Design Enhancement and Testing of a Modified Roasted Cacao Bean Cracker and Nib-Shell Separation

To improve the hulling process of roasted cacao beans, modifications were made to a cacao bean cracker and nib-shell separator. The evaluation of the modified machine was based on several performance metrics, including working capacity, cracking efficiency, losses, and purity. The modifications involved replacing the existing combined air-sieve suction mechanism with a gravity air-suction separation mechanism. The machine was tested at three different suction fan speeds (2500 rpm, 1750 rpm, and 1200 rpm) and analyzed using a Completely Randomized Design (CRD) at a 5% significance level to determine the influence of fan speed on machine performance. Mean differences among treatments were assessed through descriptive analysis and verified using the Least Significant Difference (LSD) method. The findings showed that a suction fan speed of 2500 rpm significantly impacted all evaluation parameters, resulting in superior performance across all metrics. At this optimal speed, the machine achieved a total working capacity of 19.07 kg/hr, a loss rate of 1.85%, a cracking efficiency of 99.31%, and a nib-shell purity of 97.08%. These improvements indicated that the gravity air-suction mechanism was highly effective in enhancing the separation process by efficiently removing lighter shell particles while minimizing nib losses. In addition to performance evaluation, an economic analysis was conducted. The initial investment cost for the machine was 33,127.50 pesos, which corresponds to a calculated payback period of 2.68 years and an annual return on investment (ROI) of 37.5%.