Adjustable Spot Cooler Keeps Rollers Rolling

A manufacturer of automotive power transmission shafts was experiencing frequent failure of high pressure plastic rollers on their spin tester.  There are four rollers in a 90° array that center the shaft during spin testing.  They exert a pressure of around 1,500psi onto the shaft while it’s rotating at 1,000rpm.  This generates enough heat to actually melt the rubber coating on rollers, which means stopping testing (which holds up production) while they change out the rollers.  Just for it to start all over again.

This, of course, was an ideal application for a Vortex Tube cooling solution.  They wanted to aim the cold air flow from the dual points of two Model 3925 Adjustable Spot Cooler Systems at four points of the shaft, right where it starts to contact the rollers.

Model 3925 Adjustable Spot Cooler System has a Dual Outlet Hose Kit for distribution of cold air flow to two points.

Thing was, they wanted to mount the Adjustable Spot Coolers where they could have access to the Temperature Control Valve, but the cold air Hose Kit wouldn’t reach the shaft.  So they got a couple of extra sections of the cold air hose…they needed one section of the ‘main’ (shown circled in blue, below) to reach into the test rig’s shroud, and two sections of the ‘branch’ (circled in green) to reach to each roller.

If you need a little extra reach from an Adjustable Spot Cooler or a Cold Gun, the cold air hose segments snap together, and apart, for any length you need.

Now, adding too much hose length will start to put line loss on the cold air flow, and it will pick up heat from the environment.  But if you just need that extra foot of hose to get the job done, this generally works just fine.  The extra foot or so they’ve added (5″ to the main and 6″ to each branch) has solved their problem…they haven’t had to replace a roller since the Adjustable Spot Cooler Systems were installed.

If you’d like to find out more about how EXAIR Vortex Tubes & Spot Cooling Products can prevent heat damage in your operation, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Real Heroes of Science: Rudolf Hilsch

Rudolf Hilsch helped to advance vortex tube technology into what it is today.

If you look into the history or even the definition of a vortex tube, you’re likely to find mention of a physicist named Rudolf Hilsch.  Born December 18th, 1903, Hilsch was a German physicist, professor, and manager of the Physics Institute of the George August University of Göttingen.  He received a doctorate degree by the age of 24 and spent his career furthering the advancement and understanding of numerous phenomena of physics.

Although Hilsch didn’t invent the Vortex Tube (the original inventor was a physicist by the name of Georges J. Ranque), he is entwined with their history thanks to a paper he published in 1947.  According to lore, this paper significantly changed the understanding and performance capabilities of the vortex tube, eventually being marked as the precursor for identifying a vortex tube as a real potential cooling device. (I’ve made attempts to find this 1947 publication properly translated into English, but to no avail.  If you have it or find it, please email it to me at! (Original publication in German can be found here.)

Given that vortex tubes are a known EXAIR solution, it seems reasonable that today, on Hilsch’s birthday, we give recognition to this influential physicist and his mark on thermodynamic fluid flow technology.  And, although we at EXAIR are connected to Hilsch through vortex tubes, everyone alive has been influenced by his work.  This is because Hilsch and a partner (physicist Robert Wichard Pohl) constructed the first semiconductor amplifier in 1938, prompting Hilsch to prove (in 1939) that solid-state electronics are possible.  This work paved the way for transistor and solid-state electronics technology as we know it today.  Without Hilsch and his life’s work, not only would we not have vortex tubes, we likely would have any electronic devices we use every day.

Here’s to you Rudolf Hilsch.  Thank you for your work, your discoveries, and your achievements.

Lee Evans
Application Engineer



Our Only Priority

Vortex Tubes

I know I’ve written on the topic before, but customer service isn’t just a department at EXAIR, it’s a priority.  And it’s not just a top priority, it’s our only priority.

I’m reminded of the distance between a company like ours and those in other industries whenever I’m required to interact with their service departments.  Rather than sound off about a bad experience, I think it’s more fitting, and becoming of our company culture, to give an example of our standard service level.

I fielded a call today from a manufacturer in Georgia.  They’ve used a series of Vortex Tubes to cool their product as it moves down a conveyor line for quite some time.  Process changes have resulted in greater temperatures and greater throughput, so there is a need to extend the cooling capacity to keep products up to quality.  Essentially what was needed was the same product that has worked in the past, just a few more pieces.  The only problem was that the model number was unknown.

After a search in our system turned up empty, it came to light that the company has changed names (perhaps more than once), and the most accurate way to determine the model number in question would be through a roll-stamped marking on the generator of the Vortex Tube.

The shop foreman and I walked through the disassembly over the phone, and realized that the Vortex Tubes have been in service for so long, that the roll-stamp had worn off.  So, we took it a step further and took measurements of critical dimensions on the generator.  I then cross referenced to our CAD files, and determined the unit was a 2 SCFM model 3200 series Vortex Tube.  A quick email to the shop foreman gave confirmed model number, pricing, and availability.

Situations like this are a regular occurrence for everyone at EXAIR.  If you’re having application difficulties and need a helping hand, we’ll be happy to add you to our list of success stories.

Lee Evans
Application Engineer