A manufacturer of coated paper packaging products had a machine that used a Corona discharge to generate ozone for treatment of a 10ft (~3.05m) wide roll during the coating process. Ozone, in high enough concentrations, is harmful to breathe, so they had installed a drilled pipe to blow air across the front opening of the machine to keep the ozone inside, and limit the concentration in the operator’s space to less than 0.1 ppm. The drilled pipe was able to maintain the concentration at that level (even though it used an awful lot of compressed air, and was quite loud to boot), until other enhancements in the process allowed them to increase production. This necessitated a change in the Corona system’s power from 9kW to 14kW, and the drilled pipe’s air curtain was no longer able to maintain ozone levels in the operator’s space at a safe level.
In addition to blowoff, cleaning, drying, and cooling applications, the laminar air flow of an EXAIR Super Air Knife is also particularly well suited to environmental separation. That’s a literal wall of air that’ll keep dust off sensors or lenses, prevent heat, smoke, & fumes from exiting openings in machinery, or in this case, make sure harmful gases stay inside the process boundaries so they don’t prevent a breathing hazard to personnel in the area.
After installing two, Model 110060 60″ Aluminum Super Air Knives with a Model 110900 Coupling Bracket Kit, the uninterrupted 120″ laminar air curtain was able to keep the ozone concentration consistently under 0.05 ppm…less than half their established safety limit. What could be better than increasing production AND safety?
I’ll tell you what’s better than that: lower operating costs and noise levels. While the drilled pipe did its job prior to the change in production, it used quite a bit of compressed air to do so: with a supply pressure of 80psig, their air consumption was measured to be 496 SCFM, and the ambient noise level was 94.5dBA. That’s higher than the OSHA 1910.95(a) limit for maximum allowable noise for continuous 8-hour daily exposure.
The 120″ Super Air Knife system, by comparison, uses 348 SCFM when supplied at 80psig, which, since it operates continuously, saved them $5,200.00 per year in compressed air consumption. Now, the coating machine itself is pretty loud – even with the Super Air Knife installed, the ambient noise level in the area was still 93dBA. But the 69dBA sound level of the Super Air Knife didn’t contribute to that, in any case.
Bottom line, installation of the Super Air Knife allowed for increased production of the coating machine, lowered the concentration of ozone escaping the machine, reduced the operating cost, and even improved the sound level, if only by a small amount…but every little bit helps, right?
If you use compressed air, it’s entirely likely that engineered products can help you get the most out of your system. To find out more, give me a call.
Russ Bowman, CCASS
Application Engineer
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