Optimizing Energy Use

For science buffs, energy induces much higher contemplation than last January's California crisis or the eyebrow-raising heating bills we cold-climate dwellers may get this winter. But for the monthly energy consumer, it's hard to look at a hefty bill and feel like getting cerebral.

Ironically enough, “getting cerebral” about it is exactly what's necessary. That's what ITW Foils of Mt. Pleasant, MI, did. The hot stamp foil manufacturer (formerly known as Maple Roll Leaf and headquartered in Ont., Canada) recently got to thinking and got a hold of Megtec. According to ITW, it has cut its process energy costs by more than 75% — all thanks to a customized Megtec Enterprise II regenerative thermal oxidizer.

RTO: The Way to Go
After examining its production capabilities and efficiencies, ITW determined the plant's recuperative oxidizer (which was subject to frequent malfunctions) was keeping the operation from optimal run speeds. So the company decided it was time for a change.

The first step was an energy audit. Reports ITW's operations supervisor Mike Rogers, “Our goal was to achieve a 15-to-20-percent increase in overall throughput from our coating lines. Our equipment at that time wouldn't allow us to progress toward that goal. Also, the oxidizer required a large amount of natural gas to operate, and we hoped to minimize fuel consumption.”

The audit confirmed ITW's suspicion: The facility needed to replace its old recuperative oxidizer with new regenerative technology. Says Rogers, “For many applications, regenerative thermal oxidizers [RTOs] are the most advanced, energy-efficient oxidation technology available.”

According to Rogers, the ITW team was looking for three specific requirements for the plant's new oxidizer: the ability to reclaim heat to fuel the coating lines; the ability to achieve specific volatile organic compound [VOC] destruction rates; and a solution that could integrate into the company's current process operations easily.

To devise a cost-effective solution, Rogers turned to Megtec Systems — a company with more than 20 years of energy-management experience, he adds. “We decided to go with Megtec because it was able to offer us a comprehensive solution that integrated smoothly with our operation's processes,” Rogers notes. “They helped us analyze our current energy usage and uncover efficient ways to reduce our overall energy consumption.”

“Upon evaluation of the plant's process operations,” says Rogers, “Megtec engineers provided us with a customized, 25,000-scfm Enterprise II regenerative thermal oxidizer with an auxiliary heat-recovery system to meet these requirements. The unit is sized with enough capacity to handle additional exhaust air flow from future processes.”

Heat Reclamation
“In order to create a system that could use the energy released during the oxidation process to fuel the dryer,” Rogers explains, “Megtec engineers developed a customized heat-recovery configuration. The system incorporates an automated heat-recovery damper and a custom-designed hot air-mixing chamber to provide temperature-controlled make-up-air (MUA) back to the converting process.”

With the reclamation of enough energy to power ITW's drying capacity, it's no wonder the company has cut its energy costs dramatically. “And,” says Rogers, “with regenerative heat technology, the VOCs burned provide the balance of energy needed to keep the oxidizer operating on its own without burner-fuel input. Plus, since we use the recovered heat from the oxidizer, we don't have to use gas-fired heat at the dryers, which means we can run more safely and efficiently.”

Harmonious Integration
Rogers' wish for smooth installation came true. “It was imperative the energy professionals we selected could fully understand how our processes operated and offer the best solution to the process challenges.”

Overall, according to Rogers, Megtec's solution to ITW Foils' energy problems has been a “tremendous” investment for the operation. “Our operating costs have lowered substantially. We're at about 25 percent of what we used to use for our process operations; our energy usage is down more than 75 percent. As for more precisely quantifying our savings, it's still early to put solid figures out, but our initial findings — based on the fact we used to average 8,000Ccf [1 Ccf=1 therm] usage per week on a five-day run — show a usage of only 1,700Ccf for a seven-day run.”

In addition, Rogers notes that based on the capital invested in the heat-recovery equipment alone, ITW Foils determined its financial payback to be approximately four-and-a-half years at 2000 fuel costs. If we see energy price spikes like last winter, the payback term will be even shorter — not to mention the cost savings year after year, he adds.

By combining RTO technology with proven secondary heat-recovery techniques, ITW Foils has decreased its cost of both processing and environmental compliance — a resourceful way to reduce the impact of dramatic increases in fuel costs. And with the volatility of the energy market, being resourceful will save your head for meditation on the difference between potential and kinetic energy — and keep those high-energy-bill headaches at bay.

ITW Foils Mt. Pleasant, MI; 989/772-5172; itwfoils.com

MEGTEC Systems — De Pere, WI; 920/337-1579; megtec.com

Subscribe to PFFC's EClips Newsletter