Fig. 1 shows a schematic view of the MNCSCD. Three main components of the dryer can be identified: an air-heater (primary collector), through which the drying air is heated as it flows over and under an absorber plate that is heated in turn by direct absorption of incident radiation; a drying chamber, in which the crop to be dried is placed; and a chimney, through which the moist air flows and escapes into the surrounding. Solar energy is incident on the planes of the primary collector and the drying chamber.
The primary collector is a single pass air-heater with double duct (SPDDSAH) and a nonporous absorber plate suspended between the top glass cover and the base plate providing two channels (upper and lower channels) through which air flows in the same direction on both sides of the absorber plate thus providing twice as much surface area for heat transfer to the air compared to either the single-pass air-heater with rear duct or front duct.
The drying chamber has a rectangular drying surface area and it houses three drying racks with each drying rack consisting of two drying beds arranged vertically in line (see Fig. 1). The roof of the drying chamber (i.e. secondary collector) and sidewalls are transparent. Doors are provided for access to the chamber for loading, unloading, and stirring of the crop.
The chimney runs along the entire breadth of the drying chamber to aid the natural circulation of air inside the whole assembly. An exit air vent runs across the width of the drying chamber.