Enhanced real-time paddy moisture content assessment in pneumatic drying using correction factor

Abstract

Accurate and real-time monitoring of paddy moisture content during the drying process is critical to preserving rice quality and ensuring efficient post-harvest management. This research article presents the application of weather sensor (DHT22, AM2302, Aosong Electronics Co.,Ltd)  that measures air temperature and relative humidity for evaluating paddy moisture content in drying process of a pneumatic dryer. Khao Dawk Mali 105 paddy with initial moisture content of 26%w.b. was dried by a constant drying air temperature of 70 ^ºC and the drying air flow rate of 0.0631 m³/s with paddy feed rate of 8.45 kg/min throughout the test. Two methods namely DHT-Prediction and DHT-Factor correction methods for evaluating moisture content of paddy were developed by mass balance equation and the result were compared with the reference paddy moisture content analyzed by hot air oven method. The results showed that the DHT-Prediction method gave high moisture measurement error compared to the reference paddy moisture content (R² between 0.274 - 0.359 and RMSE between 5.077 - 7.465). The DHT-Factor correction method gave the lowest discrepancy of paddy moisture content during the first 150 minutes of the drying with R² of 0.987 and RMSE of 0.515. This method also showed low discrepancy results over the entire drying period which indicated that it has high potential for evaluating the real-time paddy moisture content during drying process.