Design of a Compact Muffler for a Jumbo Drill.

摘要

The Bureau of Mines,as a part of its goal to minimize occupational hazards associated with mining and mineral processing operations,has developed and field tested a compact exhaust air muffler for mechanized, jumbo-mounted pneumatic rock drills. The muffler is constructed of 1/8-inch sheet steel and has nominal dimensions of 1 3/4by 9by 13inches. A directed air passage,flexible neoprene baffles,and an expandable slit-type outlet are incorporated to reduce drill exhaust air noise and eliminate muffler icing. Field tests in actual mining operations showed a 15-dbA reduction in exhaust noise and an 8-to 12-dbA reduction in overall drilling noise with no icing problems or decrease in drill performance. Data are presented on muffler construction,laboratory,and field test results.