Analysis of the Effects of a Flat Plate Solar Dryer Geometry on Drying Rate of Agricultural Seeds

摘要

The aim of this study is to evaluate the relationship between solar dryer geometry and the drying rate of seeds; hence the analysis of the effects of a flat plate solar dryer geometry on drying rate of Agricultural seeds is presented using a case study of Ogbono seeds (Irvingea gabonensis). Ogbono seeds were dried using a distributed type, forced convention solar drying system, consisting of a solar collector plate of a geometric area (A), thickness (D) and tilt angle (β). The drying rates of the Ogbono seeds were obtained for collector plate Areas of 0.24, 0.42 and 0.60 m2; tilt angles of 0, 5, 10 and 15o; absorber plate thicknesses of 1.50, 2.70 and 4.20 mm. The graphs of Area (A) of collector plate against drying rate showed that the drying rates increased linearly with the increase in the area of collector plate. From the graphs of angles of tilt against drying rate, it was evident that the drying rate generally increased curvlinearly to a point with the increase in the tilt angle. From that point of inflection, the drying rate decreased with the increase in the tilt angle of the plate. A maximum drying rate of 10.03% m.c/h was obtained for the Ogbono seeds during the field test. This maximum rate of drying occurred for collector plate area of 0.60 m2, tilt angle of 5o and plate thickness of 2.70 mm. The corresponding collector efficiency is 57%.