Design and construction of a cocoa seed grinder

Abstract

Africa is the largest producer of cocoa accounting for 72% of the total global production and Uganda is ranked the 6th among cocoa producing countries in Africa. If Uganda was to sell intermediate products like cocoa butter or cocoa powder it would earn three times more than what is earned when raw cocoa beans are exported. Traditionally, cocoa grinding is done by a pestle and mortar which requires a lot of effort leading to limited production capacities and poor quality of produce. Available literature indicates that the available cocoa grinding technologies are expensive and inaccessible to small scale cocoa processors. The overall objective of this study was to develop a cocoa seed grinding technology suitable for smallholder cocoa processors basing on a production capacity of 20kg/hr. A cocoa seed grinding machine was designed and constructed using locally available material. The main components of the prototype are the feed hopper, milling chamber with hammers, a motor for power supply, pulley and belt system and a sieve. The developed machine has an efficiency of 81.25% with a grinding rate of 19.37 kg/hr. With the use of the developed prototype, drudgery is reduced when compared with traditional grinding methods since it is run by a 2 HP electric motor. An economic analysis of the project was done and results indicated that the project is economically justifiable and worth taking. Stainless steel is recommended for construction of the machine rather than the use of mild steel especially for the components that get directly into contact with the cocoa.