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.
Larger air compressors, typically over 500 hp, in refineries, pulp and paper plants, chemical and other processing plants often have high-speed, multi-stage air compressors called “centrifugal” air compressors. As seen from a total system perspective, they are not much different than screw air compressors. They compress air to plant pressure from atmospheric conditions, and deliver it to the dryer. These types of air compressors have no internal wearing parts, besides bearings and seals, and are very reliable and efficient, at their best efficiency point. 
Knowing when to overhaul a unit is important, and there are certain signs indicating a unit needs attention. Performing routine fluid checks, taking oil samples and routinely checking for bearing vibration can unveil indicators suggesting an upcoming failure. Oil contamination with metal fragments usually indicates parts are wearing. It’s also important to take notice of airend temperature increases. If internal air compressor temperatures go up, it’s a good indicator the cooler may be failing.
When a system has the right combination of VFD and base-load air compressors, how do you coordinate their control? What tells the air compressors to run and load, to have just enough (or no) base-load air compressors and a VFD running, all the time air is needed? Appropriate master controls are needed. These controls are often called “sequencers” or “master control systems”.
It is becoming a “best practice” to install a variable frequency drive (VFD) air compressor whenever one is replacing an old air compressor.  As a result, real systems have fixed-speed and VFD air compressors, mixed.  I have observed several VFD compressor sizing methods.  In my last article, I referred to a common method: size one VFD compressor for the whole system.  This can work.  However, if it doesn’t meet a higher peak demand, one or more of the old compressors will be started, and a mixed system results.   Another method is to replace a compressor with the same size, but with a VFD.  If the compressor that was replaced is large, a big VFD is installed.  If small, a small one.
As an end user, have you ever heard the message to put in the biggest VFD air compressor, and the system will always be reliable and efficient.  Why do an audit?  Just add up the compressors on site and put one VFD for that size or larger.  Why have the complexity of multiple compressors, storage, sequencing, etc?  Even better, put in two of them, one for the whole system, and one for back-up.  If you could wave a wand, wouldn’t that be what every system should look like?  Perfect peace and efficiency, with 100% confidence of reliability.
The 2017 Hannover Messe attracted 225,000 visitors with 75,000 coming from outside Germany. The over-arching theme of the event was the Industrial Internet of Things – or Industry 4.0, as it is known in Germany. Dr. Jochen Köckler, Member of the Managing Board at Deutsche Messe commented,“Over the past five days, Hannover has served as a global hub for all things related to Industrie 4.0. Every sector involved in the digitalization of industry was on hand to showcase its answers to the key question faced by industrial enterprises everywhere: How can I best get my company into shape for the digital future?
A complete compressed air system assessment should provide detailed information on both the supply and demand sides of the system. The supply-side refers to the equipment supplying compressed air – the air compressor, dryers, filters, piping and storage tanks.  The purpose of this article is to illustrate what information we believe a factory should receive from a supply-side system assessment and more importantly – what information a plant should always know about their compressed air system.
A newly constructed ethanol plant experienced control gap issues shortly after comissioning.  This article discusses the cause of the issue and how the problem was solved.
This article will talk about testing.  I will assume a “typical” system, a screw air compressor mix with regenerative dryers. Testing has to be done at several stages and locations, due to the cobbled-together nature of a compressed air system.
A pharmaceutical product manufacturer spends an estimated $137,443 annually on electricity to operate the oil-free air compressors in its compressed air system. The compressed air system operates well and is providing the level of purification required.  Our team visited the plant and identified a group of projects which could reduce compressed air demand and reduce energy costs by $42,248 – or 31% of current use.