Henri Coanda: June 7, 1886 – November 25, 1972

Henri Coanda was a Romanian aeronautical engineer best known for his work on the fluid dynamic principle with his namesake, the Coanda effect. Before this, Henri patented what he labeled as a jet engine.

Jet Engine 1
Jet Engine

Henri’s patent (French patent No. 416,54, dated October 22, 1910) gives more information into how he envisioned the motor working. When air entered the front, it passed through different cavities that caused the air stream to first contract and then expand. In Henri’s opinion this contraction and expansion converted the air’s kinetic energy into potential energy.  The air ultimately was channeled to a diffuser where it was discharged.

Henri stated that the efficiency of this engine could be improved by heating the air in the cavities, Henri’s logic was that this would increase the pressure of the air passing through.

What is obviously lacking in the patent (including identical ones taken out in England and the United States) is any mention of injecting fuel, which in a true jet engine would combust with the incoming air. Judging only by Henri’s patent, it was little more than a large ducted fan and it could not have flown.  Throughout Henri’s career he changed his story many times on whether this plane actually flew or not.

Not to cast too much shade on Henri’s accomplishments he did discover the Coanda effect.  The Coanda effect states that a fluid will adhere to the surface of a curved shape that it is flowing over.  One might think that a stream of fluid would continue in a straight line as it flows over a surface, however the opposite is true.  A moving stream of fluid will follow the curvature of the surface it is flowing over and not continue in a straight line. This effect is what causes an airplane wing to produce lift, and enhance lift when the ailerons are extended while at lower air speeds such as occurs during takeoff and landing.

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Ailerons positioned for cruising speed

EXAIR uses the Coanda effect to offer you highly engineered, intelligent and very efficient compressed air products.  Our designs take a small amount of compressed air and actually entrain the surrounding ambient air with the high velocity exiting compressed air stream to amplify the volume of air hitting a surface.

nozzle_anim_twit800x320
Surrounding Air Captured (Entrained) In Exiting Compressed Air Stream
How Air Knife Works
1). Compressed Air Inlet, 2). Compressed Air Exiting EXAIR Super Air Knife 3). Surrounding Air Being Entrained With Exiting Compressed Air Stream
Super Air Amplifier
EXAIR Super Air Amplifier Entraiment

When you are looking for expert advice on safe, quiet and efficient point of use compressed air products give us a call.   We would enjoy hearing from you.

Steve Harrison
Application Engineer
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Compressed Air Uses In Industry

Air Compressor

There are so many uses for compressed air in industry that it would be difficult to list every one of them as the list would be exhaustive.  Some of the uses are the tools used in production lines, assembly & robotic cells, painting, chemical processing, hospitals, construction, woodworking and aerospace.

It is considered as important as water, electricity, petroleum based fuels and often referred to as the fourth utility in industry. The great advantage of compressed air is the high ratio of power to weight or power to volume. In comparison to an electric motor compressed air powered equipment is smoother.  Also compressed air powered equipment generally requires less maintenance, is more reliable and economical than electric motor powered tools.  In addition they are considered on the whole as safer than electric powered devices.

Even amusement parks have used compressed air in some capacity in the operation of thrill rides like roller coasters or to enhance the “wow factor” of certain attractions. Compressed air can be found in your dentist’s office where it is used to operate drills and other equipment. You will find compressed air in the tires on your car, motorcycle and bicycles. Essentially, if you think about it, compressed air is being used nearly everywhere.

Here at EXAIR, we manufacture Intelligent Compressed Air Products to help improve the efficiency in a wide variety of industrial operations. Whether you are looking to coat a surface with an atomized mist of liquid, conserve compressed air use and energy, cool an electrical enclosure, convey parts or bulk material from one location to another or clean a conveyor belt or web, chances are we have a product that will fit your specific need.

Atomizing nozzle
Atomizing Nozzles Can Apply Even Coatings
Super Air Amplifier
Air Amplifiers pull in a large volume of ambient air to increase air flow volume and are great for cooling applications!
Heavy Duty Threaded Line Vac
For conveying heavy or abrasive products the Heavy Duty Threaded Line Vacs have male NPT Threads to make permanent and rigid installation into a piping system a breeze.

If you would like to discuss quiet, efficient compressed air products, I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer
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Super and Adjustable Type Air Amplifiers

The EXAIR Air Amplifiers are a powerful, efficient and quiet air mover, whose power can be harnessed for blowoff, cooling and ventilation applications. Using a small amount of compressed air, air amplifiers pull in large amounts of surrounding air to produce a high volume, high velocity outlet flow.  Quiet and efficient, output flows with amplification ratios of up to 25 times are possible. There are two types, the Super Air Amplifier and the Adjustable Air Amplifier.

