Discomfort Analysis in Pneumatic Grinding: Steam Generator Manufacturing Industry

MANI CHIDAMBARAM; Sankaranarayanasamy Krishnasamy; Muthukumar Krishnamoorthy

doi:10.3759/joise.v3i3.3524

Abstract

Steam generator manufacturing involves a lot of custom designed components requiring intensive fabrication activities of welding and grinding. Pneumatic grinding machines of different types are widely used in such industries as they offer flexibility and ease of use. However, the deployment of pneumatic tools are associated with hand transmitted vibration and related health issues. The present study aims to evaluate the extent of discomfort levels of operators and its relationship with the grinding intensity and at various times of the day. Pneumatic grinding operators involved in manufacturing steam generator components were chosen and data was collected based on Corlett and Bishop’s body part discomfort mapping, at various time intervals from starting to end of the shift, using a structured questionnaire. ANOVA was deployed to carry out the statistical analysis. The grinding operators working in ‘drums and headers’ product group reported the maximum discomfort compared to operators working in other product groups. The discomfort increases as the shift progresses and reaches the highest at the end of the shift. The study also brought out that most operators reported discomfort in ‘shoulder’ (93%), followed by wrist (85%), neck (70%), lower back (65%) and forearm (61%). Apart from providing leather and anti-vibration protective gloves to the grinding operators, the industry is working to reduce hand arm vibration problems by experimenting with modified handles and lower weight grinders. In addition to that, distributing the exposure of grinding operators amongst different product groups could bring a balance in discomfort faced by them, by periodical job rotation.