Bifurcation Of Air – The Wonders of Science That Is The Vortex Tube

EXAIR has provided the benefits of vortex tube technology to the industrial world since 1983. Prior to that, French scientist George Ranque wrote about his discovery in 1928 calling it the tube tourbillion. But it wasn’t until German physicist Rudolf Hilsch’s research paper in 1945 on the wirbelrorhr or whirling tube, that the vortex tube entered the minds of commercial engineers. Nearly 60 years later, EXAIR is a leading provider for cooling products utilizing vortex tube technology.

More than 2,000 BTU/hr in the palm of your hand!

EXAIR Vortex Tubes produce a cold air stream down to -50° F and are a low cost, reliable, maintenance-free (there are no moving parts!) solution to a variety of spot cooling applications. These applications span a wide variety of industries and include cooling of electronic controls, soldered parts, machining operations, heat seals, environmental chambers, and gas samples. We’re always finding compelling new cooling opportunities for the vortex tubes.

How a Vortex Tube Works

So how does it produce the cooling stream? Compressed air is plumbed into the side port of the Vortex Tube where it is ejected tangentially into the internal chamber where the generator is located. The air begins flowing around the generator and spinning up to 1 million RPM toward the hot end (right side in the animation above) of the tube, where some hot air escapes through a control valve. Still spinning, the remaining air is forced back through the middle of the outer vortex. Through a process of conservation of angular momentum, the inner stream loses some kinetic energy in the form of HEAT to the outer stream and exits the vortex tube as COLD air on the other side.

The adjustable control valve adjusts what’s known as the cold fraction. Opening the valve reduces the cold air temperature and also the cold airflow volume. One can achieve the maximum refrigeration (an optimum combination of temperature and volume of flow) around an 80% cold fraction. EXAIR publishes performance charts in our catalog and online to help you dial into the right setting for your application, and you can always contact a real, live, Application Engineer to walk you through it.

EXAIR manufactures its vortex tubes of stainless steel for resistance to corrosion and oxidation. They come in small, medium and large sizes that consume from 2 to 150 SCFM and offer from 135 to 10,200 BTU/hr cooling capacity. Each size can generate several different flow rates, dictated by a small but key part called the generator. That generator can be changed out to increase or decrease the flow rate.

While operation and setup of an EXAIR Vortex Tube are easy, its performance will begin to  decrease with back pressure on the cold or hot air exhaust of over 3 PSIG. This is a key  when delivering the cold or hot airflow through tubes or pipes. They must be sized to minimize or eliminate back pressure.

The Vortex Tube is integrated into a variety of EXAIR products for specific applications, like the Adjustable Spot Cooler, the Mini Cooler, the Cold Gun Aircoolant System and our family of Cabinet Cooler Systems.

If you would like to discuss your next cooling application, please contact an Application Engineer directly and let our team lead you to the most efficient solution on the market.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

Happy Holidays from EXAIR!

It’s currently… the most wonderful time of the year.

Though 2020 has undoubtedly been a challenging year, it’s times like the holiday season that remind us why we persevere. Gifts, random acts of kindness, cherishing loved ones… the season brings a unmistakable air of hope and good will towards each other. Though this holiday season we may not be able to celebrate it the way we have in past years, we continue to make the best of our individual situations and remain grateful for the chance to spread cheer and put a smile on someone’s face.

The holidays are a joyous time here at EXAIR, in large part because the values of this season coincide seamlessly with EXAIR’s. Giving back, kindness, and gratitude… are just a few of the things we love to celebrate here at EXAIR. So as much as we know you love hearing about quality manufacturing solutions, we thought we’d give our readers a bit of what is bringing us that holiday cheer this season.

After much deliberation, countless hours of focus groups, and spirited debates laden with power point presentations and hired attorneys… we present a playlist of the tunes that our making us smile today. And if your favorite didn’t make the list, leave us a comment and tell us what songs are filling your heart this holiday.

EXAIR Holiday Playlist

  1. Mel Torme– Sleigh Ride
    https://youtu.be/tq9Ya3uD-e8
  2. Run DMC– Christmas in Hollis
    https://youtu.be/L4NKwiXGiUQ
  3. Johnny Mathis– Winter Wonderland
    https://youtu.be/DJTmadAABkI
  4. Brenda Lee– Rockin Around the Christmas Tree
    https://youtu.be/1qYz7rfgLWE
  5. Bobby Helms– Jingle Bell Rock
    https://youtu.be/itcMLwMEeMQ
  6. Chuck Berry– Run Run Rudolph
    https://youtu.be/YiadNVhaGwk
  7. Nat King Cole– The Christmas Song
    https://youtu.be/hwacxSnc4tI
  8. José Feliciano – Feliz Navidad
    https://www.youtube.com/watch?v=N8NcQzMQN_U
  9. Wham– Last Christmas
    https://youtu.be/-YUH8Xfz-jg
  10. Frank Sinatra– Have Yourself A Merry Little Christmas
    https://youtu.be/pvA7-EjaSPI
  11. The Jackson 5– Santa Claus Is Coming to Town
    https://youtu.be/nYmPZrvThW8
  12. The Drifters– White Christmas
    https://youtu.be/GfZPtkqXQIA

We hope you all enjoy the music, and continue celebrating season the best you can. Wishing everyone a very happy holidays from the team here at EXAIR.

