System Assessments

To produce healthy, high-quality cooking oil, this food processing company crushes and processes oil seeds shipped in from local farms. The oil produced is thought to be the healthiest cooking oil available, because it is low in saturated fat, high in monounsaturated fatty acid (MUFA), and polyunsaturated fat (PUFA), like omega-3 fatty acids. To increase the energy efficiency of its oil seed crushing and processing facility, the company optimized its compressed air system by combining three separate systems into one. Some end-use optimization was done to correct low pressure, particularly caused by some critical high-flow, short-duration events.

Technological trends in plastics manufacturing are driving the costs of production down. In industrial PET blow molding specifically, two innovative techniques have had major impacts over the last 15 years: “light weighting” the plastic bottles, and recirculating high-pressure compressed air. Both have helped to improve the energy efficiency of PET blow molding by reducing compressed air requirements dramatically.

PET Power Containers, a Canadian manufacturer of PET plastic containers, had plans for expanding its operations with the addition of more blow-molding equipment. Before the expansion could happen, however, the company needed to assess its compressed air system. Based in Vaughan, Ontario, PET Power provides a dizzying array of differently shaped and sized plastic bottles. Their operations run 24/7, and compressed air plays a key role in their primary manufacturing applications, including PET blow molding, PET preforming, and labeling bottles.

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.

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. 

Air-operated double diaphragm (AODD) pumps are common to many manufacturing facilities. As estimated by veteran compressed air auditor Hank van Ormer of Air Power USA, approximately 85 to 90 percent of plants in the United States have AODD pumps. They are used for all kinds of liquid transfer applications, like those found in chemical manufacturing, wastewater removal, and pumping viscous food products.

There is always something new to learn about compressed air systems – particularly in regards to compressed air dryer installations. As I discussed in Part 1 of this series, you can make compressed air dryer installations more reliable by understanding the consequences of any modifications you make to the system.  As a continuation of those ideas, Part II explores more ways to make a dryer installation more reliable. Discussions include: the difference between operating a desiccant dryer in a fixed cycle opposed to demand mode, what happens when you operate a heated desiccant dryer with the cooling air turned off, and how to deal with the unintended consequences of dedicating a desiccant dryer to a compressor. 

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.

Compressed air is used in more than 70 percent of all manufacturing activities, ranging from highly critical applications that may impact product quality to general “shop” uses. When compressed air is used in the production of pharmaceuticals, food, beverages, medical devices, and other products, there seems to be confusion on what testing needs to be performed.