Effect of Bulk Density, Moisture Content, and Grain Size on Vertical Airflow Resistance of Lathyrus (<i>Lathyrus sativus</i> L.) Grains

Abstract

The experiments were conducted to study the effect of various operating parameters on airflow resistance of lathyrus (legume) crop. The bulk density, moisture content, bed depth and grain size for lathyrus (cv. NLK- 40, Pratik and Ratan) were studied at different three levels of moisture content ranged from 7.33% to 18.80%, 6.75% to 18.30% and 7.90% to 19.40% d.b., respectively. It was observed that as airflow rate increased the pressure drop also increased significantly but not proportional for all the combinations of the operating parameters studied. At any airflow rate within experimental range, increase in moisture content resulted in decrease of pressure drop for all grains. The increase in airflow resistance was linearly proportional to bed depth for loose, medium and dense packed grain beds. The increase in grain bulk density at any moisture level resulted in an increase in pressure drop at all airflow rates. Bulk density of the densely packed lathyrus grain was found to be 9.63% to 11.67% denser as compared to the loose fill conditions. The corresponding increase in airflow resistance was about 1.41 times higher than that of loose fill condition. Smaller size grain offered significantly higher (1.61 times) airflow resistance as compared to larger size grain. The pressure drop per unit bed depth was maximum for NLK-40 followed Pratik, Ratan and soybean.