Many metalworking facilities feature large, open workspaces. While ideal for large scale production, this setting presents challenges for air quality and in assuring clean air in the work environment. Weld smoke, fumes, oil and coolant mists are harmful to workers. In any manufacturing setting where welding is done, precaution must be taken to limit worker exposure to these harmful contaminants to assure a safe plant environment.
Let's take a look at how one metal fabrication company solved this issue with the help of Parker.
Cherubini Metal Works, a fabricator of large structural steel assemblies for bridges and buildings in Nova Scotia, supplies hundreds of thousands of tons of cut, shaped, welded and pre-assembled steel into a variety of standard and custom designs. Their newest fabrication facility in Eastern Passage, Nova Scotia measuring 56,000 square feet, often has 15 to 20 welders operating at the same time in their large open workspace. The resulting weld smoke and fumes presented a challenge to the safe and productive environment the company valued.
Typically, source capture systems are used to collect weld fume contaminants. Source capture systems include fume collection hoods, ducting, air cleaning components and fans. However, in a large, open facility like Cherubini, where overhead cranes and large fabricated structural pieces were taking up substantial space, a source capture system was impractical. Cherubini's management team also determined that, due to the low outside temperatures in the winter that could range from -4° to -22°F (-20 to -30°C), they needed to re-circulate filtered air in order to avoid the high heating costs associated with warming air drawn from the outside.
Cherubini's management team consulted with Parker, a leader in the clean air system design, on how to proceed. Typically, there are two ambient air collection options for welding fumes:
- A large collection system that pulls air out of the area, forces it through a reverse pulse-jet cartridge dust collector and then re-circulates the air back into the facility.
- Multiple smaller units, electrostatic precipitators (ESPs), mounted above the plant floor to move air in a predetermined pattern. This option would allow workers unrestricted movement and would not interfere with the heavy equipment and fabricated pieces.
Re-circulating air through the Cherubini facility, as opposed to exhausting it outside, was viewed favorably as it would provide a healthy work environment while saving the company substantial energy costs. Based on Parker’s recommendation, Cherubini chose to install 10 SmogHog SG-4S mist/fume collection units with automated in-place cleaning.
SmogHogs, using electrostatic precipitators (ESP) technology, are highly efficient, heavy-duty air cleaning devices that remove smoke, fumes, dust and coolant mist from the air stream. In open-air applications, like the Cherubini facility, multiple units are installed in a pattern that circulates the air from unit to unit in a circular- racetrack- configuration.
ESP works by electronically charging both visible and microscopic contaminants and capturing them like a magnet in collection cells. Operating continuously, ESP units will then circulate clean air back into the plant.
Cherubini’s SmogHog systems re-circulate clean air throughout the facility, they also reduce exhaust make-up requirements by up to 80%. The air is recycled into the workspace, saving the company thousands of dollars a year in heating costs during the cold winter months. Maintenance is minimal. In Cherubini’s case, the 10 SmogHog SG-4S units are cleaned via an automatic wash system, depending on weld work volume.
“I continue to purchase SmogHog electrostatic precipitators because they are effective...and meet all local air quality and occupational health and safety requirements. And, because building heat is too expensive to waste.”
— Renato Gasperetto, vice president of Cherubini Metal Works Ltd.
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Article contributed by the Filtration Team.