Instrumentation

Pressure regulators are everywhere compressed air is used. These simple devices, essential for safe and steady equipment operation, can be a big waster of compressed air. This article shows how with proper regulator selection, installation and setting management you can save compressed air and lower system pressures. This article looks at regulators on production equipment not central regulators or Process Flow Controllers.

Sometime in mid-2015, I received a call from a project engineer at a major plastics firm. He had a troubling issue with one of his PET bottle plants. The bottom line was this: They could not run all five high production blow-molding machines at one time—even though they were able to do so 18 months previously.

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. 

A modern dairy without compressed air is nowadays no longer imaginable, and it is used primarily for driving control units and machinery. Approximately 60 percent of the compressed air generated is used for packaging lines. However, compressed air is one of the most expensive energy sources in dairies. Even in carefully maintained compressed air systems, about 20 percent of the generated energy is lost through leaks. In particular, vacuum leakages in separators result in high energy losses. A small leak can cost up to several thousands of Euros a year.

In recent years, we have seen an upward trend of higher production manufacturers wanting to integrate their air gauging quality checks from a stand-alone, outside-of-machine device where the operator is performing a manual check to an automated in-process gauge. There are several reasons for this trend, including higher quality standards, tighter tolerances, as well as running a leaner operation. The benefits are 100 percent inspection of the required geometric callout, as well as handshaking between measuring device and machine to make each piece better than the prior one. It also removes any bad parts.

A major Midwestern aluminum plant was experiencing dwindling compressed air capacity, primarily due to air leaks. If those capacity issues went unresolved, the facility would have needed rental compressors to keep up with demand. Instead, they turned to flow metering to identify and fix the leaks. In this article, they share their solutions with others who may be having similar difficulties.

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.

“Jurassic Park,” Michael Crichton’s 1990 novel about a theme park full of genetically engineered dinosaurs, circles around one central theme — control. In fact, there are literally nine chapters titled “Control,” and most of those chapters follow the brilliant, chain-smoking systems engineer John Arnold as he ravenously tries to restore the control systems after a catastrophic collapse.

A common adage that has been quoted many times in this journal is: “If you don’t measure it, you can’t manage it.” This is partly true. It assumes that managers are willing and able to manage the costs and reliability of their compressed air system. Without data, however, they can’t do an effective job. But because managers are at times already overwhelmed with data, more data doesn’t automatically make them a better manager. A better way of saying it is: “Appropriate measurement can make you a better manager.”

Plug an electrical device into an outlet. Does it work? Great! For some people that’s all that matters. When it comes to compressed air, many manufacturing plants operate the same way. As long as there is enough air, that’s all that matters.

But what if cost control also matters to your company? Smart compressed air users may already know how much air they’re producing, but they also want to know how much air they’re using—and whether they’re using it productively. To find out, they’re taking accurate, real-time measurements using flow meters.