Design and construction of an electrical groundnut roaster machine.

Abstract

Ground nut roasting is one of the most important stages in groundnut processing is a process of pyrolysis (time temperature dependent) which, by increasing the temperature of the groundnuts from room temperature to 1500C and above, brings about marked physical and chemical changes in the groundnuts that improve the quality of the groundnuts. The purpose of this project was to design and construct an electrical groundnut roaster machine for helping groundnut farmers improve on the quality of their products which would yield high market prices hence improving their economic wellbeing and this was achieved by roasting under controlled time and temperature conditions in order to reduce loss of desired aromas to the environment and attain uniform roasting of the groundnuts. The design of the various machine parts was carried out by analyzing forces acting on them. Force analysis led to selection of proper materials to withstand the forces to avoid failure. Stainless steels of various grades were the main materials recommended to be used because they are food grade, strong and durable. Engineering drawings of the various components were drawn before the various components were constructed and then machine parts fabricated. A fully functional prototype resulted after all the above operations. Testing of the prototype was carried out and the figures revealed that the machine was 72-7% efficient. The groundnut roaster has a total cost of 1,605,000 UGX which includes all the taxes, cost of material, machinery and hired labor to construct the machine plus overhead costs. The cost evaluation analysis of the project was based on the payback period method, the project was evaluated to breakeven in 1.23 years and on net present value method with NPV of I UGX over a period of five years.