Until recently, most plants considered clean air to be a secondary issue or a design consideration for new facilities. The source of most smoke and pollutants that contaminate the air of the plant are from the production line. Thanks to a new modular air cleaning system, there is an affordable solution that not only ensures a cleaner plant, but also will greatly reduce costly maintenance and add substantial energy savings to the bottom line.
In older facilities that produced airborne pollutants, such as welding and cutting smoke or oil mists, were simply collected and the dirty air exhausted to the outside. While acceptable to OSHA, this approach is no longer sufficient for those who realize that it sends tons of money up into the atmosphere in the form of wasted heating, air conditioning and electric power. At the same time, the traditional ventilation approach often requires greater investment in equipment and maintenance, yet may not be completely safe, as indicated by welding fires or a blue haze around the ceiling lights.
“Most companies today don’t have the in-house expertise to spec the kind of air collection and filtration systems they need on the line,” says Glen Tuplin, facilities manager at F&P Georgia, a manufacturer of components for Honda and Nissan. “Plus, there is a lot of competition for capital within a manufacturing company, and an air system is not the type of equipment where management would look for an ROI. Therefore, if a rooftop exhaust system meets OSHA compliance, it will most likely be okay with the company’s production planners.”
However, at F&P Georgia, ROI did indeed appear promising with the right air filtration system. A manufacturer of subframe and suspension components, the firm has extensive welding, stamping and painting operations within its 200,000+ sq. ft. facilities in Rome, GA.
Although the original F&P plant was built in 2001 with a traditional air ventilation system, Tuplin decided to consider retrofitting a new modular air filtration system from Clean Air America, Inc. during a 2003 plant expansion project. That system promised to do a better job of maintaining plant air while reducing costs at the same time. The Clean Air system would not only prove to be economically worthwhile, but would include many other benefits that would help make F&P Georgia’s plant the benchmark for similar Honda suppliers.
Keeping the air inside
“Heating and air conditioning costs are about $2.00 cfm and $4.00 cfm respectively,” Tuplin explains. “Our exhaust total air volume was 103,000. Because the Clean Air America system filtered and returned plant air (rather than exhausting it to the outside), it was simple math to see that we could save $200,000 annually with their system.”
The configuration of Clean Air America’s application-specific, turnkey system consisted of modular hoods for the welding cells, quick-clamp-style ducting and dust collectors to completely filter and return the air to the plant. This would provide a huge savings due to the reduction in utility consumption. Because the system is engineered to draw smoke, dust and aerosols as near as possible to the source, a cleaner, healthier and safer plant environment is maintained. The improved environment can enhance product quality due to the diminished smoke and dust in the production area.
“While most of our welding is done inside automated cells, there is some done on the floor outside these enclosures,” Tuplin says. “The Clean Air system gives us the flexibility to place air intakes within feet of re-work welders, eliminating the smoke that would normally dissipate throughout the plant.”
Fire suppression – build it in
Many different plant operations produce dust, aromatics, oil mists and other flammable substances. In the presence of sparks such as those generated by welding, they increase the hazard for internal fires. For that reason Tuplin had Clean Air America include a fire suppression system with F&P Georgia’s air filtration system.
“We use stamping oil during our stamping operation,” Tuplin explains. “When the metal is welded, the aerosols mix with the oxides and are drawn up into the smoke handling units. There is the possibility that this ‘dust’ can be ignited by an uncontrolled welding spark.
“Fire suppression is a complex and potentially nightmarish issue,” says Bertil Brahm, Clean Air America's president. “Assuming that a stamping operation is using oil, the question is, how are we trying to reduce the possibility for a spark to go where we don’t want it? From a technical point of view, we can provide protection with baffling, change of air velocity, and mechanical means of that sort. In our systems we also use a fire-extinguishing agent (Dupont FE-25). It’s a very quick suppressant like halon, although that is no longer available. FE-25 is a very good halon replacement.”
VFDs save on power, filters and maintenance
In the majority of its air filtration installations, including the F&P Georgia plant, Clean Air America used advanced variable-frequency drive (VFD) technology to control blowers and help maintain filters.
“The VFD system uses less power because it only draws the current that’s necessary to maintain the airflow that you want,” says Tuplin. “As far as we are concerned, this technology is saving significant energy and also enabling us to avoid spikes during peak usage periods.”
Brahm agrees that the VFDs can provide a significant cost savings on energy, but says there is a lot more to it. “Through the use of VFDs we can also increase filter lifetime, reduce noise levels and simply manage the filtration system much better. The VFD ‘soft starts,’ so we can program it so that you control the maximum amperage. Also, as time goes by, filters get dirtier, which causes a pressure drop in the equipment, and the air flow rate will go down. We use reverse pulse to clean our filters, which feature the patented Down Flow Technology. As the flow goes down because pressure goes up, you kick up the speed of the VFD a bit and you’ve compensated for the problem with no maintenance to speak of,” said Brahm
The VFDs give Clean Air America’s system a degree of flexibility that enables the customer to change airflow on the fly. However, it is the unique modularity of the Clean Air America approach to systems design and installation that ultimately enables plants to change their air filtration systems as production operations change, “with minimum pain and maximum efficiency,” says Brahm.
The Benchmark
Tuplin adds that in the automotive sector, plant appearance makes a difference. “When you’re dealing with auto makers of the stature and standards of Honda and Nissan, you expect them to be demanding,” he says. “And when Honda comments your plant is a benchmark for clean air quality, you know you’ve done the right thing.”