Effect of primary particle size on spray formation, morphology and internal structure of alumina granules and elucidation of flowability and compaction behaviour

Abstract

Three different alumina powders with varying particle sizes were subjected to spray drying under identical conditions and effect of particle size on heat transfer efficiency and mechanism of formation of granules was elucidated. Morphology, internal structure and size distribution of granules were studied and evaluated with respect to their flow behaviour. In order to estimate the elastic interaction of granules, the granules were subjected to compaction under progressive loading followed by periodic unloading. Compaction curves were plotted and compressibility factor was estimated and correlated with predicted and measured green density values.

Keywords

• alumina powders
• spray drying
• pressing
• structural characterization
• modelling