Thus, beyond this
limiting velocity there will be no significant increase in heat
transfer. The same principle may be applicable in case of the
fluidized bed dryer (v ¼ 45 m/s) when compared with impingement
(v ¼ 1.4 m/s) and modified impingement (v ¼ 1.6 m/s) dryers
used in the current study. Drying times were shorter for the
modified impingement dryer in which the hot air was directed only
on the top of the product, while the impingement dryer allowed an
even flow of air on both the top and bottom surfaces.