Implementation of an automatic control system on a roaster of peruvian andes grains

Abstract

This paper presents the results of the automation of a roaster of grains grown in the Peruvian Andes. The research work consisted in developing an automatic control system for the temperature and speed of rotation of the drum of a gas roaster machine with mechanical-electrical control. The new system is based on a PLC with a proportional control algorithm for temperature and an open loop for drum rotation, which allows the grain temperature to develop, in time, the predefined curves for its 3 types: Corn, broad beans and soybeans. The cultivation of these in the various microclimates along the Andes Mountains gives them unique characteristics that condition the proper roasting to the operator's experience. To that end, a matrix was developed with parameters whose values were determined by tests conducted by expert operators in manual roasting. The experimental results showed that the roasted beans reached the desired quality characteristics such as humidity, color, aroma and flavor, as well as a decrease in the duration of the process and in fuel consumption, as well as the reduction of waste for over-roasting.