Intelligent Compressed Air: Avoid Pressure Drop

A critical component to optimal performance of any compressed air operated product is ensuring sufficient compressed air flow. Simply put, inadequate air flow won’t allow you to get the job done.

As compressed air moves through the distribution system, it encounters friction inside of the walls of the pipe, tube, hose, etc. The diameter of the pipe, length, number of direction changes, and finish surface of the inner wall all play a part in this. A drop in air pressure will occur as a result of this friction. In addition to pressure drops experienced due to the distribution system, they can also occur at the point of use.

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Common analog pressure gauge

When designing and maintaining your compressed air system, pressure measurements should be taken across varying points to identify (and fix) any issues before they create a greater problem down the road. According to the Compressed Air Challenge, these are the places you should take regular pressure measurements to determine your system operating pressure:

  • Inlet to compressor (to monitor inlet air filter) vs. atmospheric pressure
  • Differential across air/lubricant separator
  • Interstage on multistage compressors
  • Aftercooler
  • At treatment equipment (dryers, filters, etc.)
  • Various points across the distribution system
  • Check pressure differentials against manufacturers’ specifications, if high pressure drops are noticed this indicates a need for service

*More recent compressors will measure pressure at the package discharge, which would include the separator and aftercooler.

Once you’ve taken these measurements, simply add the pressure drops measured and subtract that value from the operating range of your compressor. That figure is your true operating pressure at the point of use.

If your distribution system is properly sized and the pressure drops measured across your various equipment are within specifications, any pressure drop noticed at the point of use is indicative of an inadequate volume of air. This could be due to restrictive fittings, undersized air lines, hose, or tube, or an undersized air compressor. Check that the point of use product is properly plumbed to compressed air per the manufacturer’s specifications.

EXAIR Products are designed to minimize this pressure drop by restricting the flow of compressed air at the point of use. The more energy (pressure) that we’re able to bring to the point of use, the more efficient and effective that energy will be. The photo below shows two common examples of inefficient compressed air usage. With an open-ended blow off, a pressure drop occurs upstream inside of the supply line. If you were to measure the pressure directly at the point of use, while in operation, you’d find that the pressure is significantly lower than it is at the compressor or further up the line. In the other photo with modular style hose, some pressure is able to be built up but if it gets too high the hose will blow apart. These types of modular style hose are not designed to be used with compressed gases.

open end blow offs
They may be inefficient, but they sure are loud…

EXAIR’s Super Air Nozzles, on the other hand, keep the compressed air pressure right up to the point of discharge and minimize the pressure drop. This, in addition to the air entrained, allows for a high force while maximizing efficiency. If you’d like to talk about how an EXAIR Intelligent Compressed Air Product could help to minimize pressure drop in your processes give us a call.

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD

 

Pressure gauge photo courtesy of Cliff Johnson via Flickr Creative Commons License

Meet EXAIR’s Newest Application Engineer, Jordan Shouse

Hello Everyone, my name is Jordan Shouse and I’m the newest addition to the Application Engineering group here at the EXAIR Corporation! I may be new to the team here at EXAIR, but I am not new to helping my customers save money and better their process.

me

My background is in Metrology, I’ve worked with countless sectors of manufacturing including Automotive, Aerospace and Pharma to examine their quality processes then design and implement a strategy to better the quality, reduce scrap and improve the product ship rate to their customer. Working as an Application Engineer is really my bread and butter, as I enjoy digging into the hardest cases and finding a solution that even surprises myself sometimes!
While I do enjoy my work, I also enjoy my personal life. I consider myself a bit of a outdoorsman, anything from camping and hiking to just exploring new areas of this amazing earth! The past few years I’ve really gotten into the ocean, so much that I started a Salt Water Reef Aquarium about a year ago and it amazes me every day. Watching a little ecosystem that’s so complex in a 100 gallon tank grow and progress is at times breathtaking! (A lot of work, but breathtaking)

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To discuss your application and how an EXAIR Intelligent Compressed Air Product can help your process, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Jordan Shouse
Application Engineer
Send me an email
Find us on the Web 
Like us on Facebook
Twitter: @EXAIR_JS

Intelligent Compressed Air: Double-Acting Reciprocating Compressor

Evaluating all of the different types of compressors and which is right for you can seem like a daunting task. Today, I’d like to take some time to talk about the Double-Acting Reciprocating type of air compressor.

double acting compressor
Cut-out of a double-acting reciprocating compressor

Double-Acting Reciprocating compressors are a subset of the larger family of positive displacement compressor types. In positive displacement compressors, air is drawn into a chamber where the volume is then mechanically reduced. The energy used to displace the air volume is converted to an increase in air pressure. Dynamic compressors operate a little differently. They utilize an increase in air velocity to create the change in pressure. Air is accelerated to a high velocity through an impeller. The kinetic energy of the air is converted to an increase in potential (pressure) energy.

