A Noise Control for Air Carbon Arc Cutting and Gouging

摘要

Air carbon arc cutting and gouging (ACAC&G) is a welding process that exposes workers to hazardous sound pressure levels from 94 to 125 dB(A). These levels lead to hazardous noise exposures in as little as three seconds or as much as one hour. As a result, welders who perform the gouging process and other workers in close proximity to the process are at risk for noise-induced hearing loss. To address this health risk, researchers at the National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research have developed a noise control treatment for use on the ACAC&G system. A prior study by the authors found that an interaction between the electric arc, which melts a portion of the workpiece, and the air jet, which blows the molten metal, or slag, out of the resulting gouge, is the greatest generator of noise in the ACAC&G system. The A-weighted sound power generated can be reduced by up to 6 dB by adding a redirected air source. This paper is a continuation of that work, demonstrating a practical method to redirect the air jet, that not only reduces sound power, but also effectively clears the slag out of the gouge. A maximum reduction in A-weighted sound power of 4.3 dB has been achieved with this control alone. If the control is used in conjunction with lower system pressure settings, the A-weighted sound power can be reduced by as much as 8.2 dB without degradation to gouging performance.