Application of Computational Fluid Dynamics (CFD) Simulations to Spray-Freezing Operations.

A 3D computational fluid dynamics (CFD) simulation for
spray-freezing in a cold gas has been developed and used to identify
design improvements. This model includes an approximate method
to model the latent heat of fusion and is able to track particle trajectories.
The simulation predictions agreed reasonably well with
experimentally measured gas temperatures and droplet velocities.
The results suggest that a hollow-cone spray is more effective in
cooling the particles uniformly. The CFD simulation suggested that
buildup of an icy layer on the cone walls observed experimentally
was due to incomplete freezing of larger particles (>100 mm).
Collection efficiencies could be raised (from 20 to 57%) by increasing
the diameter of the chamber outlet.