Tag: hilsch

Rudolf Hilsch and How the Ranque-Hilsch Vortex Tube Came To Be

Published on by Jordan T ShouseLeave a comment

The exact beginnings of the device remain unclear. It is believed that a French inventor, Georges Ranque, stumbled upon the principle and abandoned some initial prototypes in the wake of the German Army during France’s occupation. These prototypes caught the attention of Rudolf Hilsch, a German physicist engaged in developing low-temperature refrigeration systems for the war effort. Hilsch enhanced the original design but discovered that it did not outperform traditional refrigeration techniques in reaching relatively low temperatures. Eventually, the device became recognized as the Hilsch tube.

The Original drawing from Rudolf Hilsche’s 1947 Publication.

The Hilsch tube was assembled using a pair of modified nuts along with various other components. The horizontal section of the T-shaped fitting features a uniquely machined element that fits snugly within the arm. This element has a spiral cross-section on the inside, contrasting with its outer shape. At the “step” of the spiral, there is a small opening that connects to the T’s leg. When air enters through the leg, it exits through this opening and spirals around the one-turn design. The “hot” pipe measured approximately 14 inches in length and had a half-inch internal diameter. Its far end is equipped with a stopcock to regulate the system’s pressure. Meanwhile, the “cold” pipe is about four inches long, also with a half-inch internal diameter. The end that connects to the spiral piece has a washer with a central hole of around a quarter of an inch in diameter. Additionally, washers with varying hole sizes can be used to fine-tune the system.

With EXAIR’s vortex tube, compressed air is supplied into the tube where it passes through a set of nozzles that are tangent to the internal counter-bore. The design of the nozzles forces the air to spin in a vortex motion at speeds up to 1,000,000 RPM. The spinning air turns 90° where a valve at one end allows some warmed air to escape. What does not escape, heads back down the tube into the inner stream where it loses heat and exhausts through the other end as cold air.

How a Vortex Tube Works

Both streams rotate in the same direction and at the same angular velocity. Due to the principle of conservation of angular momentum, the rotational speed of the inner vortex should increase. However, that’s not the case with the Vortex Tube. The best way to illustrate this is with Olympic Figure Skating. As the skater is wider, the spinning motion is much slower. As she decreases her overall radius, the velocity picks up dramatically and she spins much quicker. In a Vortex Tube, the speed of the inner vortex remains the same as it has lost angular momentum. The energy that is lost in this process is given off in the form of heat that has been exhausted from the hot side of the tube. This loss of heat allows the inner vortex to be cooled, where it can be ducted and applied for a variety of industrial applications.

This Vortex Tube theory is utilized in basic Vortex Tubes, along with a variety of other products that have additional features specific for your application. EXAIR’s line of Cabinet Coolers, Cold Guns, Adjustable Spot Coolers, Mini Coolers, and Vortex Tubes all operate off of this same principle.

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EXAIR HazLoc Cabinet Cooler Systems provide safe and reliable

If you’re fascinated by this product and want to give it a try, EXAIR offers an unconditional 30-day guarantee. We have them all in stock and ready to ship as well, the same day with an order received by 2:00 ET. Feel free to get in contact with us if you’d like to discuss how a vortex-based product could help you in your processes.

Jordan Shouse
Application Engineer

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Rudolf Hilsche’s Publication Drawing provided by Die Zeitschrift für Naturforschung

(Photo Link https://zfn.mpdl.mpg.de/data/1/ZfN-1946-1-0208.pdf )

Rudolf Hilsch, Shining a Light on the Vortex Tube

Published on by Jordan T ShouseLeave a comment

The Vortex Tube is also known as the Ranque – Hilsch tube is a device that takes a single source of compressed gas and splits it into two streams a hot and a cold. The Vortex Tube was invented in 1933 by French physicist Georges J. Ranque, however his findings never really went main stream until Physicist Rudolf Hilsch improved the design and published a widely read paper in 1947 on the device, which he called a Wirbelrohr. (Original publication in German can be found here.)

The Original drawing from Rudolf Hilsche’s 1947 Publication.

Compressed air is supplied into the tube where it passes through a set of nozzles that are tangent to the internal counter-bore. The design of the nozzles force the air to spin in a vortex motion at speeds up to 1,000,000 RPM. The spinning air turns 90° where a valve at one end allows some warmed air to escape. What does not escape, heads back down the tube in the inner stream where it loses heat and exhausts through the other end as cold air.

How a Vortex Tube Works

Both streams rotate in the same direction and at the same angular velocity. Due to the principle of conservation of angular momentum, the rotational speed of the inner vortex should increase. However, that’s not the case with the Vortex Tube. The best way to illustrate this is in Olympic Figure Skating. As the skater is wider, the spinning motion is much slower. As she decreases her overall radius, the velocity picks up dramatically and she spins much quicker. In a Vortex Tube, the speed of the inner vortex remains the same as it has lost angular momentum. The energy that is lost in this process is given off in the form of heat that has exhausted from the hot side of the tube. This loss of heat allows the inner vortex to be cooled, where it can be ducted and applied for a variety of industrial applications.

This Vortex Tube theory is utilized in basic Vortex Tubes, along with a variety of other products that have additional features specific for your application. EXAIR’s line of Cabinet Coolers, Cold Guns, Adjustable Spot Coolers, Mini Coolers, and Vortex Tubes all operate off of this same principle.

