The research was conducted to fabricate and develop a portable solar tunnel dryer (STD) for the drying of fruits, vegetables
and medicinal plants. The system was designed as a portable system for decentralized applications at various sites to satisfy
the drying requirements of small farmers and co-operatives. The cross sectional area of the solar tunnel dryer was trapezoidal
in shape having 0.254 m2
face area, with length and width of three meters and one meter respectively. It comprises a collector
section (1.35 m) long and a drying section (1.65 m long) and two PV powered DC fans to provide the required air flow rate
over the perishable agricultural products to be dried. Transparent polythene cover was used to close the dryer on top side to
maintain the steady state air flow within the dryer. It has been observed that the drying air temperature was easily raised by
some 8-14°C above the ambient temperature at air velocity ranges 0-1 m s
-1
. The efficiency of the solar tunnel dryer was
found to be 40-45%. Psychrometric analysis was also carried out within the dryer and the process curves were drawn. The
process curves were found similar to a conventional dryer showing that this dryer can be successfully utilized for the drying
of agricultural products using solar energy.
Anjum Munir, Umair Sultan, Muhammad Iqbal . (2013) Development And Performance Evaluation Of A Locally Fabricated Portable Solar Tunnel Dryer For Drying Of Fruits, Vegetables And Medicinal Plants, , Volume-50, Issue-3.