UniFirst is one of North America’s largest workwear and textile service companies. They outfit nearly two million workers in clean uniforms and protective clothing each workday. Founded in an eight-stall garage in 1936, the Company has grown to 240 customer servicing locations throughout the U.S. and Canada servicing 300,000 business customer locations. The subject of this article is an energy-saving Air Demand Analysis (ADA), conducted by Kaeser Compressors, at UniFirst’s centralized 320,000 square foot hub Distribution Center located in Owensboro, Kentucky.
MHPSC Canada is a large facility specializing in machining and manufacturing large pieces for power generation (gas turbines, large hydro, wind) and deep sea oil and gas operations. Smaller machining and manufacturing are also done in the facility, as well as welding and piping fabrication. MHPSC purchased flow meters for two systems, the Large and Small Machine Shops, to measure the total compressed air production. Since the two systems have piping that is physically close together, it was felt that there was an opportunity to tie the two systems together to save energy. The readings showed that the compressed air demand was indeed low enough in the two systems to enable a 100 hp VFD compressor to feed the combined systems.
Compressed air optimization measures adopted by PTMSB have reduced the consumption of compressed air by 31 percent resulting in savings of about 3,761,000 kWh per year in energy consumption. The monetary savings are MYR 1,090,627 per year ($255,000 USD). The CO2 reduction is estimated at 2,735 ton per year.
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.
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.
A Canadian fiberglass plant has completed a lengthy compressed air improvement journey and achieved significant efficiency gains by applying “the systems approach.” Along the way, the company ran across many frustrating problems, the solutions to which were only determined after the entire system was monitored holistically using data loggers. The overall compressed air audit led to a reduction in energy usage of 48 percent, yielding savings worth $17,500 per year. The project also qualified for a large utility incentive of $32,000 with a calculated payback of 4.4 years.
One of the statements made in the Compressed Air Challenge’s Fundamentals of Compressed Air Systems seminar is that improvements can always be made to every compressed air system, including new ones. The statement definitely applies to a Canadian pork processing facility built a few years ago. This article is based on a compressed air audit performed two years into the life of a brand new plant. The audit found numerous problems and made recommendations that helped reduce plant compressed air operating costs by 60 percent.
Ahresty Wilmington Corporation (AWC) was founded in 1988 and is located in Wilmington, Ohio. Currently AWC employs over 900 people with sales totaling $192 million. They have grown steadily, all while continuously improving and staying on the leading edge of technology. AWC is a tier-1 automotive supplier servicing their entire customer base in the United States. AWC has established an efficient and integrated production system that incorporates die-casting, finishing, machining, and assembly operation using just-in-time production methods to provide its customers with quality products at a competitive price.
Compressed air has moved to higher visibility in the energy conservation field, and the buzzwords abound: “the fourth utility” — “your most expensive utility” — “eight times more expensive than electricity” — “a quarter-inch leak costs $9,000 in wasted energy.” This greater awareness has also produced compressed air auditors that are springing up like summer dandelions. With audits available from many sources, it is important to understand what plant operations, engineers and maintenance managers should expect from a complete audit — or more aptly — a complete air system review.
As a reader of this journal, you are well aware that large compressed air systems often have significant wasted air — often from leaks — that represent tens of thousands of dollars of waste per year. However, it is our experience that the so-called “low-cost” measures identified often go un-repaired, while other more costly capital projects get funded. Why? With an ROI of a half year or less, they seem like IQ tests to many compressed air auditors.