Maximum Effort!!! The Two Types of Vortex Tube Generators

I am a fan of just about all things MCU (Marvel Cinematic Universe) and have always found Deadpool to be entertaining. Anytime I see a Max Cold Temp or Max Refrigeration mention when discussing or reading about a Vortex Tube I go to a miniature cut scene where Deadpool is saying Maximum Effort as they are fighting the bad guys in Deadpool 2. Enough about my love for MCU, let’s get more into my nerd love for Vortex Tubes.

When it comes to Vortex Tubes and getting the most out of them, EXAIR are the subject matter experts. If you aren’t sure what a Vortex Tube is or how it works, we’ve blogged about that, today’s blog is going to focus more on why you would select a Maximum Cold Temp vs a Maximum Refrigeration Vortex Tube and what actually changes.

Vortex generator

The difference lies in the generator that is inside the Vortex Tube. The reason to choose between the two lies with the application for the tube. In the event that the tube will be used for spot cooling or cooling a small chamber, Maximum Refrigeration generators are desired because you will generally work at a 50% cold fraction or higher. The maximum refrigeration value possible is achieved under set variables such as operating pressure, cold fraction, and incoming compressed air temperature. To see how these effect the cooling performance, check out our blogs on de-rating a Vortex Tube (Part 1Part 2). The bulk of applications that I have worked on over the 10+ years I have been part of EXAIR utilize the Maximum Refrigeration Vortex Tube because customers desire to get a product, small area, or component below ambient air temperatures and are going to be operating in the 50% to 80% cold fraction area in order to provide the performance needed.

EXAIR Vortex Tube Performance Chart

The other small fraction of applications that really need to get the lowest air temperature; in order to get that small component or spot down to -50°F (-46°C) will utilize the Maximum Cold Temperature generators. These will be the 3400 series Vortex Tubes or the “-C” versions. While max cold temperature models are less common, they regularly solve applications for temperature stress testing parts and freeze seals. Maybe you aren’t sure if the Maximum Refrigeration or Maximum Cold Temp is the one you need. That’s where the Application Engineer Team here comes in, hit us up first, and then we can also showcase just how simple it is to change the generator in a Vortex Tube out and give an idea of how many turns out from closed on the Hot Valve you will be to get close to the performance needed.

It truly is just that simple, no internal moving parts, just change out one internal component, and adjust the Hot Valve. To understand how easy that is, check the video below and you can see how big of a swing one can see with adjustments.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

Vortex Tubes Create Freeze Seals For Maintenance on Water Lines

Freeze plugs or Freeze seals are regularly used in nuclear reactor fluid systems to drain or isolate components that, for various reasons, cannot be conveniently isolated by valving. Once they are isolated, they are able to perform maintenance or upgrades without shutting down an entire system.

The United State Navy utilizes a large vortex tube to supply -50°F cooled air stream into a freeze jacket around the pipe. A time frame is chosen based on pipe size and fluid in the pipe to verify they are generating adequate cooling.  Temperature monitoring is put in place, flow through the pipe is stopped, and cooling of the freeze seal begins.  The water near the walls of the pipe freezes first.  Next, the frozen liquid continues towards the center until a solid plug of ice exists.  The freeze seal is then subcooled to a pre-determined temperature at which point the freeze is considered equivalent to a shut valve. Between the Ice plug and the small bit of pipe shrinkage at the point of cooling these seals are able to hold back thousands of pounds! (See drawing below, Shrinkage exaggerated for viewing)

Vortex Based Freeze Seal

In the attached photo bellow, (Provided by the U.S. Navy, photo by John Lenzo) this is a Freeze seal training Rig! You will see three colored lines, Blue is the cold air flow supplied by the vortex tube, red is the hot air from the vortex tube is exhausting away from the application location, and yellow is the pipe they are creating the freeze seal on. Surrounding that pipe is a jacket that holds the -50°F air in contact with the pipe.

With careful temperature monitoring in place and backup cooling methods on standby the work up stream can start.  Coolant flow throughout the rest of the system can now be reestablished.  Following the repair, flow will again be stopped for several hours while the freeze seal is given time to melt.  This ensures that the ice plug is not shot through the now repaired machine.

