How To Make Compressed Air Get Cold…A Couple Of Different Ways

The Vortex Tube makes cold air for the same reason that a can of compressed air gets cold when I clean my computer keyboard, right?

That’s a common question, and since they both start with compress air and end up with cold(er) air, it’s not an unreasonable assumption.  But the answer is no; they’re not the same.   Both are curious physical phenomena, though:

Cans of compressed air get cold while they’re discharging because of a thermodynamic principle known as the adiabatic effect.  When you pressurize a gas by compressing it into a container, you’re putting all those molecules into a smaller volume of space…and you’re adding potential energy by the compression.  Then, when you release that gas back to atmospheric pressure, that energy has to go somewhere…so it’s given off in the form of heat – from the air inside the can, as the pressure inside the can decreases.  Now, the air that’s not under as much pressure as it was when you pushed the button on top of the can is going to start coming out of the can pretty soon.  I mean, there’s only so much air in there, right?  So, since it’s given off that energy immediately upon the drop in pressure, when it comes out of the can, it’s at a lower temperature than it was before you started spraying it out.

Vortex Tubes, on the other hand, generate a flow of cold air by a completely different phenomenon of physics called, maybe not so curiously, the Vortex Tube principle:

You can get a lot more cold air – and a much lower temperature – from a Vortex Tube than you can from a can of compressed air.

If you need a reliable and dependable flow of cold air, look no further than EXAIR’s comprehensive line of Vortex Tubes and Spot Cooling Equipment.  We’ve got 24 models of Vortex Tubes to choose from, as well as “out of the box” solutions for cooling applications like the Adjustable Spot Cooler, Mini CoolerCold Gun Aircoolant Systems. and, to protect your sensitive electrical and electronic enclosures from heat, Cabinet Cooler Systems.  If you’d like to find out more, give me a call.

Russ Bowman

Application Engineer
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When Efficiency And Practicality Collide

Even if you’re a casual reader of our blogs, you already know that EXAIR Application Engineers LOVE to preach efficiency in the use of compressed air…it’s our “bread and butter;” the very nature of our business. This year, we’re celebrating thirty-five years of leading the way in the development of efficient, safe, and quiet compressed air products. Our track record of success as a solutions provider across a diverse range of industrial and commercial applications is well documented in our blogs, as well as Knowledge Base and Case Study Libraries.  We devote considerable resources (engineering, research & development, product testing, etc.) to making certain that EXAIR Intelligent Compressed Air Products cost less to operate, and perform better, than whatever you’re using right now.

Strange as it may seem, though, sometimes our products are EXTREMELY popular in cases where they INCREASE a facility’s consumption of compressed air…by replacing something that DOESN’T use compressed air at all:

*I’ve written before about how our Large Maximum Cold Temperature Vortex Tubes have replaced liquid nitrogen rigs in freeze sealing operations.  Now, a Vortex Tube directs a portion of its air supply to (usually) unusable hot exhaust, in order to generate the usable flow of cold air.  When compared to the costs of liquid nitrogen and the resources involved to get it where it needs to be, though, the cost of the compressed air needed to operate the Vortex Tube is indeed the practical solution.

A 1/4 ton of refrigeration from a product that fits in the palm of your hand, and all you need is a supply or compressed air!

*Line Vacs are probably THE prime example of the value of using compressed air where it wasn’t used before…replacing a “bucket and ladder” operation:

Straight from our Catalog, a perfect example of using valuable compressed air to save even more valuable resources.

*Then there are the situations that just come down to time.  In large spaces, our Super Blast Safety Air Guns can be used to “sweep” the floor in a fraction of the time it takes an operator with a push broom.

Super Blast Safety Air Gun makes short work of large area cleanup.

To make a long story just a little bit longer…if you’re using compressed air, you can use it better with EXAIR’s engineered compressed air products.  And there are plenty of practical applications where you’re not using compressed air right now too.  If you’d like to find out more about either one, give me a call.

Russ Bowman
Application Engineer
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How Versatile Are EXAIR Compressed Air Products?

I wish I could quantify that, but we keep finding more and more applications for them:

Vortex Tubes are used all the time for cooling applications, down to MINUS 40 degrees (Fahrenheit OR Celsius…that’s the point where they’re both the same; no math required.) They also produce a HOT air flow, which we usually call “exhaust,” but some users actually use IT for heating, and call the COLD flow the “exhaust.”

The EXAIR Vortex Tube. Cold air from one end; hot air from the other. Fully adjustable. You can use's fine with us; whatever you need.
The EXAIR Vortex Tube. Cold air from one end; hot air from the other.  You can use either…it’s fine with us; whatever you need.

Our E-Vac Vacuum Generators are popular for “pick-and-place” jobs…hook one up to a Vacuum Cup and you can move parts around all day long. One time, though, I helped a

customer who needed to “pick-and-place” individual small pieces of woven fabric, a lot like a coffee filter. Even our smallest E-Vac, supplied from a Pressure Regulator cranked all the way down, was too much…it would still pick up most of the stack. We found they could use a Model 120020 3/4″ Super Air Amplifier just fine…the Pressure Regulator was still cranked all the way down, and it picked them up one at a time.

