Verallia, which makes glass bottles, has reduced energy consumption dramatically by finding and minimizing compressed air waste in its pneumatic systems.

Verallia is a subsidiary of Saint Gobain that produces more than a million wine and champagne bottles every day in its Madera, CA, plant. That task requires a huge amount of glass feedstock. It also requires compressed air, and lots of it.

Glass making is a pneumatics-intensive business, and on a typical day Verallia's plant uses about 13,000 cubic ft/min (cfm) of compressed air. The glass-making operations consume about 10,000 cfm of the total, mostly air that blows the near-molten bottles into shape. Another 3,000 cfm drives the pneumatics for the plant's packaging lines, which include a collection of case packers, box machines, lane dividers and unitizers.

All that air does not come cheap. "A lot of people think air is free, but it's actually the most expensive consumable we produce," says Greg Rhames, Verallia's energy and asset reliability manager in Madera. How expensive? Rhames estimates that the plant's air costs $120 per cfm on an annual basis-or more than $1.56 million/year for Verallia.

Cost aside, air utilization also has sustainability implications, which is an important consideration for Verallia. As the only glass producer to have won an Energy Star award from the U.S. Environmental Protection Agency, a feat it has accomplished for three years running, Verallia has a strong track record when it comes to reducing its energy consumption and carbon footprint.

Building on Verallia's support for energy-saving initiatives, Rhames last year launched the Madera plant's first systematic effort to reduce energy consumption by eliminating inefficiencies in pneumatic systems. His first step was to find worn out pneumatic components, which together were estimated to be wasting approximately 1,000 cfm on the packaging side of the plant alone. He then began to fix the worn out components, a process that's ongoing.

This find-and-fix strategy may sound simple, but it required the implementation of a sophisticated air flow monitoring system to identify the leaks. It also triggered an ambitious modernization program to purge the plant of older, leak-prone rubber packed pneumatic components and replace them with updated components from Numatics Inc.

Finding the leaks

Rhames began the hunt for leaky pneumatic components the old-fashioned way: He walked around the plant and listened for the tell-tale hiss of escaping air. "I wish every employee recognized that sound as a waste of energy and money," he says.

Even above the background noise of the plant's glass making and packaging operations, Rhames was able to find some of the worst offenders by ear. More subtle leaks were picked up with a hand-held ultrasonic sound sensor. Rhames' "listening tour" of the plant ultimately identified dozens of leaky valves and related pneumatic components.

Simply finding the leaks, however, did not offer much insight into their impact. "Listening only tells you where the leaks are, not what they're costing you," he explains.

So to get a handle on the magnitude of the wasted air and provide baselines for leak elimination efforts, Rhames instituted air flow monitoring throughout the packaging operations. The air flow monitors give an indication of how much air each packaging machine uses-not just during its operating cycle but also during idle.

And air usage during idle is a particularly valuable data point because it is essentially a direct indication of waste. Knowing the air usage during the operating cycle, while important for optimization purposes, does not isolate leaks from other types of pneumatic losses.

According to Jando Guerra, who worked with Rhames as a pneumatics automation specialist for Air Concepts and Controls, a Numatics distributor, "Verallia's monitoring setup is both unusual and effective because of the detail it provides at the machine level."

Most cfm monitors are installed just downstream of a compressor, so they provide data only on plant-level air usage. "Putting one or two meters on the air supply side doesn't give you any useful information about what's happening to an individual machine," Guerra points out.

Finding and fixing leaks on specific machines-or specific stations on a large machine-requires a detailed approach. To that end, Rhames installed separate flow monitoring boxes on every piece of packaging equipment. The monitors sample every two seconds and show real-time flow data on a small display mounted on the machine.

Despite the use of individual monitors, the "system wasn't expensive at all, especially when you consider the potential savings, and favorable ROI," says Rhames. A basic monitoring package for a large multi-station packaging machine typically costs less than $1,000 and pays for itself in months. On a single Verallia case packer, for example, monitoring contributed to an annual savings of $7,800. The resulting ROI for the monitoring equipment was just over two months, including labor costs. "You can start a cost-effective monitoring program even with a small budget," Rhames says.

Verallia currently logs the flow data manually out on the plant floor. Rhames, however, sees an opportunity to integrate real-time cfm monitoring into Verallia's SCADA system, where the data could eventually be used for predictive maintenance purposes.

Fixing the leaks

Once Rhames identified the leaks, he began the process of fixing them by replacing worn out components. By the time his efficiency project wraps up, Rhames expects to have replaced hundreds of legacy pneumatic components.

In particular, older groups of individual valves are being phased out in favor of modern valve manifolds. According to Rhames, this approach eliminates leaks in two ways: First, the manifolds require fewer connections than individual valves, which reduces potential leak paths. Second, the manifolds, which are part of Numatics' Generation 2000 Series, have an internal construction that is inherently more leak resistant than the outdated valves they replace.

Clint Hodge, national account manager for Numatics, explains that many of the Madera plant's legacy valves had rubber packed spools that degraded over time, causing small leaks that get progressively worse. "Numatics uses a design construction that will not degrade and cause escalating leakage, even after millions and millions of cycles," Hodge says.

Big savings

Verallia's pneumatic efficiency program is a work in progress, but the company has already seen some impressive results. A unitizer's air consumption, for example, went from 60-80 cfm to 18-25 cfm. A case packer went from 30-45 cfm to 3-6 cfm. And a lane divider went from 20-25 cfm to 3-5 cfm.

On his first few passes through the plant, Rhames found worn out components that wasted 240 cfm. And he estimates that the ongoing leak reduction effort will ultimately yield an additional 760 cfm of savings for a total air savings potential of 1,000 cfm on the packaging side of the plant alone. At $120 per cfm annually, all those leak repairs will translate to $120,000 in savings each year.

The true cost savings may be even greater. Rhames calls the $120 per cfm estimate "very conservative." Indeed, air costs for manufacturing operations of Verallia's scale often reach $150 to $160 per cfm per year, according to Hodge.

What's more, energy efficiency has side benefits that improve the cost equation even more. "What's good for energy costs is good for operating costs," Rhames says. For example, the move to replace leaky components has pushed the Madera plant to standardize on Numatics components for its packaging machines. "That's already improving our inventory and repair costs," he says.

Once the packaging side of the Madera plant is done, Rhames plans to turn his attention to the glass-making operations. He will also begin the second phase of the project, which involves optimizing pneumatic systems for energy efficiency using Numatics' Numasizing software. "Leaks are the low-hanging fruit and account for roughly 85 percent of the total waste," Rhames says. "But we're not going to leave that other 15 percent on the table."

This article was prepared with input from Clint Hodge, national accounts manager for Numatics Inc.

Air Concepts and Controls Inc.,
510-471-4470.

www.airconcepts.net

Numatics Inc., 248-596-3200.

www.numatics.com