DESIGN, CONSTRUCTION AND PERFORMANCE EVALUATION OF AN IMPROVED COCOA DEHULLER AND SEPARATOR

Within the value addition chain of cocoa in Uganda, the majority of farmers export dried beans yet they could earn more if they were dehulled and winnowed. Not only would this increase their income but industries could emerge and create even more jobs. Simple value addition machines for cocoa i.e. dehullers and winnowers; suited for the Ugandan farmer are not readily available. Available machines with very superior winnowing capacities for example 99% are very bulky and expensive which makes them unsuitable for farmers. As such, a prototype was designed and fabricated at Makerere University and it achieved a dehulling efficiency of 99%, 19 kg/hr throughput capacity, spillage of between 11% - 30%, and a winnowing efficiency of 44%. This research focused on the design and fabrication of an improved prototype. The new design was fabricated using mild steel materials and tested using 4 batches of 1.5 kg each of well roasted cocoa beans. The prototype achieved a maximum winnowing efficiency of 83.3%, a dehulling efficiency of 99%, a high blower pressure, a throughput capacity of 91 kg/hr and negligible spillage. In conclusion, the new prototype is an improvement of old prototype and therefore can be adapted by farmers and entrepreneurs.