Tag: cooling tubes

Hot Air In The Aerospace Industry

Published on by Russ BowmanLeave a comment

Mankind’s adventures in aviation began with hot air, and it’s still kind of a big deal (for one particular EXAIR customer, that is) today.

How it started: In the 1780s, two French brothers, Joseph and Étienne Montgolfier, worked in their family’s paper mill. They noticed, along with everyone else, that pieces of paper were sometimes carried airborne in billows of smoke from the fires that heated the boilers. But unlike everyone else, they became curious as to why this happened…and how they might exploit this strange phenomenon to send something more substantial than some paper scraps through the air.

After a good deal of experimentation and trips “back to the drawing board” (they thought it was the smoke, not the heat, that caused the rise for a while), they began making public demonstrations of their first successful hot-air balloons in the summer of 1783. By autumn, having flown a sheep, a duck, and a rooster in a tethered balloon (to an altitude of about 1,500 feet on a flight that lasted about 8 minutes), they constructed a balloon large enough for two humans which flew successfully for almost half an hour, to a height of 3,000 feet. Early enthusiasts who came out to witness some of these flights included King Louis XVI, Queen Marie Antoinette, and American statesman (and quite the inventor himself) Benjamin Franklin.

The Montgolfier brothers decorated their balloons with the fleur-de-lis, zodiac symbols, and portraits of the King. I think it says a lot about ballooning that nowadays we have Sylvester the Cat, Tweety Bird, and even Spider-Pig.

How it’s going: I’m not going to lie; your level of fascination with the rest of this blog will depend on how fascinating you find the phenomenon of the Vortex Tube…which was, in fact, discovered by another French inventor, Georges Ranque:

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

Most Vortex Tube applications involve the use of the cold air flow, but a number of customers do indeed use the hot air flow. A material supplier to the aircraft & aerospace industry makes a flexible, porous strand of material that, after fabrication, passes through a wash tank prior to cutting to size. They wanted to speed up the drying time, but it was impractical to use electrically powered hot air blowers or heat guns. By using an EXAIR Model 3275 Large Vortex Tube set to a 70% Cold Fraction, they’re able to blow a little over 22 SCFM of 220°F air onto the strand, which effectively dries it to their specification, quickly & safely.

The EXAIR Vortex Tube. Cold air from one end; hot air from the other. Fully adjustable. You can use either…it’s fine with us; whatever you need.

Other EXAIR products that have been notably popular in the aerospace industry are engineered Air Nozzles, Static Eliminators, Air Amplifiers, and some even use Vortex Tubes & Spot Cooling Products for their COLD air flow. If you’d like to find out more about getting the most out of your compressed air system like the folks in the aerospace industry do, give me a call.

Russ Bowman, CCASS

Application Engineer
Visit us on the Web
Follow me on Twitter
Like us on Facebook

EXAIR Case Study: Tube Cooling with the Adjustable Spot Cooler!

Published on by Jordan T ShouseLeave a comment

EXAIR has an extensive library of Case Studies for your reference to learn about how our products can help. The library is organized by product, so you can easily find the information and product you are interested in. These case studies summarize how our customers have purchased, used, and benefited from our products and their implementation. These studies focus on our products and our customers’ projects. We keep our customers anonymous and only use photos, details and data that are approved to be shared.
Here is an example of my latest case study!

APPLICATION GOAL: Customer is an OEM who builds 20 automated systems every year. One of the most time-consuming applications is heating and bending Teflon tubes that route fluids around the system. They wanted to speed up the time it took to do this, and increase the accuracy of the bends.

BEFORE EXAIR: When forming Teflon tubing for plumbing runs inside these large processing machines, the tubing needs to be heated with a heat gun to soften the tube to allow for forming. After forming, the tube must cool down to hold its shape. Cooling time can take approximately 6 minutes per bend. Alternatively, ice-water-soaked rags can be used, which may decrease the time down to 2–3 minutes.  However, there is no guarantee that the form will hold at the precise angle and may need to be reformed, which starts the process over again. Also, ice water and rags create a mess and can cause a slipping hazard if dripped on the floor.

