Literature has shown several successes in mechanical shelling of melon seeds although, without separation capabilities. The use of conventional winnowing method for separating moist shelled melon seeds has failed due to high surface moisture in shelled melon seeds and similar gravimetric properties that exist between thick edges of Bara variety and its cotyledon. To tackle this challenge, an aerothermal-machine for separating melon seeds cotyledon from its shells was designed, fabricated and tested. It consist of a hopper, heat exchanger chamber, blower chamber, prime mover, drying chamber, sieve separation unit, a frame and delivery chute for clean melon cotyledons, thick edges, and lighter shells respectively. It does the separation aerodynamically and by a sieving arrangement. The machine was tested using the two major and available melon seed varieties: Serewe (thin-edge) and Bara (thick-edge) varieties. Based on preliminary investigation results carried out on the machine, 2872rpm operation speed and melon seeds moisture content level of 21.5%wb was used in the test. Samples weighing 200, 250 and 300g were prepared from each variety of the mechanically shelled melon seeds in two replicates. The analysis of the obtained data showed that the separation efficiency of the machine was 97.96% for Serewe variety and 71.84% for Bara variety. The capacity of the machine was 7.4Kg/h. This new technology can therefore be adjudged efficient, energy saving, rural and environmentally friendly, and hereby recommended for adoption.
Keywords : Aerothermal, Blower, Exhaust, Melon seeds, Heat exchanger, Separation.