Madico Inc., a pioneering leader in the window-film industry, was literally burning money to operate its coating lines.

Madico produces thin solar-control laminated films used to screen UV rays, block heat, reduce glare, increase occupant comfort, and enhance aesthetics. Madico also makes multi-ply safety and security films that reduce hazards when glass shatters. Madico's products are used on vehicles, homes, and buildings worldwide.

In 2001 the company's manufacturing plant in Woburn, Mass., was using a recuperative thermal oxidizer to destroy solvents from the drying ovens on its three process lines. Thermal energy from the oxidizer exhaust was recovered by heat exchangers and used to operate the process ovens and other in-plant systems. Unfortunately, the oxidizer's operating efficiency and capacity limitations created problems.

Too Much Energy

Madico was using more than 100,000 therms of gas monthly – an annual bill exceeding $1,000,000 at today's prices. The 20,000 scfm oxidizer was twenty years old. It used a single two-speed exhaust fan to serve three processes. The fan caused capacity and continuity conflicts between lines. This demanded continuous monitoring and adjustment by operators, and 25% lower line speeds at times. Productivity suffered. In addition, air temperatures from the exchangers exceeded 800°F, much hotter than the dryers needed. The oxidizer yielded more heat than the plant could use and valuable energy had to be vented to the atmosphere.

Seeking a Solution

Mark Fehlmann, P.E., Madico's Engineering Manager, knew that a new, high-efficiency regenerative thermal oxidizer (RTO) could reduce fuel usage. But key questions remained about capacity needs, coupling with the existing lines, and recovering the heat for process drying.

MEGTEC Systems of DePere, Wis., was one of several firms invited to review the situation. Ultimately, Madico approved MEGTEC's proposal for a 40,000-scfm CleanSwitch™ RTO. This unit has a proprietary switch valve that delivers high VOC destruction without a flush system. MEGTEC proposed a new heat recovery system and operating sequence that would run more efficiently without wasting energy. MEGTEC's engineering study had also revealed that the RTO exhaust could be safely used in Madico's drying ovens. MEGTEC also supplied upgraded equipment including T-dampers, exhaust fans, and the required hot and cold fans for the heat recovery system.

Mark notes that Madico's decision was based on the benefits of the CleanSwitch™ design combined with MEGTEC's extensive process coating and drying knowledge and their willingness to take on non-routine problems. The RTO was installed in November 2001.

Impressive Results

The CleanSwitch™ RTO achieved VOC destruction efficiencies above 99%. The fan design allows the three lines to run independently with no operator involvement. The capacity has eliminated the need to cut line speeds, so the plant sees higher production. The RTO provides process air at a more useful 400°F. Mark reports that, when all processes are on line, the CleanSwitch™ RTO spends approximately 40% of the time in self-sustain, not using any gas at all. With MEGTEC's RTO and heat recovery system, the plant's typical monthly gas use is now less than 7,000 therms, mostly due to the building's heating load. Overall, Mark reports that Madico has seen a 93% drop in gas usage. Energy savings have provided full return in only eighteen months.

MEGTEC also provided documentation Madico needed to earn a $75,000 energy savings rebate from their gas supplier. And finally, MEGTEC has introduced Madico to the philosophies of DMAIC Six Sigma training, through which Madico has already begun to receive noteworthy returns – a further sign of the commitment MEGTEC has to helping its customers be more productive and profitable.

Phone: (920) 337-1479
Fax: (920) 339-2784
E-mail: info@megtec.com
Web: www.megtec.com
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