Counter-flow – How to Mount Air Knives for Maximum Effect

counter flow

Example: Counter-flow arrangement

As with any tool, there can be a right way and a wrong way to use the tool. In this article I will explain the best way to mount a Super Air Knife in a blowing application so that you achieve the maximum force, time in contact and of course, effectiveness.

There is a term we use, “counter-flow”, to describe the opposing travel of target material/conveyor (red arrow) and the airflow coming from an Air Knife (yellow arrow). By having opposing flows, the Air Knife is able to blow the debris, contamination, water or other fluid back into the direction from which it came. Sometimes a catch pan can be used to collect and re-use the fluid. In the photo above, note that the air knife is oriented to blow from right to left and the parts are travelling on the conveyor belt from left to right. This is a simple example of how we set up counter-flow.

Also, with regard to effective Air Knife mounting strategies; the Super Air Knife in the photo is mounted using our Universal Air Knife Mounting System which allows for maximum flexibility for positioning and stability of the Air Knife once set. The Universal Air Knife Mounting System is another great accessory that you can recommend to clients to make the set up very easy. Of course a suitable compressed air filter and pressure regulator should be used for clean air and adjustability of force in the application.

Finally, in the photo above, note that the Super Air Knife is mounted up-side down. We generally recommend this kind of orientation with the cap of the Super Air Knife being closest to the material being blown off. This allows you to get the air knife a bit lower and closer to the target material. The lower the angle, the better. This allows for a longer time in contact between the Super Air Knife and the target material. When the target material spends more time in the high velocity flow, the more likely you are able to impart the desired effect whether that be drying, cooling, blowoff or static elimination. To find a good mounting angle to start, I recommend customers use the front, angled edge of the Super Air Knife cap as a guide for what part of the Super Air Knife to keep parallel to the moving surface. This is a great reference from which blowing angle can be optimized.

If you find yourself with an Air Knife application and are unsure about how to proceed with mounting it, the idea explained above is one of the core foundations we utilize for solid Air Knife mounting technique.

Neal Raker, International Sales Manager


First Time For Everything

We’ve got a lot to be proud of at EXAIR. Over 32 years of experience in providing superior engineered compressed air products for demanding applications worldwide. A 19 year track record (we can only claim 19 years because it’s when we started keeping track) of over 99.9% on-time shipments. 35 Industry Awards (and counting) for new product excellence.

The thing I want to brag on today is…well, me. OK; not just me, but the whole Engineering staff at EXAIR. See, in addition to knowing the ins & outs of 192 pages of compressed air products and accessories in our catalog, EXAIR Application Engineers are well-versed in the situations where our products will…and won’t provide a successful solution.

Sometimes, a user is looking for something different. Same principle of operation, functionality, method, etc., but in a different size. Or shape. Or material of construction. And that’s where the Design Engineers come in…we’ll work together to determine the best way to apply all those years of experience and successful track record and solve your application. And usually, pretty darn quickly.

Case in point: I had the pleasure of discussing an application requiring a special Super Air Knife yesterday afternoon with a caller. Seems they had a tight spot that they needed to fit the Air Knife into, and saw that we had made a special flat Super Air Knife:

Flat Super

This design goes back about 16 years, and has been No, at times, for other applications as the need arises. Because of the large variety of these simulations, we’re probably already pretty close to the next simulation. I realized this was the case when, within 5 minutes of submitting my request to Design Engineering, the office printer (which sits next to my desk) started up, and one of our Design Engineers was on his way over to retrieve the print…of an approval drawing for my caller. Not to swell any heads around here (past our current level of well-deserved swagger, that is,) but this was just about the same amount of time that it took the caller to communicate the requirements to me, and for me to transcribe them into my inter-departmental request.

There’s always a first time for everything…and we look forward to each one of them. If you need help with a compressed air solution, give us a call.