AFTER EXAIR: Using the EXAIR Model 3925 Adjustable Dual Spot Cooler System, they were able to decrease the cooling time to under one minute. And due to the dual hose option, it gave them the ability to spread the cold air around the tubes so they did not have to remove them from the fixture while cooling, meaning the tube holds its shape to a greater accuracy.

SUMMARY:  By reducing the cooling time from 6 minutes per bend to approx. 1 minute per, with at least 300 bends per part, we can reduce the production time for each piece of equipment by 25 hours. Producing 20 pieces of equipment per year frees up the equivalent of 20.83 working days.  With an hourly rate average of $26.40, the EXAIR Model 3925 Adjustable Dual Spot Cooler System saves them $660.00 USD per machine in work hours alone! Over the course of one year, that’s a savings of $13,200.00 USD for just work hours. Meaning the ROI is right around the use of the Adjustable Spot Cooler to build one machine.

EXAIR appreciates a good success story. We encourage you to share your successes in using one or more of our products in your application. EXAIR believes in case studies so much, we incentivize our customers’ participation. We will offer a discount to any company who will provide enough information to produce a case study. If you are interested in creating a case study (and saving money) on your next project, please contact one of our Application Engineers. We would be happy to explain the details of working through this process with you.


Jordan Shouse, Application Engineer
Send me an email
Find us on the Web
Like us on Facebook
Twitter: @EXAIR_JS

Utilizing EXAIR Accessories

Published on by Al WooffittLeave a comment

Here at EXAIR we are very proud of our Intelligent Compressed Air Products. We can spend a lot of time talking about our favorites (mine is the Vortex Tube). We have written many blogs about the advantages – no moving parts, little to no maintenance, meeting or exceeding OSHA safety standards for noise or dead end pressure. One thing we don’t talk as much about are the accessories that go along with and complement our products.

From left to right; a few value added accessories for your Vortex Tube: Hot Muffler, Cold Muffler, Automatic Drain Filter Separator, Oil Removal Filter, and Solenoid Valve/Thermostat Kit.

Some of the most commonly used accessories are our compressed air Filters and Regulators. We would recommend the use of these with all of our products (or even with products that aren’t even ours).
The Filter Separator will remove water, dirt and rust from your compressed air system. The 5-micron filter element will keep contaminants from plugging or damaging your compressed air product.
An Oil Removal Filter (always placed downstream of our Filter Separator) will provide even finer filtration by removing oil and solid particulate using a 0.03-micron element.
Our Pressure Regulators will enable you to select the operating pressure. At EXAIR we always recommend operating at the minimum pressure required to get the job done. Pressure Regulators allow you to do that, saving on unnecessary air consumption and allowing for dialing in the performance of EXAIR products within an application.

For some of our products, we have accessories made specifically for them. For use with our Line Vacs we have Line Vac Hose. We have Thermostats and Solenoid Valves to pair with our Cabinet Coolers, and for our Vortex Tubes we would recommend our Mufflers.
For our Air Knives we have several great offerings:
If you need an easy and reliable way to mount your Air Knife, then our Universal Air Knife Mounting System is what you are looking for.
If your application requires something longer than our stock Knives, or perhaps you need to control certain sections of the air flow independently, then our Coupling Bracket Kits are the perfect fit.
If you want to make plumbing your Air Knife easy, take a look at our Air Knife Plumbing Kits. They can be used for all Air Knives longer than 24″.

If you need to plumb many of our other Intelligent Compressed Air Products, then we have a selection of compressed air hoses and fittings that will make life easier.
Our Coiled Hoses pair well with our Safety Air Guns, allowing you to move more freely while operating.
Our Compressed Air Hoses are commonly used with our Industrial Housekeeping products to give the drum and dolly the reach needed.

If you need a way to mount or position your Air Nozzles, then we have our Magnetic Bases, Stay Set Hoses, and Swivel Fittings that can be added to make a complete set-up.

Whatever your application’s need is, or the product you’re looking for, we certainly have a range of complimentary accessory products that will make installation and adjustment easier. If you have any questions about these, or any other EXAIR product, feel free to contact us.

Al Wooffitt
Application Engineer

Send me an Email
Find us on the Web
Like us on Facebook
Twitter: @EXAIR_AW


Max Btu/hr or Max Cold Temperature Vortex Tube? Which is Right for your Application?

