Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/27/2007
Publication Date: 5/1/2007
Citation: Holt, G.A. 2007. Design of experiments optimization study on the powered roll gin stand - Report II. Transactions of the ASABE. 50(3):773-780. Interpretive Summary: The powered roll gin stand is a new ginning technology developed at the USDA-ARS, Cotton Production and Processing Research Unit in Lubbock, TX. The gin stand has three main components: the paddle roll, the saw, and the seed finger roll. The speeds of the three main components, as well as the loading rate on the paddle roll, has a substantial impact on ginning rate, turnout, and fiber properties of the seed cotton being ginned. This study reports on an optimization study performed on the second prototype powered roll gin stand at the USDA-ARS gin lab in Lubbock, TX. This study reports several optimal solutions depending on the variables incorporated into optimization analysis. Results are reported for samples gathered before and after one stage of lint cleaning. When all fourteen response variables were used in the optimization analysis, the optimal operating settings were: 1) paddle roll speed (rpm) = 209 (before and after lint cleaning), 2) paddle roll loading = 85% of load (before and after lint cleaning), 3) saw speed (rpm) = 831 (before lint cleaning) and 829 (after lint cleaning), and 4) seed finger roll speed (rpm) = 26 (before lint cleaning) and 21 (after lint cleaning). The results indicate very little differences in the optimal settings before and after lint cleaning. The response variables producing significant models were seed coat neps (lint), short fiber content (lint), ginning rate (production), and visible mechanical damage (seed).
Technical Abstract: The powered roll gin stand has been evaluated in numerous studies in regards to increases in lint turnout and ginning rate without adversely affecting fiber quality properties. In some cases, improvements in fiber quality over conventional gin stands were noted. However, the question remained as to what speed the various components of the powered roll gin stand should be operated to optimize performance. The three main components of the power roll gin stand are: paddle roll, seed finger roll, and saw speed. This paper presents results of an optimization study conducted on the second power roll gin stand operating at the United States Department of Agriculture, Agricultural Research Service gin lab in Lubbock, Texas. The results are based on lint samples taken after the gin stand (before lint cleaning) and after one stage of lint cleaning, seed samples, and performance data. Of the fourteen response variables evaluated, four variables resulted in significant models: seed coat neps, short fiber content, ginning rate, and visible mechanical damage. Several optimal solutions were obtained based on the input factors used in the evaluation. When including all response variables in the analysis, the optimal operational settings for a retrofitted Lummus-116 powered roll gin stand before and after lint cleaning were: paddle roll speed = 209 and 209 rpm, paddle roll loading = 17.1 and 17.0 amps, saw speed = 831 and 829, and seed finger speed = 26 and 21 rpm, respectively.