Use of Computational Fluid Dynamics to Evaluate Alternative Spray Dryer Chamber Configurations

Abstract

A computational fluid dynamic simulation study was carried out to compare the gas flow and temperature patterns as well as particle trajectories for a pressure nozzle atomized liquid slurry spray dried in four different chamber geometries. The gas and liquid conditions are held the same for all four chamber geometries. The gas flow is co-current and enters and exits centrally thus maintaining a two-dimensional axi-symmetric flow pattern. It is found that as a result of variations in the gas flow and thermal patterns in the four configurations examined (viz cylinder-on-cone, conical, hour-glass shaped, and lantern-shaped axi-symmetric) the droplet trajectories, residence times, and drying times vary. It was noted that the effective chamber volume occupied by drying particles depends on the chamber design.

Keywords:

• Atomization
• Hour-glass shape
• Lantern shape
• Modeling
• Particle trajectories
• Residence time
• Turbulence model
• Two phase flow
• Volumetric effectiveness