Jason Fox
Marketing- Holiday Music Connoisseur
E-mail: JasonFox@EXAIR.com
Twitter: @EXAIR_JF

Tools Of The Trade: The Rotameter

EXAIR’s Free Efficiency Lab

One of the free services we offer to customers here at EXAIR is our Efficiency Lab. In case you are not familiar here is a brief synopsis. Speak with an Application Engineer about your existing compressed air blowoff/point of use product and that you would like to know how much air it consumes. Fill out the brief survey and send the product you use in to our facility. Let us perform tests on calibrated test equipment to determine the force, flow, and noise level. We will then issue you a report that states what the EXAIR model would best be suited (if applicable) as well as how much compressed air you will be able to save. Order the recommendation and start saving money.

To do these evaluations, we have to have calibrated equipment that is reliable and capable of handling vast range of products we may receive in. For this, we could use a Digital Flowmeter, in some cases that is what has to be done due to large flow rates. For the majority of these though we go old school. We utilize a piece of equipment called a rotameter.

A rotameter pairs nicely with a calibrated pressure gauge as well.

The float can be seen with graduated marks for readings. The taper of the chamber is not easily seen with the naked eye.

This is a device that is designed to measure the flow rate of a fluid within a closed tube. The inside diameter of the tube is varied which causes the float within the meter to raise or lower.  They are calibrated for a specific gas at a given pressure and temperature, most are calibrated for atmospheric conditions, 14.7 psi (1.014 Bar). The meter must be mounted vertically and this is not always best suited for industrial environments.

When testing products the compressed air within the meter is pressurized which means we have to correct the reading for the given pressure, if the temperature is outside of the calibration temp then we must also perform that correction. We do this using a table provided by the manufacturer of the meter or by using the calculations shown to get exact values that may be in between the pressures in the table.

Pressure Correction Table

 

This will allow us to then multiply the Correction Factor by the meter reading and calculate our corrected flow for the point of use device at a given operating pressure and temperature.

Temperature correction table

Knowing where the values that are measured and calculated come from add validity to the reports and understanding all of the variables that go into reading like this helps to better validate the cost savings that can be seen.

In a pinch, for a field estimation, we can also use these Correction Factors and determine an approximate consumption rate of a device that has been measured at a pressure such as our cataloged 80 psig (5.5 Bar). This can often be done on the fly to help determine the flowrates currently on a system. This can be helpful when troubleshooting, giving estimated simple ROIs, and help justify results and reasons for future purchases of engineered solutions.

If you want to discuss the Efficiency Lab or any of the math behind our calculations, contact any Application Engineer, we can all help out.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

Battling Heat Transfer

If you haven’t read many of my blogs then this may be a surprise. I like to use videos to embellish the typed word. I find this is an effective way and often gives better understanding when available.  Today’s discussion is nothing short of benefiting from a video.

We’ve shared before that there are three types of heat transfer, more if you go into sub-categories of each. These types are Convection,  Conduction, and Radiation. If you want a better understanding of those, feel free to check out Russ Bowman’s blog here.  Thanks to the US Navy’s nuclear power school, he is definitely one of the heat transfer experts at EXAIR.  If you are a visual learner like myself, check out the video below.

The Application Engineering team at EXAIR handles any call where customers may not understand what EXAIR product is best suited for their application. A good number of these applications revolve around cooling down a part, area, electrical cabinet, or preventing heat from entering those areas.  Understanding what type of heat transfer we are going to be combating is often helpful for us to best select an engineered solution for your needs.

Other variables that are helpful to know are:

Part / cabinet dimensions
Material of construction
External ambient temperature
If a cabinet, the internal air temperature
Maximum ambient temperature
Desired temperature
Amount of time available
Area to work with / installation area

Understanding several of these variables will often help us determine if we need to look more towards a spot cooler that is based on the vortex tube or if we can use the entrained ambient air to help mitigate the heat transfer you are seeing.

If you would like to discuss cooling your part, electrical cabinet, or processes, EXAIR is available. Or if you want help trying to determine the best product for your process contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

Video Source: Heat Transfer: Crash Course Engineering #14, Aug 23, 2018 – via CrashCourse – Youtube – https://www.youtube.com/watch?v=YK7G6l_K6sA