Design and construction of a duo powered shea nut grinding machine.

Abstract

In Uganda, 80% of shea nut processing is done traditionally by pounding using mortars and grinding using stones. Also manual and electrical pressers are used on small scale which machines. that arc single powered that is electrical or manual. These machines are affected by load shedding and fatigue respectively. Thus a need to develop a dual powered shea nut grinding machine aiming at reducing the labour demand, improving efficiency, quality and to ensure consistency in production in case of load shedding. The Introduction is a summary of the background of shea nut, the problem statement which includes the problems faced during shea nut grinding as one of the production process. The introduction also bears the justification of this project, the objective: both main and the specific objectives and the scope of this project. Literature review contains the details of shea nut processing in Uganda, the numerous existing types of grinding machines with all their characteristics, the choice of the machine to be designed including the reasons for the choice of the design and the design methods that were used far this design. Methodology contains the construction procedures, the materials that were used for the construction of the design, the design equations; the conceptual design structure, methods that were used to test for the grinding efficiency and capacity of both the manual and motorised system of the designed machine. The Results and discussions, a duo powered machine was designed, constructed and tested for shea nut grinding efficiency and capacity was 69.3% and 5.7kg/hr respectively that was the motorized section and Shea nut grinding efficiency and capacity was 71% and 228kg/hr respectively for the manually powered. During economic evaluation, the NPV Ushs 4,349,280 is positive, meaning the project investment was viable. Further analysis shows that for every shilling invested, the return is Ushs 11.12. The appendix contains the engineering drawings during the construction of the prototype.