Particle morphology and shrinkage in spray dryers: A review focused on modeling single droplet drying

Spray dryers have a wide range of applications in the industry for obtaining powder products. Precise control of the process is crucial, as a variety of particles can be formed through atomization, resulting in particles with different sizes, shapes, and properties. The morphology and shrinkage of the particles can be influenced by various factors such as drying rate, temperature, solution concentration, and characteristics of the drying fluid. This review covers both experimental and theoretical studies. Practical experiments involve techniques such as X-ray diffraction and camera monitoring to analyze the particles, while theoretical and mathematical models are developed to predict the drying behavior, considering factors such as drying rate and temperature. In the context of the single droplet drying (SDD) process, major phenomenological models of SDD have been discussed along with their considerations emphasizing the need for further in-depth research and more precise measurements to advance in this field.