Development and Performance Evaluation of a Variable-Pitch Tapered-Shaft Screw Press for Palm Oil Extraction

Abstract

Palm fruit oil extraction is a difficult task to undertake. Screw press technology offers a solution to its extraction. However, most screw press available requires high power input for effective operation, thus affecting cost. Therefore, there is a need for improvement in order to limit cost and increase extraction efficiency. This work focuses on development of a variable-pitch tapered-shaft (VATS)screw pressfor enhancing palm fruit oil extraction efficiency. The VATS screw press machine consists of three main components including the hopper, the steamer, and the pressing unit, and was operated at temperature of 90, 110 and 130°C, shaft speed of 30, 45, and 60 rpm and heating time of 10, 15, 20 minutes. The performance evaluation carried on the machine includes oil yield, extraction efficiency and extraction loss. The results showed that the average oil yield, extraction efficiency and extraction loss were 83.72, 97.73 and 2.37% respectively. Whereas, a higher machine efficiency of 94.45% was obtained at a temperature of 130°C, shaft speed of 60 rpm, and heating time of 15 minutes. It is hoped that the information on the design concept for VATS screw press for palm fruit oil extraction will be useful for the vegetable oil industry.