Tag: Cold Gun

Vortex Tube Cold Fraction and how it Affects Flow and Temperature Control

Published on by Jordan T ShouseLeave a comment

Vortex Tubes are the perfect solution when dealing with a variety of spot cooling applications. They use compressed air to produce a cold air stream and a hot air stream, with temperatures ranging from as low as -50°F  up to +260°F (based on ambient supply temperature) and providing as much as 10,200 Btu/hr. of cooling capacity. By simply adjusting the valve in the hot end of the Vortex Tube, you are able to control the “cold fraction” which is the percentage of air consumed by the vortex tube that is exhausted as cold air versus the amount of air exhausted as hot air. Our small, medium and large Vortex Tubes provide the same temperature drop and rise, it’s the volume of air that changes with the various sizes.

The unique physical phenomenon of the Vortex Tube principle generates cold air instantly, and for as long – or short – a time as needed.

When looking at the below performance chart, you will see that “Pressure Supply” and “Cold Fraction %” setting all play a part in changing the performance of the Vortex Tubes. Take for example, an operating pressure of 100 PSIG and cold fraction setting of 20%, you will see a 123°F drop on the cold side versus a 26°F temperature rise on the hot side. By the using the same Vortex Tube and keeping the operating pressure at 100 PSIG but changing the cold fraction to 80%, you will now see a 54°F temperature drop on the cold side and a 191° rise at the hot end.

Vortex Tube Performance Data
Vortex Tube Performance Chart

We’ve looked at how the cold fraction changes the temperature, but how does it change the flow for the various Models?

Say you are using a Model # 3240 Medium Vortex Tube which consumes 40 SCFM @ 100 PSIG. Again with the cold fraction set at 80% (80% of the consumed compressed air out of the cold end), you would flow 32 SCFM at the cold air exhaust.

40 SCFM x 0.8 (80% CF) = 32 SCFM

Using the same Model # 3240 Medium Vortex Tube but now with a 20% cold fraction (20% of consumed compressed air out of the cold end), you would flow 8 SCFM at the cold exhaust.

40 SCFM x 0.20 (20% CF) = 8 SCFM

As you can see, to achieve the colder air temperatures, the volume of cold air being exhausted is reduced as well. This is important to consider when making a Model selection. Some other considerations include the operating pressure which also has a significant effect on performance. The compressed air supply temperature is important because the above temperatures are temperature differentials, so in the example of the 80% cold fraction there is a 115F temperature drop from your inlet compressed air temperature.

If you need additional assistance, you can always contact myself or another application engineer and we would be happy to make the best selection to fit your specific need.

Jordan Shouse
Application Engineer

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Twitter: @EXAIR_JS

EXAIR Mini Cooler™: Overview 

Published on by John BallLeave a comment
EXAIR Mini Coolers

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. 

Model 3308

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

Spot Cooling, Cold Gun Promotion

Published on by Jordan T ShouseLeave a comment

Like many companies, here at EXAIR we generally always have a promotional offering.  These rotate throughout the months and this month is no different.  The current offering involves the EXAIR Cold Gun Aircoolant Systems.

These spot cooling systems help to reduce cutting fluid use, increase production speeds, increase tool life, and has helped more customers than I know.  One customer in particular is a maintenance worker from a welded tube manufacturer.  This facility had very little amount of downtime permitted due to the high efficiency and high volume of orders.  When a machine went down the maintenance team went in like a trauma team to determine the cause of failure and get it fixed to get the line back up and running. One of the biggest problems they would have is when they would have to dry machine a quick part to get the machine back up and running, this would either ruin tools or they would have to slow down the machining time to get the surface finish and dimensions they truly needed.  After talking with us the team ordered a Single Point Cold Gun Aircoolant System as these parts were generally small enough to tackle with the single cold outlet (larger parts benefit from the dual point hose kit).

They received the spot cooler system in and sure enough a machine went down.  The crew went to work and once the broken part was located they got to work on their lathe trying to make a new piece.  The Cold Gun held itself straight to the headstock thanks to the integrated magnet and the flexible single point hose kit routed the cold air straight to the cutting insert point.  They didn’t have to fill up the liquid tank or setup the mist system on the lathe, they simply turned on the compressed air and let the lathe do the work.  They were able to take what had recently been around a three hour machine job with heavy wear on tooling to a two hour job, no finish pass was needed on the part, and their tools weren’t completely spent by the end of the job.

They got the part back into the machine, made adjustments, and then went to work getting the machine back into production.

Right now, if you would like to try out a Cold Gun Aircoolant System you can order before 12/31/21 and you will receive a free Dual Point Hose Kit with your qualified purchase.

Dual Point Hose Kit

Jordan Shouse
Application Engineer

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Twitter: @EXAIR_JS

EXAIR Cold Gun Overview

Published on by Tyler DanielLeave a comment

In any machining operation, tool wear is an inevitability. Cutting tools heat up due to friction and this heat contributes to premature tool wear. As tooling wears, poor tolerances and dimensional inaccuracy are common. Additionally, as the cutting edge dulls increased cutting force is required which further increases the amount of heat generated.

Coolants can be used to reduce friction and help mitigate some of the wear, but then you’re left with the mess that coolant brings along with it both on the part and in the machine itself. What if I were to tell you that there’s a way to mimic the effects of coolant, but without all of the mess? All of this can be achieved with just a supply of compressed air and one of EXAIR’s Cold Gun Systems.

EXAIR’s Cold Gun was a Product of the Year finalist in 2007. By using only a source of compressed air, the Cold Gun and High Power Cold Gun produces a stream of clean, cold air 50° (28°C) below your compressed air supply temperature. The Cold Gun is very quiet at only 70dBA and has no moving parts to wear out. Just supply it with clean, dry compressed air and it’s maintenance free!

Cold Guns Systems

The Cold Gun is pre-set to an 80% Cold Fraction. In other words, 80% of the compressed air supplied to it will exhaust from the cold end of the tube, 20% from the hot end. This prevents the Cold Gun from freezing up during use and optimizes the gun’s cooling capacity. The Cold Gun is an ideal alternative to messy and expensive coolant mist systems. It eliminates the cost of purchase and disposal of cutting fluids as well as worker related health problems from breathing airborne coolant or slipping on wet floors. Replacing a coolant-based system also eliminates the need for secondary cleaning operations after milling or drilling.

The Cold Gun is an invaluable tool for machining a wide range of plastics and other materials that may become contaminated when using traditional coolants or oils. The clean, cold air from the outlet of the Cold Gun keeps the part cool, clean, and dry. Take for example this application where an OEM for the plastics industry uses EXAIR Cold Guns in place of a coolant system.

If you have an application that you believe would be better served by the use of an EXAIR Cold Gun, give us a call. Get one on order today and take advantage of our limited time promotion and receive a FREE Dual Point Hose Kit upgrade!

Tyler Daniel, Application Engineer

E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD
Ph. 1-800-903-9247 or 1-513-671-3322