EXAIR Super Air Knives Blast Away the Competition

When a wide area is in need of cleaning, cooling, or drying there isn’t a better option available on the market than EXAIR’s Super Air Knife. It’s laminar and even airflow across the length has solved process problems and provided manufacturing solutions for thousands of customers. We’ve been manufacturing Air Knives for over 30 years now, with the Super Air Knife making its first appearance back in 1997. Since then, the Super Air Knife has undergone a few enhancements over the years as we’re constantly trying to not only introduce new products but also improve on the ones we have. We’ve added new materials, longer single piece knives, as well as additional accessories.

What sets EXAIR’s Super Air Knife above the competition is the ability to maintain a consistent laminar flow across the full length of the knife, particularly when compared against blower operated knives or even fans. A fan “slaps” the air, resulting in a turbulent airflow where the airflow particles are irregular and will interfere with each other. A laminar airflow, by contrast, will maintain smooth paths that will never interfere with one another.

Blower Style air knife

Blower knives are commonly seen in industry that also cannot provide a laminar airflow. Additionally, they are expensive to purchase, produce a high sound level, and require periodic maintenance. Costly maintenance that results to downtime, as well as the physical space the system takes on the shop floor are all eliminated when using the Super Air Knife.

One of the simplest alternatives to the Super Air Knife is a homemade drilled pipe. While it’s quite easy to put together with materials that are likely already available to you, the true hidden cost here is the operating cost. The high energy use related to the total compressed air consumption makes this “seemingly economic” solution into an expensive one quickly. Not to mention, these devices are not considered to be safe per OSHA 1910.242(b).

The effectiveness of a laminar airflow vs turbulent airflow is particularly evident in the case of a cooling application. The chart below shows the time to cool computers to ambient temperatures for an automotive electronics manufacturer. They used a total of (32) 6” axial fans, (16) across the top and (16) across the bottom as the computers traveled along a conveyor. The computers needed to be cooled down before they could begin the testing process. By replacing the fans with just (3) Model 110012 Super Air Knives at a pressure of just 40 psig, the fans were cooled from 194°F down to 81° in just 90 seconds. The fans, even after 300 seconds still couldn’t remove enough heat to allow them to test.

While the fans no doubt made for large volume air movement, the laminar flow of the Super Air Knife resulted in a much faster heat transfer rate.

Utilizing a laminar airflow is also critical when the airflow is being used to carry static eliminating ions further to the surface. Static charges can be both positive or negative. In order to eliminate them, we need to deliver an ion of the opposite charge to neutralize it. Since opposite charges attract, having a product that produces a laminar airflow to carry the ions makes the net effect much more effective. As you can see from the graphic above showing a turbulent airflow pattern vs a laminar one, a turbulent airflow is going to cause these ions to come into contact with one another. This neutralizes them before they’re even delivered to the surface needing to be treated. With a product such as the Super Ion Air Knife, we’re using a laminar airflow pattern to deliver the positive and negative ions. Since the flow is laminar, the total quantity of ions that we’re able to deliver to the surface of the material becomes greater. This allows the charge to be neutralized quickly, rather than having to sit and “dwell” under the ionized airflow.

With lengths from 3”-108” and (4) four different materials all available from stock, EXAIR has the right Super Air Knife for your application. In addition to shipping from stock, it’ll also come with our unconditional 30-day guarantee. Test one out for yourself to see just how effective the Super Air Knife is on a wide variety of cooling, cleaning, or drying applications.

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@exair.com
Twitter: @EXAIR_TD

Vortex Tubes – The Basics, And Beyond

The Vortex Tube might be just about the most interesting compressed air device around.  They have no moving parts, and they don’t need any but a compressed air supply, which they ‘split’ into a hot air stream, and a cold air stream.

EXAIR Vortex Tubes come in three sizes – Small, Medium, and Large – and 24 distinct Models across those three sizes.  They’re all in stock, along with Hot & Cold Mufflers (for sound level reduction,) Automatic Drain Filter Separators (to keep the air supply clean & moisture free,) Oil Removal Filters (to coalesce any trace of oil from the air supply,) and Solenoid Valves & Thermostats (to automate operation.)

