The GBR had an initial moisture content of 52% dry basis (d.b.).
The GBR was divided into two portions. The first portion was prepared
for the reference sample which was dried in shade. The
remaining portion was dried in a fluidized bed dryer with superheated
steam (SHS) or hot air (HA).The fluidized bed drying system
used in this study is shown schematically in Fig. 1.
The drying system was comprised of a backward-curved blade
centrifugal fan driven by a 2.2 kW motor, 13.5 kW heater controlled
by a PID controller with an accuracy of ±1 C and a small
boiler. The boiler produced the saturated steam at the absolute
pressure of 106 kPa. The steam was heated by electrical heater to
obtain the SHS at a given temperature and moved through the
cylinder-shaped drying chamber. After that, the exhaust SHS