Category: Air Wipe

How the Coanda Profile Drives Efficiency in EXAIR Products

Published on by Jordan T ShouseLeave a comment

In compressed air applications, efficiency often comes down to how effectively you use the air you already have. One of the most important aerodynamic principles that allows modern air-powered devices to operate efficiently is the Coanda Effect. This phenomenon is the foundation behind several EXAIR engineered products, enabling powerful airflow while minimizing compressed air consumption.

Understanding how the Coanda profile works can help engineers and plant managers optimize processes such as drying, cooling, cleaning, and conveying.

Compressed air flows through the inlet (1) to the Full Flow (left) or Standard (right) Air Knife, into the internal plenum. It then discharges through a thin gap (2), adhering to the Coanda profile (3) which directs it down the face of the Air Knife. The precision engineered & finished surfaces optimize entrainment of air (4) from the surrounding environment.

What Is the Coanda Effect?

The Coanda Effect describes the tendency of a fluid streamโ€”such as airโ€”to follow along a nearby curved surface instead of continuing in a straight line. As the air travels along this surface, it pulls surrounding air into the stream, creating a region of low pressure and dramatically increasing total airflow.

In simple terms:

  1. Compressed air exits a small opening.
  2. The air adheres to a curved surface (the Coanda profile).
  3. This creates a low-pressure area.
  4. Surrounding air is entrained, or pulled into the airflow.

The result is a much larger volume of moving air than the compressed air supply alone would create.

This principle was originally studied by aeronautical engineer Henri Coandฤƒ in the early 1900s while researching airflow over aircraft surfaces.

EXAIR Products That Use the Coanda Profile

EXAIR incorporates this aerodynamic design into several of its Intelligent Compressed Air Productsโ„ข.

1. Air Knives

EXAIR Air Knives use a Coanda profile to create a wide, high-velocity sheet of air across the entire length of the unit.

Examples include:

  • EXAIR Standard Air Knife
  • EXAIR Full-Flow Air Knife
  • EXAIR Super Air Knife

Inside these units, compressed air enters a plenum chamber and exits through a narrow slot. The air then follows the curved Coanda surface, turning approximately 90ยฐ and flowing down the face of the knife.

As the air moves along the profile, it entrains large volumes of surrounding airโ€”up to 30-40 parts ambient air for every 1 part of compressed air.

Common applications include:

  • Parts drying after washing
  • Conveyor cleaning
  • Web or sheet drying
  • Cooling components
  • Pre-paint blowoff

2. Air Amplifiers

Another product that relies heavily on the Coanda profile is the Air amplifier.

Super Air Amplifier Family

Example:

  • EXAIR Super Air Amplifier
  • EXAIR Adjustable Air Amplifier

Instead of producing a flat airflow like an air knife, air amplifiers generate a conical air stream. Compressed air flows across a circular Coanda profile that draws in large amounts of surrounding air.

This creates amplification ratios up to 25:1, meaning the airflow produced is far greater than the compressed air supplied.

Typical uses include:

  • Cooling hot parts
  • Ventilating smoke or fumes
  • Circulating air in enclosures
  • Removing heat from equipment

3. Air Wipes

EXAIR also applies the Coanda profile in a circular configuration for drying or cleaning cylindrical materials.

Super (left) and Standard (right) Air Wipes come in sizes from 1/2″ to 11″.

Example:

  • EXAIR Air Wipe
  • EXAIR Super Air Wipe

These devices create a 360-degree ring of air that surrounds rods, tubes, wires, or cables. As air follows the Coanda profile around the ring, it entrains surrounding air and produces a strong, uniform drying or blowoff action.

Applications include:

  • Drying wire or cable
  • Removing coolant from tubing
  • Cleaning rods or extrusions

The Coanda Effect might seem like a theoretical concept, but it has a very practical impact on industrial operations. By carefully designing curved surfaces that guide airflow and entrain surrounding air, EXAIR products turn a small supply of compressed air into a powerful and efficient airflow solution.

Whether drying parts, cooling electronics, or removing debris from a conveyor, the Coanda profile allows EXAIR products to deliver maximum performance with minimal energy use.

Jordan Shouse, CCASS

Application Engineer / Sales Operations Engineer

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Buy 1, Get 40 Free

Published on by Al WooffittLeave a comment

Buy one, get one free is a phrase many of us are familiar with. Most of the time it is a good thing; we all like free stuff. What would you say to buy one, get 30 free? Or even 40 free? That’s not far off how our Air Knives perform. They entrain large volumes of ambient air, so for every 1 SCFM of compressed air you are paying for, you are getting 30โ€“40 SCFM of additional free ambient entrained air.

So how are our Air Knives able to do this? We explain this phenomenon in more detail in this blog here, but in summary, a Super Air Knife takes advantage of the Venturi Effect. Named after Giovanni Venturi, who found out that when you increase the speed of a fluid through an orifice, the surrounding fluid will move along with it. This creates a region of low pressure, and the faster the speed, the lower the pressure. With low pressure, the air around rushes in to fill that gap and join the airstream. The quantity of ambient air that gets โ€˜pulledโ€™ into the airstream is entrained air, or free air.

