Vortex Tubes for Dummies

Vortex Tubes are intriguing. We can obtain such extreme cold or hot air with nothing more than compressed air and the Vortex Tube. We can adjust the temps very easily with the turn of a screw. Before we dive into how to adjust and get the right temps for your application, let me share a diagram of how the Vortex Tube works:

The unique physical phenomenon of the Vortex Tube principle generates cold air instantly, and for as long – or short – a time as needed.

Now that we have seen how it works, we need to define how to make it work for your specific application! First we need to set the cold fraction… Setting the “cold fraction” is all about how cold or hot you need the air to be. When we talk about this cold fraction, we are talking about the amount of the cold air that comes out of the cold side of the Vortex Tube, which also affects the temperature of that cold air. In other words, a 60% cold fraction equals 60% of the input compressed air exiting the Vortex Tubes cold side.

For example, if you are supplying 80 psi to our medium sized Vortex Tube, you will be generating between 10 and 40 SCFM (depending on the size of the generator). Let’s assume for this example that you are using our 3230 Vortex Tube, generating 30 SCFM. At an 80% cold fraction, 24 SCFM (80% of 30) will be flowing out of the cold end of the Vortex Tube. And it will be flowing at a temperature that is 50°F colder than the temperature of the compressed air provided. Yes, that is correct, assuming that your inlet air temp is 72°F, you will be flowing 24 SCFM of 22°F air from the cold end of the Vortex Tube. But what about the other 6 SCFM? Well, that will be flowing out of the hot end at a whopping 252°F. We must take into account both ends of the Vortex Tube. You can see the performance table below.

EXAIR Vortex Tube Performance Chart

Let’s look at one more example of this same Vortex Tube 3230. Let’s assume that we need to heat something up. Assuming that your compressed air is 72°F, and we want to heat something up to 115°F, we need to add 43°F to the temp of the compressed air. We can see in the chart that by supplying 80 psig of compressed air, and a 30% Cold Fraction on the Vortex Tube that we can add 43° to the temp of the air. We know that the cold end will give us 9 SCFM (30% of the overall 30 SCFM) and it will flow at -110°F, or -38°F. But we will reach our 115°F desired temp on the hot end, but that will only be at 21 SCFM. If we still need that higher SCFM, we may need to change the generator (explained below) or increase to a larger Vortex Tube all together.

As you can see from the above performance table, there are many ways to get to your desired temperature, be it hot or cold.

Adjusting the Vortex Tube

Next comes the question of how do we adjust the cold fraction. 1st, let me note that unless specified, these always ship to you set at or close to the 80% cold fraction, but, if you want them set to a precise cold fraction, we can permanently set these for you prior to shipping. As you see in the picture to the left, the slotted valve can be turned to adjust the cold fraction. For precision purposes it is always recommended to use a thermometer to set this where you need it (insert the thermometer into the cold flow of air). As a guide, you should seat the valve softly, and back off an 1/8th, a 1/4, or a 1/2 turn (for the small, medium, and large sizes respectively) to drop approximately 20% on the cold fraction scale.

We offer 3 sizes of Vortex Tubes, small, medium and large. Each size offers 3-5 different interchangeable size generators, with a total offering of 12 stock Vortex Tubes. The size of the generator will determine the BTU/hr, as well as the SCFM generated. See the following table for more details:

There are a few other key details to know about the Vortex Tubes. They do not like back pressure. As you can imagine, the magic that makes these work is spinning the generator inside. If that is slowed down due to back pressure, well, it will hinder the results of the entire Vortex Tube. Many people have air coolers or heaters on their compressed air system, keep in mind that the temps generated by the Vortex Tubes are ± the temperature of the compressed air, so it is important to know the temp of your compressed air.

Vortex Tubes can be very loud. We almost always sell these with the Cold and Hot Mufflers. In order to keep most of them under the OSHA standards for sound, you will want the mufflers. Lastly, as with all of EXAIR’s products, it is recommended to use a pressure regulator with a gauge at the point of use. With the Vortex Tubes, it is imperative if you are looking for an accurate temperature.

If you have any questions about the Vortex Tubes, or any of our intelligent air products, please do not hesitate to reach out.

Thank you for stopping by,

Brian Wages

Application Engineer

EXAIR Corporation
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Product Spotlight: Soft Grip Super Air Scraper

Have you ever dipped your hand into a warm bath of paraffin wax? You can feel your hand relaxing. When you pull it out and begin to peel the wax away you can already tell how soft and refreshed your hand feels. And then someone gives you a hand massage while you sit there in complete bliss, your hand completely relaxed and rejuvenated. Well, this is not at all how the Soft Grip Super Air Scraper makes your hands feel. But the Soft Grip handle is very comfortable and does feel better than any other option on the market.

The Soft Grip handle is ideal for continuous use without causing fatigue. The design keeps your hand in a comfortable position and the large trigger allows an easy pull with one finger or all of them. This is built to endure the toughest industrial environments, and it even comes with a convenient hangar hook for easy storage.

Scrape off, and blow away, stubborn debris with the Model 1244-48 Soft Grip Super Air Scraper.

Once we get past the comfortable handle, we move down to the purpose. The Air Scraper portion will assist in removing some of the toughest debris found in industrial facilities. The patented design uses the scraping blade along with powerful compressed air flow. This is perfect for any of those sticky substances like caulk, sealants, gaskets, adhesives, tape, paint stickers, labels, grease, lubricants, and so much more. This will help you keep your machining tables, and assembly stations clean and functional.

