Proper Supply Line Size And Fittings Provide Peak Performance

Many times when we provide the air consumption of an EXAIR product, we get a response like…. “I’ve got plenty of pressure, we run at around 100 PSIG”. While having the correct pressure available is important, it doesn’t make up for the volume requirement or SCFM (Standard Cubic Feet per Minute) needed to maintain that pressure. We commonly reference trying to supply water to a fire hose with a garden hose, it is the same principle, in regards to compressed air.

When looking to maintain an efficient compressed air system, it’s important that you use properly sized supply lines and fittings to  support the air demand (SCFM) of the point-of-use device. The smaller the ID and the longer the length of run, it becomes more difficult for the air to travel through the system. Undersized supply lines or piping can sometimes be the biggest culprit in a compressed air system as they can lead to severe pressure drops or the loss of pressure from the compressor to the end use product.

Take for example our 18″ Super Air Knife. A 18″ Super Air Knife will consume 52.2 SCFM at 80 PSIG. We recommend using 1/2″ Schedule 40 pipe up to 10′ or 3/4″ pipe up to 50′. The reason you need to increase the pipe size after 10′ of run is that 1/2″ pipe can flow close to 100 SCFM up to 10′ but for a 50′ length it can only flow 42 SCFM. On the other hand, 3/4″ pipe is able to flow 100 SCFM up to 50′ so this will allow you to carry the volume needed to the inlet of the knife, without losing pressure through the line.

Pipe size chart for the Super Air Knife

We also explain how performance can be negatively affected by improper plumbing in the following short video:

 

Another problem area is using restrictive fittings, like quick disconnects. While this may be useful with common everyday pneumatic tools, like an impact wrench or nail gun, they can severely limit the volumetric flow to a device requiring more air , like a longer length air knife.

1/4″ Quick Connect

For example, looking at the above 1/4″ quick disconnect, the ID of the fitting is much smaller than the NPT connection size. In this case, it is measuring close to .192″. If you were using a device like our Super Air Knife that features 1/4″ FNPT inlets, even though you are providing the correct thread size, the small inside diameter of the quick disconnect causes too much of a restriction for the volume (SCFM) required to properly support the knife, resulting in a pressure drop through the line, reducing the overall performance.

If you have any questions about compressed air applications or supply lines, please contact one of our application engineers for assistance.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

Controlling Temperature And Flow Of An EXAIR Vortex Tube

If you need a reliable, consistent flow of cold air, look no further than the EXAIR Vortex Tube:

A 1/4 ton of refrigeration in the palm of your hand!

Getting the performance you want comes down to answering two simple questions:

What temperature do I need? 

Vortex Tubes produce a DROP in temperature, so your compressed air supply temperature is our starting point to determine what the actual cold air temperature will be.  The magnitude of the temperature drop is dependent on two factors:

  • Compressed air supply pressure – the higher the pressure, the higher the temperature drop.
  • Cold Fraction setting of the Vortex Tube – this is the percentage of the air supply that’s directed to the cold end.  The same temperature drop is produced, regardless of model, for a given Cold Fraction.  The lower the Cold Fraction, the greater the temperature drop (and hence, the lower the air temperature.)

EXAIR has two distinct series, or types, of Vortex Tubes:

3200 Series are used when Cold Fractions above 50% are desirable.  This provides maximum refrigeration…high flows and temperature drops that are optimal for many spot cooling applications such as tool cooling, setting hot melt adhesives, quick cooling of soldering/brazing, etc.

3400 Series are used for lower Cold Fractions (below 50%) and generate VERY cold air flow…as low as -50°F.  Some common applications for these are cryogenic lab sample cooling, circuit testing, or freeze seals in certain piping systems.

Temperature drops are dependent only on supply pressure and Cold Fraction setting. These values apply to any Vortex Tube, regardless of size/model.

Cold Fraction is adjusted by turning the Hot Air Exhaust Valve to let more, or less, hot air out, as shown in this short video:

What flow do I need?

Both the 3200 and 3400 Series Vortex Tubes are offered, from stock, in twelve distinct models of each series.  These are defined by the compressed air consumption, and the cold air flow is determined by the Cold Fraction setting.

Small Vortex Tubes come in three Models for each series, and consume 2, 4, or 8 SCFM when supplied with compressed air @100 psig.

Medium Vortex Tubes come in five Models for each series, and consume 10, 15, 25, 30, or 40 SCFM @100 psig.

Large Vortex Tubes come in four Models for each series, and consume 50, 75, 100, or 150 SCFM @100 psig.

Converting a Vortex Tube to a different Model (in the same size class) is as easy as changing the Generator (and the Taper Sleeve, for the Small Vortex Tubes):

The Generator and Taper Sleeve (*Small VT’s only) are changed by removing the Cold Cap.