Russ Bowman
Application Engineer
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Versatile, Efficient And Quiet: The EXAIR Super Air Knife

It would be a memorable day in Application Engineering if one of us didn’t handle at least one call regarding a Super Air Knife. They’re just used for so many different purposes: from debris blow off, to drying, to cooling – in fact, a good number of “Super Air Knife calls” start as “Vortex Tube calls,” because both have their place, depending on factors such as how hot the part to be cooled is, what temperature you want to get it to, how fast does it need cooled, etc. More on that here, and here…today, I’m going to write about environmental containment and separation.

In a nutshell, that means keeping smoke, fumes, powder, etc., inside an area, or at the very least, away from another area. A couple of examples of this are documented in the Super Air Knives section of our latest catalog. If you don’t have one, click here.

The first features:

lens clearing

(2) Model 110024 24″ Aluminum Super Air Knives, which keep the smoke from machining oil that burns off during an engine test directed into the vent hood.

The second utilizes:

A Model 110006 6" Aluminum Super Air Knife to keep the slag, spatter, and smoke from a laser cutter away from the lens of the machine's visual inspection system.

A Model 110006 6″ Aluminum Super Air Knife to keep the slag, spatter, and smoke from a laser cutter away from the lens of the machine’s visual inspection system.

A third, which I don’t have pictures of yet because it’s brand-new, is a little larger scale: a recent caller was looking for a way to keep ALL the powder inside his powder coating spray booth. There’s an open vent with runs all the way across the top, and, when the booth is in operation, a very small plume exits along its 90″ width. They purchased a Model 110296 96″ Aluminum Super Air Knife Kit to blow a continuous curtain of air across this 4″ wide gap, angled down slightly into the booth. The Kit’s Pressure Regulator allows them to “dial down” the air flow to a level just high enough to keep the powder from exiting the gap, but also low enough to not disturb the powder coating process inside the booth.

A self contained blower unit was actually their first idea…these are very popular for large doorways…you’ve probably even seen them on large doors on shipping docks, or forklift paths inside plants where it’s necessary to keep pollutants from one room from entering another. For this situation, though, the compact size, low sound level, and precise adjustability of the Super Air Knife’s air flow made it the logical choice.

If you’d like to know more about EXAIR Super Air Knives, or any of our Intelligent Compressed Air Products, give me a call.

Russ Bowman
Application Engineer
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Video Blog: How To Clean An EXAIR Air Knife

From time to time, cleaning of an EXAIR Air Knife may be necessary. Watch the video below for a walk through of the cleaning procedure.

Lee Evans
Application Engineer

Thinking “Inside” the (Election) Box

With Election Day coming up in November and everyone gearing up for next year’s presidential race, a thought popped into my head about the infamous Florida hanging chads during the Bush-Gore Race years ago. What if the Florida Election Board had installed an EXAIR product to blow the chads away as they were punched through the ballet? True, I do not think it would have resolved all the chads still hanging, but it might have blown enough away that there would have been less questionable votes. Although not really practical – air compressors at each booth?! – and likely not feasible or economical, it still is an interesting idea. Running with it a bit, what could they have used? EXAIR offers many different ways to accomplish blowoff. In this case, two options come to mind: air knife and safety air gun.

A standard air knife (dictated by budget, after all), the length of the ballet, could be installed on one the side of the election booth. As the chads are pushed through, the air would blow underneath to push them into a trough on the other side of the booth. Unobtrusive, easy, no mess.

The second option is the safety air gun. This is a bit more manual and would probably need to have the voters trained in use to insure privacy. The soft grip version is a definite; Florida has more senior citizens than any other state and comfort is a must. In this scenario, the voter would vote, then pick up the ballet and use the air gun to spray the chads off to one of the booth’s back corners were the chads would drop down into a collection chute to the rear underneath. I feel this method would not be quite as successful as the first, for a multitude of reasons – dexterity, blowing the ballet away, potentially messy, voter misconduct, etc.

In the years since, states have gotten away from using chad-type ballets. But if you are reading this and your state is still hanging and stuck with chads, you may want to suggest an EXAIR method of helping out in the next election. Just imagine the headline: “Compressed Air Decides Election!”

