Industrial Utility Efficiency    


Introduced in the 1960s and operated successfully worldwide, the Heat of Compression (HOC) Desiccant Dryer has been a viable and successful compressed air drying technology for over 50 years.  In our ongoing series on missed-demand opportunities, we’ll discuss basic operating parameters of HOC dryers and shed light on common misperceptions associated with the technology.

Air Compressors

After getting its start manufacturing cost-effective products to the healthcare industry, 40 years later, 1888 Mills has become the fourth largest towel manufacturer in the world, and the largest towel manufacturer in the U.S. With facilities in the United States, Pakistan and Bangladesh, 1888 Mills’ towels are used in almost every corner of the world. 1888 Mills is recognized as a leader in innovation in the textile industry and produces 176,000 pounds of towels per week.

Air Treatment

In modern and industrial work settings, people spend more than 90% of their time in enclosed spaces, such as warehouses, office buildings and factories. In most indoor environments, the air contains a variety of chemical and microbial particles, commonly defined as indoor pollutants, which can severely affect human health and product quality (1). Industries like food and beverage, medical devices and pharmaceutical manufacturers rely on their scheduled compliance testing to confirm the presence or absence of issues in workflow pipelines that are detrimental to the daily output and safety of the product.


High speed bearing technology is applicable for aeration blowers operating at much higher speeds than the typical 60Hz, 3600RPM for cast multistage units. High Speed Turbo (HST) units are usually single stage (though some utilize multiple cores) and rotate from 15,000 to 50,000RPM. At such high speeds, standard roller bearings cannot offer the industry standard L10 bearing life. Two types of bearing technologies have come to dominate the wastewater treatment market for these types of machines: airfoil and magnetically levitated. Often the two technologies are compared as equals, however, in many significant ways they are not.

Compressor Controls

Often, multiple centrifugal air compressors are set up to simply react to air demand, which requires the system to not only meet the new demand, but also make up for air depleted in the main header. This typically results in too much supply, which results in bypassing the air to atmosphere. The result is wasted energy use.


In terms of compressed air systems, it’s not unusual to see a plant with 10 to 15 air compressors, each of which is rated to provide 3,000 to 4,000 scfm of air. The air is used for everything from moving product, to powering pneumatic tools, pumps, and fans, to cleaning. There are easily 1,500 pneumatic control valves at a single plant.


For more than 20 years, Hungarian-based Doroti Pack Ltd. has specialized in the production and servicing of state-of-the-art packaging machines. Their focus is on developing, manufacturing, producing and selling premium-quality packaging equipment, including their line of DorPack thermoforming machines which are often used for food products such as fresh meat, fish, dairy products, bakery ware, confectionery and ready-cooked foods. Dorati Pack chose to incorporate Aventics pneumatic components in latest thermoforming machine for optimal productivity and machine longevity.


It’s one thing to move materials during the production process, but when it’s a finished product on the packaging line, choosing the right material handling system is essential. Getting it wrong results in squandered production time when product loss occurs, and wasted raw materials.

Cooling Systems

As a result of compressed air awareness training and a focus on energy management, two facilities in different parts of the world have reduced their compressed air demand substantially by removing vortex style cabinet coolers from some of their electrical panels and reworking the cooling systems.  These facilities were previously unaware of the high cost of compressed air and how much could be saved if other methods of cooling were used. This article describes some of their efforts in demand reduction.
The project, which also involved the addition of a booster air compressor and receiver tank – along with the installation of an important pressure control valve – gives the automaker the ability to run fewer centrifugal air compressors during peak production. In so doing, the plant saves nearly 6.1 million kWh and more than $600,000 per year in energy costs. The project also qualified for a $369,374 rebate from the local utility, resulting in a six-month project payback – all while improving system reliability.
The compressed air system at the mail sorting facility has been in service since the 90’s. Two older 50-horsepower (hp) air-cooled fixed-speed lubricated air compressors are housed in the equipment room of the facility. The air compressors duty cycle alternates between one another on a set schedule. A 240-gallon wet storage receiver is used to help with air compressor control, with the air flowing through the receiver to a non-cycling refrigerated air dryer and system filters before finally being passed to the plant.
A chemical packaging facility had done everything right when they last upgraded their compressed air system a few years ago. They installed a Variable Speed Drive (VSD) air compressor and implemented other energy efficiency measures, but plant expansions caused increased system demand, which exceeded the capacity of the system. The packaging lines were now seeing low pressure, causing shut downs in production. And projections showed plant demand would increase even further.
Long gone are the days when cost and performance could be the only concern for companies manufacturing refrigerated compressed air dryers using refrigerant compressors. In 2019, accelerated governmental (Europe) regulations and a global concern for sustainability have brought new considerations to the table. What is the Global Warming Potential (GWP) of the refrigerants used in dryers and what is their environmental impact?
Brewing is normally broken down into four stages-malting, mashing, boiling and fermenting. The complex chemical processes begin with a few simple ingredients - hops, grain, yeast and water. Recently there have been technological advancements to safeguard that these steps are attained accurately, efficiently and with cost-savings. One particular improvement is the use of nitrogen during the brewing process. The addition of an onsite nitrogen generator allows brewers to reduce their nitrogen costs, eliminate downtime, and reduce safety risks related to bulk gas cylinder delivery and changeouts.
Experienced auditors become wary when they see desiccant dryers installed in customers’ plants. These dryers are required when a plant needs instrument-quality compressed air, or when compressed air piping is exposed to freezing temperatures. However, while desiccant dryers can gain this level of quality, the energy cost of stepping up from a dewpoint of 35 oF to a level of -40 oF increases quite considerably. To attempt to reduce the energy costs of drying to these low levels, heated blower desiccant styles may be used. This article describes three common desiccant dryer types, as well as some experiences, good and bad, with heated blower types.
Compressed Air Best Practices® interviewed Sang Woo Lee, CEO of Coaire Corporation. I had enough experience with compressors used in refrigeration to see there was a lot of area for growth, particularly with scroll technology given that its an oil-less air compressor in addition to its efficiencies, noise level and ability to offer customers longevity. I also liked that Coaire has a long history of innovative air compressor technology. In 1968, it became the first Korean company to develop and manufacture a reciprocating air compressor. Later, it became the first Korean manufacturer of rotary screw air compressors, which occurred after it established ties with SRM to develop unique airend technology.
In most industrial plants, data is everywhere. It resides in flow through pipes, pressure in tanks, vibration on rotating equipment, temperatures in heat exchangers, and electrical energy power consumption in motors. If we can acquire this data and make sense out of the patterns we can take actions to make our plants more efficient and reliable.
To address a mandate for cutting operations energy usage at facilities by 25 percent without major capital expenditures, a major manufacturing company set its sites on better control of its compressed air systems.  The project, implemented at 10 manufacturing plants over the course of three years, saves the company $977,093 annually in energy costs – and was completed with zero out-of-pocket costs.
Held September 16-19, 2018 in Chicago, the first-ever event drew 750 attendees who came together to learn and share ideas about the countless ways to achieve efficiencies with compressed air, blower, vacuum and cooling systems – and in the process – save energy and improve profitability.