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.

The Vortex Tube, right out of the box, is easily adaptable to a wide range of cooling (or heating) applications.  If your needs are specific, though, we can customize a Vortex Tube to meet them:

  • Material of construction: our stock Vortex Tubes are made of 303SS and are equipped with a plastic Generator and Buna o-ring.
    • For high temperature (>125F ambient) applications, we can install a brass Generator and Viton o-ring, suitable for ambient temperatures up to 200F.
    • If the environment is particularly aggressive, or if industry codes (I’m looking at you, food & pharma) call for it, we can also make them out of other materials.  We’ve, for instance, made them out of 316SS, complete with material certifications, when needed.
  • Flow & temperature: the Hot Valve can be opened or closed to dial in a particular Cold Fraction (that’s the percentage of the supply air which is directed to the cold end.)  If you know what flow rate and temperature you want, we can replace the Hot Valve with a non-adjustable plug, so your Vortex Tube’s cold flow is only dependent on the compressed air supply temperature and pressure.
  • Accessories: if you’re looking for features like a magnetic base, or a flexible cold air hose, you might consider an Adjustable Spot Cooler.  If you like the idea of tool-free change of air flow/temperature, that’s definitely the way to go.  If you want those other options, and don’t mind using a screwdriver to adjust the Cold Fraction, those other options are compatible with any Medium Vortex Tube.

Model 3925 Adjustable Spot Cooler

These are just a few of the most common possibilities for customizing a Vortex Tube.  If you have a spot cooling application you’d like to discuss, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Vortex Tubes: What, Why, Where?

The most common questions about Vortex Tubes are “How long have they been around?” and “How do they work?”. These questions are simple enough and answering someone how long Vortex Tubes have been around is the easy answer, Vortex Tubes have been around since 1928 with what may seem as an accidental existence by the developer George Ranque.

As to how they work, these are a phenomenon of physics and the theoretical math behind them has yet to be proven and set in stone. They have been called various names such as “Maxwell’s Demon” which posited that a demon was splitting the hot and cold air molecules prior to leaving the Vortex Tube.  They have also been referred to as  the “Ranque Vortex Tube”, “Hilsch Tube”, and the “Ranque-Hilsch Tube” which highlight some of the prominent people in developing vortex tubes. 

WHAT: EXAIR defines a Vortex Tube within our catalog as “a low cost, reliable, maintenance free solution to a variety of industrial spot cooling problems. Using an ordinary supply of compressed air as a power source, vortex tubes create two streams of air, one hot and one cold, with no moving parts.”

The scope of Vortex Tubes include being able to produce temperatures from -50 degrees to 260 degrees Fahrenheit with flow rates from 1 to 150 SCFM and refrigeration up to 10,200 Btu/hr. Temperatures, flows and cooling power can be easily adjusted with the control valve located on the “hot” end of the tube.

WHY: EXAIRs’ Vortex Tubes offer low cost and reliable solutions primarily for product cooling and sometimes heating. Constructed of stainless steel, our vortex tubes are resistant to corrosion and oxidation providing for years of reliable maintenance-free operation. Vortex tubes operate with a source of compressed air with no moving parts or electricity.

EXAIR offers two series of vortex tubes. The 32XX series is “Maximum Refrigeration (cooling) and is typically used for process cooling, part cooling or chamber cooling. The 34XX series provide lowest cold temperatures at low cold airflow and typically used in cooling lab samples and circuit testing.

EXAIR offers a cooling kit with interchangeable generators that are easily changed so you can experiment and find what temperature and airflow works best for your application.

WHERE: There are many uses for EXAIR Vortex Tubes including but not limited to cooling electronics, machining operations, CCTV cameras, soldered parts, gas samples, heat seals, environmental chambers, ultrasonic weld horns, welds and setting hot melts.

The history of EXAIR Vortex Tubes and the variety of uses has derived new products designed for specific applications like our Spot Coolers and Cabinet Coolers. These items can be found in our catalog or at www.EXAIR.com.

