Improved Face Ventilation by Spray Jet Systems.
2nd Annu Mining Institute 1979 :1-12
Under a Bureau of Mines contract, methods were developed to increase significantly the amount of fresh air that reaches the front of a continuous mining machine. The emphasis was on removing methane buildups that occur at the cutterhead. Using a full-scale plywood mockup of a coal mine working face area, the study showed that in many instances only about 20 pct of the fresh air heading toward an exhaust brattice or tubing actually gets to within 1 ft of the face. To provide more air at the face, the natural airflow pattern should be enhanced and moved forward. The change in the natural airflow pattern can be accomplished by taking advantage of the air-moving abilities of a conventional water spray. It was discovered that by realigning a few nozzles on the side of the machine opposite the curtain and tilting the front sprays slightly toward the curtain side, the ventilation efficiencies of 70 pct or more were achieved regularly. This meant that if 9,000 cfm of air was entering the brattice, at least 6,300 cfm of the air was reaching to within 1 ft of the face.
2nd Annu. Mining Institute 1979, Tuscaloosa, Alabama, Apr. 11-13, 1979, PP. 1-12