Industrial Utility Efficiency    

System Assessment

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.

Compressor Controls

It was early summer, the air compressors were above the production floor on a mezzanine, and temperatures were heating up both outdoors and indoors. The compressed air system was comprised of three 500-horsepower centrifugal air compressors, and one 350-horsepower variable speed drive oil-free rotary screw air compressor.

Piping Storage

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.

End Uses

Plant personnel had experienced ongoing problems with its process grinder performance due to unstable compressed air pressure. This created potential problems in terms of product quality. Grinders do not work properly without the proper pressure. Additionally, plant staff wanted to address these concerns, prior to a proposed 30% increase in production, and suggested raising the header pressure from the current operating pressure of 98 psig to 125 psig. The thought behind this was if the pressure from the header to the grinder process was dropping to 63 psig, then raising the pressure to the process would give the grinders enough pressure to work through higher peak production times.  

Pressure

A food processor was having compressed air problems, so they invited a compressed air auditor into their plant for an assessment and to help them size future permanent air compressors. The plant was experiencing low air pressure and detecting water in the compressed air lines despite having a desiccant air dryer. The auditor thoroughly analyzed the compressed air system production equipment and did end-use assessment and leakage detection. This article discusses the findings leading to a potential cost savings of 52% of the current level.

Air Treatment/N2

This plant has three production lines producing snack food. Depending on the time of year and production demand the plant can operate anywhere from no production lines to all three production lines. A thorough supply and demand-side system assessment was done at this plant. This article will focus on some recommended demand-side reduction projects including nitrogen generation, air vibrators, leaks and vacuum venturis.

Leaks

So you’ve purchased an ultrasonic leak detector after a sales person gave you a demonstration on detecting compressed air leaks. You’ve read all those articles on how air leaks are wasteful, expensive and leakage programs provide good paybacks. Perhaps you’ve even had a go at a leakage survey. Either way, by now you’ve realised leakage programs are not as simple as they sound and without an ongoing plan of attack, you will probably never see the results you thought you could achieve. This article is written to illuminate common mistakes made in leak surveys and hopes to provide guidance on how to turn that around.

Pneumatics

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.

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.
Technology is available which enables a compressed air flow meter to measure not only the magnitude of the flow, but also the direction. Why is this important? In this article we will describe two case studies where bi-directional compressed air flow measurement plays a key role to come to the right conclusions. In the first case study, we will describe an electronics manufacturing plant, which has a large interconnected ring network with two air compressor rooms located in different buildings. The two air compressor rooms are about five hundred feet apart. In the second case study, the effect of compressed air flow measurement upstream of a local receiver tank is described.
The objective of this project is to help the building automation industry develop novel products that more cost-effectively identify faults (unwanted conditions) and inefficiencies in the operation of the compressed air plants of industrial facilities.  More cost-effective fault detection and diagnostics (FDD) products can come to the building automation marketplace only after that industry makes very significant advances in the state-of-the-art of its FDD software tools from what it currently offers.  Those advances require making common practice of rules-based artificial intelligence (AI) methods that the building automation industry has shown little to no familiarity with in its technology so far.  This project will utilize, under controlled conditions, the compressed air plant of the NIST campus as a facility for test and development of an embedded rules-based FDD tool based upon NIST expertise.
As a result of compressed air awareness training and a focus on energy management, two facilities in different parts of the world have reduced their compressed air demand substantially by removing vortex style cabinet coolers from some of their electrical panels and reworking the cooling systems.  These facilities were previously unaware of the high cost of compressed air and how much could be saved if other methods of cooling were used. This article describes some of their efforts in demand reduction.
When a successful Midwestern United States-based packaging company reached out to Cleveland, Ohio-based Diversified Air Systems, Inc. (Diversified), it was simply looking to fulfill its need for backup air. Compressed air is a vital component of the packaging company’s business, used for a variety of purposes, such as in its corrugating machines, conveyors, actuators, and more. In the end, the company received much more than just air redundancy, including a new variable speed drive, two-stage air compressor, a completely reconfigured and upgraded piping system, improved system efficiencies, energy savings, and a significant energy rebate.
In aerospace manufacturing, tiny details matter most. For instance, if proper torque is not applied to the screws and bolts fastening an aircraft fuselage, catastrophic failures can result. Compressed air is used to power the tools needed to apply that torque, making the compressed air system a critical part of the facility, though it largely stays behind the scene.
During an Energy Review at a relatively new health care garment factory, in the Southwest, we found all three of the 100 psig nominally rated rotary screw air compressors were operating at 115-120 psig continuously. We asked the Production Superintendent if this was normal or if something had recently changed. He explained that initially they operated two air compressors but had to begin running the 3rd unit in ‘trim’ mode after some converting machines were up-graded. Then, a new larger converting machine was recently installed and air pressure quickly became a production issue. Since capital funds were tight, the project engineering team determined the third air compressor had sufficient capacity.  
Energy, in all forms, has always been a key Lantech focus. It was, in fact, a key element of the core packaging problem the company’s founders set out to address. They saw an opportunity to capitalize on an inexpensive and under-used resource – stretch film – to displace a high materials cost and energy intensive way of unitizing pallet loads of products – shrink bagging.
Figuring out the energy savings for the switch from pneumatic to electric tools requires an estimate of energy use for each case. The effect of replacing a few tools in a large compressed air system may be too small to detect using power monitoring on the air compressors. However, it is still a good practice, and when part of a larger program to reduce air consumption, the combined efforts will amount to something measurable. Another positive aspect may be that reduced compressed air use frees up needed air compressor capacity.
A large fabric mill has implemented an energy management system based on the ISO 50001 standard to track their compressed air system efficiency.  As a result of information gained from this system, and measures learned in some recent compressed air training, the company has reduced their compressed air system costs while at the same time achieving increased fabric production output. The savings were gained by not only optimizing the supply side of the system, but by also addressing the end uses.
A Canadian chemical plant installed a large heated blower-purge style compressed air dryer, years ago, to condition the instrument air system against freezing temperatures.  The dryer selected was oversized for the connected air compressors and had unused on-board energy savings features.  A compressed air assessment revealed the site air compressors and compressed air dryers were running inefficiently and causing in-plant pressure problems.  Repairs to a compressed air dryer and the replacement of aging air compressors and dryers has reduced compressed air energy costs by 31 percent.