ABSTRACT
The large surface area for heat and mass transfer
and the high convective heat and mass transfer coef-
ficients, which take place at these units, result in high
drying rates and as a result, high drying capacity. The
size of particulates to be dried is usually in the range
of 10-500 mm. One of the features of these types of dryers is the relatively short contact time between
the hot air and the particulate materials (0.5-10 s)
at the drying section. Because of this the material
temperature stays always low in the drying process.
