Industrial Utility Efficiency    

System Assessment

While late summer may not be the time of year many of us think about heat recovery, the potential for energy savings in compressed air systems should be on our minds year-round. For those involved with the compressed air systems within International Wire Group’s facilities, energy savings is on their minds each day. This culture of continuous improvement has everyone on the lookout for savings wherever possible.

Compressor Controls

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.

Piping Storage

The company specializes in fabrication of precision assembled customized parts for OEM’s and system integrators. Since 1997 the company has steadily grown in size and capacity as the demand for its high quality fabrications has increased.  Through the years, many new CNC machines, laser cutters and powder coat painting operations have been added, but with all the expansion the facility has amazingly kept the plant compressed air consumption low. This has been achieved by following excellent “best practice” compressed air efficiency principles and by keeping watch on system waste.

End Uses

A chemical plant spends an estimated $587,000 annually on electrical energy to operate their compressed air system. In addition, the plant has an expenditure on rental air compressors of equal or greater size - but this will not be covered in this article. The plant was built in the 1940s and modernized in the 1970s. The plant generates its own power and serves many processes. The average cost per kWh is $0.0359.

Pressure

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.

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

Petro Chemical Energy, Inc. (PCE) specializes in energy loss surveys for the refining and chemical industries. We’ve been providing Compressed Air Leak Surveys, Nitrogen Leak Surveys, Steam Leak Surveys and Steam Trap Surveys – for over twentyfive (25) years. We operate totally independent of all equipment manufacturers to ensure our clients receive a complete and unbiased report of the leaks in their facility. PCE has conducted compressed air leak surveys for hundreds of customers at thousands of sites. Undetected, compressed air and gas leaks rob efficiency in manufacturing and processing industries. As a result, businesses lose millions of dollars annually in energy costs and lost production time.

Pneumatics

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.

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.
Compressed Air Performance Specialists (CAPS Inc.) is a compressed air consultancy located in Calgary, Alberta. In its most recent compressed air project, the company reduced a 200-hp, multi-compressor system down to a single, 100-hp variable speed drive (VSD) air compressor utilizing 75 hp of compressor energy (kWh), resulting in $70,000 in annual energy savings.
There is a partly true idea floating around some plant maintenance circles that “compressed air is free.” Readers of this journal know that isn’t true. But, what if non-compressed air could be seen as “free?” Is there something we can get for free from nature to reduce the cost of our compressed air? What if lower temperature intake air was nature’s gift? What if all we need is a bit of tin to duct air from a different source?
Replacing air compressors, dryers and filters with more efficient models has saved electrical costs and improved compressed air reliability at the Canada Bread plant in Winnipeg, Manitoba. In addition to this, plant personnel found some additional savings by reducing air leakage and eliminating inappropriate uses. As a result, the plant reduced its compressed air electrical costs by 58 percent and qualified for a utility incentive.
A major snack food manufacturer spends an estimated $148,220 annually on energy to operate the compressed air system at its food processing plant located in the Mid-Atlantic area.  As electric rates rise from their current average of 8 cents per kWh, their annual expenditure will only increase.
Cement production facilities have a significant number of dust collectors. Many have continuing problems with short bag life and low-pressure problems at the further points from the central air system. They often run on timers. When they try to run on demand control, they often get extreme short cycling, which causes even more bag problems. Most have gauges at the entry, on at least half of the dust collectors, and the compressed air feed lines are always the same size as the connector opening. This article reviews where these problems come from and provides some troubleshooting ideas.
As plant personnel know, repairing compressed air leaks can be an expensive, labor intensive and never-ending process. This article discusses ways plant personnel can reduce and maintain their leak rate at a lower level without repairing leaks. It discusses how pressure/flow controllers, variable speed and variable displacement compressors, automation, and addressing critical plant pressures allow plant personnel to lower the header pressure, which eliminates artificial demand and controls the leak rate. More importantly, the article brings a new dimension to the idea of turning off the air to idle equipment by focusing plant personnel’s attention on the idle time within the cycle of operating equipment.
Compressed air is often overlooked in energy studies. For those willing to look, however, it is a land of opportunity. Since it takes about 8 hp of electrical energy to produce 1 hp worth of work with compressed air, it is also particularly rewarding to evaluate and optimize the compressed air system in your facility. In this article, we evaluate four specific areas of a compressed air system that can provide significant energy savings.
In this article, we review the operating principles of both basic types of pulse-jet dust collectors — bag (sock), and reverse flow filter. We then examine the effects of various installation and accessory selection issues through several case studies, providing examples of how to fix the issues and optimize the system’s compressed air use.
Vale in Thompson, Manitoba, Canada has reconfigured a system of large turbo compressors in their mining, milling, smelting and refining operation and gained very large energy savings through a series of improvement projects. In addition, these projects qualified for some significant financial incentives from their local power utility.  Vale is a large multinational mining company with headquarters in Brazil.  Vale operations focus on the production of iron ore, coal, fertilizers, copper and nickel.  The Thompson Manitoba operations consist of mining, smelting, milling, and refining of Nickel in the 250 acre complex that employs 1,500 people.
Compressed air audits for chemical and petrochemical plants have many characteristics in common with audits in other industries, but there are some differences in the way these businesses run that impact the goals of the typical audit and how that audit is conducted. In chemical and petrochemical facilities, the reason for auditing the demand side is different than that of other industries. Additionally, there are frequently applications with opportunities for improvement that are not always seen in other industries.