Cotton Gin Drying Systems – Patterns in Fuel Energy Use

Abstract.

Fuel cost increases and consumption variability threaten gin profitability. Twenty-three U.S. cotton gins were audited to elucidate drying system components, layouts and process control strategies that made better use of fuel. Seed cotton samples were obtained before and after each drying system and the difference in their respective moisture contents was used to quantify drying. Air flow and temperature were measured to estimate fuel consumption in each drying system. The ratio of drying to heating energy indicated fuel use efficiency. For the commercial gins analyzed so far fuel use efficiency ranged from 3 to 38 percent. First stage systems averaged 21% and second stage systems averaged 9%. From the limited data available it was not possible to separate fuel use efficiency differences by specific dryer types. Gins with duct insulation made better use of dryer fuel, and the improvement was proportional to the fraction of duct length insulated. Fuel use efficiency also improved with burner proximity to mix point.