John Pinchek
Application Engineer

The Time When The Only Thing Better Than An EXAIR Product…

…was another EXAIR product. And actually, it happened twice, just today:

  • An insulation manufacturer was using an open pipe blow off to push air into a five foot wide “blanket” of their product to uniformly flatten it, and blow stray fibers out and into a vacuum system for recycling. They tried a Super Air Knife, which blew the stray fibers out just fine, but didn’t produce the flatness they desired, even with additional shims installed. They then experimented with a manifold system, using a series of Model 1104 High Force 3/8 NPT Super Air Nozzles, which provided the force required to blow the loose fibers out, and to produce the uniform material thickness. With a sound level of only 82dBA (which you won’t find ANYWHERE ELSE from a device that delivers 1.9 lbs of force,) they’ve also made the area much quieter.
Definitely try a Super Air Knife first, but if the job calls for high force, Super Air Nozzles can be easily fitted into a pipe manifold like this.

Definitely try a Super Air Knife first, but if the job calls for high force, Super Air Nozzles can be easily fitted into a pipe manifold like this.

  • A major producer of adhesive labels and specialty packaging had been using our Line Vacs extensively for scrap trim removal. They tried them on a new application where the trim was very lightweight. I’ve written before about When You Can Use An Air Amplifier, or A Line Vac, or…Either? – and this was again the case. They tried a couple of Adjustable Air Amplifiers: a Model 6044 4″ unit for the larger pieces, and a series of Model 6043 3″ units to gather in the rest, as the product traversed the production line.

Normally, we like to reserve our bragging on EXAIR products to how much better they’ll perform than the competition’s.  Which we do regularly, and we’ve got the data & experience to back it up.  But, with such a diverse product line, there are going to be situations – like these – where more than one product might fit the bill.  If this is the case, give us a call; we’re here to help you get the most out of your compressed air usage – whichever EXAIR product that may be!

Russ Bowman
Application Engineer
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Multiple Products Provide a Solution to Improve a Laminated Sign Making Process

A manufacturer that produces laminated signs contacted EXAIR for a blow off application. Being that we are experts in this area, I thought this would be a simple solution. The conversation started out about the signs that they manufacture. They are laminated sheets that have a thin aluminum film with a coating on the front and back sides. Their process was to cut stacks of these signs that he called books to specific dimensions. Here is how the conversation went in a shortened version:

Problem –

  1. I need to blow off chips from the saw process.
  2. It has to be strong enough to remove the chips that are melted into the face of the laminate.
  3. When the blade gets dull, the chips become hotter. The operator has to blow on the blade as it is cutting to reduce the amount of chips that melt into the laminated face.
  4. After the machine finishes and the books are removed, the table lifts up and disposes of the excess chips.

Solution –

  1.  Model 1122 2” Flat Super Air Nozzle to blow a wide area off the top of the signs after sawing.
Model 1122: 2

2″ Flat Super Air Nozzle

2.  Model 5330 High Power Cold Gun with dual point hose to place on the saw blade. This will extend the life of the blade and help keep the chips cool. Eliminating the melting into the face.

5330 High Power Cold Air Gun

High Power Cold Gun System

3.  Model: 110248 Super Air Knife Kit to blow the chips from the table after it is lifted.

Super Air Knife

Super Air Knife

As you can see, with a simple initial question, it became complicated rather quickly. Instead of looking at one area of the application, I was able to improve their entire process. In any manufacturing plant, scrap and downtime are the two biggest culprits in reducing profits. The scrap occurred when the faces were scratched and damaged. The downtime happened during the cleanup between book change-overs and when the saw blades were being replaced. Overall, their process improved in efficiency and speed.

Whenever you need to look at the overall process for improvement, EXAIR may have multiple solutions to offer. You can speak to an Application Engineer to see how EXAIR can increase your efficiency and reduce your scrap. You can either call 800-903-9247 or send an email to

John Ball
Application Engineer


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