Re: vortex question

James J. Jiamachello ( (no email) )
Sat, 02 May 1998 17:13:55 -0400

Keith and Shelley Schmidt wrote:
>
> This may not be the right place to ask this, but I've seen several
> conversations about vortexes. At work one of our machine operators
> showed me a device that is used to keep the workpiece cool during
> machining. He said it was a vortex cooler. Compressed air is brought
> into cylindrical chamber at about 90psi (flowrate unknown). It is
> caused to swirl. The air drawn off the center is very cold. There is
> an air bleed on the side of the cylinder which also has air coming out
> which is quite warm. There don't appear to be any moving parts and
> the
> unit has no electical connections. Could someone explain what it
> happening?
>
> Keith

Hi Keith

What you see is a Hilsch vortex tube. One of the best do it your self
articles I have on it was from a Scientific American, Amateur Scientist
article from 1958 Nov, page 145. I have a copy from a compendium of
such experiments published in the late 70's.

It is not overunity but is a way for an amateur to achieve very cold or
very hot temperatures by using an air compressor.

The jet of air is directed against a curved surface whose radius is
decreasing, and orifice is placed on the cold side to let the slower
molecules in the center escape, the hotter molecules exit the other open
side of the "swirler".

There are also one sided versions, not as efficient, where the hot and
cold exit in the same direction but on a different radius.

Is is sort of a gas driven centrifuge that separates the higher energy
molecules by radius.

Check out: http://club.eng.cam.ac.uk/~ttc/rhvtinfo.html
http://physics.umd.edu/deptinfo/facilities/lecdem/f4-24.htm
http://www.eskimo.com/~billb/wirbel.txt

An index of the Amateur Scientist articles is found at:
http://web2.thesphere.com/SAS/SciAm/sciamidx.html

Jim