Thanks for accepting my suggestion of "Hilsch Tube" as the official
answer to your question. I've gathered a bit of info about the Hilsch
Tube that I hope you'll find interesting.
"Compressed air at room temperature goes into a Hilsch tube and comes
out as a hot stream and a cold stream of air... Compressed air can be
split into its hot and cold components. The following explains how a
Hilsch tube accomplishes this. Compressed air shoots around a spiral
and forms a high-velocity vortex of air. Molecules of air at the
outside of the vortex are slowed by friction with the wall of the
spiral. Because these slow-moving molecules are subject to the rules
of centrifugal force, they tend to fall toward the center of the
vortex. The net result of this process is the accumulation of
slow-moving, low-energy molecules in the center of the whirling mass,
and high-energy, fast-moving molecules around the outside.
'High-energy' and 'low-energy' mean high and low temperatures
respectively. The end result of this process: separation of a stream
of gas into hot and cold streams."
University of Colorado: Hilsch Tube
http://www.colorado.edu/che/CLASSES/3320f/pages/hilsch.html
"The origin of the device is obscure. The principle is said to have
been discovered by a Frenchman who left some early experimental models
in the path of the German Army when France was occupied. These were
turned over to a German physicist named Rudolf Hilsch, who was working
on low temperature refrigerating devices for the German war effort.
Hilsch made some improvements on the Frenchman's design, but found
that it was no more efficient than conventional methods of
refrigeration in achieving fairly low temperatures. Subsequently the
device became known as the Hilsch tube."
Society for Amateur Scientists: About a Remarkably Simple Device to
Attain Low Temperature
http://www.sas.org/E-Bulletin/2003-07-25/labNotesAS/body.html
SX List: The "Hilsch" Vortex Tube
http://www.sxlist.com/images/com/visi/www/http/~darus/hilsch/hilsch.html
"The Ranque-Hilsch vortex tube confines two vortices formed from
compressed air within a tube. Through an unknown phenomenon two
streams of air are produced, one hot, the other cold... While the
vortex tube has found a respectable niche of spot cooling in
manufacturing, the tube has never gained widespread use for many
reasons. Perhaps most important is the lack of understanding the
mechanism by which the two streams of air are produced. Currently no
one can definitively explain why the vortex tube operates as it does.
The process itself is straightforward. Compressed air is inserted into
a tube from one or two tangentially arranged input valves. The air
begins to spin around the wall of the tube at high speeds creating a
vortex. The air begins to move to the far end of the tube, known as
the hot end. At the hot end, a conical valve allows only air spinning
closely against the tube wall to escape. The rest of the air is forced
back through the low-pressure center of the first vortex, creating a
second, inner vortex, which moves towards the opposite end of the
tube, known as the cold side. At the cold side only air from the very
center of the tube is allowed to escape, the rest is pulled back into
the first vortex and repeats the process."
University of California, Berkeley: Ranque-Hilsch Vortex tube
http://www.ocf.berkeley.edu/~dlk/tangents/vortex/vortex_public.php
More information than you're likely to need is available in this FAQ
from EXAIR, a company that manufactures vortex tubes:
EXAIR: Vortex Tube FAQ
http://www.exair.com/faq/faq_vortex_tubes.htm
My Google search strategy was greatly simplified by the fact that I
was aware of the Hilsch Tube, having been a Science Fair Geek in the
1960s. Vortex tubes were much discussed in Science Fair Geek circles
in the sixties. ;-)
Google Web Search: hilsch tube
://www.google.com/search?hl=en&q=hilsch+tube
Since my colleague juskaskscott has piqued your interest in the Hirsch
Funnel, I suggest that you post a new question on that subject. If you
place a phrase such as "For justaskscott-ga" in the subject title,
this will ensure that he will be the one to post your answer.
I hope this is helpful! If anything is unclear or incomplete, please
request clarification; I'll be glad to offer further assistance before
you rate my answer.
Very best regards,
pinkfreud |