The Double-Acting Reciprocating compressor is a close relative to the Single-Acting Reciprocating compressor. In these types of compressors, an “automotive-type” piston driven by a crankshaft provides the compression. In a Double-Acting Reciprocating compressor, air is compressed as the piston moves in each direction. Hence the name, “double-acting”. In a Single-Acting Reciprocating compressor, air is only compressed on each full revolution of the piston. This makes the Double-Acting Reciprocating compressor much more efficient than its brethren.

Double Acting Recip
Double Acting Reciprocating Air Compressor

Double-Acting Reciprocating compressors are also available in much larger sizes. While Single-Acting compressors can be found up to 150HP, generally they’re much less common any larger than 25HP. Whereas a Double-Acting compressor is available from 10HP-1,000HP, making it a better choice for larger plants that require a significantly greater volume of compressed air. While they’re a bit more expensive due to the added mechanisms to produce the double-action compression, this cost is quickly offset by the increase in efficiency. At a performance of 15-16 kW/100 cfm, they’re 32% more efficient than a single-acting reciprocating compressor.

If you’re in the market for a new compressor and are struggling to determine the most suitable compressor, talk with your local compressor sales representative. Once you’re up an running, EXAIR has a wide-range of products that’ll make sure you’re using your compressed air safely and efficiently!

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@exair.com
Twitter: @EXAIR_TD
Image courtesy of Best Practices for Compressed Air Systems – second edition

 

Starting a Leak Prevention Program

Since all compressed air systems will have some amount of leakage, it is a good idea to set up a Leak Prevention Program.  Keeping the leakage losses to a minimum will save on compressed air generation costs,and reduce compressor operation time which can extend its life and lower maintenance costs.

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There are generally two types of leak prevention programs:

  • Leak Tag type programs
  • Seek-and-Repair type programs

Of the two types, the easiest would be the Seek-and-Repair method.  It involves finding leaks and then repairing them immediately. For the Leak Tag method, a leak is identified, tagged, and then logged for repair at the next opportune time.  Instead of a log system, the tag may be a two part tag.  The leak is tagged and one part of the tag stays with the leak, and the other is removed and brought to the maintenance department. This part of the tag has space for information such as the location, size, and description of the leak.

The best approach will depend on factors such as company size and resources, type of business, and the culture and best practices already in place. It is common to utilize both types where each is most appropriate.

A successful Leak Prevention Program consists of several important components:

  • Baseline compressed air usage – knowing the initial compressed air usage will allow for comparison after the program has been followed for measured improvement.
  • Establishment of initial leak loss – See this blog for more details.
  • Determine the cost of air leaks – One of the most important components of the program. The cost of leaks can be used to track the savings as well as promote the importance of the program. Also a tool to obtain the needed resources to perform the program.
  • Identify the leaks – Leaks can be found using many methods.  Most common is the use of an Ultrasonic Leak Detector, like the EXAIR Model 9061.  See this blog for more details. An inexpensive handheld meter will locate a leak and indicate the size of the leak.

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    Using the Model 9061 Ultrasonic Leak Detector to search for leaks in a piping system
  • Document the leaks – Note the location and type, its size, and estimated cost. Leak tags can be used, but a master leak list is best.  Under Seek-and-Repair type, leaks should still be noted in order to track the number and effectiveness of the program.
  • Prioritize and plan the repairs – Typically fix the biggest leaks first, unless operations prevent access to these leaks until a suitable time.
  • Document the repairs – By putting a cost with each leak and keeping track of the total savings, it is possible to provide proof of the program effectiveness and garner additional support for keeping the program going. Also, it is possible to find trends and recurring problems that will need a more permanent solution.
  • Compare and publish results – Comparing the original baseline to the current system results will provide a measure of the effectiveness of the program and the calculate a cost savings. The results are to be shared with management to validate the program and ensure the program will continue.
  • Repeat As Needed – If the results are not satisfactory, perform the process again. Also, new leaks can develop, so a periodic review should be performed to achieve and maintain maximum system efficiency.

In summary – an effective compressed air system leak prevention and repair program is critical in sustaining the efficiency, reliability, and cost effectiveness of an compressed air system.

If you have questions about a Leak Prevention Program or any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
Send me an email
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Twitter: @EXAIR_BB

“Go Green” in 2019 With EXAIR’s Super Air Nozzles & Jets!

If one of your New Year’s resolutions for 2019 is to help improve your impact on the environment, look no further than EXAIR’s Engineered Air Nozzles & Jets. By upgrading your blowoff, cooling, and drying operations to use one of our Super Air Nozzles or Jets you can save as much as 80% of your compressed air usage when compared with an inefficient solution.

open tubes
Example of a manifold of open pipes

An open copper pipe or tube, even if “flattened” as we’ll commonly see, wastes an excessive amount of compressed air. This wasted compressed air can create problems in the facility due to unnecessarily high energy costs and the pressure drop that can be experienced affecting other processes. In addition to simply using too much compressed air, an open pipe or tube will often produce sound levels in excess of 100 dBA. At these sound levels, according to OSHA, permanent hearing damage will occur in just 2 hours of exposure.

