Industrial Utility Efficiency    

End Uses

There are a tremendous variety of unique and creative ways people in the food industry have overcome their need for compressed air blowoffs used for cleaning, drying, cooling, conveying and overall processing. You may have seen some of them yourself. It is not uncommon to view open copper tubes, pipes with a crushed end, plugs or caps with holes drilled into them, modular flex coolant lines or nozzles designed for liquid application but blowing air.
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.
A comprehensive compressed air system analysis should include an examination of both air supply and usage and the interaction between the supply and demand. Auditors typically measure the output cfm of a compressed air system and the input kW, calculate energy consumption in kilowatt-hours, and determine the annual cost of operating the system. The auditor may also measure total air losses caused by leaks and locate those that are significant.
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.
With energy cost increasing at 7.5% per annum for the past few years, most facilities managers and maintenance professionals are looking for the best opportunities for excellent return on investment projects, which can drive their operating costs in the opposite direction. Compressed air is an area where significant improvements are readily available.
A basic element in the Compressed Air Challenge® (CAC) philosophy is that compressed air system optimization should be addressed using the “Systems Approach”. This method recognizes that improving and maintaining peak compressed air system performance requires addressing both the supply and the demand sides of a system and understanding how the two interact. “The road to energy efficiency involves more than just fixing the leaks,” says Ross Orr, an experienced auditor with Scales Industrial Technologies and a certified CAC instructor.
Perhaps your facility recently had a compressed air system survey, conducted by an air systems services company, that resulted in a couple of major recommendations, such as:  • Install a new smaller compressor and new control systems on all of the units • Repair the many air leaks (identified as 30% of your system capacity)  
This factory currently spends $735,757 annually on the electricity required to operate the compressed air system at its plant. The group of projects recommended in the system assessment will reduce these energy costs by an estimated $364,211 (49% of current use). Estimated costs for completing the recommended projects total $435,800. This figure represents a simple payback period of 14.4 months.
Compressed air leaks - every system has them.  Is a leak identification and control program economically rewarding and/or necessary? Upper management sometimes doesn’t recognize the true cost of not repairing air leaks.  Knowing the high cost of compressed air, why wouldn’t every facility with a compressed air piping system implement a continuous leak identification and repair program?
The snack food facility is running with two normally separated compressed air production systems: the main plant system and the nitrogen system.