Bob Eckstein’s Vortex Cold Air Gun

Bob says:

I have recently made several small vortex tubes which provide a stream of cold air that can be directed at cutting heads, lathe tooling etc. where you may not want to use a flowing liquid or spray for purposes of lubrication and/or cooling. The exit air is much colder than can be obtained by adiabatic expansion through a simple orifice. The model shown uses a little under 4 cfm. @ 90 psi. Depending on your source of compressed air, you can attach any of a variety or adapters to the inlet tube by way of compression fittings, solder, etc. Commercially available vortex tubes are pretty expensive, and this one is under $25.00 ( less if you raid the junk box ) The inlet tube is 1/8 brass tubing with an insert of 1/16 tubing sweat soldered inside it. The nozzle is protruding 1/16 tubing cut at a 30 degree angle. The solder I use is a 4% silver bearing alloy. The brass tubing may be found in craft / hobby supply shops ( K&S product ). Bob Eckstein