Diseño y construcción de una máquina tostadora de café con capacidad de 3 kg utilizando una fuente energética de biomasa (pellets)

Abstract

This graduation project aimed to design a prototype for coffee roasting using a biomass fuel source, specifically to observe the roasting results when using an alternative fuel (pellets). First, employing the QFD methodology and morphological matrix, the best design alternative was selected, determining the initial parameters for the prototype, including a capacity of 3 kg of coffee. This work encompasses mechanical and thermal design considerations, material selection, and control aspects. The design of the prototype's support structure was validated using finite element analysis, applying loads of 34.26 N corresponding to the weight reactions on the bearings. The AISI 304 stainless steel was chosen to ensure food quality and prevent corrosion. The prototype achieved a medium to dark roast level, with Agtron scale values of 55-25, demonstrating that the objective of obtaining an appropriate roast was accomplished within 55 minutes for a 3 kg coffee capacity, using 1.5 kg of pellets and reaching a temperature of 200 °C in the roasting drum. Therefore, it is concluded that using biomass as an energy source for coffee roasters is feasible, allowing for the characteristic roast that enhances the coffee's organoleptic properties. Further research is recommended for grain roasting using pellets and analyzing the feasibility of utilizing an ecological fuel.