Separation of a compressed gas into a hot stream and a cold stream 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 tangentially into a swirl chamber and accelerates to a high rate of rotation. 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. There are different explanations for the effect and there is debate on which explanation is best or correct. What is usually agreed upon is that the air in the tube experiences mostly "solid body rotation", which simply means the rotation rate (angular velocity) of the inner gas is the same as that of the outer gas. This is different from what most consider standard vortex behaviour-where inner fluid spins at a higher rate than outer fluid. The (mostly) solid body rotation is probably due to the long time which each parcel of air remains in the vortex--allowing friction between the inner parcels and outer parcels to have a notable effect. It is also usually agreed upon that there is a slight effect of hot air wanting to "rise" toward the center, but this effect is negligible--especially if turbulence is kept to a minimum. One simple explanation is that the outer air is under higher pressure than the inner air (because of centrifugal force). Therefore the temperature of the outer air is higher than that of the inner air. Another explanation is that 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. 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.
When used to refrigerate, heat-sinking the whole vortex tube is helpful. Vortex tubes can also be cascaded. The cold (or hot) output of one can be used to pre-cool (or pre-heat) the air supply to another vortex tube. Cascaded tubes can be used, for example, to produce cryogenic temperatures. History 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, whirl pipe). Vortex tubes also seem to work with liquids to some extent. Efficiency 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 45 °C (80 °F). Proposed applications * Dave Williams, of dissigno, 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 gases. Using vortex tube energy separation may be a method to recover waste pressure energy from high and low pressure sources. References 1. ^ exair.com - Vortex tube theory -- http://www.exair.com/Cultures/enUS/Primary+Navigation/Products/Vortex+Tubes+and+Spot+Cooling/Vortex+Tubes/A+Phen omenon+of+Physics 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 General references * G. Ranque, Expériences sur la Détente Giratoire avec Productions 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. * M. Kurosaka, Acoustic Streaming in Swirling Flow and the Ranque-Hilsch (vortex-tube) Effect, Journal of Fluid Mechanics, 1982, 124:139-172 * M. Kurosaka, J.Q. Chu, J.R. Goodman, Ranque-Hilsch Effect Revisited: Temperature Separation Traced to Orderly Spinning Waves or 'Vortex Whistle', Paper AIAA-82-0952 presented at the AIAA/ASME 3rd Joint Thermophysics Conference (June 1982) * Gao, Chengming. Experimental Study on the Ranque-Hilsch Vortex Tube. Eindhoven : Technische Universiteit Eindhoven. ISBN 90-386-2361-5. See also * Windhexe * Helikon vortex separation process External links * G. J. Ranque's U.S. Patent -- http://patft.uspto.gov/netacgi/nphParser?Sect2=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearchbool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN%2F1952281 * airtxinternational.com - AiRTX International, how vortex tubes work -http://www.airtxinternational.com/how_vortex_tubes_work.php * Tim Cockerill's pages on the Ranque-Hilsch Vortex Tube, including his 1995 Cambridge University thesis on the subject, and a mailing list. -- http://www.cockerill.net/rhvtmatl/ * How to Make Ice Out of Thin Air: Cool Heat Transfer, Daren Fonda, Sep. 4, 2005, Time Magazine. (Requires membership) -http://www.time.com/time/magazine/printout/0,8816,1101299,00.html * Oberlin college physics demo -http://www.oberlin.edu/physics/catalog/demonstrations/thermo/vortextube.html * itwvortec.com - Manufacturer of vortex tubes, information page -http://www.itwvortec.com/vortex_tubes.php * The Hilsch Vortex Tube - Online copy of the Scientific American article by C. L. Stong -http://www.visi.com/~darus/hilsch/ * Home-brew vortex tube made from off-the-shelf parts - David Buchan's Ranque-Hilsch effect tube project using only off-the-shelf plumbing parts -http://www.pdbuchan.com/ranque-hilsch/ranque-hilsch.html
http://www.arizonavortex.com Vortex tube uses and how do they work -- http://www.arizonavortex.com/vortex-tube
Vortex Tubes - Sub-Zero Spot Cooling from Compressed Air Vortex Tubes are an effective, low cost solution to a wide variety of industrial spot cooling and process cooling needs. With no moving parts, a vortex tube spins compressed air to separate the air into cold and hot air streams. While French physicist Georges Ranque is credited with inventing the vortex tube in 1930, Vortex was the first company to develop and apply this phenomenon into practical and effective spot cooling solutions for industrial use. Vortex Tube Applications: Vortex Tubes have a very wide range of application for industrial spot cooling on machines, assembly lines and processes. # Cool Machining Operations # Set solders and adhesives # Cool plastic injection molds # Dry ink on labels and bottles # Dehumidify gas operations # Cool heat seal operations # Thermal test sensors and choke units # Cool cutter blades # Temperature cycle parts How a Vortex Tube Works Fluid (air) that rotates around an axis (like a tornado) is called a vortex. A Vortex Tube creates cold air and hot air by forcing compressed air through a generation chamber which spins the air centrifugally along the inner walls of the Tube at a high rate of speed (1,000,000 RPM) toward the control valve. A percentage of the hot, high-speed air is permitted to exit at the control valve. The remainder of the (now slower) air stream is forced to counterflow up through the center of the high-speed air stream, giving up heat, through the center of the generation chamber finally exiting through the opposite end as extremely cold air. Vortex tubes generate temperatures down to 100°F below inlet air temperature. A control valve located in the hot exhaust end can be used to adjust the temperature drop and rise for all Vortex Tubes. Vortex Tubes Features & Benefits • Vortex Tubes use only compressed air for spot cooling- no electricity or refrigerants are required • Vortex Tubes are maintenance free - Since Vortex Tubes have no moving parts there is no maintence required Vortex Tubes are Exceptionally reliable
