Figure 2 shows a schematic diagram of south facing solar dryer system, which consists of an absorber plate,
a transparent plastic cover which create a triangular cavity and drying chamber in which the material to be dried is
kept on perforated tray. The length, width, and gap of the solar dryer were 4.9 m, 4.8 m, and 0.1m, respectively. Forces
responsible for the flow of air through solar collector are buoyancy forces created due to pressure drop. Pressure drop
across the collector is obtained as a result of air temperature increment while flowing along the absorber. Flat plate
collectors having constant cross section areas yield low pressure driving force. Thus velocity of air flowing through
collector is less. Lower value of air velocity affects the net heat transfer from the absorber plate to air limiting is
maximum temperature. To achieve higher air velocity the cross sectional area of collector is designed in trapezoidal
shape (similar to a Venturi)