Three-dimensional modelling of two-phase flow and transport in a pilot centrifugal spray dryer

Highlights: • A 3D mathematical model of spray drying formulated and solved numerically. • Spray drying experiments conducted on a pilot centrifugal spray dryer. • Excellent agreements between experimental and numerical temperatures achieved. • Physical field distributions of gas phase and motion trajectories of droplets visualized. • Influencing factors discussed and mass and heat transfer mechanisms analyzed. Understanding of droplet evaporation and motion is of great value in optimizing the spray drying process. A numerical study based on the Euler-Lagrange approach was performed with experimental verification in a pilot centrifugal spray dryer. Predicted temperatures agreed well with measured values with a maximum relative error of 2.76%. Gas multiphysics distributions and droplet trajectories were visualized. Air backflow phenomena and droplet vortex motions were observed during drying. Increasing inlet air temperature could accelerate the drying rate and increasing disc rotational speed might cause the wall adherence. The results can help guide the future design and operation of spray dryers.