In this paper, an indirect solar dryer using a new type of collector is studied. The collector is built with hemispherical concentrators with an axially-centered Fresnel lens placed on top of each. That allows the collector's aperture area of 0.32m2 to fully contribute to the hot spot generated in the hemispherical concentrators. The dryer was installed permanently, sun-tracking free, and drying experiments were taken at a cloudy period (From the end of May to the beginning of June) to correspond to the most-needed time of crops conservation in Ouagadougou, Burkina Faso. Mango and ginger were charged in the chamber, weighted separately and without tray permutation to see the weight loss for each of the 5 trays' products. As outcomes, dryer's collector efficiency was evaluated at 42.45%. Mango was dried with temperatures ranging from 57 to 67°C around the trays with a dryer's efficiency of 41.2% and in 8 hours. In conclusion, the novel collector built with hemispherical concentrators, enhanced by Fresnel lenses and mounted on a sun tracking free indirect solar dryer is proven effective for agricultural crops drying.

emispherical concentrators Solar bowl Natural convection Sun-tracking free indirect solar dryer