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.
Maintenance is the customer of controls and energy engineering is the customer of monitoring. And I discussed potential problems that can occur when combining monitoring and control in the same system. In this article, I will get more specific about building practical systems that address both controls and monitoring.
Launched in 2006, the TTU-IAC program provides manufacturers in the state with free energy, productivity, and waste assessments – including best practices for compressed air systems, and blowers and vacuum, as well as cooling towers and chillers. The assessments to date have provided manufacturers in the program with $27.48 million in recommended cost savings, equaling 3.82 trillion British thermal units of energy savings.
This article reviews the benefits and design considerations of controlling system pressure from the air compressor room to the production headers and selected production processes and areas. Over the last several decades, the phrase “demand-side control” has become the generic term to describe establishing a “flat line” header pressure using proper storage and an appropriate pressure regulator, or “pressure flow controller.” Use of a demand-side controller to control pressure and flow can be implemented at the entry to the production area header(s) and at selected production areas or processes.
In a strategic approach to improving its management of compressed air, the company initiated an upgrade of its compressed air system at its Midway plant. In so doing, SumiRiko Tennessee saves 2.1 million kWh and $100,000 in energy costs per year at the plant.  Additionally, lower energy use resulted in the reduction in CO2 of 800 tons per year. With a utility rebate, the project paid for itself within two years.
Many OEMs of air compressors, dryers, sensors and master controls are integrating monitoring features and capabilities into their components. It would seem a no-brainer to keep it simple and use those sensors and systems for both control and monitoring. What could be simpler? 
By far the most important development in the world of screw type air compressors has been the introduction of variable speed control using electronic variable frequency drives (VFD’s). Systems that run with at least one air compressor at part load can almost always operate more efficiently if a well-controlled VFD is added to the system. But what if a system has two or more VFD units? This article discusses the challenges in controlling multiple VFD air compressors with some suggested solutions.
Compressed air represents one of the largest opportunities for immediate energy savings, which accounts for an average of 15% of an industrial facility’s electrical consumption. In fact, over a 10-year period, electricity can make up 76% of the total compressed air system costs. Monitoring compressed air usage, identifying compressed air waste and inefficiencies, and making investments in new compressed air equipment – including piping – are tangible ways businesses can cut their operating costs by lowering their electricity bill.
The advent of manifold-mounted, plug-in pneumatic valves has been a boon for machine builders. It allows them to mount complete valve packages in a safe and secure location on a machine. Using a D-sub connector, serial interface module, or similar single-point wiring system, all of the electrical control outputs can feed into one location on the manifold, greatly simplifying the wiring.
Baseline measurements include flow, power, pressure, production output, and other relevant variables impacting compressed air use. These data evaluate trending averages to develop Key Performance Indicator (KPI) and Energy Performance Indicator (EnPI) parameters and establish base‑year performance. The focus of this article is the application, evaluation, and analysis of baseline measurements to provide information necessary to improve Compressed Air Supply Efficiency.
The project, which also involved the addition of a booster air compressor and receiver tank – along with the installation of an important pressure control valve – gives the automaker the ability to run fewer centrifugal air compressors during peak production. In so doing, the plant saves nearly 6.1 million kWh and more than $600,000 per year in energy costs. The project also qualified for a $369,374 rebate from the local utility, resulting in a six-month project payback – all while improving system reliability.