The Air-Arc Interaction in Air Carbon Arc Gouging

摘要

Air carbon arc cutting and gouging is a welding process that exposes workers to hazardous sound levels from 108-120 dB(A). 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) investigated and identified the gouging process components affecting noise generation and researched methods for attenuating their effects. In the gouging process, an electric arc melts a portion of the metal workpiece and an air jet blows the melted metal out of the resulting gouge. The research revealed that both the arc and the air jet generate significant noise. Further, there is an interaction effect between them that increases noise generation. During gouging, when both noise sources are present, the sound power measured was 9 dB higher than the sum of each source measured alone. NIOSH researchers investigated redirection of the airflow relative to the cutting torch, using a reconfigurable air nozzle to determine whether the air-arc interaction effect could be diminished. A-weighted sound power measurements of various configurations yielded a maximum reduction of 6 dB, illustrating that airflow redirection can reduce air-arc interaction noise.