Effect of Feed Properties and Drying Kinetics on Particle Morphology in Spray Drying

Spray drying is one of the basic techniques for the formation of particles from liquid solutions, suspensions or slurries. The process involves spraying a solution in the stream of a hot drying medium, usually air. As a result of the rapid spray extension, intensive moisture evaporation takes place without a significant increase in dried material temperature. Short drying time and low product temperature in spray drying are beneficial in many industries, from pharmaceuticals, through food, to chemicals, especially for drying heat-sensitive materials.
Spray drying is a complex process. Many process parameters affect not only the operation of drying towers but also the final properties of the product. This complexity makes modelling of spray drying difficult, and the developed mathematical models are usually dedicated to the specific processes and materials(Filkova et al., 2015). Even though the spray drying process has been used for over a century in the industry, mathematical models are still elaborated to predict the physicochemical properties of powders, based on drying process parameters and rheological properties of the sprayed solution.
The research program presented for IFPRI assumes finding the relationship between the rheological properties of the solution and the drying speed on the morphology of the particles obtained by the spray drying method. For this purpose, in the first year of the project, the following tasks were assigned to be implemented:
• Selection of suitable experimental media and determination of quality criteria.
• Measurements of rheological properties of aqueous solutions of selected materials.
• Adaptation of the existing equipment to the project requirements.
• Design of particle-free fall SDD measurement system.