How EXAIR Uses Fluidics To Make Efficient, Quiet, and Safe Compressed Air Products

EXAIR Intelligent Compressed Air Products incorporate several distinct principles of fluidics into our engineered designs. To be clear, these principles aren’t exclusive to making quiet and efficient compressed air products. I personally have used them all for business and pleasure over the years. In the Navy, for example, the air ejectors that pulled vacuum on the main condensers where our turbines dumped their ‘used’ steam were basically great big Venturis – they restricted the diameter through which a fluid (steam, in this case) flowed, gradually increased that diameter, and doing so, changed the velocity so that a low pressure area (or vacuum) developed in the throat:

Graphic representation of the Venturi effect.

EXAIR E-Vac Vacuum Generators use the Venturi effect to draw vacuum of up to 27″Hg. They’re typically used with Vacuum Cups for pick-and-place material handling applications.

Here are a few examples of Mr. Venturi’s discovery, implemented in modern industry.

I first learned about the Bernoulli principle on a grade school field trip to the National Air Force Museum at Wright Patterson Air Force Base, about an hour from where I grew up. See, this Bernoulli guy discovered that when there is an increase in the speed of a fluid, a simultaneous decrease in fluid pressure occurs at the same time. That’s why airplane wings are shaped like they are – flat on the bottom and curved on top…when the air flowing that extra distance over the top speeds up to get to the back of the wing as fast as the air that’s simply flowing underneath the wing does, the decrease in pressure on top causes the wing (and the plane it’s attached to) rise in the air.

Bernoulli’s Equation: this is the math that proves it works.

The Bernoulli principle is incorporated in to the design & operation of EXAIR engineered Air Knives, Air Wipes, Air Amplifiers, and Air Nozzles.

The Coanda effect is the third fluidics principle that’s incorporated into the design & operation of many EXAIR engineered compressed air products. Its namesake, Henri Coanda, was an early 20th Century aeronautical engineer who discovered that if a jet of fluid exiting an orifice flows across a surface, it’ll tend to not only adhere to and follow that surface (even if it curves or bends), but also entrain fluid from the surrounding area.

EXAIR Intelligent Compressed Air Products such as (left to right) the Air Wipe, Super Air Knife, Super Air Nozzle, and Air Amplifier all use the Coanda effect to entrain enormous amounts of air from the surrounding environment.

There are a couple of easy – and interesting – experiments that demonstrate the Coanda effect, both of which I used when I was a Cub Scout leader and our Pack’s Webelos den was earning their Science Activity Pin:

Turn a faucet on and let the running water flow over the convex ‘bottom’ of a spoon. Everything we know about the laws of gravity say that when the water reaches the ‘bottom-most’ point on the spoon’s convex surface, it ought to fall straight down…but it doesn’t:

Another experiment that defies everything we think we know about gravity can be performed with a ball, and a source of air flow. Here’s a short video, showing how the air flow from an Air Amplifier ‘wraps’ around a ball and holds it in that jet of air:

The Webelos den did this with a leaf blower and a playground ball. Unlike a lot of things I’ve done, I DEFINITELY encourage you to try THAT at home.

For forty years now, EXAIR has been putting these principles of fluidics into practice by engineering & manufacturing the most efficient, quietest, and safest compressed air products on the market. If you’d like to find out how we can help you get the most out of our products – and your compressed air system – give me a call.

Russ Bowman, CCASS

Application Engineer
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TurboBlast Safety Air Guns – Up To 23 Pounds Of Force At The Push Of A Button

I had the pleasure, recently, of talking with a customer at a paper good manufacturing facility who needed an air gun with a LOT of force for some applications, a little less for others, and was hoping to find one device that gave the operator control over it. They were using a piece of 1/2″ pipe on the end of a ball valve. The operators were trying (and mostly failing) to get precise control by throttling that valve. When they needed a LOT of force, it was no problem – just open the valve all the way. Unfortunately, though, ball valves aren’t known for being precision throttling devices, so most of the “little less” force jobs were getting too much force (and making a bigger mess) or not enough (leaving the existing mess) around the machinery.

After reviewing our Safety Air Guns catalog, they decided to try the Model 1927 TurboBlast Safety Air Gun. They liked:

  • Hard hitting power – the Model 1118 High Force Super Air Nozzle‘s flow (when supplied @80psig) generates 15 pounds of force at a distance of 12″ from the target.
  • Nozzle Guard – there was a great potential for the tip to get banged up from incidental contact with the machinery. The rugged Nozzle Guard protects not only the Air Nozzle, but the equipment as well, as the Zinc Aluminum Super Air Nozzle could have left scratches in some of the parts that were painted.
  • Adjustable Gate Valve – this provides the precise control their operators need to clean up the aforementioned mess, without creating a bigger one.
  • Pushbutton control – the low profile button trigger actuates with just a slight squeeze. Much more ergonomic than having to grasp the ball valve’s handle tight, especially when they needed it in a partially open position.
Features & benefits of the new TurboBlast Safety Air Gun

No matter what the scope of a blow off application is, EXAIR has a wide selection of Safety Air Guns to meet your needs. If you’d like to find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
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Pipe ID Clean out Made Easy With EXAIR’s Back Blow Safety Air Gun

In certain applications such as blowing chips or debris forward, out of a pipe or blind hole, may not be possible. The pipe may be long, making it impossible to push the debris all the way down the pipe, the other end of the pipe may not be open or there could be some process or area to which it is attached, that would become contaminated if debris were blown in that direction. In any of these scenarios, a Back Blow Nozzle is the right tool for the job. An array of holes located around the outside diameter of the Back Blow Nozzle head provides a powerful 360° airflow pattern that will pull and clear out any leftover coolant or chips ahead of it within a pipe from a machining or any other process.

