vortex tube cooling gun

[Elninio]

Anyone tried making one of these? http://www.subtleenergies.com/ormus/...ch/Vortrap.htm

100PSI air in, -50Celcius and 200Celcius air out [aprox].

Edit: this seems like a bad idea as it consumes too much air - I don't think my rotary vane pump can handle it at all. Commercial models run as low as 2 cfm, but with 100psi minimum (my pump is 10cfm, 10psi). A better alternative that HSM'ers have concluded - for non-ferrous metals - would be to use ethanol mist. It's 15$ for 4L, but you're using it as mist ...

[knedvecki]

I have used store-bought ones. They help, but not as much as a decent coolant.

[JoeLee]

I've seen these advertised, just wondering how they work. A blast of compressed air tends to feel cool but I think there is more to it than that.

JL....................

[Elninio]

I've seen these advertised, just wondering how they work. A blast of compressed air tends to feel cool but I think there is more to it than that.

JL....................

It creates a vortex; air molecules on the outside of the vortex have higher momentum ( mass x velocity), and thus are hotter. There is a wide outlet at the back (basically a hole almost-plugged by a cone), and a thin outlet at the front (washer). The thin hole allows only low-velocity molecules to exit, which are colder.

http://www.instructables.com/id/The-Hilsch-vortex-tube/ (intro)
http://www.erkim.com.tr/Vorteks_Tupleri.html (plan)

[Black_Moons]

It works, but mine never did more then 0c output, and my second version did'nt even get that cold.

I think one of the really important things is you have a very smooth ID on the tube that is not disturbed by any connections, Basicly make the jets into the tube, don't try and solder on connections or make a seperate 'jet' chamber or anything fancy.

Ethonal mist sounds.. dangerious. Flamable.. explosive... and I don't think inhailing the denaturing ingrediants would be any good.

[Elninio]

It works, but mine never did more then 0c output, and my second version did'nt even get that cold.

I think one of the really important things is you have a very smooth ID on the tube that is not disturbed by any connections, Basicly make the jets into the tube, don't try and solder on connections or make a seperate 'jet' chamber or anything fancy.

Ethonal mist sounds.. dangerious. Flamable.. explosive... and I don't think inhailing the denaturing ingrediants would be any good.

Its good for non-ferrous machining due to its high latent heat, 800F ignition temp, room temperature flash point, and Evan has even pasted a link to an article on using it as coolant high speed machining of aluminium.

http://www.mmsonline.com/articles/0706rt1.html

[Evan]

Ethanol mist will work ok as long as you are only machining non sparking materials. It is used in industry for ultra high speed aluminum machining because it is a zero residue coolant and has excellent cooling properties. I wouldn't recommend it in a very small shop. Not because of an explosion hazard but because of the possibility of getting intoxicated. The usual denaturant is a bitterant oil in very small quantities and is non-toxic.

It should be used in a very minimal coarse wet mist and localized directly on the cut. It is often applied as individual squirts every few seconds. It isn't at all likely to produce an explosive atmosphere when used in correct quantities. I have used it for years and never had a problem. At room temperature ethanol will form an explosive vapor concentration but that tendency is reduced if using 95% ethanol in water instead of absolute ethanol. The main reason that it is quite safe is that it has a high autoignition temperature, nearly 700 degrees Fahrenheit.

In order to produce an explosive atmosphere it would need to be at a 3% concentration in air. If it got that high in the shop you wouldn't notice if it exploded.

[darryl]

What is actually wanted here- a cooling system for the shop, or the experimental fun of a vortex cooler? If you're looking to blow cold air on a workpiece in the lathe or mill, the vortex cooler IS going to consume a lot of air. I think you'd be better off to come up with a coolant misting system with a high volume low pressure suction collection system. Of course, having a vortex cooler in your hand with hot air coming out one side and cold air out the other is- cool! I think it's worth exploring ways to make it more efficient, and consider how you could use it in the shop for heating and cooling parts simultaneously for press fits, etc.

[JanvanSaane]

They do use a lot of air, I haven't used mine in a while. They were really handy for automatic chokes on carburetor equipped cars. Another note, they are very noisy with the air coming out of them. Jan

[Elninio]

Where do you get 95% ethanol from? Everclear is prohibited in Ontario.