Published on by Tyler DanielLeave a comment

EXAIR’s Vortex Tubes are a low-cost, reliable, and maintenance-free solution to a variety of industrial spot cooling problems. With just an ordinary supply of compressed air, the Vortex Tube produces two streams of air: one hot and one cold. The Vortex Tube is capable of achieving a temperature drop/rise from your compressed air supply ranging from -50°F to +260°F (-46°C to +127°C). Flow rates range from 1-150 SCFM (28-4,248 SLPM) and cooling capacities of up to 10,200 Btu/hr. With all Vortex Tubes constructed of stainless steel, they’re resistant to corrosion and oxidation, ensuring you years of reliable, maintenance-free operation.

Two primary different styles of Vortex Tubes are offered: maximum refrigeration and maximum cold temperature. Tubes for maximum refrigeration have an “R” type generator installed. These tubes are optimal for most industrial applications. Model numbers containing 32XX all have an “R” generator installed and should be used at cold fractions 50% or greater. For “cryogenic” type applications such as cooling lab samples or circuit testing, the maximum cold temperature tubes are recommended. These tubes have a “C” type generator installed. Model numbers beginning with 34XX are all designed for maximum cold temperatures and should be used when the cold fraction must be set to below 50%. The difference between the two is in the volume of air at the cold end. While the 34XX tubes deliver a colder temperature, there is much less volume of cold air.

To help illustrate the difference in cooling capacity from one style of tube vs the other, let’s walk through a calculation for each. For these examples, we’ll consider our 30 SCFM style tubes (3230 for maximum refrigeration, 3430 for maximum cold temperature).

We know that both tubes will consume 30 SCFM of compressed air when supplied at 100 PSIG. We also know that for most applications, maximum refrigeration occurs around 80% cold fraction (80% of the air exhausts from the cold side of the tube, relative to the total consumption). So, for our 3230 cooling power calculation, we’ll set the tube at 80% cold fraction. At 80% cold fraction, and 100 PSIG, there will be 24 SCFM of cold air exhausting from the tube.

The next step is to determine the temperature of the air at the cold end of the tube. For this, we’ll assume a starting temperature of 70°F. We then look at the chart shown in the catalog to determine the temperature drop, at 100 PSIG, and 80% cold fraction:

Under these conditions, the net cold temperature would be 16°F (70°F – 54°F). We now know that we’ll be delivering 24 SCFM of 16°F cold air from the Model 3230 in this scenario. Next, we’ll do the very same for the Model 3430.

We know that the 34XX series tubes are designed to be used in cold fractions below 50%. Let’s assume that the 3430 in this scenario has been set to 30% cold fraction, also at 100 PSIG:

Under these conditions, the net cold temperature would be -48°F. With the tube set to 30% cold fraction, we then know that we have 9 SCFM of air at -48°F (30 SCFM x 30%). To determine the cooling capacity for each tube under these conditions, we’ll plug the values into the refrigeration formula using a target temperature of 95°F. 

1.0746 (Btu/hr constant) x SCFM of cold flow x ΔT = Btu/hr

For the Model 3230 at 80% cold fraction, the ΔT is 75°F (95°F-16°F). For the Model 3430 at 30%, the ΔT is 135°F (95°F – (-48°F).

Model 3230 – 1.0746 x 24 SCFM x 79ΔT = 2,037 Btu/hr

Model 3430 – 1.0746 x 9 SCFM x 143ΔT = 1,383 Btu/hr

While the 3430 provides a SIGNIFICANTLY colder stream of air at -48°F, the warmer air is more effective at cooling in this example due to the increase in volume that is being provided. For most applications, the maximum refrigeration style of tubes are the best fit. In applications where an EXTREMELY cold temperature is needed, that’s where we would consider using the tubes designed for maximum cold temperatures.

Feel free to reach out to an Application Engineer if you need help in selecting the proper Vortex Tube. Or, order a Cooling Kit to ship the same day from stock and have the ability to test them all out yourself in the application!

Tyler Daniel, CCASS

E-mail: TylerDaniel@EXAIR.com

Twitter: @EXAIR_TD