If you have any questions regarding these products or any products that EXAIR offers I hope to hear from you.

Eric Kuhnash
Application Engineer
E-mail: EricKuhnash@exair.com
Twitter: Twitter: @EXAIR_EK

EXAIR Super Air Knives: Controlling the Force

EXAIR has been manufacturing Intelligent Compressed Air® products since 1983.  In the beginning, the Standard Air Knives and Full Flow Air Knives were very effective at that time.  But as leaders in this market, EXAIR did not want to stop there.  We were able to engineer a more efficient and more powerful air knife, the Super Air Knife.

Super Air Knife has 40:1 Amplification Ratio

Bernoulli’s principle explains how a high velocity fluid can generate a low pressure.  The EXAIR Super Air Knife creates a high velocity air stream to produce a low pressure to entrain ambient air.   What does this mean for you?  It will save you much money by using less compressed air.  The mass of the ambient air is added into the air stream to give a strong blowing force.  The Super Air Knife has an amplification ratio of 40:1. For every 1 part of compressed air, 40 parts of ambient air is drawn into the blowing air stream.  Ambient air is free, and compressed air is expensive.  EXAIR was able to engineer a design to use the Bernoulli’s principle to make one of the most efficient air knives in the market place.    In this blog, I will discuss how you can change the air usage and force of the EXAIR Super Air Knives.

We manufacture and stock the widest range in lengths and materials.  To start, EXAIR has Super Air Knives ranging from 3” to 108” (76mm to 2,743mm) in three different materials; aluminum, 303 stainless steel, and 316/316L stainless steel.  There is no-one else in this industry that can manufacture to those lengths.  EXAIR also offers Super Air Knives in PVDF material with Hastelloy hardware for chemical resistant applications from 3” to 54” (76mm to 1,372mm).  Depending on the application requirement, temperature, chemical resistance, and OSHA and FDA regulations, we probably will have one on the shelf for you.  If EXAIR does not have it, we can make special air knives in different lengths and materials to best fit your application.

Pressure Regulators

To adjust the force and air usage a Pressure Regulator is a very helpful tool. The regulator would be considered a fine adjustment for the Super Air Knife.  With the laminar flow, the force is very consistent across the entire length; so, you can “dial” in the exact force.  EXAIR always recommends to use the least amount of pressure to “do the job” because this will save you even more money.  For the coarse adjustment, EXAIR Super Air Knives have replaceable shims.  So, you can increase or decrease the gap to get a variety of force ratings.  The Aluminum version uses colored plastic shims for visual verification.  They come stock with a 0.002” (0.05mm) red shim installed.  We have other thicknesses in our Shim Sets which includes a 0.001” (0.03mm), 0.003” (0.08mm), and a 0.004” (0.10mm) colored as amber, green, and tan respectively.

The Stainless Steel Super Air Knives come with a stainless steel shim for higher temperatures and chemical resistance.  Stock units have the 0.002” (0.05mm) thickness as well.  The Shim Sets come with three additional 0.002” (0.05mm) shims to stack.  EXAIR does have the ability to manufacture other thicknesses in stainless steel.  Similarly, the PVDF Super Air Knives use a PTFE shim for maximum chemical resistance.  It is also 0.002” (0.05mm) thick, and there are three more shims in the Shim Set.

This unique feature of using shims allows for the most flexibility in creating forces for different applications ranging from a blast to remove rocks from a conveyor to a breeze for light duty work.

We can include the pressure regulator, filter, and Shim Sets in our standard kits.  It will make our Super Air Knives a more complete system that is properly sized.  With the today’s cost in making compressed air, it is important to do it as efficiently as possible.  And with the Pressure Regulator and Shim Sets available, you can control the blowing force and air usage.  From now until December 31st, EXAIR is having a promotion.  You will receive a model 1210 Safety Air Gun for free, a $91.00 value, with qualified purchases.  (Check it out HERE).  If you have any questions about the Super Air Knife or if you would like to discuss an application, you can contact an Application Engineer at EXAIR.   We will be glad to help you.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb