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Keeping work cool is a sure-fire way to improve accuracy during machining, but every method has drawbacks. Liquid cooling is very effective and lubricates well, but it’s messy and the hardware’s expensive. Air cooling, while cheap, doesn’t do the job as well. A company called ITW Vortec markets a device which is advertised as combining the advantages of both, courtesy of a subzero air stream. Their Cold Air Guns take 100psi compressed air, spin it around a tube’s inner diameter at a million RPM, and the resulting air currents send hot air out one end and cold air out the other. Sounds like science fiction, but there seems to be good science backing up their claims.

Pricing is targeted at a middle ground between liquid cooling and conventional air cooling setups. A kit, complete with air filter, stand, and gun, runs for $364 from Vortex Air themselves, or $343 from Production Tool supply. They’re asking a hefty price for what seems to be a very simple product, but it’s a lot cheaper than a liquid cooling setup. With no moving parts, odds are they won’t need any servicing, so the price should be a one-time deal.

Cold-air guns [ITW Vortec]
ITW Vortec Cold-Air Guns [Vortex Air]
ITW Vortec Cold-Air Gun [Production Tool Supply]

 

14 Responses to Subzero Air Cooling

  1. T says:

    One caveat about these things: they suck down the air. To get rated performance on a small unit like this, you need between 15 and 30 scfm. I’m more familiar with Exair’s product line, but these look similar in size, so probably use the same amount of air.

  2. Jerry Vandesic says:

    One of my favorite books as a child was “The Amateur Scientist” by C.L. Stong. It was a collection of his Scientific American column from the 1950’s, and covered things like buiding your own x-ray machine to amateur rocketry (including how to build an earthen bunker to protect yourself). Amazing stuff, especially the fantastic illustrations by Roger Hayward.

    One of the columns (Nov. 1958) was about building a Hilsch vortex tube, which is what the cold air gun is. If you are intersted in building your own, the article is available online at http://www.visi.com/~darus/hilsch/

  3. Tetsubo says:

    I heard about this technology about 15 years ago. I don’t doubt the science in the least. But I’ve always wondered about the noise level.

  4. Jaxx says:

    I’m assuming the air is also sped up somewhat, and if so do you really want all your swarf blown about at high pressure?

  5. Dave P says:

    @ Jaxx – No, you get a low-volume, medium velocity cold air stream. The hot air side blows a LOT more.

    These are very useful in very limited circumstances…..there’s a reason they aren’t used in a lot of machining operations.

  6. Maxebitda says:

    agree w/ dave p…i have one and they work as claimed…it is truly voodoo…

  7. rick says:

    very cool idea, pun intended, but hugely inefficient. I suspect there are much more efficient ways to cool a part… but there are probably quite a few uses for this guy

  8. Cameron Watt says:

    @rick: Amen! They’re very inefficient.

    A 30 cfm demand on your air system might take 7-8 horsepower (5-6KW) of your compressor capacity. That kind of power could buy you a lot of cooling using other methods.

    By the way: Compressed air can be expensive when you add up all of the costs.

    @Lex Dodson: As for it being cheaper than a liquid-coolant system, you need to look at the operating costs as well; often consumable and power costs over the life of a tool will kill you if you don’t properly consider them. There’s a little commentary about it here: http://madwelder.wordpress.com/2009/09/18/9/

  9. Lex Dodson says:

    @Cameron Watt

    You raise a good point, but are power and coolant costs over the life of a liquid cooling system really less than the power requirements for a cold air gun? My intuition says no, but I’ve never managed a shop before. I suppose the fact that I’ve never actually seen one of these, whereas I’ve worked with plenty of liquid cooling setups, is telling.

  10. Pezdad says:

    If the drawings from Scientific American (linked above by Jerry) are correct, this thing is about $5 of fittings with a $350 markup for the novelty factor – if Harbor Freight ever had their Chinese factory knock it off, we could buy one for $10.

  11. Cybergibbons says:

    We made one of these at school after reading about them in a very old book of strange devices.

    It certainly worked, but it ate air at an impressive rate, and made the same kind of noise you would expect when moving 20cfm at 100psi.

    We never considered it as cooling for machining though.

  12. Paul says:

    if you want to read up on it, look up “Vortex Tube”, there should eb a ton of info on them. I had to do a little project based on them in a mechanical engineering heat transfer class, another student group made one as a senior project. They are a great idea but and work well but are not efficient, IE you wouldn’t use one as an air conditioner because it has no parts to break, because the air supply would need to be enormous.

  13. Jim says:

    I heard long ago that in WWII the Allies captured a number of Nazi labs and found some of these kicking around. Our guys scratched their heads for a while, then put one on compressed air to see what it would do. I hear they used to use them for spot cooling applications on trains – the maintenance-free cooling was cheap for them given their abundant supply of compressed air.
    I, of course, can’t verify any of this…

  14. mikep says:

    Vortec also makes a “air amplifier” as a regular blow-it-off air nozzle. Actually works pretty well if you’re dusting stuff off (doesn’t help for cooling)

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