Cotton gin pneumatic conveying systems

Authors: Whitelock, Derek; BUSER, MICHAEL - Oklahoma State University; Holt, Gregory; Hardin Iv, Robert; GREEN, KELLEY - Texas Cotton Ginners Association; Fabian, John; MCCOOK, DUNCAN - Lummus Corporation

Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/8/2019
Publication Date: 8/8/2019
Citation: Whitelock, D.P., Buser, M., Holt, G.A., Hardin IV, R.G., Green, K., Fabian, J.C., McCook, D. 2019. Cotton gin pneumatic conveying systems. Journal of Cotton Science. 23:182-217.

Interpretive Summary: Cotton gins use air to move seed cotton, lint, cottonseed, and trash through conveying pipes. Also, this air is often used for drying or adding moisture. Cotton gins have become larger with higher capacities and, thus, use large quantities of air for conveying. To convey cotton and other materials in the gin, it is common for a gin to move more than 675,000 pounds of air per hour in its conveying pipes. Typically, more than 60-65% of the total electrical power consumed by a cotton gin is used for conveying material with air. To maximize efficiency, minimizing energy costs, and decrease downtime, it is essential for ginners to understand these air conveying systems and know how to determine if they are operating properly. The last Cotton Ginners Handbook was published in 1994 and is in need of updating. This update of the Handbook provides current technical information on cotton gin pneumatic systems in an understandable manner. It draws heavily on the knowledge and experience of current and past instructors of the Air Systems classes from the National Cotton Ginners’ Association Gin Schools.

Technical Abstract: Cotton gins use air to move seed cotton, lint, cottonseed, and trash through conveying pipes. In gins, pneumatic conveying systems are the principal means of moving material from one processing stage to another throughout the entire ginning plant. Further, material drying or moisture restoration can be accomplished by heating or humidifying the conveying air. Pneumatic systems are a critical and fundamental component of cotton ginning. Cotton gins use large quantities of air for pneumatic conveying. It is common for a gin to use 4,248 m3 (150,000 ft3) or more of air per minute in its various material conveying systems. Since the density of dry standard air is about 1.2 kg/m3 (0.075 lb/ft3), a typical gin using 4,248 m3/min (150,000 ft3/min) of air moves 305,860 kg (675,000 lb) of air per hour. This mass of air per hour is usually about 1.5 times the total mass of material handled per hour. Typically, more than 60-65% of the total electrical power consumed by a cotton gin is attributed to moving material pneumatically. Properly taking air measurements, determining air flow requirements, sizing conveying pipes, sizing fans to generate required air flow rates, and accounting for specific machinery air requirements are essential to maximizing machine utilization, minimizing energy costs, and decreasing system downtime. This update of the Cotton Ginners Handbook provides current technical information on cotton gin pneumatic systems in an understandable manner. It draws heavily on the knowledge and experience of current and past instructors of the Air Systems classes from the National Cotton Ginners’ Association Gin Schools.