It is also noticed that the drying rate for all the trays is very
close after the first couple of hours in all runs. During the first
couple of hours, the drying rate is the highest and the drying is
gas-phase controlled, thus it depends much on the drying air
conditions. However, after the initial high drying rates, the
conditions of the drying air are not the main effective variable,
since the diffusion inside the plants becomes slower (due to
lower moisture content). Thus, by approaching the final dry
plants, the drying rate over the trays becomes closer.