Small 1004SS easily clears debris

EXAIR has three different size Back Blow Nozzles; the 1004SS (M4 x .5), the 1006SS (1/4 NPT), and the 1008SS (1” NPT). The 1004SS is recommended for use on pipes as small as ¼” and up to 1”. The 1006SS can be used for a wide range of pipe sizes, from 7/8” up to 4”. The 1008SS nozzle offers the greatest overall force for stubborn or sticky materials stuck to the inside diameter of the pipe. This nozzle is suitable for use in pipes ranging from 2”-16”. As the Back Blow Nozzle will be blowing chips and debris back out of the pipe towards the operator, it is always recommended that a Chip Shield is used. The strong, polycarbonate Chip Shield will keep an operator safe from flying debris and keep your company in compliance with OSHA directive 1910.242(b). For visual representation of the performance of the Back Blow Nozzle, take a look at this short video clip that demonstrates its use.

All of EXAIR’s Back Blow Nozzles are available with extensions. For the 1004SS we have extensions from 6”-36”, and from 12”-72” for the 1006SS and 1008SS. The Back Blow Nozzle can also be installed on our VariBlast, Soft Grip, Heavy Duty, and Super Blast Safety Air Guns. With such a wide range of available sizes and configurations, we can tackle just about any internal pipe cleaning application. If you have a process in your facility that may benefit from the use of one of these nozzles, give us a call and get one on order today!

Tyler Daniel, CCASS

Application Engineer
Twitter: @EXAIR_TD

Combining Products For Total Blow Off Of Objects With Complex Geometry

EXAIR Super Air Knives are extremely efficient at blowing off flat surfaces. The laminar air flow they generate makes a stripping/sweeping action, as opposed to the turbulent flow from a non-engineered blow off, which really just beats on the surface. If the object being blown off, though, has features such as holes, recesses, grooves, bosses, “nooks & crannies”, etc., it may be challenging to get those features 100% blown off, 100% of the time.

If the object you’re blowing off is flat, the laminar air flow from a Super Air Knife is ideal. They come in lengths from 3 inches to 9 feet long.

Depending on the size & shape of the feature presenting the challenge, the first thing we might recommend is to adjust the angle at which the Air Knife’s flow contacts the surface. For most applications, you can optimize performance by blowing at as low of an angle as practical. You may need to aim the Air Knife at a steeper angle, for example, if you’re blowing off something that’s dense (like shot blast or garnet, as opposed to dust or chips), or if it’s somewhat adherent to surface (like grease or mud, as opposed to water or light oil). This can also work if you’re trying to blow out a hole, recess, or groove in an object.

EXAIR manufactures a wide variety of engineered Air Nozzles, designed for safety, efficiency, and quiet operation.

Other times, a dedicated blow off may be necessary to pick up where the Air Knife leaves off. In situations like that, we can specify an appropriately sized Air Nozzle, Air Jet, Air Amplifier, or maybe even a smaller Air Knife, to provide more complete removal of whatever you need to get off of the object. It’s fairly common to use Air Nozzles for these applications, and our Air Nozzles & Jets catalog section is a great tool that can be used for selection. It lists them all, from smallest to largest, with airflow patterns, performance data, and dimensions.

EXAIR offers solutions for plumbing, installation, and aiming the Air Nozzle too:

  • Swivel Fittings are installed on threaded pipe, and provide 50° of angular movement. Just loosen the lock nut, aim the Nozzle, and re-tighten for rigid & secure placement.
  • Stay Set Hoses are likewise be threaded into 1/4 FNPT connections, with the Air Nozzle secured onto the other end. These come in lengths from 6″ to 36″, with 1/8 FNPT or 1/4 MNPT threads for the Air Nozzle.
EXAIR Stay Set Hoses and Swivel Fittings are ideal for installation and positioning of your Super Air Nozzle.

Metal tubing with compression fittings is another option, that can be used to install & aim an Air Nozzle. Copper tubing is relatively easy to bend by hand. Stainless steel tubing usually requires a tube bender tool, with the advantage that it can’t easily be bent by hand…on purpose or by accident. While metal tubing is certainly an option, it is generally reserved for applications where the ability to readjust is not necessary. The Stay Set hoses and Swivel Fittings tend to work better when flexibility is required.

The copper tube used to have a crimped end that was aimed at the part in the chuck. They simply cut it off and used a compression fitting to install the Super Air Nozzle.

If you’ve got a blow off application that’s not working the way you want it to, it’s highly likely that EXAIR has a solution. We would love to share our ideas with you. Give me a call.

Russ Bowman, CCASS

Application Engineer
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