Is your Cold Gun still working like when it was new? If not, check out this video – you can very likely restore it to “as new” performance with a simple disassembly & cleaning.
If you have any questions about maintenance on your Cold Gun, or any of our products, give me a call.
Russ Bowman, CCASS
Application Engineer
EXAIR Corporation
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EXAIR offers a line of spot cooling devices to blow cold air to remove heat. Heat can cause premature failures and shortened tool life. We use the Vortex Tube phenomenon to make very cold air without any moving parts or Freon. They only need compressed air as the “engine” to spin the air streams into two parts; hot air and cold air. They are maintenance free and can supply cold air down to a temperature of -50oF (-46oC). EXAIR “dresses up” a Vortex Tube to make a more functional device for spot cooling. In this blog, I will cover the smallest of our spot coolers; the Mini Cooler™.
The EXAIR Mini Cooler was designed for tight areas to cool small objects. It has a cooling capacity of 550 BTU/hr (139Kcal/hr). It only uses 8 SCFM (227 SLPM) at 100 PSIG (6.9 bar). The system will come with a manual drain Filter Separator with mounting bracket, a Swivel Magnetic Base with 100 lb. (45.5Kg) pull magnet, and a flexible hose kit. We offer two options for the flexible hose kit; a Single Point Hose Kit, model 3808, and a Dual Point Hose Kit, model 3308. The Single Point Hose Kit will give you one flexible outlet to easily position the cold air stream near the target point. It will also include a round point tip and a flat-fan tip. The Dual Point Hose Kit adds a split to have two separate cold outlets; still including the round and flat-fan tips. With these features, the Mini Cooler is easy to mount, use, and move for optimal cooling and blowing.
When using the Mini Cooler, the flexible cold outlets can easily bend around fixtures, spindles, and welding horns. The swivel magnetic base gives extra adjustment at the base of the cooler to aid in “hard to reach” places. To further the benefits of the cooler, the operating pressure can be changed to lower or raise the cooling capacity to meet your demands. At 100 PSIG (6.9 bar), the cold air flow can reach a temperature as low as 20oF (-7oC).
Some applications for the Mini Cooler would include small diameter milling and drilling where the cold air can keep the tool cool and remove the chips. It can also be used for soldering, industrial sewing, ultrasonic welding, or even small punching applications to list a few. With the dual point hose kit, it is ideal for targeting two sides of a cutter, aiming at multiple blades where material is being slit, or cooling multiple ultrasonic points for faster cycle times.
If you believe that you have an application where spot cooling could increase production rates and/or extend tool life, you can contact an Application Engineer at EXAIR. We can offer the Mini Cooler for smaller targets; or, larger versions like the Adjustable Spot Cooler and Cold Gun Aircoolant System™. We are looking forward to hearing from you.
John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb
It’s been almost 100 years since Georges Ranque discovered the vortex tube phenomenon. Since then, they’ve become one of the best worst kept secrets in industry…I talk to callers all the time who have a piece of equipment that came with one of our Cabinet Cooler Systems installed, and they want to know how to get cold air like that for a machine tool cutting or spot cooling application. Other callers have discovered Vortex Tubes for the first time via a web search, or they saw one at a customer’s (or vendor’s) facility. They often sound like someone asking a magician to reveal the secret behind a trick. Of course, it’s not magic (not really) – but it is certainly a neat trick:
Then, the discussion turns to product selection. EXAIR Vortex Tubes come in three sizes, with multiple Models in each size range. Those different Models are all the same Small, Medium, or Large Vortex Tube, with a different Generator installed, which determines the amount of compressed air the Vortex Tube will consume…and the Cold Fraction range. These two variables go hand in hand when determining which Vortex Tube is right for the application.
‘Cold Fraction’ is the term for the percentage of the supply air that’s directed to the cold end. The higher the Cold Fraction, the higher the flow, and the temperature, of the cold air flow. Conversely, the lower the Cold Fraction, the lower the cold air flow…and temperature.
