Tag: Georges Ranque

Controlling Temperature And Flow From A Vortex Tube

Published on by Russ BowmanLeave a comment

The Vortex Tube is among the most fascinating air-operated devices to me. It’s right up there with the pneumatic impact wrench, which is my HIGHLY preferred method of removing (and replacing) a tire on a vehicle. While there are several different types of impact wrenches, they all basically use air pressure to move internal parts in a manner in which they strike (or impact) a rotating element with a socket on the end, resulting in a lot more torque being applied than if it was simply spinning a propeller attached to the shaft.

Vortex Tubes, on the other hand, all work on the same principle, discovered by a French engineer, Georges Ranque, while he was experimenting with a new design of a vacuum pump in 1922. There doesn’t seem to be any record of him completing the work on his newfangled vacuum pump, but he did continue experimenting with this device that made hot air come out one end, and cold air come out the other, getting a patent for it in 1931.

How a Vortex Tube Works: compressed air enters the vortex spin chamber (big blue arrow from above left), where the Generator imparts a spinning motion to it (red ribbon, moving to the right). When the spinning air flow reaches the other end, some of it is forced to change direction and, while still spinning, flow the other way (blue ribbon, moving to the left). The rest exits through the hot valve (represented by the yellow cone). When the spinning air flow changes directions, it gives off energy in the form of heat, causing hot air to exit one way, and cold air to exit the other.

EXAIR offers two series of Vortex Tubes:

  • 32XX series, or Maximum Refrigeration. These make the highest flows of cold air, at temperatures suitable for rapid cooling of warm objects to ambient (or below) temperatures.
  • 34XX series, or Maximum Cold Temperature. These will give you the coldest air possible – as low as minus 50°F – but at lower flows, relative to the 32XX series. I’ll go into more detail on both of these in a minute.
Sub-zero air flow from Model 3408 Vortex Tubes cools & solidifies chocolate in candy molds.

Both of these series consist of Vortex Tubes in three sizes, with multiple models in each size. The difference between the models in each series is the compressed air consumption:

You can control the temperature, and the flows (both hot and cold), of any Vortex Tube in a few different ways:

  • Supply pressure affects the total flow of the two air streams, and the magnitude of the change in temperature. Since higher pressure equals more energy, it stands to reason that, at higher pressures, the hot air will be hotter, and the cold air will be colder.
  • Cold Fraction is the percentage of the compressed air supply that gets directed to the cold end. You can get VERY cold air from a Vortex Tube by setting it to a low cold fraction. This is done by opening the Hot Valve to let more hot air out. That causes the flow rate, and the temperature of the air coming out of the cold end, to drop.
Turning the Hot Valve counterclockwise (blue arrow) lets more hot air out, which lowers the cold air flow, and temperature. Turning it clockwise (red arrow) lets less hot air out, which raises the cold air flow…and temperature.
  • Two types of Generators can be installed in an EXAIR Vortex Tube – these are what determine the series I mentioned above:
    • Type “R” (Maximum Refrigeration) Generators allow for Cold Fraction adjustments from 50-80%. With an air supply pressure of 100psig, the cold air will be 54°F (when set to an 80% Cold Fraction) to 100°F (at a 50% Cold Fraction) lower than the compressed air supply temperature. This makes them suitable for applications where rapid cooling of an object is needed.
    • Type “C” (Maximum Cold Temperature) Generators give you Cold Fraction adjustments from 20-50%. A Vortex Tube with a “C” Generator installed will give you the same 100°F temperature drop as the “R” Generator will at a 50% Cold Fraction, but at a 20% Cold Fraction, it’ll be 123°F colder than the supply. These are used where cooling to temperatures below 0°F is needed.
How to tell which Generator is installed in a Vortex Tube.

If you need to remove & replace a tire, I strongly recommend using a pneumatic impact wrench. If you need to blow cold air for something, I just as strongly recommend using an EXAIR Vortex Tube. Different applications require different series, models, and settings. Give me a call if you’d like to find out which combination of those is right for your application.

Russ Bowman, CCASS

Application Engineer
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Georges J Ranque: Father of the Vortex Tube

Published on by codybiehleLeave a comment

Georges J. Ranque is known as the inventor and father of the Ranque-Hilsch Vortex tube. The vortex tube is device that takes a compressed gas and generates hot and cold streams from a source of compressed gas. George accidentally discovered the phenomenon on accident while studying physics at Ecole Polytechnique in Paris France. Ranque was looking was performing an experiment on a vortex-based pump to vacuum up iron fittings; during the experiment he noticed that warm air was being expelled out of one side and cold air out of the other when he inserted a cone into one end of the vortex. In 1931 Ranque filed for a patent for the vortex tube and two years later presented a paper on it.

Georges vortex tube was all but lost and forgot about until 1945 when the German physicist Rudolph Hilsch published a paper on the device. This paper became widely read and exposed the vortex tube to the industrial manufacturing environment. This paper revived what was thought to be lost and led the vortex tube into what we see today.

