Resistance of Bulk Chickpea Seeds to Airflow

Knowledge of resistance to airflow through agricultural products is an important consideration in the design of drying, cooling, or aeration systems and proper fan selection for these systems. Resistance to airflow of bulk chickpea seeds was studied at moisture contents in the range of 9.21 to 21.36 % (wet basis) for airflow rate range from 0.02 to 0.50 m3 s-1 m-2, using an experimental test column. The effects of airflow rate, bed depth (0.25 to 1 m) fill method (loose and dense) and moisture content on airflow resistance of chickpea samples were investigated. Results indicated that the airflow resistance of chickpea seeds increased with increase in airflow rate, bed depth, and decreased moisture content. One percent increase in moisture content decreased the pressure drop about 2.94%. The dense fill method resulted in an increase in resistance to airflow by about 33.17% more than that of the loose fill. Three models (Shedd’s, Hukill and Ives’s, and Ergun’s models) were fitted to the experimental data at each moisture level and were examined with two parameters. Shedd’s model that gave a higher value for the coefficient of determination and a lower value for the mean relative percentage error of pressure drop predication was found to be the best model to describe airflow resistance of chickpea seeds.