If you think you have an application that would benefit from Vortex tube technology, give us a call! We have a team of Application Engineers in from 7AM-4PM EST M-F! Or shoot us an email to techelp@exair.com and one of those Engineers will reach out to you!

Jordan Shouse
Application Engineer

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Freeze Seal Image Provided by the U.S. Navy

Process Cooling Utilizing Vortex Tube Technology

Vortex Tube Theory

What is a Vortex Tube? How long have they been around? How do they work? Vortex Tubes have been around since 1928 with what may seem as an accidental existence by the developer George Ranque. George accidentally discovered the phenomenon while studying physics at Ecole Polytechnique in Paris France. Ranque was performing an experiment on a vortex-based pump to vacuum up iron fillings; during the experiment he noticed that warm air was being expelled out of one side and cold air out of the other when he inserted a cone into one end of the vortex. In 1931 Ranque filed for a patent for the vortex tube and two years later presented a paper on it.

George’s vortex tube was all but lost and forgot about until 1947 when the German physicist Rudolph Hilsch published a paper on the device. This paper became widely read and exposed the vortex tube to the industrial manufacturing environment. This paper revived what was thought to be lost and led the vortex tube into what we see today.

As to how they work, these are a phenomenon of physics and the theoretical math behind them has yet to be proven and set in stone. But the basics are this, high pressure compressed air (typically 100 PSIG) is fed into a chamber which contains a generator. The generator takes that high pressure air and spins it at a very high rate of speed. As the air spins it starts to heat up on the inner walls of the vortex tube as it moves towards the control valve. A part of that hot air exits at that valve. The rest of the air which has now slowed down is forced back up the tube through the center of the first high speed air stream. The middle stream of slower air gives up energy in the form of heat to the outer faster moving air. And because of this the inner stream exits the opposite end as extremely cold air! (Check out image below for a visual representation)    

How a Vortex Tube Works

Now the question is how can this technology be integrated into a production process? See below for applications.

Cold Air Gun Application

A few months ago, a high-performance knitted products manufacturer called. They operate 128 Spindle motors on circular sock machines (CSM) that require couplings. These couplings use hi-speed, hi-temperature bearings that have been failing regularly and prior to the predicted run life. This was resulting in loss of production while the circular sock machines are down and the bearings are replaced. Additional costs associated with refurbishing the failed bearing include labor and new bearings. The average cost of a failed circular sock machines bearing including lost production was around $1925.00 and on average they were seeing 180 premature failures each year.

My recommendation was using a Cold Gun with the dual outlets to spread the cooling around the bearing. They had tried fans and electric blowers and they noticed no benefits. However, when they placed the 3925 on the largest trouble maker that was burning bearings at the highest rate, they noticed a prolonged lifetime of over 260%!!!

The enhanced run life of the circular sock machines was noticed immediately as the non-cooled circular sock machine bearings continued to fail at a much higher rate when compared to the positions with the Cold Air Guns installed.

Based on the average cost of a failed circular sock machine bearings including lost production ($1925.00) and an average of (180) premature failures each year, their estimated annual savings using the Cold Gun is $346,500.00 on just the 12 high fail rate machines they have put these on to date. They are expecting to place a Cold Gun on every circular sock machine within 5 years focusing on the high fail rate machines first. 

If you think you have an application that would benefit from Vortex tube technology, give us a call! We have a team of application Engineers in from 7AM-4PM EST M-F! Or shoot us an email to techelp@exair.com and one of those Engineers will reach out to you!

Jordan Shouse
Application Engineer

Send me an Email
Find us on the Web 
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Twitter: @EXAIR_JS

Vortex Tubes Video – How Fast Can They Produce Cold Air?

Today’s video is going to showcase for you just how fast an EXAIR Vortex Tube or spot cooling product produces cold air to published values. The answer may surprise you. Take a couple minutes and watch, then if you have any questions or want to discuss it further, please contact an Application Engineer.

A Vortex Tube produces cold air instantly, cools down the temperature probe in seconds!

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF