Spray drying is a widely applied method for producing shelf-life stable powders such as food ingredients. During drying, a liquid feed is atomized into small droplets and exposed to hot air which induces rapid droplet drying yielding a powdered product.
Spray-dried powders are highly valued for their excellent functional properties such as flowability, reconstitution behavior, bulk density, and mechanical stability. These desired properties are largely attributed to the agglomeration of small particles into bigger structures. A disadvantage is that the spray drying process significantly impacts the environment due to high energy consumption and dust emissions. It is thus crucial to strive for first-timeright production and prevent unnecessary rework and dust emissions. This can be achieved by better control of agglomeration to obtain desired functional properties and reduce dust emissions.
Therefore, the overall aim of this thesis was to create knowledgebased guidelines to steer particle structure formation, targeted at both the primary particle morphology and the creation of a secondary structure through agglomeration. Pilot-scale experiments complemented with computational fluid dynamic (CFD) modeling and single droplet drying (SDD) were performed in this PhD research to investigate various aspects of the spray drying process (e.g. the material properties, drying parameters, and design aspects of the spray dryer) aiming to develop such guidelines. In each chapter, one or more of these phenomena was studied.