Design and development of small-scale virgin coconut oil (VCO) mill

Celo et al. (CSU) developed and evaluated a village type VCO processing machine, which consisted of a grating unit, oil expeller, feeding hopper, discharge hopper, prime mover, power transmission system, and frame assembly. It is powered by 1.5 hp electric motor. At three treatments of grating angular speeds (1678 rpm, 1042 rpm, and 617 rpm) and expelling angular speeds (18 rpm, 16 rpm, and 14 rpm), the researches evaluated and optimized the performance of the grater and expeller in terms of grating capacity, expelling capacity, coconut milk extraction rate, VCO extraction rate and energy consumption rate. Findings of the study revealed the following: The grating angular speed significantly influenced the grating capacity and the energy consumption rate. Least significant difference (LSD) test showed the grating capacities obtained at an angular speed of 1042 rpm and 1678 rpm were not significantly different but were significantly different compared to the grating capacity obtained from 617 rpm. Furthermore, the energy consumption rate of 1.52 kW-hr/hour, 0.35 kW-hr/hour and 0.72 kW-hr/hour obtained at grating angular speeds of 1678 rpm, 1042 rpm, and 617 rpm were significantly different from one another. The results showed that the optimum performance of the grater was at angular speed of 1042 rpm. At this speed, the highest grating capacity of 12.89 kg/hour was obtained. The expelling angular speed did not significantly affect the expelling capacity and energy consumption rate, but had high significant effects on VCO and coconut milk extraction rate. Based on the results, optimum performance of the coconut meat expeller was not an expeller angular speed of 16 rpm. At this speed, the highest VCO extraction rate (175 mL/kg) and the highest coconut milk extraction rate (1230 mL/kg) were attained. Investment cost for a unit of virgin coconut oil mill can be recovered within a minimum of 1.8 months. Financial sensitivity analysis showed that at 20% increase in operating cost and 10% decrease in revenues, the ROI is still high (100%) and the payback period is 1 year. Further studies should be done towards the improvement of the expeller capacity, VCO and coconut milk extraction rates. Feeding and metering mechanism should be designed and installed on the expeller. The mill should be piloted at the processor's level to determine the machine's adaptability and acceptability. Feedbacks from the end users will serve as vital inputs for further improvement of the machine.