Industrial Utility Efficiency    

System Assessment

One of the most satisfying parts of being a compressed air system auditor is resolving compressed air system reliability issues. This article exposes a seldom, if ever, mentioned problem that can occur when air dryers are dedicated to air compressors. It examines a real-world application and discusses the action taken to remedy the situation.

Compressor Controls

In the absence of the control system, the air compressors were loading and unloading according to pre-set pressure bands, which forced the system to operate at higher pressures and run inefficient combinations of compressors in order to effectively match air demand. When switched on, irrespective of air demand, the control system was able to control all compressors on a single, tight pressure band and efficiently match output with demand.

Piping Storage

This article will focus on the suitability of plastic pipe systems as well as joining methodology in compressed air applications. 

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.

Pressure

Most industrial systems like compressed air have essentially random demand if you look at the long-term life cycle of the system. Hundreds, even thousands of independent small and large subsystems require constant or varying flow. These demands are typically not timed or synchronized with each other, so they aggregate to a fairly random flow profile, within a range. That range changes significantly when production processes change. Certainly a 2-week audit might show some patterns that appear predictable for demand A (“production”) and demand B (“non-production”) or day type, but they change over time as the plant adapts to new production systems and removes old ones. If demand was that profile forever, a lesser experienced auditor might be tempted to size one set of compressors that work perfectly for that profile but not for alternates.

Air Treatment/N2

Regular testing of pure gases helps to ensure the safety of consumers and of end products. Whether the pure gas is used directly for medical patients, or in the manufacturing of food, beverages, or pharmaceutical products, quality is of the highest importance. Inadequate levels of purity or unsafe contamination can be detrimental to the products or consumers.

Leaks

Awareness and interest in leak detection only continues to grow thanks to a number of factors. What we have seen over the last 20 years is a more sustainable way of thinking, established international energy efficiency standards, reliable leak detection technology, and best practices to implement leak detection.

Pneumatics

In manufacturing and packaging facilities that rely on pneumatics, there’s a four-letter word worse than virtually any other: leak. Unidentified air leakage and unexpected maintenance in pneumatic systems are significant sources of revenue and productivity loss but identifying the cause of leakages and preventing unforeseen downtime is typically a challenge.

Vacuum Blowers

Every municipality and utility is facing the reality of rising energy costs. In 2010, the Town of Billerica, MA, which is located 22 miles northwest of Boston with a population of just under 40,000 residents, engaged Process Energy Services and Woodard & Curran to conduct an energy evaluation of the Town’s Wastewater Treatment Facility (WWTF) and pump station systems sponsored by National Grid. The objective of the evaluation was to provide an overview of each facility system to determine how electrical energy and natural gas were being used at the facility and to identify and develop potential costsaving projects.
In most industrial plants, data is everywhere. It resides in flow through pipes, pressure in tanks, vibration on rotating equipment, temperatures in heat exchangers, and electrical energy power consumption in motors. If we can acquire this data and make sense out of the patterns we can take actions to make our plants more efficient and reliable.
On a recent project, at a polyethylene terephthalate (PET) blow-mold and filling operation, a very effective measurement plan resulted in a full synchronization of the supply side air to blow molds with significant reduction in total air use and increases in productivity and quality.  
To address a mandate for cutting operations energy usage at facilities by 25 percent without major capital expenditures, a major manufacturing company set its sites on better control of its compressed air systems.  The project, implemented at 10 manufacturing plants over the course of three years, saves the company $977,093 annually in energy costs – and was completed with zero out-of-pocket costs.
By finding a better way to control and manage its compressed air system, North American Lighting, Paris, Ill., has reduced its total compressed air energy use by 27 percent – and in the process – saves over 1,100,000 kWh/year for a total annual savings of $91,000. The project also achieved a payback of less than one year.
A food processor in Western Canada hired an auditor to assess the energy efficiency of its compressed air system. The results revealed surprises about the operation of some important elements of the system, and detected that the air compressors were having control gap problems. Additionally, the audit led to initial energy savings of $20,000 – and identified the potential to achieve overall operational savings of 45%. The following details some of the audit findings and results.
Machines for filling milk or juice must often work around the clock. Given the critical importance of uptime, Elopak opted for Aventics food-compliant pneumatics when developing its E-PS120A - the first fully aseptic filling machine for gable top packaging. With an output of up to 12,000 cartons per hour, disruptions and downtime are not welcome with the aseptic filling machine.
Whenever we start a compressed-air energy survey there are always two key topics plant personnel feel are paramount – leaks and reducing pressure. In this installment of our series on missed demand-side opportunities we’ll address the importance of compressed air system pressure.
The University of Manitoba Bannatyne Campus, Canada, upgraded its compressed air system to include variable speed drive (VSD) air compressors and the use of internal heat-of-compression (HOC) drying, replacing oil-free air compressors and refrigerated dryers that reached the end of useful life. In doing so, the campus reduced annual energy consumption by 15%, improved the quality of the compressed air to modern day instrument air standards and gained additional compressed-air capacity. The local utility also awarded the medical campus an incentive of $13,500, offsetting the cost of the initiative.  
Replacing unreliable air compressors is often a smart choice. Sometimes there is a better one. Take the case of a wallboard plant with two compressed air systems, including one for its board mill and another for its rock mill. Each had two 100 horsepower air compressors, all of which constantly overheated. When they did, plant personnel had to scramble to turn on a machine manually every time a unit shut down. Three units ran the plant so any shutdown had them walking on pins and needles.
Air Operated Double Diaphragm (AODD) Pumps are popular and versatile. Often, they also offer an excellent opportunity to lower the demand for compressed air, especially given the latest advances in controls and the energy savings to be realized.