International Journal of Engineering and Technology

Spray drying has been used recently for producing a large variety of high-value particles. The aim of the present paper is to analyze the drying mechanism of slurry droplets consist of nanosized particles in the industrial-scale spray dryer. For this purpose, a mathematical model is developed comprising a comprehensive model for the heat and mass transfer for a single droplet and a model for the flow of droplets and gas, and the heat and mass transfer in the dryer. Using the developed model, the drying behaviour of slurry droplets in the spray dryer is investigated in the initial heating-up, constant rate and falling rate periods by analyzing the profiles of air temperature and humidity, and the droplet velocity, average temperature and moisture content in the dryer axial direction as well as the distributions of temperature and water vapor concentration in the droplet.