Saving Compressed Air – The Fourth Utility

We all know the value of electric, water and gas but what about compressed air? Your compressed air system has an annual cost and deserves to be treated as a cost center. In my previous career, I was guilty of not having a budget for compressed air in my business plan and wish I knew then what I needed for a more efficient compressed air system. Compressed air carries a significant value and deserves to be a cost center with aggressive annual efficiency planning.

Unfortunately, several misconceptions about how to reduce energy costs through increased compressed air efficiencies have prevented many industrial operations from taking control of their compressed air energy costs. There are 2 main focuses about compressed air systems that can begin to reduce expenditures, improve the reliability of your systems and generate savings for future equipment improvements. First, you can look at energy savings in the compressor motors but this is a more complicated and more expensive endeavor that can be a next step when tackling compressed air savings head on. Second, the demand side of the compressed air system is where many efficiencies can be gained. A focus on leaks, storage, pressure and inefficient use are generally simple and inexpensive to address.

Increasing the pressure isn’t always the answer. In fact, frequently it is not. An efficient compressed air system is characterized by stable pressure levels. Steady pressure levels are achieved by addressing two things: air demand patterns and the minimum acceptable pressure level required for reliable production. Unfortunately, many operators who fail to properly diagnose the causes of system problems simply increase pressure to improve performance. Arbitrary increases to the pressure without understanding the root causes of performance issues can lead to increased energy costs. An audit completed by your compressed air specialist will reveal which aspects of your compressed system can be fine-tuned in order to reduce energy costs and increase reliability. Use of the “Six Steps to Optimizing Your Compressed Air System” will help achieve your goals for cost savings and efficiencies.

Begin with establishing a baseline for your system and learn what your typical air use looks like. This can be done with a flow meter installed at the compressor outlet. A flow meter is also useful at each machine or process demanding compressed air because they can (1) indicate if a machine or process is operating atypically and consuming more air than usual and (2) identify where high demand machines or processes are located in your facility.

It is estimated that up to 20% of compressed air produced by industrial air compressors is wasted due to leaks in typical facilities.¹ Approximately 20% of the air produced for industrial applications ends up being lost through leaks. The use of EXAIRs’ model 9061 Ultrasonic Leak Detector will enhance your efforts in finding leaks.

Choose engineered products to apply compressed air, these product have a focus on efficiency and outperform commercial products which do not concern themselves with air reduction.

When moving around your facility, look for applications of compressed air which can be turned off when personnel are on break or can be turned off in between parts. This step is very simple and can reap big savings.

Be sure to store compressed air close to high demand applications, this will prevent peaks and valleys in your compressed air demand which contributes toward less maintenance for your compressor.

Also lower your pressure at compressed air points of use. Keeping the pressure at the minimum pressure required for a successful application can also help keep system wide pressure to a minimum, which will increase lifetime of your compressor.

The good news is that, in most cases, lower energy costs are completely attainable for industrial operations that have not optimized their compressed air systems. To begin saving please contact EXAIR about compressed air products that can lower your compressed air costs today.

Eric Kuhnash
Application Engineer
E-mail: EricKuhnash@EXAIR.com
Twitter: @EXAIR_EK

  1. Best Practices for Compressed Air Systems, second edition. From The Compressed Air Challenge.

Optimization:  Step 6 – Control the air pressure

Since air compressors use a lot of electricity to make compressed air, it is important that you use it as efficiently as possible.  EXAIR generated a chart with six simple steps to optimize your compressed air system.  Following these steps will help you to cut overhead costs and improve your bottom line.  In this blog, I will cover the sixth step; controlling the air pressure at the point of use.

Pressure Regulators

One of the most common pressure control devices is called the Regulator.  It is designed to reduce the downstream pressure that is supplying your system.  Regulators are commonly used in many types of applications.  You see them attached to propane tanks, gas cylinders, and of course, compressed air lines.  Properly sized, regulators can flow the required amount of gas at a regulated pressure for safety and cost savings.

EXAIR designs and manufactures compressed air products to be safe, effective, and efficient.  By replacing your “old types” of blowing devices with EXAIR products, it will save you much compressed air, which in turn saves you money.  But, why stop there?  You can optimize your compressed air system even more by assessing the air pressure at the point-of-use.  For optimization, using the least amount of air pressure to “do the job” can be very beneficial and practical.

