INTERGRANULAR AIR MOVEMENT AND GRAIN DRYING IN SILOS WITH FULLY, PARTIALLY AND SLANTED PERFORATED FLOOR

Intergranular air movement and its relation with moving drying front i n a grain bulk were investigated experimentally. An improved computer simulation model was developed to analyze the drying or cooling proces s in a bed of grain with non-parallel airflow from a partially or slan ted perforated floor. The model first simulates the airflow, then calc ulates the heat and mass transfer between air and grain along the airf low streamlines. The results were compared with the simulated and expe rimental results from a fully perforated floor configuration. The degr ee of agreement between the computed and the experimental moisture con tents depended upon the floor configuration. The model was not capable of predicting the temperatures to the accuracy of the predicted moist ure contents, especially when airflow stream lines were not parallel t o each other. For further improvement of the drying simulation model, an improved airflow model and computer program is required. Comparison of the simulated results with experimental data also revealed that th e iso-traverse line is not able to represent the drying process or the movement of the drying front in drying beds where air flow stream lin es are not parallel to each other.