terminal velocity in spray dryer

elmariachi

I am working on a problem involving spray dryers. The material to be dryed would be injected through a centrifugal disk with spherical multiple openings of about 0.5 mm in diameter. Hot air would be blown from the dryer's bottom part. I was wondering how can I approach the problem to find out the particle's terminal velocity. The wet material at somepoint in the dryer will fully or partly loose its water molecules. will it be affecting the terminal velocity too and how is terminal velocity related to reynolds number.any help will be appreciated.

thanks