Single droplet experimentation on spray drying:evaporation of sessile droplets deposited on a flat surface

Abstract: Individually dispensed droplets were dried on a flat surface to mimic the drying of single droplets during spray drying. A robust dispensing process is presented that generates small droplets (dp>150 µm). A predictive model based on Bernoulli’s law accurately describes droplet size with varying liquids and dispensing parameters. Shrinkage of the droplets, monitored with a camera, was described using mass balance equations. Finally, a Sherwood correlation was derived to describe the mass transfer coefficient for sessile droplets. This work forms the basis for the development of a platform for high throughput experimentation on spray drying.