Design and construction of a multipurpose vegetable oil press.

Abstract

Vegetable oils and fats have gained popularity in food, cosmetic, soap, pharmaceutical and industries for the. production of cooking oil and margarine, pomades toilet soaps, drugs and -medical ointments respectively. Many Ugandans use vegetable oil for cooking. The intensity of the use of these oils declines as one moves from urban households to the rural households. This decline is as a result of the income disparity among these two settings and due to absence of technologies that can help the rural Ugandans extract their own vegetable cooking oil from the vegetable oil seeds that they cultivate- The aim of this work is to provide an appropriate technology which can help the rural people extract their own -oil from the abundant vegetable oil seeds such as Simsim; Groundnuts, Sheanut, Soybean, among others that they cultivate' The' objectives of this work are: to design a small scale screw press vegetable oil press, to fabricate the. components of' the expeller based on the design specifications, and to test the expeller for efficiency and social acceptability. During the designing and construction, emphasis where put on the design equations and purchasing power of the rural Ugandans who are the intended users of the machine to come with the material's selected for the different components of the expeller, The design was limited to 'basically two. sample oil seeds, that is Simsim oil seeds and groundnut oil seeds. The basic functional parts of the machine• included barrel, worm shaft, feed hopper, oil -outlet cake outlet, the •mail' frame. and bearings. The worm shaft has spiral worms which. are at a decreasing screw diameter from the: feed end to the cake end which insures maximum pressure for oil extraction and cake. extrusion process. The ban-el has perforations which allow the pressed oil out Lo the oil outlet tray. In operation, the worm shaft conveys the crushed oil seeds, presses and squeezes oil out of the seeds into the oil' outlet: via the oil channel The residual cake from. where the oil is extracted 'is extruded out of the cake outlet: in form of flakes. The machine was. tested 'by people of different sex and age group and 011 two oil seeds. The results gave an average extraction efficiency of 51 .13% for Simsim oil seeds and 47.73% Groundnut oil seeds, the extraction losses where high among females of age. group 20-32 years, the press: is powered by human hand and. weighed approximately 59K g: the Cost: of a unit 01.' the vegetable oil press was estimated be 499,400 Uganda shillings only.