ANALYSIS OF THE IMPACT OF HOT AIR INSUFFLATION ON CHANGING OF TEMPERATURE AND HUMIDITY OF A SUBSTRATE

Abstract

This project presents the assembly of a laboratory-scale experiment using automation systems and forced aeration with pre-heated insufflated air in order to evaluate the temperature and humidity in a substrate from Carolina Soil. The measurement of such parameters was made with the DHT22 temperature and humidity sensor and the YL-69 soil moisture sensor both of which were inserted in a box of 29x29x40 cm dimensions containing ambient temperature substrate. This way it is possible to have a better understanding of how the system works, about how to control the parameters for future implementation in full-scale forced aeration composting systems. The pre-heated air simulates the heat released from organic matter mineralization made by the microorganisms. The air was injected into the substrate through a 20 mm tube parallel to the ground, set near the base of the box. This tube had three 8 mm holes drilled in it from where the air flows into the substrate. The velocity in which the air was blown was maintained by the frequency inverter (VFD) connected to the motor. It was kept at 25 Hz during all the experiments. The data was gathered and stored thanks to the Arduino Mega 2560 board and the software CoolTerm.