2. Materials and methods
2.1. Equipment
The dryer used in these experiments is presented in
Fig. 1 and consisted of a centrifugal fan that was used
to blow air into the heating unit through a 100 mm
diameter metallic duct. By using a metal flap to control
the fan opening, the amount of air delivered could be increased
from no airflow at all (when fully closed) to a
maximum of 22 m3/min when the fan was fully open.
However, in all experiments the flap opening was set
to deliver air to the drying sample at a velocity1m/s
and could maintain flowrate within ±0.05 m/s.