On-line version ISSN 2411-9717
J. S. Afr. Inst. Min. Metall. vol.109 n.5 Johannesburg May. 2009
A technique for estimating the sound power level radiated by pneumatic rock drills and the evaluation of a CSIR prototype rock drill with engineering noise controls
P.G. KovalchikI; F.T. DudaI; G.S. HarperII
INIOSH, Pittsburgh, Pa., USA
IICSIR Miningtek, Johannesburg, South Africa
Overexposure to noise remains a widespread, serious health hazard in the US mining and other industries despite 25 years of regulation. Most categories of illnesses and injuries associated with mining have improved, with the exception of hearing loss. The drilling of rock in a confined work environment contributes to high levels of noise exposure in mining.
The National Institute for Occupational Safety and Health (NIOSH) is conducting research to reduce the noise exposures of jackleg drill operators and to prevent additional cases of noise induced hearing loss (NIHL) by developing and evaluating low-cost retrofit noise controls for equipment. This report describes the procedure for the measurement and reporting of noise from portable pneumatic tools such as jackleg drills. The technique used in this research allows for the determination of the source A-weighted sound power levels and the radiation patterns in octave and 1/3 octave bands. Overall sound power level is also determined. This paper also reports the results obtained by using this procedure to evaluate a SECO S215 standard production drill and a CSIR Miningtek prototype rock drill incorporating engineering noise control measures.
It was found that by using the manufacture's recommended operating pressure of 496 kPa (72 psi) that the CSIR prototype's sound power was 10 dB(A) less then that of the SECO S215.
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1. SUMMERS, C.R. and MURPHY, J.N. Noise Abatement of Pneumatic Rock Drill. Bureau of Mines Information Circular 7998, 1974. pp. 1-45. [ Links ]
2. VISNAPUU, A. and JENSEN, J.W. Noise Reduction of a Pneumatic Rock Drill. Bureau of Mines Information Circular 8082, 1975. pp. 1-23. [ Links ]
3. HARPER, G.S. and SCANLON, T. Develop a quiet non-atmosphere polluting blast hole drilling system. Final Report, Safety in Mines Research Advisory Committee. GEN 207 November 1997. pp. 1-70. [ Links ]
4. Acoustics-Determination of sound power levels of noise sources using sound pressure-Engineering method in an essentially free field over a reflecting plane. ISO 3744, Second edition 1994-05-001. pp. 1-31. [ Links ]
5. Drill rigs-Safety. EN 791:1995. pp. 1-47. [ Links ]
6. ALJOE, W.W., STEIN, R., and BARTHOLOMAE, R.C. Test Apparatus for Measuring Sound Power Levels of Drills. Bureau of Mines Information Circular 9166, 1987. pp. 1-35. [ Links ]
7. A Guide for Manufacturers to the Evaluation of Uncertainties. The Noise Emission in the Environment by Equipment for Use Outdoors Directive, 2000/14/EC, URN 00/605, First edition July 2000. pp. 1-11. [ Links ]