Laboratory evaluation of noise and airflow for haul truck fans.
NOISE-CON 2013. The 28th Conference of the Institute of Noise Control Engineering, August 26 - 28, 2013, Denver, Colorado. Washington, DC: The Institute of Noise Control Engineering of the USA, 2013 Aug; :NC13-55
Haul truck operators in underground metal/non-metal mines are often overexposed to noise. Sound levels at the operator's ear often exceed 90 dB(A). In addition, haul trucks are used continually throughout a work shift. The National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) has determined that the cooling fan is the dominant noise source on haul trucks. In an effort to reduce the noise exposures of haul truck operators, NIOSH OMSHR tested numerous cooling system configurations in an attempt to reduce fan noise while maintaining airflow. NIOSH OMSHR performed laboratory measurements of sound power level and airflow with a test apparatus that simulated the engine compartment of a Mine Technologies International (MTI) DT-1604 haul truck used in underground metal/non-metal mines. This publication discusses the laboratory sound power level and airflow results for a variety of fans and installation parameters, such as insertion percentage and blade angle. Numerous fan installation configurations were tested and compared to the stock fan installation for an underground haul truck. The test results showed that using a 50-mm-diameter larger fan with a sickle blade profile spinning 400 RPM slower than the stock fan decreased the A-weighted sound power level by nearly 3 dB, while maintaining the stock airflow of 27,000 m3/hr. Under the Mine Safety and Health Administration's permissible exposure level, a haul truck cooling package based on this configuration would reduce haul truck operators' noise exposures by up to 34%; based on NIOSH's recommended exposure limit, this package would reduce exposures by as much as 50%.
Trucking; Mining-industry; Underground-mining; Metal-mining; Hazards; Noise-levels; Noise-exposure; Noise-induced-hearing-loss; Sound; Ears; Cooling-systems; Nonmetal-mining
David S Yantek, National Institute for Occupational Safety and Health, Office of Mine Safety and Health Research, 626 Cochrans Mill Road, Pittsburgh, PA 15236
NOISE-CON 2013. The 28th Conference of the Institute of Noise Control Engineering, August 26 - 28, 2013, Denver, Colorado