Abstract

An oil screw expelling machine previously developed at the Department of Agricultural Engineering Technology, Rufus Giwa Polytechnic, Owo was evaluated. The economic analysis and effect of machine speed on the performance parameters namely: machine feed rate, output capacity, mass of cake produced, efficiency and oil yield were investigated. The test results revealed that increase in machine speed resulted in increase in the feed rate, output capacity and the mass of cake produced. At machine speed of 800rpm, the feed rate was 88kg/h, the output capacity was N72kg/h and the mass of cake produced was 2.5kg. At machine speed of 650rpm, the machine efficiency was 68% and mass of oil yield was 1.9kg. Further increase in the machine speed resulted in the decline of the machine parameters. The economic analysis of the machine suggested that the startup capital is minimal and return over investment very high.