Model 1100

Why are regulators important for compressed air systems?  Because it gives you the control to set the operating pressure.  For many blow-off applications, people tend to overuse their compressed air.  This can create excessive waste, overwork your air compressor, and steal from other pneumatic processes.  By simply turning down the air pressure, less compressed air is used.  As an example, a model 1100 Super Air Nozzle uses 14 SCFM of compressed air at 80 PSIG (5.5 bar).  If you only need 50 PSIG (3.4 bar) to satisfy the blow-off requirement, then the air flow for the model 1100 drops to 9.5 SCFM.  You are now able to add that 4.5 SCFM back into the compressed air system. And, if you have many blow-off devices, you can see how this can really add up.

In following the “EXAIR Six Steps To Optimizing Your Compressed Air System”, you can reduce your energy consumption, improve pneumatic efficiencies, and save yourself money.  I explained one of the six steps in this blog by controlling the air pressure at the point of use.  Just as a note, by reducing the pressure from 100 PSIG (7 bar) to 80 PSIG (5.5 bar), it will cut your energy usage by almost 20%.  If you would like to review the details of any of the six steps, you can contact an Application Engineer at EXAIR.  We will be happy to help. 

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Opportunities To Save On Compressed Air

Even casual readers of the EXAIR Blog will notice that we Application Engineers are keen on efficiency.  I just counted sixty-seven blogs on the site that discuss our Six Steps To Optimizing Your Compressed Air System.  Some offer a broad overview, while others focus on specific steps, and one tells us more than I ever expected to learn from an engineering blog about…Bigfoot.

I’m going to take a different tack here – no; I’m not going to write about the Yeti or the Loch Ness Monster, but I may try to get the Jersey Devil into a blog someday.  I will, instead, relate some real-life examples of the success of implementing each individual step.  It’s important to note here that they don’t have to be done in order, or even in total, to achieve impressive results.

  1. Measure the air consumption to find sources that use a lot of compressed air.  Like I just said, you don’t HAVE to do these steps in order, but if you DO intend to pursue a comprehensive solution, this is where you want to start.  The facility manager of a large manufacturing plant did just that when a series of Digital Flowmeters were installed in the branch lines to their production cells.  By comparing their present-day actual usage to the original design specifications, they noticed that usage in a certain cell (due to business growth) had increased to the point that they had raised the main header pressure in an attempt to keep point-of-use pressures at proper levels.  By installing a larger diameter branch line to that cell, they were able to reduce main header pressure from 120psig to 100psig, reducing their compressors’ energy usage (and their share of the electric bill) by 10%.
    Summing Remote Display (left) for remote indication and totalizing data. USB Data Logger takes data from the Digital Flowmeter to your computer and outputs to its own software (shown above) or Microsoft Excel.
  2. Find and fix the leaks in your compressed air system.  A factory once noticed they were losing header pressure overnight, when they were closed.  Using an Ultrasonic Leak Detector, they identified some small leaks that nobody thought were all that significant…until they did the math, comparing previous compressed air consumption (including those leaks) to that of their “new and improved” leak-free system.  Fixing those leaks saved them just over a million cubic feet of compressed air a year.  The exact figure was 1,062,500 cubic feet, annually.  I know this is accurate, because it was us.

  3. Upgrade your blowoff, cooling and drying operations using engineered compressed air products.  This could apply to almost every single order we process, so I’m going use an example from my first day here.  During training, I learned that a customer had recently called to get air consumption data on some EXAIR products they were going to implement as part of an upgrade that was also going to involve purchasing a new compressor.  Their main usage was a number of open-end blow offs that ran continuously.  After outfitting those with Model 1100 Super Air Nozzles and Model 9040 Foot Pedals (so the operators had simple, hands-free control over blowing cycles), they not only found they didn’t need a new air compressor, but were able to shut down an existing 50HP air compressor.
    Foot Pedal + Air Hose + Super Air Nozzle = Instant Blow Off System!
  4. Turn off the compressed air when it isn’t in use.  There are a few methods for doing this, and they’re all pretty easy:
    • Good.  Manual shutoff valves (1/4 turn ball valves are great for this) can be used by mindful operators to shut off compressed air use between production cycles, during lunch breaks, and (I hope this is patently obvious to the most casual observer) at closing time.  I’ve talked to users about doing this, but I don’t have any great success stories about this method.  It relies on someone’s memory in knowing when to operate the valve…and nobody’s remembered to call me back with a full report either.
    • Better.  If you only need air blowing while a machine is running,
      EXAIR stocks Solenoid Valves in a variety of sizes & voltages

