Control System for a Cacao Drying Process: Case Study Cylindrical Dryer

The purpose of this article is to develop a system for the control of the parameters that are involved in the artificial drying process of cacao with the objective of optimizing its duration, preserving its quality and reducing time. The project is based on the use of a cylindrical dryer, with a capacity of 23 kg, where a flow of hot air was applied to reduce the humidity in the product in order to transfer heat and stabilize the temperature at the desired value. An automatic control system based on an ESP32 microcontroller is designed to regulate the variables of air flow, temperature and weight in order to achieve optimum drying, minimizing operation times and preserving the properties of the product. An interface is available for the visualization of the main variables of the process in real time in order to have the possibility of having an analysis of the performance curves of the parameters involved in the process. This proposal shows the viability of acquiring the parameters involved in the process, complying with INEN NTE 176 standards for the commercialization of cocoa beans, where the required humidity of 8% was achieved in a time of 3 h and 35 min, stabilizing the system by means of a PID temperature control influencing the air flow.