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

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

An air receiver tank (sometimes called an air compressor tank or compressed air storage tank) is a type of pressure vessel that receives air from the air compressor and holds it under pressure for future use. The tanks come in a range of sizes and in both vertical and horizontal configurations. An air receiver tank provides temporary storage for compressed air. It also helps your compressed air system run more efficiently.

End Uses

For Imerys S.A. there’s little question about the importance of managing dust collection systems it uses to control and reduce harmful particulates in its worldwide minerals processing facilities. And now there’s zero doubt about the tremendous energy savings it stands to save by reducing the amount of compressed air needed for these same dust collectors.

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

Dew point is simply the temperature to which air must be cooled for the water vapor within to condense into dew or frost. At any temperature, there is a maximum amount of water vapor that the air can hold. This maximum amount is called the water vapor saturation pressure. If more water vapor is added beyond this point, it will result in condensation.

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.
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.
As many well know, system measurement is essential to ensuring a compressed air system is running efficiently and effectively, with good air quality and adequate pressure.  This is also well understood by a multi-national food company (name has been withheld to protect the innocent) who started a focused effort to measure and improve their compressed air systems in their many processing plants worldwide. 
Chicago Heights Steel, Chicago Heights, Ill., leveraged an advanced data monitoring system and adopted a demand-based compressor air management approach to save 2.5 million kWh and $215,037 per year in energy costs. With an incentive of $188, 714 from local utility ComEd, the project delivered a payback of 2.4 months.
As energy costs continue to rise it becomes increasingly important for industrial operations to reduce waste and inefficiencies wherever possible. It’s why an innovative company known as Lightapp has developed an intelligent resource management software platform to help manufacturers and other industrial users reduce energy consumption and save costs in the process.
In this ongoing column, we share insights into technologies that offer the opportunity to affordably and easily lower compressed air use and generate energy savings – all while achieving relatively quick payback. But finding these technologies on the production floor isn’t always easy or straightforward. In fact, there are many times when a technological solution is far less than obvious. Such is the case with cooling of control enclosures, which represent a significant area for high-energy savings with little upfront investment. Here is some out-of-the-box thinking…  check that… inside-the-box thinking… for optimizing control of enclosure cooling and coming out ahead.
Spruce Products Limited operates with five separate compressed air systems in their various buildings. A few years ago a sharp-eyed air compressor service representative noticed the screw compressors on site had less than optimal loading to operating hours ratios. Recognizing this was a problem, he suggested the company get in touch with their local power utility for a free compressed air scoping assessment. As a result, SPL has optimized two of their compressed air systems to-date, saving significant operating costs. One system is operating at 86% less energy consumption than previous levels.
As consumer awareness of the attributes of aluminum tubing have driven its popularity, so have a swell of additional well thought-out questions.  One question is asked with regularity, “What is done to protect the inside of the tubing”? Even though most all aluminum compressed air piping systems feature a painted or powder coated exterior, the interior of the tubing has no coating.
When the 18th Century Italian physicist Giovanni Venturi discovered when air is forced through a conical nozzle its velocity increases as the pressure decreases, neither he nor anyone could conceive it would ultimately spawn one of the most used and most highly controversial products in the industry today- the Venturi vacuum generator (aka, ejector).
A flour based frozen foods manufacturer orders a compressed air efficiency audit. The audit establishes the cost of compressed air at $0.27/1000 cubic feet. The study finds the 116 pulse jet dust collectors represent the greatest opportunity for compressed air demand reduction and energy cost savings. A dust collector optimization study/service is suggested and the customer agrees to proceed. In this facility, pulse jet dust collectors are used to filter dust from raw materials entering the plant, for conveying and mixing of ingredients, and for the final packaged finished products leaving the plant.  
In the last ten years, the design of pneumatic systems has changed dramatically, mainly due to developments in the technologies that create them. Pneumatic manufacturers’ online tools for sizing components have evolved, the fieldbus systems are ever-changing, component designs are constantly improving, and network devices such as the Industrial Internet of Things (IIoT) have reshaped the industry. All these advances play a large role in optimizing the efficiency of pneumatic systems, but the age-old practice of routine maintenance must not be overlooked. This article will focus on proper air compressor sizing, proper pneumatic component sizing and predictable preventative maintenance.