(654d) Effect of the Micro-Packing Status On the Bulk Behaviour of Loose Agglomerated Nano-Powders

Nano-agglomerated Fluidized Bed (NAFB) has been extensively studied in recent years, in which nano-powder is the key factor. Nano-powders are classified as belonging to Geldart-C group. Some of them show good agglomerate flow or fluidization behaviour, while many others are difficult to flow. The Geldart classification, which separates powders by the density and average diameter of the primary particles, is not general enough to explain the diversity. The effect of the micro-packing status (MPS) and inter-agglomerate forces (van der Waals force) are analyzed in this work. The results show that both the fluidization behaviour and the maximum angle of stability of nano-powders are related to the MPS, i.e., whether nano-powders behave like Geldart-C group or not is dependent on MPS. This is helpful to understand the bulk behaviour of nano powders more correctly, and could be considered as an extension of the Geldart classification.