The compliance with environmental regulations during welding processes
27.02.2017
Welding operations release dust and smoke. Their level at some point becomes so high that it begins to be hazardous to operators and other employees who work in the area.
For this reason, most countries have introduced measures to regulate the quality of air in the work environment. Capturing of the noxious can be done at source, right next to the venue of the production process, or within the entire room.
When organizing the removal of dust and fumes at the source it is recommended to work with individual specialized equipment or networks provided with more collection points (arms).
Individual specialized equipment is directly connected to the exhaust extraction nozzle from the torch welding. This method ensures the best capture of smoke and contaminants released during the process. The big advantage is that the equipment is portable, easy to install and involves low maintenance costs.
A similar version is the equipment that captures the smoke in the immediate area of seam welding. They do not require modification and loading of the torch, facilitating the welding process but are less efficienct when it comes to the level of pollutant uptake in comparison to personal protective equipment (PPE). Mobility remains high, but the using of this solution is limited by the arm's length and the size of the welding parts.
Similarly, the suction of welding fumes can be achived through networks provided with capture arms. Mobility is reduced in this case, and the system should be sized according to the number of welding stations.
When organizing a network capture harm is not possible, or when you have to weld parts with high volume in an enclosure relatively small, or if you have to complete the local capture, you can use so-called towers of air purification systems or diluters.
The tower of air purification is a filter equipped with filter cartridges. It is recommended to use it in enclosed spaces.
Contaminated air is aspired near the floor, filtered and blown back into the workshop at the top, through nozzles.
The unit is also easy to install. It should only be connected to the compressed air and power supply.
The towers are useful in the production facilities in which large pieces are processed and where it is difficult to capture the smoke directly near the weld. Compact, they do not need suction / discharge compunds or driving arms for trapping pollutants.
If the ultimate goal is only to reduce the concentration of pollutants in a room, the ideal way to do it is to install a Push Pull system.
The Push Pull system consists of suction points (pull) and introduction points (push), ducts, filter and fan. The installation has two mirrored lines. On one side of the hall there is a channel with mounted grills able to organize the fume extraction. The exhaust fumes are filtered through a centrally placed filter and then blown through a second line with grills, which is placed parallel to the extractor, on the other side of the hall.
Therefore it is very important to enable a continuous operation of filters because air particles are separated from them. The automatic cleaning of filters keeps the process efficiency at a high level.
The system does not require intervention of the welder and can be installed in addition to other methods of capturing the pollutants.
The solution is not suitable for welding stainless steel, copper alloys and nickel-based and it is not a method to protect the welder. If the room where welding operations are performed is provided only with this air purification method, it requires for the welders to wear personal protective equipment.
