It is known that companies with facilities that are clean, safe and offer a healthy environment have greater success in recruiting and retaining employees. Employees spend a significant amount of their time at their workplace, so the environment is a main factor in deciding to take a job. Employee expectations for a safe work environment include good air quality, which directly impacts their long-term health and safety.
“Everyone understands there is a labor shortage, and potential employees can stand to be a little choosy,” says Justin Badger, national sales and marketing manager for Imperial Systems Inc. “Certainly, people interviewing for welding positions are looking for a clean environment. More and more welders are starting to think about their health when they go to work, more so than what they may have thought about it in the past. Previously, they may have just been looking for the highest paying offer where now they also consider cleanliness.”
Prolonged exposure to welding smoke in the workplace increases the risk of respiratory problems, making fume extraction systems a must. Managing welding smoke and dust means dealing with hazardous fumes, small particle sizes and combustible metal dust. Whether it’s referred to as a smoke eater, fume extractor or dust collector, choosing a proper collection system to remove the smoke and dust from the work area is key to preventing hazardous contaminants from entering the airstream.
However, steps must be considered to ensure safe operation of the dust and fume collectors themselves, including maintenance and efficiency. These key actions will keep employees safe – and happy – regarding fume extraction.
Add a collector
“Signs of a dirty shop include smoke in the air that just hangs,” Badger says. “Also, dust appears on all the equipment and makes the lighting low. A lot of times, the walls have turned a brownish-red.”
To provide a clean facility, protect workers’ health and comply with required local, state and federal regulations, manufacturers rely on collection systems with high-efficiency, cartridge-style filtration. Fume collection systems come in three types to accommodate different space requirements. Most of the choice depends on the size of the product being welded, although shops can use all three types.
Source capture equipment captures smoke and dust as close to the source as possible. It’s probably the best at capturing smoke, but it’s really for working on small parts that are being welded in the same spot over and over. Next, a closed capture hood sits above, behind or below the part and continually draws air through to filter out the smoke. This type also works best with smaller parts because with larger parts it is harder to maneuver around under the hood, especially with overhead cranes.
The third type is an ambient system, which is a series of ductwork throughout the facility that draws in air. The air is cleaned and returned into the facility or exhausted outside away from the plant. One of the biggest advantages with an ambient system is that it can recirculate heated or air-conditioned air back into the facility for a big cost savings.
“Basically, the closer you are to the part, the more efficiently you collect the smoke, and the farther away you are, the less efficiently – but sometimes, that’s easier and more manageable,” Badger says. “It’s important that the welder doesn’t have to spend their time making changes or adjustments, and that’s what ambient systems allow to happen. You just turn it on and it runs all day. With the other types, the welder might have to move it to make sure it’s placed properly, but that doesn’t always happen.”
Badger suggests companies locate their dust collectors outside, whenever it’s an option. Locating collectors outside is a great way to save space, and floorspace is a premium these days.
Keep in mind, though, that an outside dust collector needs to be able to withstand the elements. For example, Imperial’s Cmaxx dust and fume collector for outside use features a fully welded construction with an arched roof that prevents water from collecting and creating rust. Also, there are no external bolt holes for water to enter the collector. An outside collector with combustible dust also poses less of a fire risk.
“Fires do occur, so it’s much better for your dust collector to be outside than in the building,” Badger says. “Fortunately, there are lot of things you can do to reduce that risk of fire in a collector.”
Combustible issues
For combustible dust, companies must follow the National Fire Protection Association (NFPA) 68 standard, which requires explosion venting of combustible gases and pressures resulting from a deflagration within the dust collector. An explosion isolation valve can prevent a fire from traveling back through the ductwork. Spark arrestors are also important in keeping most sparks from getting to the collector. Chemical control systems can suppress or extinguish a flame, but only certain chemicals are approved for fires involving metal dust.
Filters can also be important for fire suppression in a dust collection system. Filters with a fire-retardant coating, such as DeltaMaxx filters, resist burning to prevent a fire from occurring inside a dust collector.
Also, for combustible dust, one of the key requirements of NFPA 652 is completing a dust hazard analysis. A dust hazard analysis is a review process that looks at each part of the facility’s processes and evaluates any fire, deflagration or explosion hazards that are present anywhere in the facility as the result of combustible dust.
The first step is to have the dust analyzed, and if the dust is determined to be combustible, the facility’s dust collection system should be evaluated by an expert to identify the appropriate explosion-protective equipment that can be added to the collector.
Filter changes
Whether combustible or not, practicing safe dust collector maintenance affects employee safety. Dust disposal is an important aspect of the collection process, and if the collector isn’t emptied and cleared out on a regular basis, the dust can build up in the hopper. Even if it’s not a potential fire risk, it may impede the system’s operation.
“When it comes to maintenance, the downside of a dust collector located outside is that sometimes, it’s out of sight, out of mind,” Badger says. “The operation must have the proper maintenance procedures to ensure someone goes outside and makes sure the drums are empty and don’t have dust in them.”
Just like residential HVAC filters, the filters in dust collection systems need to be changed regularly. If filters become overfilled, they will no longer work efficiently and can also present a fire hazard.
Unlike residential filters, however, changing dust collection filters can sometimes be a hazard for employees. Fortunately, many dust collectors provide cartridge-style safe access to the filters, as they easily slide in and out of the housing, and pulse cleaning systems. Filters that don’t need to be changed as often are also a plus.
With ease of use being a major goal, Badger adds that Cmaxx dust and fume collectors are simple to use. “We have our ‘safety pentagon,’ which is basically a redundant safety feature that makes sure that everything is operating correctly after the operator changes the filters.”
The Cmaxx also uses a vertical filter arrangement with longer filter life and better pulse cleaning versus filters that sit horizontally inside the dust collector.
Because there is so much equipment and regulatory information to consider when it comes to mitigating dust risks, it is important to consult with a dust control expert to assess the facility’s needs and design a dust collection system for specific applications.
“We are a solution-based company, so we help with the whole solution – the dust collector, ductwork and proper filtration – to produce a good clean facility,” Badger concludes. “A good and well-designed dust collection system rarely makes a company money, but it does help attract and retain good employees. It also leads to employees taking less time off due to illness. It keeps their facility cleaner, requires less maintenance costs and provides good clean air. There are a lot of hidden benefits people don’t think about. A good dust collector doesn’t make money, but it saves a lot of money.”
