Industrial Utility Efficiency    

Technology

Among the many “systems” plant personnel are concerned with, the compressed air system often provides the biggest opportunity for improvement and overall savings. There are many manufacturers and several air compressor technologies to choose from. Reciprocating or rotary? Fixed speed or variable speed? Oil flooded or oil free? Single-stage or two-stage technology? It’s enough to make anyone want to run and hide!

Air Compressors

Properly sizing a compressed air system can help determine if your facility has enough air to adequately supply your production equipment. Designing a cost effective system that minimizes any interruptions to productivity requires thoughtful planning and design. Typically, the desired outcomes of such a system focus on stable pressure and efficient operation, though it is important to note that each of these elements requires a unique solution. This article will provide guidance in proper selection considerations and suggest when a centrifugal air compressor may be ideal for your needs.

Air Treatment

Air compressors can produce a lot of water. Humidity in ambient air, once compressed, results in much of this water falling out, which we know as condensate. On a warm and humid summer day with inlet air temperatures of 80 oF, a 75-horsepower (hp) air compressor running fully loaded can produce over 25 gallons of condensate in just one eight-hour shift, with another five gallons being produced once the compressed air is sent through a dryer. The compression process allows for the air, water vapor, and lubricating fluids to mix. Once the condensate leaves the system, trace amounts of lubricant travel with it. This condensate should be processed through an oil-water separator before being discharged to groundwater or wastewater treatment plants.

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

Companies will experience periods of increased production, as well as periods of slower or stopped production. It’s the nature of being in business. Understanding the implications of these business shifts for compressed-air installations (the powerhouse behind a facility’s production) is key for ensuring that air compressors remain functional and efficient. Here are guidelines to ensure your facility’s compressed-air system operates at top performance, no matter the speed of production.

Instrumentation

Like any system, to properly manage compressed air equipment some measurements have to be taken. Typically, some sort of data logging equipment is installed to measure various pressures, amps or power, flow, and sometimes temperatures and dewpoints. Placing this equipment on a system is like putting an electrocardiograph machine on a human heart, the heartbeat of the compressed air system in a plant can be analyzed to determine if everything is normal or if there is a problem, all without interrupting the system. 

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.
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.
The team is building on engineering concepts that were used to develop the first hydraulic air compressor at Dominion Cotton Mills, Magog, Quebec, Canada, over 100 years ago. The basic principles of the HAC were then used to produce compressed air at 17 locations worldwide, including the last at Ragged Chutes near Cobalt, Ontario, Canada, over 100 years ago.  This article discusses the development the HAC in this decade and the continuing work at Laurentian University, Ontario, to modernize the concept.
Compressed air represents one of the largest opportunities for immediate energy savings, which accounts for an average of 15% of an industrial facility’s electrical consumption. In fact, over a 10-year period, electricity can make up 76% of the total compressed air system costs. Monitoring compressed air usage, identifying compressed air waste and inefficiencies, and making investments in new compressed air equipment – including piping – are tangible ways businesses can cut their operating costs by lowering their electricity bill.
The advent of manifold-mounted, plug-in pneumatic valves has been a boon for machine builders. It allows them to mount complete valve packages in a safe and secure location on a machine. Using a D-sub connector, serial interface module, or similar single-point wiring system, all of the electrical control outputs can feed into one location on the manifold, greatly simplifying the wiring.
Baseline measurements include flow, power, pressure, production output, and other relevant variables impacting compressed air use. These data evaluate trending averages to develop Key Performance Indicator (KPI) and Energy Performance Indicator (EnPI) parameters and establish base‑year performance. The focus of this article is the application, evaluation, and analysis of baseline measurements to provide information necessary to improve Compressed Air Supply Efficiency.
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.
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.
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.