      most any qualified industrial electrician can wire a solenoid valve into the on/off control of the machine.  Better yet, if the system has programmable logic control (PLC), it can be used to open & shut that same solenoid valve, to effect blow off only as needed.  I worked with an automotive parts manufacturer who had a robot passing parts between a pair of Model 110042 42″ Aluminum Super Air Knives.  They had taken care to accurately position the Air Knives, and program the robot’s movement & speed, to optimize blow off…but the Air Knives were running continuously.  After a brief conversation with the line foreman, they bought and installed a Model 9065 1 NPT 24VDC Solenoid Valve and “told” the PLC to turn air flow on as the robotic arm approached the Air Knives, and turn it off right after the part had passed through.
    • Best.  In the absence of programmable logic, the simplicity of the EXAIR EFC Electronic Flow Control just can’t be beat.  It’s a standalone system that consists of a Solenoid Valve that’s operated by a photoelectric sensor and controlled by a programmable timer.  Whether it’s a tenth of a second, or a few minutes, waste is waste, and it adds up.  Consider this application writeup from our Optimization Products catalog section:
      Turning air off when it’s not needed adds up, even if it’s just for a few seconds at a time.

       

       

       

  5. Use intermediate storage of compressed air near the point of use.  If
    Prevent intermittent demands from starving other loads with intermediate storage.

    compressed air is used in any sizable amount in your facility, odds are, you have a compressor room.  If it’s done right, this is a good thing for your compressor, but it CAN present some challenges for distribution over large areas.  A user of EXAIR Super Ion Air Knives, for example, installed a Model 9500-60 Receiver Tank in an area some distance from the compressor room to maintain higher air pressure than line loss (from the length of the header pipe) was allowing.  Their other option was to increase their overall header pressure; this allowed them to maintain current costs…increasing system pressure by 2psi equates to a 1% increase in compressed air generation costs.
  6. Control the air pressure at the point of use to minimize air consumption.  In addition to controlling OVERALL compressed air system pressure (see examples 1 & 5 above), using Pressure Regulators to control the supply pressure to specific compressed air operated products will save you money too…the lower the supply pressure, the lower the consumption.  A Model 1101 1/4 MNPT Super Air Nozzle, for example, uses 14 SCFM when supplied at 80psig…that’s where we publish its performance, because that’ll give a good, strong blast of air, suitable for a wide range of typical industrial air blowing applications. A tube manufacturer once replaced two open blow off devices that used about 38 SCFM each with Model 1101’s.  Even though that cut their air consumption by more than half, they were able to cut it even further by regulating the supply pressure to 56psig…that’s the pressure at which they could still get the job done consistently, resulting in ANOTHER 25% reduction in compressed air consumption.

If you’d like to find out more about any, or all, of the Six Steps To Optimizing Your Compressed Air System, give me a call.

Russ Bowman, CCASS

 

 

 

Application Engineer
EXAIR Corporation
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Find Compressed Air Leaks with an Ultrasonic Leak Detector

The Ultrasonic Leak Detector (ULD) is a hand-held, high quality instrument that can locate costly leaks in a compressed air system. The definition of Ultrasonic as defined by Merriam-Webster is: “having a frequency above the human ear’s audibility limit of about 20,000 hertz —used of waves and vibrations.” The human hearing range depends on pitch and sound. Sound is a measure of how low or high the volume of loudness in terms of decibels (dBA) and “Pitch” is measured in Hertz (Hz).The overall spectra of the emitted ultrasonic sound is “white noise”, white noise is the broad band emission of sound.

Humans can detect sounds in a frequency range from about 20 Hz to 20 kHz. (Human infants can actually hear frequencies slightly higher than 20 kHz, but lose some high-frequency sensitivity as they mature; the upper limit in average adults is often closer to 15–17 kHz.)

The Model 9061 ULD is designed to locate the source of ultrasonic sound emissions and is used to find compressed air leaks. These ultrasonic sound emissions are converted by the ULD to a range that can be heard by humans. All this being said, the EXAIR ULD makes finding your air leaks fast and efficient.

The Model 9061 comes complete with with a hard shell plastic case, headphones, parabola, tubular adapter, tubular extension and a 9 volt battery. The ULD can be adjusted to filter out background noise typically heard in manufacturing environments by using the X1, X10 and X100 sensitivity settings. The “on/off” thumb wheel can be used for sensitivity adjustment within each of theses settings. The parabola or tubular extension can be attached to the ULD masking out background noise and finding the ultrasonic sounds being generated from the leaks.

Compressed air is an expensive cost center so using the ULD to detect and fix air leaks can not only be fun but also show a payback on investment with just one leak detection. The illustration below demonstrates just how a payback occurs.

EXAIR has many tools and accessories for your intelligent air needs and want to hear from you as we have Application engineers ready to assist your projects and compressed air challenges.

Eric Kuhnash
Application Engineer
E-mail: EricKuhnash@exair.com
Twitter: Twitter: @EXAIR_EK