EFFECT OF NOZZLE CONFIGURATION ON PERFORMANCE OF A SPRAY DRYER

Abstract

In this work, hydrodynamics and drying characteristics of spray dryer is numerically investigated using computational fluid dynamics (CFD) using Euler-Lagrangian (EL) approach. The gas phase is modelled as the continuous phase and solid particle as the dispersed phase. The turbulence in the gas phase is predicted using RNG version of k-ε model. As air flow pattern influences the time spent by particle in drying chamber, the spatial variation of air velocity and its circulation rate is quantified. Accordingly, optimum conditions for drying the feed slurry are determined. Further, five different outlet pipe locations are chosen and the optimum location is identified which supports the highest evaporation rate. To improve the product quality, conventional nozzle is modified and particle impact positions are analyzed. The particles impact positions on the dryer’s surface are found to be minimum for the proposed nozzle configuration and it improves the final product quality.