where Qs is the rate of solar energy absorbed, It is the rate of
incidence of the radiation for a unit area of the collector, Ac is the
collector area,and τα is the effective product transmittance
absorptance. Basically, τα depends on the transmittance of the
transparent covers and on the absorptance of the absorbent.Solar
energy for drying purposes was investigated in the literature by
many researchers,particularly for agricultural purposes.