When welding takes place, it always goes hand in hand with UV radiation, high temperatures, and exhaust fumes, which will be more or less hazardous depending on the particular welding process. The welding fumes produced often contain harmful contaminants, however these do not present a problem if the right welding extraction system is used.
How is This Harmful to The Respiratory System?
The contaminants enter the airways when you breathe in, and pass through the bronchial tubes into the lungs. Due to their microscopic size, these nanoparticles – known as particulates – are able to directly enter the pulmonary alveoli through the cell wall. It is essential that this is prevented.
These harmful airborne contaminants – which occur in concentrated form mainly in plant, container, machine, and steel construction, in the automotive industry and its component suppliers, as well as in rail vehicle manufacturing and shipbuilding – can be removed at source using a
fume extraction welding torch in combination with welding fume extraction system.
On-Torch Extraction – The Best Welding Results with Optimal Protection
Complete or near-complete welding fume extraction at the point of origin is the holy grail.
Factors affecting extraction efficiency:
Welding process The welding process itself is a big factor in the development of fumes (e.g., welding high-alloy materials)
Torch geometry: The torch geometry has a significant effect on the shielding gas flow and extraction
Welding position: e.g., hot fumes rise, CO2 drops to the floor
Extraction capacity: If the extraction capacity is too low, the extraction efficiency will drop, if it is too high, the shielding gas will be extracted and welding faults will occur.
Shielding gas: The shielding gas and the shielding gas flow rate affect the welding results and the extraction efficiency. Gases react in different ways, e.g., CO2 generates more fumes than argon.
Shielding gas is a gas used to replace the ambient air. It protects the weld seam from oxygen and other gases in the ambient air. It is not possible to produce a clean, durable weld seam without shielding gas.
The Challenge Lies in Removing Welding Fumes but not the Shielding Gas
Where direct welding fume extraction is used, the oxygen concentration is relatively high, so shielding gas will also be extracted, which could result in the formation of pores in some materials. However, using a high shielding gas flow rate to counter this leads to high shielding gas consumption.
To produce a high quality weld seam, a shielding gas supply between 13 and 16 l/min is the norm. The Fronius fume extraction welding torch has been designed so that the welding fumes flow to the side and only then are they captured. This means a lower shielding gas flow rate is needed. High quality welding results can be achieved with a flow rate of 10 l/min (laboratory values), with the potential for significant savings. Other torches with nozzle openings on the torch tip capture the shielding gas directly and so need a higher shielding gas flow rate of at least 13 to 16 l/min to achieve good seam quality.