Desenvolvimento de módulo de controle de umidade automatizado para um secador de bancada

Abstract

Drying methods may have better performance if they are carried out in controlled environments, where there is control of the temperature and relative humidity of the air process, for example. The objective of this work was the construction of an automated humidity control module, to be applied in a bench dryer. The control method used was the PID, and it was applied via Arduino in communication with the module. The programming language used for the control implementation was C++. The control module was structured by parts printed by a 3D printer using PLA. The humidity control works together with the existing temperature control in the bench dryer, the data is presented to the user via a graphical interface, where it is also possible for the user to send the desired set point values for the drying process to the computer. The humidity control proved to be efficient for the applied tests, with variations of a maximum of 0.5% of the desired value. The tests were carried out for three different temperatures. The PID parameters were calculated using the Ziegler-Nichols method for first-order open-loop processes. The main problems found were sealing the bench dryer to prevent the leakage of internal relative humidity produced by the generator, and maintaining the water level inside the control module box. In general, the humidity control module carried out the relative humidity control in the air as expected and will be used in the bench dryer developed at UTFPR.