No matter what you need to pick-and-place, we've got you covered.
No matter what you need to pick-and-place, we’ve got you covered.

Our Super Air Knives are perfect for blow off, drying, and cooling applications…whether you’re trying to rid your product of dirt/debris, water, or heat, a laminar curtain of adjustable air flow is a “textbook” solution. But I recently had the pleasure of helping a customer who needed to KEEP SOMETHING IN PLACE and called to ask about an Air Knife. They had small cups running single-file down a conveyor belt, with an overhead brush roller pushing down on them at one point so they could be treated on one side. Without something holding them in place, the tooling would simply push them off the side of the conveyor. It required frequent adjustment because they run different sized cups…and they almost always lost some cups when they switched to a different size, while “dialing in” the brush tension. By installing a Model 110036 36″ Aluminum Super Air Knife in place of the brush, they can hold any size cup in place with the downward air flow “curtain.” No more lost product when they don’t get the brush adjustment just right!

Continuous, even, fully adjustable curtain of air...EXAIR Super Air Knives come in lengths from 3 inches to 9 feet.
Continuous, even, fully adjustable curtain of air…EXAIR Super Air Knives come in lengths from 3 inches to 9 feet, in stock.

If you have a compressed air application you’d like to discuss, give me a call.  Perhaps we’ll find the next level of versatility!

Russ Bowman
Application Engineer
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Cabinet Cooler Systems – Around The Clock (And Calendar) Heat Protection

So it was 19°F (-7°C) when I walked outside this morning. The layer of ice on my windshield was thin, but particularly stubborn, and I muttered under my breath. I have no business complaining about the cold…see, I moved to Ohio (on purpose) from Florida, in 1991. In November, to be exact. I still remember where I surrendered my “complain-about-the-cold” card:

If you’re headed north on I95, the next sign you’ll see is in Georgia. And if you’re not careful, you can end up “Up North.”

Why am I writing a blog about solutions to heat problems when, even though I do have a really nice pair of gloves, my fingers still aren’t even really thawed from ice removal duty this morning? Well, I’ve got three reasons:

1. Outside temperature doesn’t necessarily have any bearing at all on the temperature inside. Sure; there’s a reason we call July and August “Cabinet Cooler Season” – summer heat will do a number on sensitive electronic & control panels in spaces with no climate controls, but the problem goes away as winter approaches. In fact, there’s even such as thing as a cabinet HEATER, if the equipment in question is exposed to the elements.   Sometimes, though, heat is an issue year ’round…think blast furnaces, boiler rooms, foundries, chemical plants.  If your process generates heat, it’ll affect a control panel in the dead of winter just the same as on the dog days of summer.  We can quickly and easily specify the right Cabinet Cooler System for you with just a few key pieces of data…here’s a link to our Cabinet Cooler Sizing Guide if you want to find out.

2. It’s not winter all over the world.  Here in the Midwest United States, I full well realize we’re just gearing up for windshield scraping, snow shoveling, slipping-on-the-ice (some people call it skating and do it intentionally) season.  But right now, our friends in the Southern Hemisphere are getting ready for heat waves, sunscreen, and (hopefully) air conditioning.  So, in essence, they’re moving towards what we call “Cabinet Cooler Season.”

3. Our Cabinet Cooler Systems are so great, the 316SS Cabinet Cooler Systems with Electronic Temperature Control are actually up for Plant Engineering’s Product of the Year Award.  Because of their 316SS construction, they’re optimally suited for installation in harsh or demanding locations.  The Electronic Temperature Control offers continuous indication of internal temperature, and the ability to change the thermostat setpoint with the push of a button.  If you’re a current user, and you agree that they’re great, we’d appreciate your vote.  If not, I’m reluctant to encourage you to vote for it, but I suppose I can’t stop you from taking my word for it…

EXAIR NEMA 4X 316SS Cabinet Cooler System with Electronic Temperature Control installed on control panel in a pharmaceutical plant.

If you’d like to talk about protecting sensitive electronics from the heat, or from the environment, or both, I’d love to hear from you…give me a call.

High Temperature Vortex Tube for Sensor Cooling

Last year I worked with a power company that was having issues with Position Feedback Sensors overheating causing erroneous readings and early failures.  The sensors were located above a steam turbine, and the ambient temperatures reached 128°F with spikes to 140-150°F.  The customer had called in looking for a way to keep the sensors cool, using minimal compressed air, and in a robust package.  After reviewing the details, we recommended the High Temperature Vortex Tube, model HT3210.  While using just 10 SCFM of 100 PSIG compressed air, the HT3210 provides 8 SCFM of cold air at a temperature drop of 54°F from the supply air temperature.  Bathing the sensor with this cool air keeps prevents it from heating up and has eliminated the bad readings and prevented the early failures.

The customer recently implemented the same fix for another set of sensors.

