Industrial Utility Efficiency    

Technology

According to the United States Department of Agriculture, more than 30,000 food and beverage processing plants across the United States employ more than 1.5 million workers.1 Each of those plants applies a wide range of processes to raw agricultural goods to produce consumable food and beverage products.

Air Compressors

By far the most important development in the world of screw type air compressors has been the introduction of variable speed control using electronic variable frequency drives (VFD’s). Systems that run with at least one air compressor at part load can almost always operate more efficiently if a well-controlled VFD is added to the system. But what if a system has two or more VFD units? This article discusses the challenges in controlling multiple VFD air compressors with some suggested solutions.

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.

Blowers

The plant upgrades, in combination with a progressive management strategy, allows the plant to consume less energy and reduce its reliance on outside contractors for biosolids removal, resulting in total operational savings of approximately $60,000 per year.  The plant is also positioned to efficiently manage the area’s wastewater for decades to come.

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.

Instrumentation

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.

Pneumatics

In this article, we discuss problems associated with static electricity in industrial manufacturing operations and how to effectively address them. At the atomic level, materials have a balance of positively charged protons in the nucleus and negatively charged electrons in the shell. Balance requires the same number of each.  A static charge occurs when that balance shifts due to the loss or gain of one or more electrons from the atom or molecule. The primary mechanism for this loss or gain, among several possibilities, is friction.

Vacuum

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.
A large pharmaceutical company needed huge flow rates of 30 psig air to aerate multiple fermentation processes which create food-grade materials.  Flow could vary from about 12,000 scfm to 35,000 scfm.  There were a variety of batch processes, mostly running independently.  An hour-by-hour schedule for anticipated air flow is developed every afternoon for the next day.  Based on that schedule, the boiler operators run the air compressors that can handle the load range for the whole day. In reality, the peak flow can be higher than anticipated.
Compressed Air Best Practices® Magazine interviewed Mr. Warwick Rampley, the National Sales Manager for Sydney (Australia) based, Basil V.R. Greatrex Pty Ltd. It’s not every day one is asked to deliver a system able to provide both a reliable compressed air dew point of -80°C (-112°F) and high purity nitrogen.  We work with some excellent technology suppliers and have engineered a rather interesting system.  Although our firm was founded in 1919, this application is one of the most demanding we’ve encountered. Basil V.R. Greatrex is a unique company as we focus only on compressed air measurement, compressed air quality and compressed air efficiency.
The Lafarge Cement Distribution terminal located in Winnipeg, Canada has significantly reduced the site electrical demand and energy charges by changing the way they transport their cement.  Two new low-pressure rotary screw air compressors have replaced two large high-pressure air compressors that previously powered their dense phase transport system.  The resulting power reduction has saved the company 46 percent in transport operating costs.
FABTECH 2016, North America’s largest collaboration of technology, equipment and knowledge in the metal forming, fabricating, welding and finishing industries, welcomed 1,500 exhibiting companies and a total of 31,110 attendees from over 120 countries last week to the Las Vegas Convention Center.
A centrifugal air compressor operates over a range of flows and discharge pressures. The operating performance curve is shaped by the selected individual internal components and affected by operating conditions such as inlet pressure, inlet temperature, and cooling water temperature. The process of dynamic compression, as applied in a centrifugal compressor operating stage, is velocity and kinetic energy converted to pressure and temperature as the flow is restricted. Another term for this process is mass flow – the power requirement to deliver the rated cfm of flow at the rated pressure (psig) is determined by the weight of the air.
Compressed air is dried to prevent condensation and corrosion which can disrupt manufacturing processes and contaminate products. Water is the primary promotor of chemical reactions and physical erosion in compressed air systems. A myriad of desiccant dryer designs have been devised to provide “commercially dry” air, air having a dew point of -40°F or less, to prevent corrosion.  Desiccant dryers use solid adsorbents in granule form to reduce the moisture content of compressed air.
IWF is largest woodworking technology trade show in North America and is held every other year at the Georgia World Congress Center in Atlanta, Ga. It is ranked among the largest trade shows in the world.
Quite often the typical variability in compressed air flow demand does not proportionately translate into power reductions at the air compressors. This can be a result of numerous problems with the compressed air supply system. It is important to understand the supply-side’s ability to respond to the demand-side of the compressed air system. If the air compressors, on the supply-side, are not able to translate flow reductions into energy savings, implementation of demand reduction projects should be re-evaluated.  
Optimal compressed air system performance, defined by efficiency, reliability and air quality, has now become the main goal when operating, installing, purchasing or designing compressed air products. Whether you are the air compressor manufacturer, distributor or end user - everyone in the compressed air industry needs to be aware and work towards these goals.
In general, this article focuses on the definitions of terms often used to understand centrifugal air compressor performance. Comments are also made on how to measure power consumption. This article is not intended to be an engineering discussion of the various types and designs of centrifugal and other air compressors.