Vortex Tubes are Compact and lightweight Vortex Tube technologoy is Cycle repeatablity with ± 1 ° Vortex Tubes from Vortec drops inlet temperature by up to 100°F providing exceptional spot cooling
PDF Scans 1 -- Popular Science (May 1947 ); "Maxwell's Demon Comes to Life" 2 -- Compressed Air Mag. (August 1986 ) 3 -- Cooling Vest ( Lab Safety Supply ) 4 -- Roy McGee Jr : Refridgerating Engineering ; "Fluid Action in the Vortex Tube" 5 -- E. Eckert & J. Hartnett : "Investigation of the Energy Distribution in a High Velocity Vortex Type Flow" ( Armour Research Symposium, May 1955 ) 6 -- C. Pengelley : "Thermal Phenomena in a Vortex" ( Armour Research Symposium, May 1955 ) 7 -- G. Scheper Jr : J. Amer. Soc. Refr. Engg. ( Oct. 1955 ); "The Vortex Tube -- Internal Flow Data & a Heat Transfer Theory" 8 -- R. Hilsch : Review of Scientific Instruments 18 (2), Feb. 1947; "The Use of the Expansion of Gases in a Centrifugal Field as Cooling Process" 9 -- Greg Stone : Popular Science ( October 1976 ); "Vortex Tube Blows Hot and Cold" 10 -- C. Fulton : J.A.S.R.E. ( May 1950 ) ; "Ranque's Tube" 11 -- Popular Science ( November 1967 ) ; "Homemade Maxwell's Demon Blows Hot and Cold" 12 -- Lab Safety Supply : "A Short Course on Vortex Tubes and Application Notes" 13 -- Leon Ranque : French Patent # 1066484 ; "Generatrice a Vapeur en Circuit Ferme
US Patent # 1952281 "Method & Apparatus for Obtaining from a Fluid Under Pressure Two Currents of Fluids at Different Temperatures" G. Ranque
The Ranque-Hilsch Vortex Tube William A. Scheller, George M. Brown Ind. Eng. Chem., 1957, 49 (6), pp 1013–1016 DOI: 10.1021/ie50570a035 Publication Date: June 1957
http://www.springerlink.com/content/u4146950k3050673/ Cryocoolers 12 Publisher Springer US ISBN 978-0-306-47714-0 (Print) 978-0-306-47919-9 (Online)
Study of a Vortex Tube by Analogy with a Heat Exchanger Y. Cao2, Y.F. Qi3, E.C. Luo3, J.F Wu3, M.Q. Gong3 and G.M. Chen2 (2) Institute of Refrigeration and Cryogenic Engineering, Zhejiang University, Hangzhou, China, 310027
(3) Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, China, 100080 Abstract -- Based on the models of Scheper, Lewins, and Bejan, a new model has been established to study the influence of the cold mass flow fraction on the temperature separation effect in a vortex tube. The model is based on making an analogy between the vortex tube and a counterflow heat exchanger. The results show the model can accurately explain the correlation of cold mass flow fraction to the temperature separation effect.
Newsgroups: sci.physics.fusion From: [email protected]
(W. Robert Bernecky) Subject: Wirbelrohr or vortex tube Sender: [email protected]
(Scott Hazen Mueller) Date: Sat, 1 Jul 1995 23:11:02 GMT The following may be relevant to the Potapov device. It contains excerpts from "And yet it moves...strange systems & subtle questions in physics," by Mark P. Silverman, Cambridge University Press, 1993; Chpt 6 "The Wirbelrohr's roar". [BILL B. NOTE: also see Scientific American, November 1958 for a Hilsch-tube construction article in Stong's THE AMATEUR SCIENTIST] "It was a Wirbelrohr, he explained; you blew into the stem, and out one end of the cross-tube flowed hot air, while cold air flowed out the other. I laughed; I was certain he was teasing me. Although I had never heard of a Wirbelrohr, I recognised a Maxwell demon when it was described." "...he machined in his basement workshop a working model which I received from him shortly afterwards. The exterior was more or less just as he had described it: two identical long thin-walled tubes (the cross-bar of the T), were connected by cylindrical collars screwed into each end of a short section of pipe that formed the central chamber; a gas inlet nozzle (the stem of the T), shorter than the other two tubes but otherwise of identical construction, joined the midsection tangentially (Fig. 6.1). Externally, except for a throttling valve at the far end of one output tube to control air flow, the entire device manifested bilateral symmetry with respect to a plane through the nozzle perpendicular to the cross-tubes. "Only someone with the lung capacity of Hercules could actually blow into the stem. Instead, the nozzle was meant to be attached to a source of compressed air. Taking the Wirbelrohr into my laboratory, I looked sceptically for a moment at its symmetrical shape before opening the valve by my work table that started the flow of room-temperature compressed air. Then, with frost forming on the outside surface of one tube, I yelped with pain and astonishment when, touching the other tube, I burned my fingers!" "...With the few parts of the Wirbelrohr laid out on my table, I understood better the significance of the German name, Wirbelrohr, or vortex tube. The heart of the device is the central chamber with a spiral cavity and offset nozzle. Compressed gas entering this chamber streams around the walls of the cavity in a high-speed vortex. But what gives rise to spatially
separated air currents at different temperatures? ...the placement in one cross-tube (the cold one) of a small-aperture diaphragm effectively blocked the efflux of gas along the walls of the tube, thereby forcing this part of the air flow to exit through the other arm whose crosssection was unconstrained. |-----------| --------------| |-----------------| "COLD" PIPE "HOT" PIPE |