For jobs that call for rapid cooling to ambient temperature (or a little below), a “Max Refrigeration” Generator is installed in a 3200 Series Vortex Tube. They are designed to direct most of the compressed air flow to the cold end, exhausting a smaller amount out of the hot end. A Vortex Tube set at an 80% Cold Fraction is generally very close to being optimized for these applications: they’re putting out a decent amount of air flow, with a 54F temperature drop. Assuming the compressed air supply is roughly room temperature, that means you’re blowing 20 to 30F (-6.6 to -1.1C) air onto your part. Most of the time, it’ll cool it down in a real hurry. The final piece of the puzzle, then, is determining the cold air flow rate. Our lowest capacity Small Vortex Tube with a Max Refrigeration Generator will use 2 SCFM @100psig, and generates a flow of 1.6 SCFM of cold air. On the other end of the spectrum, our highest capacity Large Vortex Tube uses 150 SCFM @100psig, and gives you a cold flow of 120 SCFM. There are ten Models in between, so we can come quite close to an optimal selection for just about any size/shape of part that needs cooled.
Keep in mind that there are two variables in a convection/conduction air cooling application: the flow rate of the air, and the difference in temperature in the cooling air and the hot part. We’ll always recommend starting at the highest cold fraction, but you may find that a little bit lower flow…and the lower temperature that comes with it…might suit your needs better. Good news is, that doesn’t change the compressed air consumption, so you can optimize performance at no additional cost of operation.
Other applications call for air that’s just as cold as possible. For those, we offer our 3400 Series “Max Cold Temperature” Vortex Tubes. Where the 3200 Series’ Cold Fractions are adjustable from 50-80%, the 3400 Series can be adjusted from 20-50%. Assuming, again, that the compressed air supply is roughly room temperature, at a 20% Cold Fraction and 100psig supply pressure, your cold flow can be as low as -50F (-45.6C). If you’re trying to get something to a particularly low temperature – lab samples or circuits that need to be tested at a certain temperature, or freeze seals in piping systems, for instance – then a 3400 Series Vortex Tube is just what you’re looking for. These come in the same sizes & Models as the 3200 Series, from 2 to 150 SCFM.
Another nice thing about using a Vortex Tube for cold air is that you can turn them on and off as frequently (or as seldom) as needed. They’re generating cold air flow, at their published rated temperature, instantly. There are no moving parts to wear, so you can cycle them on and off rapidly, or let them run continuously. In fact, if you supply them with clean, moisture free air, they’ll run darn near indefinitely, maintenance free.
Here’s a short video, showing how to adjust the Cold Fraction of a Vortex Tube. If you’d like to find out more, give me a call.
Russ Bowman, CCASS
Application Engineer
EXAIR Corporation
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The operation of a Vortex Tube is one of the more peculiar phenomena in fluidics, and a particularly unique method of producing cold air. Since they don’t perform “heat transfer” in the classical sense (see below), there’s no RATE of heat transfer…they’re generating cold air, at rated flow and temperature, instantly.
EXAIR Corporation’s Vortex Tubes come in a range of sizes & cooling capacities, and are integrated into a number of Spot Cooler Products which add convenience and flexibility to their operation. Consider:
One of the main advantages of using these Vortex Tube products with the pre-set higher cold fractions is the prevention of freeze-up…while the cold air generated is usually just a little below 32F (0C), ambient conditions in the areas where they’re used typically add enough heat to prevent mass freezing of any moisture condensed in the cooling process. A number of applications, however, do indeed call for much colder air flow than this, and for those, we’ve got the Adjustable Spot Cooler:
Their versatility makes them a great “utility player” – when very cold air (well below zero) is needed, the Temperature Control Knob is turned counterclockwise. If another application calls for higher flow (like the Mini Coolers or Cold Guns), it can be turned clockwise for instant adjustment of flow and temperature.
Adjustable Spot Cooler Systems are available with Single or Dual Point Cold Air Hose Kits, and come with three Generators: 15 SCFM (installed), 25 SCFM, and 30 SCFM, to select the compressed air consumption, and hence, the overall flow range.
If you’ve got a spot cooling application, EXAIR Corporation has a Vortex Tube solution for you. Give me a call; let’s talk cold air!.
Russ Bowman, CCASS
Application Engineer
EXAIR Corporation
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