A computational fluid dynamics study of a tall-form spray dryer

Two phase simulations have been performed of a tall-form Delaval skim milk spray dryer in order to evaluate the applicability of current computational fluid dynamics models to this type of simulation, and to examine the characteristics of the flows that exist within these complex devices. The simulations have been performed with and without milk particles included, for a variety of droplet nozzle injection velocities, and for two dryer inlet throat geometries. Limited validation of the results has been achieved by comparing the simulated product moisture contents against data measured in experiments'. It was found that the simulated product moisture contents were of the same magnitude, but generally slightly lower than those found during experiments. It was also found that the behaviour of the dryer is largely determined by the relationship between the initial momentum of the injected particles and the gas flowfield within the dryer.