Technical Advances Can Turn Utility Costs Into Savings

From steam generation to compressors to motor drives, inefficiencies in plant utilities can drive up costs and sap profitability. Technology that flips the equation can introduce needed change.

By Kevin T. Higgins, Managing Editor

1 of 2 < 1 | 2 View on one page

In the daily scramble to fill customer orders and make sure food defenses are functioning as intended, it’s easy for plant personnel to neglect facility upkeep and let infrastructure upgrades slide.

Chiller systems are among the biggest energy consumers for many companies, and inefficient performance and breakdowns can quickly magnify costs. Yet almost half (43 percent) of respondents to a survey conducted by Goodway Technologies say they do not use Eddy current testing to troubleshoot corrosion and scaling in tube walls, a maintenance shortcut that adds cost and can result in unscheduled downtime.

Assuming the fundamentals of preventive maintenance are being executed, plant managers and maintenance personnel can access a number of alternative technologies to address plant utility needs. For facilities with refrigeration systems, one option that can render a boiler redundant is a heat pump integrated in a single-screw compressor to recover latent heat.

The concept first was applied six years ago at a Nestle chocolate plant in the U.K. Kraft and other major food companies are among the early adopters. It was developed by the Vilter Manufacturing division of Emerson Climate Technologies (www.emersonclimate.com).

The waste heat from compressors typically is too low-grade to warrant recovery and reuse, but the heat pump is able to extract enough energy from return gases to raise the temperature of water to 140-150° F, according to Wayne Wehber, vice president-business development for Cudahy, Wis.-based Vilter. Two manufacturers that have integrated the compressors have since “shut off the boiler,” he reports.

High pressure is required to attain those temperatures. The single-screw compressors elevate the returning gas to about 360 psi, double the normal discharge pressure. The biggest impediment to applying the technology is determining how much demand a facility has for hot water, says Wehber. Between plant expansions and other variables, “it becomes a moving target” to calculate hot water demand, he says. Without that information, it’s impossible to calculate how many skid-mounted compressors will be required.

“The energy savings are amazing,” Wehber adds. “The key is being able to reliably compress the ammonia to a higher temperature and pressure.” Each unit measures about 12-by-6 ft. and is powered by about a 300 hp motor. Prevailing energy costs and the amount of piping and hot-water holding tanks necessary determine if ROI expectations can be met.

To weld or crimp?

A wide variety of utility pipes course through food & beverage facilities. The cost of piping — black pipe for gas, copper for glycol, stainless for process water — varies significantly, but one constant is the welds, sanitary and otherwise, needed to join them. Some manufacturers are concluding saving time is worth more than saving money by welding and are turning to pressed-in fittings.

Barrel O’ Fun’s Phoenix snack food plant makes extensive use of pressed-in fittings, with much of the work since 2008 done by local contractor Niemeyer Brothers. Supply lines for nitrogen, process water and compressed air are among the thousands of feet of piping installed, according to Rick Niemeyer, president, with more on the way. A new steam system is being installed at Barrel O’ Fun, which was acquired early this year by Shearer’s Foods.

“Pressed-in fittings were a huge labor savings, and it’s a lot more adaptable than welded pipe,” Niemeyer maintains. “People are always afraid to use a new product, but we’re seeing more and more demand. Hospitals and medical facilities love it because it eliminates solder.”

Many of Barrel O’ Fun’s pipes are copper and galvanized steel and are housed above a walkable ceiling. When the pipe drops below the ceiling to production areas, it transitions to 304 or 316 stainless. Niemeyer uses components from Viega ProPress for the fittings and to make the dielectric transition to different materials.

1 of 2 < 1 | 2 View on one page
Show Comments
Hide Comments

Join the discussion

We welcome your thoughtful comments.
All comments will display your user name.

Want to participate in the discussion?

Register for free

Log in for complete access.

Comments

No one has commented on this page yet.

RSS feed for comments on this page | RSS feed for all comments