DEVELOPMENT AND PERFORMANCE EVALUATION OF A LIQUEFIED PETROLEUM GAS-POWERED FLUIDIZED COFFEE ROASTER

Abstract

In this study, a fluidized coffee roaster has been successfully designed, constructed, and tested. This prototype has a capacity of 500 grammes per batch to aid small-scale coffee shops in roasting coffee beans. This fluidized coffee roaster is easy to use, cheap and has an appropriate capacity for the small business requirements. The coffee roasting components of the machine consisted of a blower (600 watts), a heat exchanger, a jet burner, a cylindrical roasting chamber, a chaff and dust collector, and a frame. At a range of airflow of 4-6 m/sec, the average temperature increase in the furnace and roasting chamber was 26 °C and 7.8 °C per minute, respectively. Performance tests revealed that the developed fluidized coffee roaster had been able to roast Robusta and Arabica coffee to light, medium, and dark roasting levels. For Robusta coffee, the time required to achieve light, medium, and dark levels were 8.18, 9.85, and 12.03 minutes, respectively, with final roasting temperatures for each level of 209 °C, 220 °C, and 248°C. For Arabica coffee, the time required was 5.32, 7.67, and 11.72 minutes, respectively with the final roasting temperatures of 207 °C, 210 °C, and 218 °C.