Melon seeds are popular in the sub-Saharan Africa and Asia. Egusiis a staple in Nigeria. The method of shelling egusi in Nigeria is cumbersome, employing the use of hands, which takes almost a whole day. This study focuses on devising a better method for the removal of the shell to obtain the seeds. Results from preliminary investigations carried out on some physical and engineering properties of the pod seed were used in the design of the shelling machine. The machine consists of a frame, the hopper, the shelling chamber or unit made of a rotating impeller disc, rotor and the seed or discharge outlet. The shelling unit consists of a rotating impeller made of mild steel of 15mm thick. The discs, it is reported, are separated by vanes, 5mm thick and 10mm high. The vanes are attached to provide a central feeding port of 70mm diameter and the seeds are modeled through the vanes. The impeller is mounted horizontally on the vertical shaft, centrally positioned with a cylindrical ring of 360mm internal diameter and thickness 8mm. The machine was tested with melon seeds at constant speed and feed rate, using moisture contents of dried seeds, 5%, 10%, 15%, 20% and 25% by weight (w.b). The melon shelling efficiency (MSE) increased as the moisture content increased, but beyond 20% w.b, there was a decrease. The maximum shelling efficiency estimatedat moisture content of 20% w.b. is 84%. The high shelling efficiency obtained in the shelling of melon and minimal loss has shown that there is a prospect in the mechanization of the processing and handling operation.
Keywords : Melon seeds, Egusi, shelling efficiency, pod, shelling.