Single droplet drying to steer particle agglomeration during spray drying

Summary

Spray drying is widely used in the food industry to transform liquids into agglomerated powders. Despite its widespread use, optimal drying and agglomeration protocols in spray drying are currently still established via empirical procedures. The big scale and closed nature of an industrial spray dryer makes it virtually impossible to obtain mechanistic insights within the process itself. This PhD thesis focused on the development of advanced single droplet drying approaches to improve mechanistic understanding of the spray drying process. A single droplet drying platform was developed that can mimic actual spray drying conditions. Moreover, binary collisions can be studied with the new platform to investigate the process of agglomeration. Physical phenomena underlying the drying and agglomeration behavior were characterized experimentally and described by numerical modeling. Learnings obtained provided important new insights to steer particle agglomeration during spray drying processes. Overall, this study contributed to guidelines for first-time-right manufacturing and thus less waste and dust formation during powder production.