Capture Efficiency of Integral Fume Extraction Torches for GMA Welding — Part 1

Abstract

The Econweld Project identified the development of a lightweight and ergonomic fume extraction GMAW torch as a high priority research need. This report has been completed in response to this need. At source, capture is the most efficient method for eliminating welding fumes from the metalworking environment, particularly from the breathing zone of the welder. Worker productivity can increase by up to 20% when an integral suction torch is installed in a welding fabrication shop, resulting in less sick leave taken by welders and improved employee morale. Moreover, significant energy savings can be achieved when source capture is used compared to general ventilation methods. The state-of-the-art of existing fume extraction torches and requirements for improving torch performance have been analysed, considering the weight, flexibility and fume extraction capability, with particular emphasis on the integral extraction torch adopted by the EC-funded Econweld Project. Through a historical survey of the evolution of integral suction torches, the recent methods for evaluating their capture efficiency have been analysed, the early developments of fume extraction torches have been reviewed and the more effective improvements in commercial torches have been investigated, both for their increasing efficiency and enhanced ergonomic assessment. The modern Computational Fluid Dynamics (CFD) approach has been briefly described, in order to model the fume plume dispersal and capture efficiency, with results validated by prestigious scientific institutions.