OSHA Chart

By simply replacing the open tubes and pipe with an EXAIR Super Air Nozzle, you can quickly reduce air consumption AND reduce the sound level. Sound level isn’t the only thing an OSHA inspector is going to be concerned about regarding an open pipe blowoff, in addition OSHA 1910.242(b) states that a compressed air nozzle used for blowoff or cleaning purposes cannot be dead-ended when using with pressures in excess of 30 psig. I don’t know if you’ve ever tried to use an air gun with 30 psig fed to it, but the effectiveness of it is dramatically reduced. This is why there needs to be a device installed that’ll prevent it from being dead-ended so that you can operate at a higher pressure.

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EXAIR Super Air Nozzle entrainment

EXAIR’s Super Air Nozzles are designed with fins that serve two purposes. They help to entrain ambient air from the environment, allowing us to maximize the force and flow from the nozzle but keeping the compressed air consumption minimal. In addition, these fins are what prevents the nozzle openings from being completely blocked off. Using an OSHA compliant compressed air nozzle for all points where a blowoff operation is being performed should be a priority. Each individual infraction will result in a fine if you’re subject to an OSHA inspection. Inspections are typically unannounced, so it’s important to take a look around your shop and make sure you’re using approved products.

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The fins along the outside of the Super Air Nozzle prevent it from being dead-ended

So, go ahead and make 2019 the year of energy savings, increased efficiency, and improving worker safety. You’ll find all of the tools you need in EXAIR’s 32nd edition of the catalog. Click here if you’d like a hard copy sent directly to you! Or, get in touch with us today to find out how you can get saving with an Intelligent Compressed Air Product.

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@exair.com
Twitter: @EXAIR_TD

 

Intelligent Compressed Air: Estimating Your Leakage Rate

waste

The electricity costs associated with the generation of compressed air make it the most expensive utility within an industrial environment. In a   poorly maintained compressor system, up to 30% of the total operational costs can be attributed simply to compressed air leaks. While this wasted energy is much like throwing money into the air, it can also cause your compressed air system to lose pressure. This can reduce the ability of the end use products to function properly, negatively impacting production rates and overall quality. Luckily, it’s quite easy to estimate the leakage rate and is something that you should be including in your regular PM schedule.

According to the Compressed Air Challenge, a well-maintained system should have a leakage rate of less than 5-10% of the average system demand. To estimate what your leakage rate is across the facility, first start by shutting off all of the point of use compressed air products so that there’s no demand on the system. Then, start the compressor and record the average time it takes for the compressor to cycle on/off. The compressor will load and unload as the air leaks cause a pressure drop from air escaping. The percentage of total leakage can be calculated using the following formula:

Leakage % = [(T x 100) / (T + t)]

Where:

T = loaded time (seconds)

T = unloaded time (seconds)

The leakage rate will be given in a percentage of total compressor capacity lost. This value should be less than 10% for a well-maintained system. It is not uncommon within a poorly maintained system to experience losses as high as 20-40% of the total capacity and power.

A leak that is equivalent to the size of a 1/16” diameter hole will consume roughly 3.8 SCFM at a line pressure of 80 PSIG. If you don’t know your company’s air cost, a reasonable average is $0.25 per 1,000 SCF. Let’s calculate what the cost would be for a plant operating 24hrs a day, 7 days a week.

3.8 SCFM x 60 minutes x $0.25/1,000 SCFM =

$0.06/hour

$0.06 x 24 hours =

$1.44/ day

$1.44 x 7 days x 52 weeks =

$524.16 per year

A small leak of just 3.8 SCFM would end up costing $524.16. This is just ONE small leak! Odds are there’s several throughout the facility, quickly escalating your operating costs. If you can hear a leak, it’s a pretty severe one. Most leaks aren’t detectable by the human ear and require a special instrument to convert the ultrasonic sound created into something that we can pick up. For that, EXAIR has our Model 9061 Ultrasonic Leak Detector.

ULD_Pr
Model 9061 ULD w/ parabola attachment checking for compressed air leaks

Implementing a regular procedure to determine your leakage rate in the facility as well as a compressed air audit to locate, tag, and fix any known leaks should be a priority. The savings that you can experience can be quite dramatic, especially if it’s not something that has ever been done before!

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@exair.com
Twitter: @EXAIR_TD

Happy Thanksgiving!

Here’s to enjoying the company of good friends and family. Everyone at EXAIR wishes all of you a happy Thanksgiving, and would like to express our gratitude for being our customers and vendors – we appreciate you.

EXAIR will be closed Thursday and Friday, November 22 and 23 to be with our family and friends.

Enjoy the holiday,
The entire EXAIR Team