by Steve Robertson
Nederman Canada’s Steve Robertson discusses managing welding fumes in the shop
Why is it important to have a fume extraction system in place?
Fume extraction protects people, environment and production. Cleaner businesses have healthier and more productive employees and attract higher quality employees. Thermally generated fumes, such as welding fumes, become airborne from heat, meaning they will spread throughout the workshop unless properly extracted. These fumes will eventually settle on equipment and other surfaces—perhaps even your own products—as dust. This can result in increased costs in re-tooling, maintenance and warranties. If the quality of your products is affected, it will likely hurt your brand as well. Most importantly, welding fumes must be captured at the source because they are hazardous to human health.
Is it always possible to capture fumes at the source?
In most welding workshops, yes. However, the methods used to do so differ, depending on how the fumes are created. Most manual welding processes can be addressed by using an extraction arm or on-tool extraction. Extraction arms use a “low vacuum” system to capture high volumes of air from the work surface. The air is transported to a filtration device, where it is removed from the building or cleaned and recycled back into the facility.
With on-tool extraction, an industrial “high vacuum” system is used to capture the fumes right where they are generated. The fumes are extracted via openings in the nozzle at the tip of the torch, and then transported through a hose to a central or portable vacuum system. The fumes are filtered and clean air is returned to the plant or workshop.
Which methods of fume extraction are the most useful when it comes to robotic welding?
The most efficient and effective method for fume extraction for robotic welding is a high vacuum system with a nozzle located near the weld where the smoke or fumes are generated. The nozzle is in a fixed position over the weld point or, if the robot is generating multiple weld points, it could be a small diameter hose attached to the robotic arm terminating in a custom nozzle. The design ensures the nozzle or hose does not impede the robotic movements in any way, and the system is calibrated to ensure air velocity does not affect shielding gases or cause porosity. If the robot is not able to carry any additional weight, or if the robot model is older and no suitable on-torch accessories are available, the welding fumes are extracted through general venting. General venting would be a custom designed low volume system with a hood positioned near the weld area, that would not interfere with the process.
How can I determine which fume extraction method I should use?
Determining the most efficient extraction method will depend on the details of your manufacturing process. By considering the following factors, you should be able to conclude what would be the best solution for your workshop:
Type of welding process: If wire feed, on-torch extraction may be an option. In the case of stick welding, an extraction arm, hood or downdraft table would be your options.
Dimensions of the facility: Larger facilities with numerous welders and various processes may want to look at a general push/pull system, which will intake and filter all the air.
Manufacture process: If your process is assembly with stationary/repetitive points of welding, then a hood would be sufficient. If the process requires long welds, on-torch extraction would be a better choice as the welder would be unencumbered by moving the hood to follow the weld.
What is the awareness surrounding fume extraction among Canadian companies?
The awareness is growing. Younger generations of welders are more concerned about air quality, and training facilities are more diligent about implementing fume extraction at the inception of training. Since we live in a four-season environment where doors are closed and heating is required, it becomes critical in the months of October to April to ensure a supply of fresh breathable air while retaining heat. Most welders are familiar with extraction arms, and on-torch extraction is gaining popularity as the welder does not have to stop working in order to move an extraction hood.
The awareness is also heightened by the ownership of companies, as the economic realities of a healthy work space as it pertains to profitability become evident. Having clean breathing air in the workplace means less down time and increased productivity. SMT
Steve Robertson is solution sales manager at Nederman Canada