Location: Cotton Ginning Research2012 Annual Report
1a. Objectives (from AD-416):
Our goal is to increase the profitability of the U.S. cotton production system through new and improved cotton ginning equipment and processes resulting in enhanced market value and utility of ginned cotton lint in the global market. We will focus on the following objectives: 1) Refine the design, operation, and management of existing cotton ginning machinery to increase productivity and reduce short fiber content, neps, and seed coat fragments; 2) Improve cotton gin processing by comprehensively investigating the impact of cotton cultivar on fiber quality and non-lint content and develop improved relationships between measurable cotton traits and the value of the final products; 3) Improve automated measurement of relevant properties and control of gin processes for more efficient management, especially related to moisture, fiber quality, and energy use; and 4) Optimize the entire ginning system from module to bale, particularly related to air quality issues, energy use, and control of cotton moisture content.
1b. Approach (from AD-416):
The objectives are interrelated and success in one contributes to success in another. Improved measurement and control will allow better response to changing gin conditions, including those caused by variation in cultivar. Better machinery design and management can be used to respond to these variations in seed cotton. Improved ginning machinery and better measurements of the cotton being processed will contribute to optimization of the entire ginning system. 1) Refine the design, operation, and management of existing cotton ginning machinery. We will test modifications to existing machinery and new machine designs for the three main functions of ginning machines–seed cotton cleaning, fiber-seed separation, and lint cleaning. We plan to develop machinery with adjustable operating parameters for use in control systems to optimize product value and quality. New management strategies will also be tested. 2) Improve cotton gin processing by improving measurement and use of measurements. Three issues will be addressed under this objective: 1) some important properties are unidentified; 2) no technique exists for measuring certain important properties, particularly in real-time at the gin; and 3) analysis using the current variables results in interactions, which may result from not measuring the correct variables or an incomplete understanding of the processes. First, we will simplify the control problem using cotton from a limited number of known cultivars and growth conditions. Second, we will find measurable traits which will allow adjustments to the ginning process for optimal processing of different cultivars, without knowledge of the cultivar. Finally, a control system using these properties will be developed to maximize fiber value and quality, accounting for variation due to cultivar and growth conditions. 3) Improve automated measurement of relevant properties and control of gin processes for more efficient management, especially related to moisture, fiber quality, and energy use. Currently, many important properties to gin management cannot be measured accurately, or in real-time at the gin. Sensors will be developed to measure these parameters. Advanced statistical techniques will be used to integrate information from many sensors and develop predictive models. The final step will be to develop a control system using these sensors and logic which will result in improved gin management, as demonstrated by improved fiber quality or more efficient use of resources. 4) Optimize the entire ginning system from the seed cotton module to lint, seed, and byproduct use. Dust emissions from cotton gins will be measured, so that regulatory agencies have accurate data. Energy use will be monitored throughout cotton gins. Systems will be designed that can alert ginners to conditions reducing energy efficiency or automatically conserve energy without negatively impacting gin processing. Improved systems will be designed for controlling drying and moisture addition to improve gin efficiency, product storage, and fiber quality.
3. Progress Report:
A survey of seed cotton cleaning in commercial cotton gins showed that some gins regularly exceed the recommended seed cotton cleaner loading. Scaled tests showed that significantly higher processing rates could be used without reducing cleaning performance. Testing in a commercial gin at the recommended maximum rate and double that rate showed some loss in cleaning ability at higher rate. Laboratory analysis of the material removed by seed cotton cleaners from multiple cultivars and locations (processed identically) is ongoing. Roller ginning produces lint with greater fiber length and less short fiber than saw-ginning with Upland cottons in the West. A high-speed roller ginning system was tested with Upland cotton grown in the humid Mid-South and analysis showed an improvement in fiber when using the roller gin line compared to the traditional saw-gin line. Differences in processing for different cotton cultivars have been observed. Because different cotton cultivars respond differently to ginning processes conventional ginning systems do not process all cotton optimally. To quantify these differences the energy and time for ginning a number of genotypes were measured. The energy needed to gin different cotton genotypes was inversely correlated with ginning rate. The cotton variety trials included 10 varieties and 6 locations in 2010, and 10 varieties and 5 locations in 2011. Potential sources of variability in fiber maturity included variety, soil type, weather, irrigation, terrain (hills vs. delta), and other “environmental” factors. Samples were ginned and spun into yarn with standard spinning/yarn data collected. Cotton gins use energy in material transport, processing, and drying. Survey data has shown that the energy used per bale produced varies by over 2:1 even for gins of the same size. Initial analysis of energy use in commercial gins shows that less energy per bale is used when the gin stands are kept fully loaded. Power demand in commercial gins when no cotton is being processed was 2/3 of the fully loaded systems. Electricity use was monitored in four commercial gins during the 2011-2012 ginning season. Additional monitoring equipment was installed to measure air flow and dryer temperatures at two gins. One gin used 1.45 L/bale for the first stage dryer and 0.32 Liter/bale for the second stage dryer. The other gin required 1.27 Liter/bale for the first stage dryer and did not use the second stage dryer. The effect cotton gins have on air quality and issues in measuring and modeling the effect on air quality are being studied at several locations over several years. These samples and data will be analyzed and results shared with relevant regulatory agencies. Moisture content measurement and control in the gin continues to be a problem for stakeholders. Moisture measurement and management work was expanded, especially in relation to final bale moisture content, and meetings with stakeholders were held for technology transfer. The result of a study of commercially available sensors was presented to several groups of stakeholders and additional work in this area is being planned, based on stakeholder requests.
Whitelock, D.P., Armijo, C.B., Boykin Jr, J.C., Buser, M.D., Holt, G.A., Barnes, E.M., Valco, T.D., Findley, D.S., Waston, M.D. 2011. Beltwide cotton quality before and after lint cleaning. Journal of Cotton Science. 15:282-291.