Vortex tube

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(In vorticity dynamics, a 'vortex-tube' is also a surface in the fluid formed by all the vortex-lines passing through a given reducible closed curve drawn in the fluid - see George Batchelor's book, section 2.6)

The vortex tube, also known as the Ranque-Hilsch vortex tube, is a mechanical device that separates 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). The gas is split into two streams, one giving kinetic energy to the other, and resulting in separate flows of hot and cold gases. 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. They are also characterized by no moving parts and low efficiency.

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 1945 on the device, which he called a Wirbelröhre (literally, vortex tube).

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).

Another application is for uranium enrichment. South Africa used vortex tubes in their Helikon vortex separation process.

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

Vortex tubes also seem to work with liquids to some extent.

[edit] See also

Windhexe

[edit] References

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.
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.
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.
R.T. Balmer. Pressure-driven Ranque-Hilsch temperature separation in liquids. Trans. ASME, J. Fluids Engineering, 110:161–164, June 1988.