Technology

Compressed air users looking for energy reduction often identify their air compressors as a prime area for savings potential. But …what about end uses? There are a large number of obvious measures that can be implemented, such as leakage reduction, reducing open blowing and eliminating inappropriate uses..however, there are other more technical opportunities available that involve properly specifying or redesigning existing pneumatic circuitry in compressed air operated machines and processes.

Recently, The Kroger Company’s Indianapolis bakery identified the use of compressed air in a blow-off and conveyor gap transfer as a major source of energy loss and cost waste. According to the U.S. Department of Energy, “inappropriate use” of compressed air like blow-off produces high pressure atmosphere bleed leading to significant energy loss and unnecessary operational costs. Carrying a 10-15% efficiency return (according to the Department of Energy), compressed air applications can often be achieved more effectively, efficiently and less expensively with alternative solutions using a high flow rate and moderate pressure.

While biodegradable, energy efficient, and recyclable are terms that come to mind when thinking about protecting the environment we live in today, these three terms are also, ironically, directly related to protecting a company's bottom line... profit.

It's simple physics that compressing air gives off heat. The heat energy is concentrated in the decreasing volume of air. To maintain proper operating temperatures, the compressor must transfer excess heat to a cooling media before the air goes out into the pipe system. As much as 90 percent of that heat can be recovered for use in your operation. If you can supplement or replace the electricity, gas or oil needed to create hot water for washrooms, or direct warm air into a workspace, warehouse, loading dock, or entryway, the savings can really add up.

One major problem that causes severe damage or system failure for any water treatment station is water hammer shock waves. “Water Hammer” or “Hydraulic Shock” is a pressure surge or shockwave resulting when a fluid (usually a liquid but sometimes also a gas) in motion is forced to stop or change direction suddenly (momentum change). The reversed momentum then continues to multiply the further it travels before being stopped.

A new cogeneration system installed at the Budd Inlet Treatment Plant by the LOTT (Lacey, Olympia, Tumwater, and Thurston County) Clean Water Alliance late last year uses treatment by-products as fuel to generate electricity and heat energy. This renewable energy system, combined with an aeration blower retrofit currently underway at the Budd Inlet Treatment Plant, is expected to save LOTT more than \$228,000 per year in utility costs.

"The Numbers Don’t Lie". It’s a popular saying everyone has heard before, applied to a variety of situations – political statistics, figures backing up an athlete’s performance and budget data.

Thirty percent is a big number. Applied to the above scenarios, it could entail a landslide victory or a hitter gaining entry into the Baseball Hall of Fame. But just imagine, if the manager of a wastewater treatment facility were to trim 30 percent from their operating costs, he or she might also consider that a landslide victory of their own.

Since the cost of energy has dramatically increased during the past few years, it seems that energy audit companies have opened shop on more city street corners than coffee shops in Seattle. 

In addition to the mass numbers and abundant varieties of these energy savings promoters, there have been an equal number of energy audit articles written for the engineering magazines.

When it comes to conserving energy in compressed air nothing is sexier than a big, old, oil-free 300 horsepower variable speed drive air compressor coupled with a heat of compression dryer tied to an energy management system with all the trimmings. If you’re like me, it’s hard not to let out a manly grunt after reading that sentence.

A leading soft drink bottling manufacturer’s compressed air needs were threatening to exceed its Michigan plant’s compressed air capacity. Faced with the cost of buying a new compressor, the soft drink bottling manufacturer re-assessed their compressed air use to identify compressor and energy savings opportunities. In the audit, the soft drink bottling manufacturer identified the use of compressed air in a gap transfer as a source of compressed air and energy inefficiency.