The scraper is made of corrosion resistant steel and is attached to a 2″ Super Air Nozzle. It is very formidable to provide the strength necessary for the toughest scenarios. This comes with a 3/4″ extension for those close up needs, but we offer extensions for this from 6″ to 72″ long so that you can reach table tops, walls, inside machines, and floors.

Please reach out to us at anytime with questions about the Soft Grip Super Air Scraper, or any of our other amazing products.

Thank you for stopping by,

Brian Wages

Application Engineer

EXAIR Corporation
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Air Amplifiers to Increase Volume of Airflow Aid in Cooling, Cleaning, Circulation, Venting

Air Amplifiers are a perfect solutions for utilizing air for Venting, Exhausting, Cooling, Drying, or Cleaning with no moving parts. As the name implies, these tools produce a high volume and a high velocity of outlet flow. These are very quiet, efficient and can amplify your air consumption up to 25 times… Here is a great diagram and description of exactly how these work:

Air Amplifiers use the Coanda Effect to generate high flow with low consumption.

As you can see, these fine pieces of engineering genius have no moving parts, and require no electricity. You can easily control the flow, force and velocity by opening or closing the air gap (fixed with a shim) and regulating the the supply air. These can also be ducted on each end to either pull in or remove air or fumes from one room or area to another.

SUPER?? What makes our Super Air Amplifier super? I’m glad you asked. The Super Air Amplifier has a patented design that uses a special shim to maintain critical position of the component parts. This results in a precise amount of compressed air to be released at exact intervals towards the center of the Super Air Amplifier. These jets of air create a constant, high velocity outlet flow across the entire cross-sectional area. This balances out the airflow to maximum performance, this simultaneously minimizes wind shear, causing sound levels up to 3 x’s quieter than other comparable air movers. To completely understand how much air this Super Air Amplifier amplifies (try saying that fast 5 times), please see the below chart.

As you can see, the amplification ratio is between 12 and 25 x the amount of air consumed. For the right applications, these are game changers… Pro tip – notice that even the highest level still falls under OSHA guidelines for noise!!

If you have any questions, or would like to discuss your application directly, please reach out today. We would love to speak with you, and help wherever we can.

Thank you for stopping by,

Brian Wages

Application Engineer

EXAIR Corporation
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OSHA Says Keep Compressed Air Use Safe and Quiet: EXAIR Does Just That

The Occupational Safety and Health Act was signed by Richard Nixon in 1970. Under the United Sates Department of Labor, shortly thereafter; OSHA, or the Occupational Safety and Health Administration was born. OSHA is a large regulatory agency tasked to assure safe and healthy working environments by setting and enforcing standards as well as to provide training, outreach and assistance. Although some people’s first response is to cringe at the word OSHA, they have been instrumental in dramatically reducing injury rates and injury costs without negative effects on employees or companies.

Sure we can all cringe by looking up OSHA horror stories on YouTube. And many of us have a story about that one company that was fined 10’s of thousands of dollars for x, y, or z violations… But in reality, OSHA are not the bad guys. They are not looking for fines, in fact they generally give warnings and timelines to fix possible issues, prior to an incident. The fines typically are generated when companies fail to comply. Yes, I know there are always exceptions, but exceptions are not the rule. We hear and hold on to the radical stories, and the day to day, mundane stories fall to the wayside. Regardless of how we feel, we all must comply.

When it comes to EXAIR products, there are two OSHA standards that we must adhere to. One is related to “sound” and one is related to “dead end pressure”.

First let’s look at the dead end pressure. OSHA Safety requirement 29 CFR 1910.242 (b) discusses the possibilities for air embolisms when more than 30 psi is “dead ended” into your skin. EXAIR products have pathways for air to exhaust so that they cannot be “dead ended”. Each product has a way for the air to exhaust to avoid danger. Here are a couple of examples:

Air nozzles have multiple paths to exhaust pressure
Air Knives exhaust the entire path, as well as out each end

Take note that when being used properly (no horseplay) the airflow will have some path to escape and cannot be blocked. They are designed so that air will escape prior to any danger.

Next we will take a look at OSHA requirement 29 CFR-1910.95 (a). This regulation deals with occupational noise exposure. Measuring sound in decibels (dBA) the magic number is 90. Anything under 90 dBA has no limitations on how long you can be exposed to it. For a reference 60 dBA is about the sound level of a normal conversation, or an air conditioner. 70 dBA is about the noise of a washing machine, 80-85 is like city traffic. Then we start getting loud like a motorcycle around 95, shouting or barking is about 110, and standing near a siren is about 120dBA.

Hearing loss is the best known, but not the only, ill effect of harmful noise exposure. It can also cause physical and psychological stress, impair concentration, and contribute to workplace accidents or injuries.

As mentioned, 90 dBA or less is our target to avoid needing alternative solutions such as noise barriers or PPE. Nearly all EXAIR products are compliant at or under 90 dBA. The few exceptions are with some of our high force / extensive reach products such as our High Force Air Nozzles.

Please reach out at anytime if you have any questions, or want to discuss EXAIR and OSHA compliance, or any EXAIR questions at all.

Thank you for stopping by,

Brian Wages

Application Engineer

EXAIR Corporation
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