MODELING AND SIMULATION OF DRYING MILK EMULSION IN SPRAY DRYERS

This work aims at modeling and simulating the drying of whole milk emulsion in spray dryers. Drops and particles compound the discrete phase, being distributed into temporal compartments following their residence time into the dryer. Air is the continuous and well mixed phase. Mass and energy balances are developed for each one phase, considering their interactions. Constitutive equations for describing the drop swelling and drying mechanisms as well as the heat and mass transfer between particles and hot air are proposed and analyzed. A set of algebraic-differential equations is obtained and solved by specific numerical codes (DASSL-code and Particle Swarming Optimization). Results from experiments performed in a pilot spray dryer are used to validate the model developed and their numerical algorithmic. Comparing the simulated and experimental data, it is shown that the model predicts well the individual drop-particle history inside the dryer as well as the overall outlet air-particle temperature and humidity.