A CLOSED LOOP PNEUMATIC CONVEYING SYSTEM FOR COTTON

Authors: Laird, Joseph - Weldon

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/8/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary: Meeting increasingly rigorous air quality standards has become a serious problem for most agricultural operations including cotton gins, especially in areas designated as non-attainment areas. Substantial research and development effort has been expended to increase efficiency of cyclone exhaust cleaning systems. In some instances, the cyclones must be supplemented with final air cleaners which are expensive to install and operate, and may overload air handling equipment. In some areas this still fails to meet air quality goals and gins are threatened with shutdown. A closed loop seed cotton unloading system was tested as an alternative solution to cleaning exhaust streams to meet emission standards. The closed loop suction unloading system eliminated the high volume exhaust air discharge that usually causes difficulty for cotton gins in meeting air quality standards. The closed loop system also gave about 50 percent reduction in operating energy costs that would quickly pay for the installation and provide the gin with reduced operating expenses thereafter.

Technical Abstract: Pneumatic suction unloading systems for cotton gins can be constructed as a closed loop without the high volume exhaust air discharge that causes difficulty in meeting air quality standards. Tests comparing a closed loop suction unloading system with a standard open exhaust suction unloading system showed that the closed loop system can be operated at a performance level equal to the standard suction system using 110 horsepower compared t 250 horsepower for a 30 bale per hour system. This is a substantial savings that demonstrates a big advantage of the closed loop system that would justify it even if it did not eliminate exhaust emissions. Returning the exhaust into the fan inlet eliminated the energy cost associated with entry and exit losses experienced in conventional systems. The cost savings would quickly pay for the installation and provide the gin with reduced operating expenses thereafter. The closed loop suction unloading system helps solve the air quality problem that is currently critical for cotton gins and helps to attain the air quality goals of the clean air act because it totally eliminates one major emission source.