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.
*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:
*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.
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.
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.”
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 Amplifierjust fine…the Pressure Regulator was still cranked all the way down, and it picked them up one at a time.
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!
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!
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:
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…
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.
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.
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.
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.
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.
If you’d like to find out how to get the most from a Vortex Tube Spot Cooling Product, give me a call.
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.
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:
If you need to cool parts or tools down, and want it to be effective and clean, give me a call.
The principle behind a Vortex Tube is rooted in the Ranque-Hilsch effect which takes place inside of the tube. As a compressed air source is fed into the Vortex Tube, the air flows through a generator and begins to spin down the length of the tube, “hugging” the ID of the tube. When this spinning air contacts a deliberate obstruction at the end of the tube, it is forced to reverse directions, which requires a change in diameter to the vortex. The original vortex must decrease in diameter, and in order to do so, it must give off energy. This energy is shed in the form of heat, and a portion of the incoming air is directed out of the tube with a drastically reduced temperature via what is called the “cold end”. Another portion of the air escapes through the “hot end” of the tube, resulting in a cold airflow at one end, and a hot airflow at the other end of the tube.
Small, but powerful, Vortex Tubes really are a marvel of engineering. And, like most useful developments in engineering, Vortex Tube technology begs the question “How can we control and use this phenomena?” And, “What are the effects of changing the amount of air which escapes via the cold end and the hot end of the tube?”
These answers are found in the understanding of what is called a cold fraction. A cold fraction is the percentage of incoming air which will exhaust through the cold end of the Vortex Tube. If the cold fraction is 80%, we will see 80% of the incoming airflow exhaust via the cold end of the tube. The remaining airflow (20%) will exhaust via the hot end of the tube.
For example, setting a model 3210 Vortex Tube (which has a compressed air flow of 10 SCFM @ 100 PSIG) to an 80% cold fraction will result in 8 SCFM of air exhausting via the cold end, and 2 SCFM of air exhausting through the hot end of the Vortex Tube. If we change this cold fraction to 60%, 6 SCFM will exhaust through the cold end and 4 SCFM will exhaust through the hot end.
But what does this mean?
Essentially, this means that we can vary the flow, and temperature, of the air from the cold end of the Vortex Tube. The chart above shows temperature drop and rise, relative to the incoming compressed air temperature. As we decrease the cold fraction, we decrease the volume of air which exhausts via the cold end of the Vortex Tube. But, we also further decrease the outlet temperature.
This translates to an ability to provide extremely low temperature air. And the lower the temperature, the lower the flow.
With this in mind, the best use of a Vortex Tube is with a setup that produces a low outlet temperature with good cold air volume. Our calculations, testing, and years of experience have found that a cold fraction of ~80% can easily provide the best of both worlds. Operating at 100 PSIG, we will see a temperature drop of 54°F, with 80% of the incoming air exiting the tube on the cold end (see red circle in chart above). For a compressed air supply with a temperature of 74°F-84°F (common compressed air temperatures), we will produce an output flow with a temperature between 20°F and 30°F – freezing cold air!
With a high volume and low temperature air available at an 80% cold fraction, most applications are well suited for this type of setup. When you order a Vortex Tube from EXAIR we will ship it preset to ~80% cold fraction, allowing you to immediately install it right of the box.
The cold air from an EXAIR Vortex Tube is effective to easily spot cool a variety of components from PCB soldering joints to CNC mills, and even complete electrical control panels. Contact an Application Engineer with application specific questions or to further discuss cold fractions.