Plant Photo
Power Generation Process, with (3) Position Feedback Sensors
Position Feedback Sensor

The High Temperature Vortex Tube is a special Vortex Tube offering from EXAIR that utilizes a brass generator and hi-temp seal for use in ambient temperatures up to 200°F.  Simply supply clean, dry compressed air, and get cold air starting at 50-54°F lower than the supply air temperature.  With sizes ranging from 2 to 150 SCFM, there is a Vortex Tube that will meet most applications.

Vortex tube
High Temperature Vortex Tube

If you have questions about the Vortex Tubes, or would like to talk about any of the EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Adjustable Spot Cooler: How Cold Can You Go?

I had the pleasure of discussing a spot cooling application with a customer this morning. He wanted to get more flow from his Adjustable Spot Cooler, but still keep the temperature very low.  He machines small plastic parts, and he’s got enough cold flow to properly cool the tooling (preventing melting of the plastic & shape deformation) but he wasn’t getting every last little chip or piece of debris off the part or the tool.

After determining that he had sufficient compressed air capacity, we found that he was using the 15 SCFM Generator. The Adjustable Spot Cooler comes with three Generators…any of the three will produce cold air at a specific temperature drop; this is determined only by the supply pressure (the higher your pressure, the colder your air) and the Cold Fraction (the percentage of the air supply that’s directed to the cold end…the lower the Cold Fraction, the colder the air.)

Anyway, the 15 SCFM Generator is the lowest capacity of the three, producing 1,000 Btu/hr of cooling. The other two are rated for 25 and 30 SCFM (1,700 and 2,000 Btu/hr, respectively.)

He decided to try and replace the 15 SCFM Generator with the 30 SCFM one…his thought was “go big or go home” – and found that he could get twice the flow, with the same temperature drop, as long as he maintained 100psig compressed air pressure at the inlet port.  This was more than enough to blow the part & tool clean, while keeping the cutting tool cool, and preventing the plastic part from melting.

Model 3925 Adjustable Spot Cooler System comes with a Dual Outlet Hose Kit, and three Generators for a wide range of cooling performance.

If you’d like to find out how to get the most from a Vortex Tube Spot Cooling Product, give me a call.

Russ Bowman
Application Engineer
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The Case For The Cold Gun

Albert Einstein famously said, “Nothing happens until something moves.” And unless it’s in a perfect vacuum when it moves, there’s gonna be friction. Especially if it’s in contact with something else besides air.  And where there’s friction, there’s heat. This pretty much applies to almost every single evolution in the manufacture of…well, just about everything.

I’m probably not telling you anything you don’t already know, but heat can be a BIG problem.  It can:

  • Shorten tool life. Not only do worn tools take longer to cut, they can also present safety issues.  You can get hurt WAY worse by a dull blade than a sharp one.
  • Cause thermal expansion. If you’re machining something to a precise tolerance, and friction heat causes it to grow, it won’t be the same size when it cools down.
  • Melt plastics. And even softer metals.  This isn’t good for the part…or the tool, either.

Those are just a few of the problems heat causes in manufacturing operations, and they’ve been traditionally addressed with mist (liquid) coolants.  And they work just fine…most of them are water-based, and if you want to get heat out of a solid piece of something, water will do the job VERY quickly.  Other additives in the coolant provide a measure of lubricity, corrosion control, emulsion prevention, etc.  It’s easy, well-known, and time-tested.  There are some drawbacks, however:

  • It can be messy.  When a part (or a tool) in motion gets sprayed down with liquid, it tends to fling that liquid all over the place.  That’s why most machines fitted with mist coolant have spray shields.
  • Not only is it a hassle to clean up, if you don’t stay on top of the clean-up, it can lead to slip hazards.
  • Speaking of hazards, if you can smell that mist (and you know you can,) that means you’re breathing it in too.  Remember the lubricants, corrosion inhibitors, emulsion preventers, etc., I mentioned above?  Yeah…they’re not all what you might call “good for you.”
  • Recirculation systems are common, which means the coolant sump is gathering solids, so the lines and/or spray nozzles can clog and be rendered useless.

EXAIR Cold Gun Aircoolant Systems not only address all of the above problems with heat, but eliminate all the problems associated with liquid coolant:

  • They incorporate EXAIR’s Vortex Tube technology to produce a stream of cold air.
  • They’re reliable.  There are no moving parts; if you supply them with clean, dry air, they’ll run darn near indefinitely, maintenance free.
  • They’re quick & easy.  With a built-in magnet for mounting and a flexible cold air hose, you can be be blowing cold air right where you want it as quickly as you can attach an air hose and open the valve.
  • Speaking of opening the valve, that’s all it takes to run a Cold Gun.  They’re producing cold air at rated flow and temperature, right away.  No “ramp up” time to get into operation.
  • They’re clean.  That cold air stream just becomes…well, air.  No mess.  No slip.  No clean up.  No smell.  No problem.

We’ve got four Models to choose from, depending on the nature of the application:

Both the standard and the High Power come with a Filter Separator, and are available with a one, or two, outlet cold air hose.

If you need to cool parts or tools down, and want it to be effective and clean, give me a call.

Russ Bowman
Application Engineer
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