Rice Grain Cooling Using Intermittent Adsorption and Desorption of Water Vapour: Development of a Mathematical Model

Abstract

A one-dimensional heat and mass transfer model was developed for predicting grain temperature in a deep bed of paddy exposed to intermittent adsorption and desorption cycles and the numerical solutions of the model were approached by finite difference method. The inlet temperature and relative humidity of air were used as the model inputs. The model was validated using a laboratory scale experimental setup. The data were collected by forced air ventilation with moist air following intermittent adsorption and desorption cycles of 5 and 10 min in a 0.15 m bed of paddy in a 0.11 m diameter circular bin. The measured and predicted grain temperatures at different layers were in close agreement over the test period with an accuracy of ± 0.5 °C. Thus, the mathematical model developed can be used in predicting the rice grain temperature with similar applications.