ARS | Publication request: Influence of grid bar shape on field cleaner performance

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings/Symposium
Publication Acceptance Date: February 10, 2009
Publication Date: N/A

Interpretive Summary: Approximately half of the US cotton crop is grown on the High Plains of Texas and is stripper harvested. Stripper harvesters use onboard cleaning machines (field cleaners) to remove large foreign material such as burrs and sticks from harvested seed cotton. These machines have been shown to be effective at removing approximately 50 ¿ 60% of large foreign material in the field before the cotton is taken to the gin. Early development work on these machines focused on identifying machine design parameters that maximized cleaning efficiency and minimized seed cotton loss. Some of these studies pointed to the shape of the grid bars as having a significant influence on machine performance, although no subsequent study specifically addressed the issue. The objective of this work was to investigate the influence that the cross sectional grid bar shape has on the performance of field cleaners. Ten cross section shapes were tested in twenty-eight machine configurations during a set of laboratory screening tests to identify grid bar geometries that performed better than the conventional (round) shape. Results show that the experimental grids tended to improve cleaning efficiency more when placed on the bottom cleaning saw cylinder rather than the top cylinder. Over half of the experimental machine configurations exhibited improved cleaning efficiency when compared to the control and six showed both better cleaning efficiency and seed cotton retention. No adverse influence on fiber quality was observed for the experimental configurations compared to the control. Similar to previous research, it was observed that the configurations tending to remove more foreign matter also tended to remove more seed cotton. Thus, a compromise must be reached when selecting grid bar configurations to optimize cleaning efficiency and seed cotton loss.

Technical Abstract: Extractor type cleaners are used on cotton strippers and in the seed cotton cleaning machinery in the ginning process to remove large foreign material such as burrs and sticks. Previous research on the development of extractor type cleaners focused on machine design and operating parameters that maximize foreign matter removal and minimize seed cotton loss. Early research indicated that the shape of the grid bars used in extractors may influence the performance of these machines but no study was conducted to specifically address this issue. Therefore, the objective of this work was to evaluate the influence of grid bar cross sectional geometry on extractor performance with regard to foreign matter removal, seed cotton loss, and fiber quality preservation. Nine experimental grid bar geometries were evaluated against the conventional round grid bar geometry in twenty eight machine arrangements. During each test seed cotton was fed through a John Deere 7445 field cleaner at a constant rate and seed cotton samples were collected to determine the amount of foreign matter removed by the machine and the moisture content during cleaning. Results show that over half of the experimental machine arrangements removed more foreign material from the burr cotton than the conventional configuration. Six of the experimental machine arrangements exhibited both better cleaning performance and reduced seed cotton loss than the conventional configuration. AFIS and HVI fiber analyses indicated that the experimental machine arrangements did not damage the fibers more so than the conventional configuration. Two of the experimental machine arrangements were selected based on the results of the laboratory screening tests for use in field scale evaluations conducted during the 2008 cotton harvest season. The findings of this work confirm previous research in that a compromise must be reached when selecting the appropriate grid bar geometry for use in cotton stripper field cleaners based on foreign matter removal and seed cotton loss.