WELDING TORCH SYSTEM FOR USE IN WELDING OR CUTTING OPERATIONS, WELDING TORCH FOR USE IN SUCH A WELDING TORCH SYSTEM AND METHOD FOR WELDING USING SUCH A WELDING TORCH SYSTEM OR SUCH A WELDING TORCH

摘要

Welding torch system for use in welding or cutting operations during which fume is created. The welding torch system has a welding torch comprising a contact tip holder and a coaxial nozzle comprising an inner shield gas conduit having a shield gas outlet for supplying a shield gas. The inner shield gas conduit surrounds the contact tip holder. An outer shell at least partly surrounds said inner shield gas conduit. The welding torch system further comprises a shield gas generator and supply unit for supplying shield gas through the shield gas outlet and a fume extracting assembly for extracting fume and ambient air. The welding torch system is arranged for—during operation—supplying shield gas through the shield gas outlet at a velocity between about 1.5 m/s and 10 m/s. By operating the fume extracting assembly to generate a flow of between 10 and 100 m3/h, preferably a flow of about 55 m3/h a reduction in the area of 90%-95% of hazardous fumes can then be realized. A welding torch for use in such a system has an inner shield gas conduit having an end portion with an inner surface of which the diameter decreases towards the shield gas outlet. In a method for welding the shield gas is supplied through the shield gas outlet at a velocity between about 1.5 m/s and 10 m/s.

主权项

1. Welding torch system for use in welding or cutting operations during which fume is created, said welding torch system including a welding torch comprising:
a contact tip holder having formed therein a longitudinal passageway with a head end through which can be supplied welding wire having a free end forming a contact tip; a coaxial nozzle comprising an inner shield gas conduit having a shield gas outlet for supplying a shield gas, said inner shield gas conduit surrounding said contact tip holder, an outer shell at least partly surrounding said inner shield gas conduit, said outer shell having a head end, wherein between an inner surface of said outer shell and an outer surface of said inner shield gas conduit a fume extracting passageway is formed and wherein a plurality of openings is provided in a distal end of the outer shell for extracting ambient air and fume into the coaxial nozzle; said welding torch system further comprising: a shield gas generator and supply unit operatively connectable to the inner shield gas conduit for—during operation—supplying shield gas through the shield gas outlet; and a fume extracting assembly operatively connectable to the fume extracting passageway for—during operation—extracting fume and ambient air; wherein the welding torch system is arranged for—during operation—supplying shield gas through the shield gas outlet at a velocity between about 1.5 m/s and 10 m/s.