Solar Dryer for Large/Medium Scale Ripening and Drying of Dates; A Case Study of Dates Growing Area of Pakistan

This study describe the design features and performance of unglazed transpired solar dryer for large medium scale drying Dates in growing area Pakistan. The has designed capacity to dry 500 Kg from Khalaal (70% humidity) Tamar (25% humidity), at 55 C ± 5 72 continuous hours using biomass furnace as an auxiliary heat source it covers approximately 256 m2 areas. is ideal humidity condition store one year without any further degradation. In traditional open sunshine huge quantity are dried over 150 h requires hectare spread Dates. Moreover, quality affected badly due two main reasons. Firstly, heavy dust that sticks during process makes them unable eat. Secondly, Monsoon rains months July August also destroys placed areas drying. Dera Ismail (D.I.) Khan, a remote district Khyber Pakhtoon Khawa province Pakistan, was selected dryer, where insolation 700-750 W/m2 August. were continuously off used. containing eight trolleys each trolley loaded with twelve trays, first Pakistan amount such way can withstand dusty atmosphere D.I. Khan protect rainy water period. does not have adverse effect on around 350 days sunny per thermal technology economically feasible compared other conventional energy resources payback period 3 7.5 years un-subsided subsided cost Natural Gas respectively. cheapest But yet popular lack information, fear initial capital weak government policies renewable energies. incorporates recommendations overcome these issues regarding Solar Thermal Technology, PACS Number: 44.40.+a, 89.30.Cc, 84.60.- h, 89.30.-g.