How an EXAIR Vortex Tube operates

During World War 2 Georges Ranque started to develop different steels that would be used in military aviation efforts. He later went on to work at Aubert et Duval Steelworks as the Director of Metallurgical Laboratory. While at Duval he would continue to developing alloys for the aviation industry.

Interestingly, in 1972 he went on to publish a book on the search for the Philosophers Stone, a mythological chemical substance that Alchemist’s thought could be used to turn base metals into Gold. The following year in 1973 he passed away in his home just outside of Paris.

Here at EXAIR we have expanded the uses of Ranque’s original vortex tubes for various different cooling uses. The vortex tube can be found in our Cold Guns, Spot Coolers, and Cabinet Coolers. In many cases EXAIR’s spot coolers and cold guns have been used to replace coolant in simple milling and grinding applications. Also, EXAIR’s Cabinet Coolers have been keeping control cabinets from overheating for many decades. 

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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Georges J. Ranque and the Vortex Tube

Published on by Jordan T ShouseLeave a comment

The Vortex Tube was invented by accident in 1928, by George Ranque, a French physics student. He was performing experiments on a vortex-type pump that he had developed for vacuuming iron filings and noticed that warm air exhausted from one end and cold air from the other when he inserted a cone at one end of the tube! Ranque quickly stopped work on the pump, and started a company to take advantage of the commercial possibilities for this odd little device that produced both hot and cold air, using only compressed air, with no moving parts. The company was not successful, and the vortex tube was forgotten until 1945 when Rudolph Hilsch, a German physicist, published a widely read paper on the device.

How A Vortex Tube Works

A vortex tube uses compressed air as a power source, has no moving parts, and produces hot air from one end and cold air from the other. The volume and temperature of the two air streams is adjustable with a valve built into the hot air exhaust.  Temperatures as low as -50°F (-46°C) and as high as 260°F (127°C) are possible.

During the second world war Georges J. Ranque started developing steels that would be used in military aviation efforts. After the war he took a job at  Aubert et Duval steelworks as director of metallurgical laboratory where he continued developing alloys for use in the aviation industry.

In 1972 he published a book on the search for the Philosophers stone, a legendary chemical substance capable of turning base metals such as mercury into gold. And in 1973 he passed away in his home just outside of Paris.

If you have any questions of want more information on how we use our vortex tubes to better 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.

Jordan Shouse
Application Engineer
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People of Interest: Rudolf Hilsch

Published on by John BallLeave a comment

Vortex Tubes

The EXAIR Vortex Tubes use compressed air to generate a cold air stream at one end and a hot air stream at the other end.  The history behind this phenomenon is rooted in the Ranque-Hilsch tube.  In 1931, a French physicist, Georges Ranque, tried to use a cyclone vortex to separate iron filings from the air.  He noticed that when he capped one end with a slight opening, the air would become very warm.  Being disappointed with the separation, he shelved his patented idea for several years.  In 1946, Rudolf Hilsch picked up this idea from Georges Ranque and “tweaked” the design.  This product has now become known as the Vortex Tube.  In this blog, I will cover Rudolf Hilsch as a person of interest.

Rudolf Hilsch was born in December 18th, 1903 in Hamburg, Germany and died on May26th, 1972.  In 1927, Rudolf received his doctorate at the age of 24.  In 1938, he worked with a colleague, Robert Pohl, to create one of the first working semiconductor amplifier.   From 1941 to 1953, Hilsch was a professor of physics at Erlangen, and in 1947, he published his paper of the Ranque-Hilsch tube which he called the “Wirbelrohr”, or whirl pipe.  This publication became well known and was the start of the Vortex Tube.  To continue on with his career, in 1953, he became a full member of the Bavarian Academy of Sciences.  Also, at that same time, he started teaching physics at the Physics Institute of the Georg August University of Göttingen well into the 1960s.

Inside the Vortex Tube

To expand a bit more into his publication, the design for spinning the air at a high rate of speed can produce a separation of temperatures.  It starts with a generator to help facilitate a vortex.  As the vortex travels toward one end, a portion of that air will travel back through the center toward the opposite end.  (Reference animation above).  As these two vortices interact, conservation of momentum forces the inner vortex to give off energy in a form of heat to the outer vortex.  This separation of temperatures will give you a hot air stream and a cold air stream.  This type of device can do this without any moving parts or Freon.  You just have to supply a compressed gas.

EXAIR manufactures Vortex Tubes that utilize this phenomenon with compressed air.  We stock units with cooling capacities up to 10,200 BTU/hr and can reach temperatures from -50oF to +260oF (-46oC to +127oC).  So, thank you Mr. Ranque and Mr. Hilsch for creating a product to generate hot and cold air in a single unit.  If you would like to discuss any applications where cooling or heating is needed, you can talk with one of our Application Engineers.  We will be happy to help.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb