Model of Heat and Mass Transfer in an Industrial Counter-Current Spray-Drying Tower

Abstract

The paper presents a unique methodology of CFD modeling of heat and mass transfer during a counter-current spray-drying process based on the concept of a negative heat source reflecting the energy necessary for evaporation of water. The volumetric internal heat source term in Navier-Stokes equations describing heat transfer was used to determine energy transfer from explicit to latent heat. Total power consumption during the drying process was estimated on the basis of extensive industrial measurements of air temperature distribution along the axis and radius during regular tower operation. The probability function to control the distribution of density of power consumption as a function of the distance from the atomizers was determined by the trial and error method to fit experimental temperature measurements in the industrial tower. This approach allowed us to carry out 3D CFD accurate calculations of the counter-current spray-drying process analyzing continuous phase only. General methodology applied in the developed CFD model of heat and mass transfer is universal and can be applied for scaling up of the countercurrent spray-drying process.

Keywords:

• Counter-current spray-drying
• Energy distribution
• Industrial dryer
• Industrial measurements
• Temperature profiles