Noise source identification on a continuous mining machine.
Camargo-HE; Smith-AK; Kovalchik-PG; Matetic-RJ
Proceedings of NoiseCon2008/ASME NCAD, July 28-30, 2008, Dearborn, Michigan. New York: American Society of Mechanical Engineers, paper no. NCAD2008-730242009, 2008 Jul; :187-194
Noise Induced Hearing Loss is the most common occupational disease in the U.S. and of paramount importance in the mining industry. According to data for 2006 from the Mine Safety and Health Administration (MSHA), Continuous Miner operators accounted for 30.2% of underground mining equipment operators with noise doses exceeding the Permissible Exposure Limit (PEL). This figure becomes more significant considering that 49% of the 2006 national underground coal production was extracted using continuous mining methods. Thus, there is a clear need to reduce the sound radiated by Continuous Mining Machines. The first step towards efficient noise control of a Continuous Mining Machine requires identification of the various noise sources under controlled operating conditions. To this end, a 42-microphone phased array was used in conjunction with 4 reference microphones to sample the acoustic field of a machine in the Hemi-anechoic chamber of the Pittsburgh Research Laboratory. These data were processed using a frequency-domain beamforming algorithm to obtain acoustic maps of 5 sides of the machine. The focus of the test was on the conveyor noise since previous studies showed that operation of the conveyor is the most important contributor to the sound radiated by the machine. From the acoustic maps, the following potential areas for noise control were identified, and included: chain-tail-roller interaction, chain flight tip-side board interaction, and chain-upper deck interaction.
Mining-industry; Noise-exposure; Noise-induced-hearing-loss; Hearing-loss; Hearing-impairment; Hearing-disorders; Hearing-conservation; Coal-workers; Coal-miners; Coal-mining; Mining-equipment; Underground-mining; Underground-miners; Miners; Mine-workers; Engineering-controls; Control-technology; Sound-attenuation
National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, 626 Cochrans Mill Rd., Pittsburgh, PA 15236
Proceedings of NoiseCon2008/ASME NCAD, July 28-30, 2008, Dearborn, Michigan