The engineered surface of the Super Air Knife is designed to minimize as much loss in air speed as possible, which maximizes the amount of free air that is being entrained. The ratio between free air and compressed air used is called the amplification ratio. Super Air Knives have an amplification ratio of 40:1, with our Standard Air Knives having an amplification ratio of 30:1. For comparison, a pipe with holes drilled will have an amplification ratio of between 2:1 and 5:1. As you can see, with a Super Air Knife you are getting a much better deal on your compressed air usage.

This additional free air adds more mass, which allows the Super Air Knife to do more work. You will get a harder hitting force than a comparable product while using less compressed air. This makes Super Air Knives especially good for cooling and drying applications, where moving large volumes of air is ideal.

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

It’s not just our Air Knives that take advantage of the Venturi effect to produce large amplification ratios. Many of our products are designed with efficiency in mind, including our Air Amplifiers, Air Wipes, and Air Nozzles and Jets, to name a few. If you would like to discuss how an EXAIR engineered compressed air product can amplify your process, then give us a call!

Al Wooffitt
Application Engineer

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Protecting Precision: Air Wipe Ensures Accurate Measurements

Published on by Tyler DanielLeave a comment

Imagine investing in a high-end laser measurement system, capable of gauging product dimensions down to fractions of a micron, only to have the readings thrown off by something as small as a speck of dust or a thin film of residue. For one of our customers, who specialize in repairing and calibrating laser gauges, this wasnโ€™t just a โ€œwhat if.โ€ It was a real challenge that needed a reliable solution.

The answer came in the form of EXAIRโ€™s Air Wipe.

In their setup, cylindrical products pass through a laser gauge that verifies their diameter. Any contamination on the surface risks altering the accuracy of that measurement. By installing an Air Wipe just upstream of the gauge, they created a 360ยฐ wall of compressed air that strips away residual coolant, debris, or dust. The result is a clean, consistent surface before every scan โ€” ensuring the gauge is reading the product, not the contaminants.

Split ring design eliminates the need for product “threading” through the Air Wipe.

The beauty of the Air Wipe lies in its design. A hinged, split-body housing makes it easy to install around existing lines, while the engineered air gap creates a uniform, high-velocity sheet of air that fully encircles the product. Unlike multiple nozzles aimed at different angles, the Air Wipe eliminates guesswork and guarantees complete coverage without gaps.

This customer chose it for metrology, but the same principle applies across industries:

  • Extrusion lines use Air Wipes to remove cooling water from plastic or rubber profiles.
  • Wire and cable manufacturers rely on them to dry and clean before printing or spooling.
  • Pipe and tubing producers install them before coating or inspection processes.
  • Medical and electronics manufacturers trust them when cleanliness and precision are non-negotiable.

For this customer, the Air Wipe turned a potential weak point in their process into a strength. Instead of worrying about contaminants interfering with measurement, they can now focus on providing precise, reliable results for their clients.

Itโ€™s a simple solution that makes a big difference: when the measurement has to be right, start by making sure the surface is clean. EXAIR offers a wide variety of products that utilize a laminar flow of compressed air for cleaning, cooling, and drying operations. Give us a call today to discuss your application!

Tyler Daniel, CCASS

Application Engineer

E-mail: TylerDaniel@EXAIR.com

X: @EXAIR_TD

The 30-Day Guarantee Gives You Confidence.

Published on by Al WooffittLeave a comment

When you make a purchase, you want to have confidence that the solution that you’ve spent money on is going to work. With many of the applications that we discuss with customers, the solutions are tried and tested. If your electrical panel is getting too hot, then an EXAIR Cabinet Cooler is exactly what you need. If there’s static on your assembly line, a Gen4 Static Elimination product is the way to go. And if you need to blow off excess water from an extruded pipe, a Super Air Wipe is the perfect fix.

There are plenty of situations where the solution isn’t clear-cut. We believe our products can make a difference, but with so many variables, it’s impossible to just plug everything into a formula and predict the exact outcome. The only way to know for sure is to test. That’s where EXAIR’s 30-day unconditional guarantee comes into play. Every one of our cataloged products is covered by this guarantee. Once you buy one of these items, you have a month to really test it out; change the angle, tweak the operating pressure, or swap out shims. If you manage to find the right setup to fix your issue, awesome! If not, weโ€™ll gladly take it back and give you a full refund! The only thing you need to cover is the shipping to return it to us.

A great example of where testing is key is our Line Vacs. There are several factors to consider: the bulk density of the material, its size, whether it’s abrasive, the desired conveyance rate, and the distance for conveyance – both vertical and horizontal. By using the data we’ve gathered from our controlled in-house tests, we’re going to be able to give you a solid recommendation on which model will suit you best. However, to truly understand how our Line Vac will perform with your specific material and operational conditions, it needs to be put through its paces at your facility. When you buy from us, you get 30 days to try it out risk-free.

At EXAIR, we want to ensure you are getting the best possible solution. Our 30-day unconditional guarantee is one way that we make that a reality. If you would like to discuss how our products can help with your application, give us a call!

Al Wooffitt
Application Engineer

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