Abstract

Stored grain should be preserved as much as possible during storage process, because of the occurrence of chemical, biochemical, physical and microbiological changes. The grain storage process consists of storing this material for a later use after a certain period. This study aims at to develop a prototype for grain aeration; to develop a software to control aeration strategies; and to evaluate the development of strategies for controlling the aeration of stored corn. The metallic silo is built in a cylindrical shape (0.9 m diameter and 3 m high), with a fully perforated bottom, which was adapted to an aeration system (plenum, axial fan, with three-phase motor of 1.47 kW and PVC pipe Ø 0.10 m). The silo was externally isolated using glass wool (0.06 m) thick, and the airflow controlled and determined in 0.1 m³ min^-1 t^-1, where t is ton of grain. To work with data relating to the experiment, it was necessary to use sensors, positioned at the center of the silo (spaced 0.5 m), from the plenum. The sensors were connected to an Arduino board, in order to register the temperature of grain mass. After the installation of the sensors in the silo, this was loaded and the surface of the grain mass was leveled. Control strategies were implemented: Continuous aeration; control of dry bulb temperature; control via timer and temperature control via temperature difference between the grain and the ambient air. Operating results obtained with the software developed, were effective for control of grain aeration processes stored in the prototype. In conclusion, the system for automated aeration of stored grain was effective in the storage of grain and the control strategy, aeration of grain via the temperature difference between the grains and the environment and night aeration were the best for the aeration process in region of Anápolis - GO.

Key words: Storage, grain cooling, prototype, Arduino.