Design, Fabrication, and Performance Evaluation of a Batch-Type Fluidized Bed Coffee Roaster for Small-Scale Coffee Growers

Abstract

A batch-type fluidized bed coffee roaster was designed, fabricated, and evaluated at the College of Engineering and Applied Technology, Benguet State University to help small-scale farmers roast quantities of coffee beans. The machine is inexpensive with lower capacity, uncomplicated design, and simple to operate. The machine comprised a roasting assembly that included a blower, heating element, roasting chamber, chaff collector and frame. Performance evaluation results showed that the optimal airflow rate was at 9.2m/s with highest capacity and efficiency of 94.06% and 96.46% for medium and dark roast, respectively. Airflow rate of 9.7m/s attained the highest uniformity of 99.80% for medium roast while 10.2m/s attained the highest uniformity of 99.97% for dark roast. The fastest duration of roasting for medium roast took 13.68 min at 234.33°C while 17.98 min at 261.67°C was recorded for dark roast. The cost of the machine was computed at Php21,636. The payback period for medium roast is 1.2 months with return of investment of 212.27% while 1.92 months for dark roast with return investment of 131.37%. The break-even point of 155.18kg of coffee beans per year for medium roast and 185.24kg of coffee beans per year for dark roast.