirring can improve the fluidization quality of nanoparticle agglomerates. However, the fluidization quality is no longer improved, or even worsen when the vibration or stirring parameter exceeds a critical value. Compared with fluidization assisted by vibration or stirring separately, the combination of the two methods can further decrease the minimum fluidization velocity, and increase the bed expansion ratio. More importantly, the segregation of the agglomerate sizes can be significantly reduced by using the combined method. This study provides a new reliable method to assist the fluidization of nanoparticle agglomerates.