DEVELOPMENT AND PERFORMANCE EVALUATION OF AN OIL EXPELLER FOR SELECTED OIL-SEEDS

Abstract

The domestic and industrial uses of vegetable (edible) oil necessitate mechanized extraction tin order to enhance profitability and hygiene of the product. The aim of the research was to develop an indigenous and affordable oil expeller with high extraction efficiency using locally available materials. The fabrication of all components of the designed oil expeller which include the tapered screw shaft, cylindrical barrel, hopper, feed gate, controllers and frame were fabricated, machined and asembled in the Department of Agricultural and Environmental Engineering Workshop, The Federal University of Technology, Akure. The performance evaluation of the machine was carried out using two oil seed (melon and groundnut), Tests were conducted by starting the machine and feeding a known weight of the seeds into the machine, and. After each run, the oil and cake were being collected from the discharge outlet and weighed accordingly. The processing parameters which include the input quantity, the quantity of oil extracted, the quantity of cake produced and the time spent in processing the seed were measured. The result shows that the extraction efficiency, capacity and loss of the oil expeller ranges from 28.1% - 68.4%, 2.78 kg/h - 6.74 kg/h, and 6.25% - 20.69% respectively when evaluated with melon seed, and ranges from 28.94% - 76.1%, 2.85 kg/h - 8.51 kg/h, and 7.53% - 23.11% respectively when evaluated with groundnut seed. The highest extraction efficiency (68.4%) was recorded for melon seed at roasting temperature of 100 °C,, roasting time of 30 min,, machine speed of 800 rpm, and feed rate of 525 g/min while that of groundnut (76.1%) was obtained at roasting temperature, roasting time, machine speed and feed rate of 100 °C, 30 min, 263 rpm, and 300 g/min respectively, the change in the extraction efficiency of the oil expeller significantly (P<0.05) depends on the change in roasting temperature followed by the roasting time, whilst the differences in the extraction capacity and extraction loss of the oil expeller significantly (P<0.05) depends on the feed rate followed by the machine speed. The developed model in this study can significantly (P<0.05) predict the about 99.81% and 99.33% variation in the extraction efficiency; 99.33% and 0.99.11% variation in the extraction capacity; 94.56% and 96.18% change in the extraction loss for melon and groundnut respectively, therefore, the model can be used for effective prediction of the oil expeller performance in small and large scale.