So, for example, if you have a Model 3210 (10 SCFM consumption, 1,000 Btu/hr rated cooling) set to an 80% Cold Fraction, supplied with compressed air @100 psig & 70°F, it’s making a 16°F cold air flow of 8 SCFM.  If your situation calls for more flow, you can change the Generator…for example, if you convert it to a Model 3240 (40 SCFM, 2,800 Btu/hr rated cooling) – leaving the Cold Fraction at 80%, you’ll now get 32 SCFM of 16°F air.

What if you need colder air?  You can convert this same Medium Vortex Tube to a Model 3440 (40 SCFM consumption, max cold temperature) by changing the Generator again…and if you lower the Cold Fraction to 20%, it’ll make a -53°F cold flow of 8 SCFM.

Powerful and versatile, EXAIR Vortex Tubes are suitable for a wide range of applications requiring a consistent and reliable flow of cold air.  For help in selecting the right one for your needs, give me a call.

Russ Bowman
Application Engineer
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Video Blog: Which EXAIR Air Knife Is Right For You?

The following short video explains the differences between the 3 styles of Air Knives offered by EXAIR – The Super, Standard and Full-Flow. All of these Models are IN STOCK, ready to ship, with orders received by 3:00 PM Eastern.

If you need additional assistance choosing your EXAIR Air Knife, please contact an application engineer at 800-903-9247.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

 

Drying and Cleaning Tubes Using The Standard Air Wipe

A tubing manufacturer called looking for a better way to dry their 3″ (O.D.) tubes after a rinse application. In their current setup, the tubes are being cut by a band saw, which uses flood coolant to keep the blade cool and evacuate chips. After the tubes are cut, they are then bundled together and dipped into a rinse tank to remove the cutting fluid and any machining debris on the surfaces. The tubes are then fed, one by one, through a series of blower driven air knives placed around the outside  of the tubing to dry and clean them before a painting and bar code process. The air knives were working somewhat, but they were seeing some residual streaking on the surface of the tubes that needed to be manually cleaned by hand, slowing down the process.

Example of a typical band saw used for cutting metals and other rigid material.

I recommended the customer use our 4″ Standard Air Wipe in their application. EXAIR Air Wipes provide a 360° uniform, high velocity airflow that adheres to the outside surface, as it passes through the throat of the device. Here is a short video we made showing the cleaning power of our Standard Air Wipes.

The Standard Air Wipe is available in stock sizes from 1/2″ up to 11″. The aluminum construction and PVC hose (included on sizes up to 4″) is suitable for most “general” industrial environments with ambient temperatures reaching as high as 150°F. We also offer Stainless Steel Super Air Wipes, which have the same performance as the Standard, for processes requiring superior corrosion resistance and/or where higher temperatures are possible, up to 800°F.

Super (left) and Standard (right) Air Wipes – ideal for drying, cleaning or cooling round shapes like tubing, hose, pipes, etc.

For help selecting the best product to fit your particular need, please contact an application engineer for assistance.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

FMB FMB Titan Bandsaw Gravity Feed image courtesy of Kitmondo Marketplace via Creative Commons license.

Video Blog: The EXAIR Ultrasonic Leak Detector Works for Vacuum Leaks?

 

A brief video showcasing the EXAIR model 9061, Ultrasonic Leak Detector’s, performance on vacuum leaks.  For more information or questions on what else the ULD can be used for, contact an Application Engineer!

 

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF

Video Blog: Assembling the Dual Cabinet Cooler Hardware Kit

Dual Cabinet Cooler Systems consist of two Cabinet Coolers and a model 4908 Dual Cabinet Cooler Hardware Kit.  This hardware kit will connect the Cabinet Coolers together for a single compressed air supply port. This video shows you how to assemble the hardware kit to the Cabinet Coolers, and then illustrates installing the Dual Cabinet Cooler System on an enclosure.

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

 

Super Air Knife Shim Design Reduces Operation Costs

A customer of ours had an application where they needed to cool and dry parts on two conveyors that ran side by side.  A single 36″ Super Air Knife was chosen to provide coverage over the full width and to simplify the air plumbing and installation.  As we learned more about the application, it was discovered that there was 10″ section in the center where the the two conveyors butted up, where no parts would pass through, and hence no air was needed.

Fortunately, the EXAIR Super Air Knives can be supplied with custom shim designs to match the air flow requirements of the application.  These shims can be of various thicknesses to increase/decrease the air flow, of alternate materials such as a stainless steel shim in an aluminum air knife to increase the temperature range, or as in this case, designed to provide specific air flow patterns.

By utilizing the special shim design, it is estimated to save $865 per shift per year in compressed air costs versus the standard configuration.  That is a significant savings, and using less compressed air is high on everyone’s priority list.

Check out the video below to learn more about the EXAIR Air Knives.

akvideo

EXAIR manufactures 3 different types of air knives, in 4 different materials, up to 108″ in length.

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

Brian Bergmann
Application Engineer

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