|Ingles, Maria elena|
Submitted to: Applied Engineering in Agriculture
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/1/2006
Publication Date: 9/1/2006
Citation: Ingles, M.A., Casada, M., Maghirang, R.G., Herrman, T.J., Harner, J.P. 2006. Effects of grain-receiving system on commingling in a country elevator. Applied Engineering in Agriculture. 22(5):713-721. Interpretive Summary: Fundamental data and prediction tools are needed that identify and quantify where commingling occurs during identity preserved grain handling at grain elevators so that grains with special desirable characteristics can be kept at a desirable level of purity. This study measured the level of commingling when receiving corn and soybeans at a country elevator in Manhattan, Kansas. Commingling was greater than 1% only during the first 75 to 135 seconds (40 to 80 bu of grain received), except for the gravity-type dump pit configuration where commingling remained in excess of 1% for the duration of the test (840 seconds or 290 bu of grain). Measured mean cumulative commingling was 1.25% for the combined effect of gravity-type pit and elevator leg, 0.30% for the combined effect of leg and pit with drag conveyor, and 0.23% for the bucket elevator alone. A simulation model based on this data predicted that a facility equipped with a bucket elevator and receiving pit with drag conveyor receiving 10 t of grain would yield a final commingling of at least 0.28%, of which 0.27% would be from the effect of the leg. With minimum cleaning between loads, a load of grain handled immediately after a load of a different grain type would generate the highest amount of commingling. This information is needed by elevator operators to better segregate grain with desirable characteristics into separate channels for delivery to end-users. The information is also useful to grain processors for improving their handling of specialty grains.
Technical Abstract: The shift from commodity-based to quality-based systems has challenged the grain-handling industry to meet desired purity levels as part of its identity-preservation programs. Very few resources are available for development of management strategies. This study aimed to provide information on commingling during grain transfer as influenced by receiving configuration of an elevator. The facility, located at Manhattan, KS, has three pits and one bucket elevator with a handling capacity of 190 t/h (7000 bu/h). The experiments involved moving soybeans through one of the receiving pits, followed by corn through the same flow path, without special cleaning between the two operations. Corn samples, collected at specific time intervals, were used to calculate commingling, the percentage of soybean kernels mixed in corn. Commingling was greater than 1% only during the first 135 s (first 2 t received), except for the gravity-type pit configuration where commingling remained in excess of 1% for the duration of the test (840 s or 7.3 t of grain). Measured mean cumulative commingling at the end of operation was 1.25%, 0.30%, and 0.23% for the combined effect of gravity-type pit and elevator leg, combined effect of leg and pit with a drag conveyor, and effect of leg, respectively. ARENA simulation was used to predict commingling using different levels of initial impurities of incoming grain. The model predicted that a 10-t load through a pit with drag conveyor would result in a cumulative commingling of 0.28%, of which 0.27% would be from the effect of the leg.