Experimental Set Up: The experimental set up, shown in
Fig. 1, mainly consists of a drying cabinet with sample
holding meshed tray(300×250mm), a flat plate solar
collector (1500×500mm) and a circulation fan. The air was
sucked through the solar collector by means of an
electrical fan for admitting the air to the drying cabinet. In
order to convert the drying system from mixed mode to
indirect, a thick cover was spread on transparent front
wall of the dryer.
In this work, grains were collected from the
Ferdows city farms locating in the eastern part of Iran.
Grains were cleaned by hand and stored at fixed
temperature 4°C in a cooling device. For each treatment of
experiment, a stabilized sample of 70-80 gr was spread
evenly (as a thin layer) on a meshed tray. Average initial
moisture content of the grains was about 43 % on dry
basis (d.b).
Solar collector was constructed from sheet iron with
dimension of 1500mm×500mm. A transparent sheet was
located over the collector, which allows the air was