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For the term 'vortex-tube' used in fluid dynamics please see: vorticity

The vortex tube, also known as the Ranque-Hilsch vortex tube, is a mechanical device that separates a compressed gas into hot and cold streams. It has no moving parts.

Pressurized gas is injected into a swirl chamber and accelerates to a high rate of rotation (over 1,000,000 rpm). Due to the conical nozzle at the end of the tube, only the outer shell of the compressed gas is allowed to escape at that end. The remainder of the gas is forced to return in an inner vortex of reduced diameter within the outer vortex. As both vortices rotate at the same angular velocity and direction, the inner vortex has lost angular momentum. The decrease of angular momentum is transferred as kinetic energy to the outer vortex, resulting in separated flows of hot and cold gas. ^[1]

This is somewhat analogous to a Peltier effect device, which uses electrical pressure (voltage) to move heat to one side of a dissimilar metal junction, causing the other side to grow cold.

Contents 1 History 2 Efficiency 3 Proposed applications 4 References 4.1 General references 5 See also 6 External links

The vortex tube was invented in 1933 by French physicist Georges J. Ranque. German physicist Rudolf Hilsch improved the design and published a widely read paper in 1947 on the device, which he called a Wirbelrohr (literally, vortex tube). ^[2] Vortex tubes also seem to work with liquids to some extent. ^[3]

Vortex tubes have lower efficiency than traditional air conditioning equipment. They are commonly used for inexpensive spot cooling, when compressed air is available. Commercial models are designed for industrial applications to produce a temperature drop of about 80 °F (45 °C).

• Dave Williams, of Engineers Without Borders, has proposed using vortex tubes to make ice in third-world countries. Although the technique is inefficient, Williams expressed hope that vortex tubes could yield helpful results in areas where using electricity to create ice is not an option.

• There are industrial applications that result in unused pressurized gasses. Using vortex tube energy separation may be a method to recover waste pressure energy from high and low pressure sources. ^[4]

1. ^ exair.com - Vortex tube theory
2. ^ *Rudolf Hilsch, The Use of the Expansion of Gases in A Centrifugal Field as Cooling Process, The Review of Scientific Instruments, vol. 18(2), 108-1113, (1947). translation of an article in Zeit. Naturwis. 1 (1946) 208.
3. ^ R.T. Balmer. Pressure-driven Ranque-Hilsch temperature separation in liquids. Trans. ASME, J. Fluids Engineering, 110:161–164, June 1988.
4. ^ Sachin U. Nimbalkar, Dr.M.R. Muller. Utilizing waste pressure in industrial systems. Energy: production, distribution and conservation, ASME-ATI 2006, Milan

• G. Ranque, Expériences sur la Détente Giratoire avec Prodctions Simultanées d'un Echappement d'air Chaud et d'un Echappement d'air Froid, J. de Physique et Radium 4(7)(1933) 112S.
• H. C. Van Ness, Understanding Thermodynamics, New York: Dover, 1969, starting on page 53. A discussion of the vortex tube in terms of conventional thermodynamics.
• Mark P. Silverman, And Yet it Moves: Strange Systems and Subtle Questions in Physics, Cambridge, 1993, Chapter 6
• C. L. Stong, The Amateur Scientist, London: Heinemann Educational Books Ltd, 1962, Chapter IX, Section 4, The "Hilsch" Vortex Tube, p514-519.
• J. J. Van Deemter, On the Theory of the Ranque-Hilsch Cooling Effect, Applied Science Research 3, 174-196.
• Saidi, M.H. and Valipour, M.S., "Experimental Modeling of Vortex Tube Refrigerator", J. of Applied Thermal Engineering, Vol.23, pp.1971-1980, 2003.

• Windhexe
• Helikon vortex separation process

• G. J. Ranque's U.S. Patent
• airtxinternational.com - AiRTX International, how vortex tubes work
• Tim Cockerill's pages on the Ranque-Hilsch Vortex Tube, including his 1995 Cambridge University thesis on the subject, and a mailing list.
• How to Make Ice Out of Thin Air: Cool Heat Transfer, Daren Fonda, Sep. 4, 2005, Time Magazine. (Requires membership)
• Oberlin college physics demo
• itwvortec.com - Manufacturer of vortex tubes, information page
• The Hilsch Vortex Tube - Online copy of the Scientific American article by C. L. Stong