EXAIR HazLoc Cabinet Cooler Systems provide safe and reliable heat protection in classified environments

If you’re fascinated by this product and want to give it a try, EXAIR offers an unconditional 30-day guarantee. We have them all in stock and ready to ship as well, same day with an order received by 2:00 ET. Feel free to get in contact with us if you’d like to discuss how a vortex-based product could help you in your processes.

Jordan Shouse
Application Engineer

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

Rudolf Hilsche’s Publication Drawing provided by Die Zeitschrift für Naturforschung

(Photo Link https://zfn.mpdl.mpg.de/data/1/ZfN-1946-1-0208.pdf )

Vortex Tubes: What, Why, Where?

Published on by EricKuhnash@EXAIR.comLeave a comment

The most common questions about Vortex Tubes are “How long have they been around?” and “How do they work?”. These questions are simple enough and answering someone how long Vortex Tubes have been around is the easy answer, Vortex Tubes have been around since 1928 with what may seem as an accidental existence by the developer George Ranque.

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. They have been called various names such as “Maxwell’s Demon” which posited that a demon was splitting the hot and cold air molecules prior to leaving the Vortex Tube.  They have also been referred to as  the “Ranque Vortex Tube”, “Hilsch Tube”, and the “Ranque-Hilsch Tube” which highlight some of the prominent people in developing vortex tubes. 

WHAT: EXAIR defines a Vortex Tube within our catalog as “a low cost, reliable, maintenance free solution to a variety of industrial spot cooling problems. Using an ordinary supply of compressed air as a power source, vortex tubes create two streams of air, one hot and one cold, with no moving parts.”

The scope of Vortex Tubes include being able to produce temperatures from -50 degrees to 260 degrees Fahrenheit with flow rates from 1 to 150 SCFM and refrigeration up to 10,200 Btu/hr. Temperatures, flows and cooling power can be easily adjusted with the control valve located on the “hot” end of the tube.

WHY: EXAIRs’ Vortex Tubes offer low cost and reliable solutions primarily for product cooling and sometimes heating. Constructed of stainless steel, our vortex tubes are resistant to corrosion and oxidation providing for years of reliable maintenance-free operation. Vortex tubes operate with a source of compressed air with no moving parts or electricity.

EXAIR offers two series of vortex tubes. The 32XX series is “Maximum Refrigeration (cooling) and is typically used for process cooling, part cooling or chamber cooling. The 34XX series provide lowest cold temperatures at low cold airflow and typically used in cooling lab samples and circuit testing.

EXAIR offers a cooling kit with interchangeable generators that are easily changed so you can experiment and find what temperature and airflow works best for your application.

WHERE: There are many uses for EXAIR Vortex Tubes including but not limited to cooling electronics, machining operations, CCTV cameras, soldered parts, gas samples, heat seals, environmental chambers, ultrasonic weld horns, welds and setting hot melts.

The history of EXAIR Vortex Tubes and the variety of uses has derived new products designed for specific applications like our Spot Coolers and Cabinet Coolers. These items can be found in our catalog or at www.EXAIR.com.

If you have any questions regarding these products or any products that EXAIR offers I hope to hear from you.

Eric Kuhnash
Application Engineer
E-mail: EricKuhnash@exair.com
Twitter: Twitter: @EXAIR_EK

A Cold Winter’s Chill and Vortex Tubes

Published on by codybiehleLeave a comment

Two weekends ago I had the pleasure of flying out to meet my friend in Colorado Springs and ski the weekend at Breckenridge. As an avid skier Breckenridge has been one of the resorts I have been wanting to ski since I started skiing out west. The weather was amazing and I couldn’t ask for better; the Saturday blue skies and cool breeze followed up by a Sunday of snow fall. The Trip was a dream come true. Breckenridge is specifically known for having high winds that howl across the peaks that stand at a max of 12,998 ft. above sea level. These chilling winds would freeze just about anyone if you aren’t dressed prepared for them as they blow right in your face on the lift. As I was sitting on the lift with these cold winds blowing in my face it brought to mind EXAIR’s Vortex Tubes, Cold Guns, and Cabinet Coolers.

EXAIR’s Vortex Tubes and similar products provide everything from a cool blast of air to a frigid breeze to cool off various parts and products. In a lot of smaller milling and grinding applications the Cold Gun has been used as a replacement to costly coolant-based alternatives. Vortex tubes have been used in cooling applications since 1945 and assist in everything from stress testing electronics to cooling down plastic parts during ultrasonic welding.

 Vortex tubes use a source of compressed air to create a hot and cold stream of air coming out on opposite ends of the device. This means that not only can the vortex tube be used for cooling but also heating applications. In one case a vortex tube was used to heat up an adhesive before it was sealed to get a better adhesion. Although the vortex tube can be used for heating purposes those applications are few and far between as usually a heating element or other heating source is more applicable.
Vortex tubes are quickly adjustable, just as the winds of Breckenridge can change from being a breeze to almost blowing you off of the mountain. Weather in the mountains is always varying and so are EXAIR’s Vortex Tubes.

If you have any questions or want more information on how we use our vortex tubes to improve processes all over industry. Give us a call, we have a team of application engineers ready to answer your questions and recommend a solution for your applications.

Cody Biehle
Application Engineer
EXAIR Corporation
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