"Bob La Londe" wrote in message ...
"Ed Huntress" wrote in message
...
On Wed, 14 Mar 2012 20:25:39 -0700, Winston
wrote:

wrote:
On Mar 14, 4:54 pm, Ecnerwal
wrote:



If it were a one-day deal or the like, I'd agree with you, but I'd
choose refrigeration in a heartbeat for any regular use. I'm intimately
aware of the hassles of salt-ice refrigeration, and I'm quite certain
that if I were making ice cream and sorbet as a busness rather than for
myself, it would be an easy decision to spend the money for a
refrigerated mixer - for home use it's a lot of money, so I use salt
and
ice.


Another approach would be to use a solid state cooler and a bit of
compressed air.

Peltier Junction Thermo Electric Heat Pump


One could refrigerate a jug of water for a few days
then use it as a heat sink for the copper tube.
That'd be inefficient but it might be cheaper
because it would eliminate the trip to the store
for bags of ice.

Who needs a store? I make my own ice in a little stand-up freezer. In
the summer, when I'm fishing, I make about 10 to 20 pounds of it every
couple of days.

Yeah, I took all the shelves out of the freezer in my shop fridge and put a
great big tub under the little ice maker in there. It holds 30-40 pounds of
ice if I remember to turn the tub around so the other side fills. In the
summer when I am fishing a lot that is never a problem. LOL.

It's a lot cheaper than running a compressor at the low efficiencies
of a Hilsch tube...or buying ice.

I would consider using the freezer part of the fridge to pre-cool a coil of
air, but its on the other side of the shop. I actually considered putting
my CNC computers inside a little apartment fridge in the shop. Maybe now is
the time to get a second shop fridge. LOL.


The problem is, for instance, aluminum melts at approximately 1220 deg F and cooling your air supply down by a paltry 60 or so degrees will have a neglible efferct on total heat transfer at best--at worst, no effect or perhaps it could even be negative.

You've intentionally reduced total mass air flow to the part itself by throwing away the heated portion--air which is in all probablilty is say 150 deg F or so--IOW, no where near the temp where there is a significant danger of any cutting tools clogging up and that sort of thing....air which all by itself (though hot to the touch) would be perfectly adequate where the goal is keep the part / chips / temp at some temperature well below the danger zone....

When it comes down to it, despite the claims of the various vendors, I really do have serious doubts that any more heat is carried away from the workpiece by using the cold air out of a vortex tube than would be carried away by simply using the same amout of total of mass air flow that would have been output into a standard air nozzle at room temp directly from the compressor instead.