Thermistor based system for grain aeration monitoring and control

• A low cost aeration control system (AERSY) was proposed and evaluated.
• The AERSY system was efficient in maintaining safe grain storage conditions.
• The system is suitable for use mainly in small and medium silos.
• The system can be adapted for use in greater storage facilities.

Aeration is a popular tool, used to modify the grain bulk microclimate and to control the product quality. The aeration controllers are designed to provide automatic starting and stopping of aeration fans based on a selected strategy. However, most of the already proposed automatic controllers are unviable for small and medium farmers due to the high capital costs associated with them. In this work a low cost aeration controller is proposed, which should be easily adopted for small and medium farmers located in different regions of the world. The proposed controller is called AERSY and is based on the AERO control strategy joined to a low cost data acquisition system with thermistors. AERSY was tested, presenting reliable operation. The aeration control strategy was also efficient in maintaining safe storage conditions during the studied period, but the simulation procedures can be improved regarding the grain moisture content estimations. When comparing the capital costs for installation, AERSY was 44% cheaper than an aeration control system with the same features, but based on thermocouples. The system was found to be suitable for use mainly in small and medium silos (up to 8000 m3) but it can be adapted for use in larger storage facilities.