The Super Air Amplifier, with sizes ranging from 3/4″ to 8″, has a patented design (patent #5402938) that uses a special shim to maintain critical position of the components parts. It is through this critical gap setting that a precise amount of compressed air is passed at exact intervals controlled by the shim toward the center of the of the Super Air Amplifier.  The jets of air create a high velocity flow across the entire cross sectional area, which in turn pulls in large amounts surrounding air, resulting in the amplified outlet flow.  Because the outlet flow remains balanced and minimizes wind shear, sound levels are typically three times lower than other types of air movers. The shims are available in thicknesses of 0.003″ (supplied as standard), 0.006″ and 0.009″, and changing to a larger shim will increase the force and flow of the outlet air. The 8″ Super Air Amplifier is supplied with a 0.009″ shim, with a 0.015″ shim available.

2″ Super Air Amplifier and Patented Shim Design

For high temperature applications (up to 700°F/374°C) a special 1-1/4″ High Temperature Air Amplifier is available, with performance equal to the 1-1/4″ Super Air Amplifier. Its surfaces are protected from heat stress by a mil-spec coating process. The High Temperature Air Amplifier is highly effective at pushing large amounts of hot air to areas that typically remain cool.

The Adjustable Air Amplifier, with sizes ranging from 3/4″ to 4″, does not use a shim, and has an infinitely adjustable air gap, which regulates the air consumption and outlet flow from a light breeze to a powerful blast. A highly effective air mover, it can be tailored to meet the exact air flow and force of your specific application. They are available in aluminum and in stainless steel (Type 303) for food service, higher temperatures (400°F/204°C) and corrosive environments.

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2″ Adjustable Air Amplifier, in Aluminum or Stainless Steel

Force and flow of the Adjustable Air Amplifier is changed by loosening the knurled lock ring and turning the exhaust end to open or close the gap.  Once the desired force and flow is achieved, the knurled ring can be tightened to lock the device at the current setting. Typically, an air gap of 0.002″ to 0.004″ provides the required performance.

The table below summarizes the key features of the Super Air Amplifier and Adjustable Air Amplifier.  Please contact an Application Engineer if you need assistance in making a selection.

Air Amp Selection Chart

Note that EXAIR can manufacture special Air Amplifiers to your specification including special flanged mounting style or with a PTFE plug to avoid sticky material build up.

To discuss your application and how a Super or Adjustable Air Amplifier or any EXAIR Intelligent Compressed Air Product can improve your process, feel free to contact EXAIR, myself, or one of our other Application Engineers. We can help you determine the best solution!

Brian Bergmann
Application Engineer

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EXAIR Super Air Amplifiers Compared to Fans

Super Air Amplifier

EXAIR Super Air Amplifiers and fans are designed to move air.  Fans use motors and blades to push the air toward the target.  There are two types, centrifugal fans and axial fans.  Centrifugal fans are also called blowers or “squirrel” cages.  The air enters into the side of the fan and is redirected 90 degrees to the outlet.  The axial fans are box fans, ceiling fans, and industrial fans.  The motor and spindle are attached to blades.  The air enters from directly behind the fan, and the blades “slap” the air forward to the target. The EXAIR Super Air Amplifiers does not have any blades or motors to push the air.  They use a Coanda profile with a patented shim to create a low pressure to draw in the air.   (You can read more about it here: Intelligent Compressed Air: Utilization of the Coanda Effect.)  I will expand a bit more in this blog about how each one performs in moving ambient air.

The reason to move air can vary by application from cooling, drying, cleaning, and conveying.  The more air that can be moved, the better the performance for each of these functions.  With the Super Air Amplifiers and fans, these products can move the air, but what affects air flow?  Velocity, turbulence, and static or back pressure.  As we look at each one, we can start to see the effectiveness within each application.

Super Air Amplifier – flow region

Velocity is air flow per unit area.  This is the speed at which the air is traveling.  Some fan designs can affect the velocity, like the motor and spindle in the center of the axial fan.  Some of the area is removed from the middle of the flow region.  So, the velocity is very weak in the center.  (Reference diagram below).  With the centrifugal fan, the air velocity has to be redirected and pushed out the exhaust.  The velocity profile is very disoriented and will work against itself within the flow region.  If we look at the EXAIR Super Air Amplifier, the center is open as shown above.  There are no obstructions.  Since we are drawing in the ambient air, the velocity profile is laminar meaning that the flow is even across the entire flow region.  Laminar flow is optimum for a uniform force and effective blowing.

Axial Fan velocity profile

Turbulence is the “action” of the air flow.  If the turbulence is high, the air flow pattern is interrupted and chaotic.  It causes the velocity of the air to decrease quickly.  By the time the air reaches the target, it has low energy and force.  As a result of turbulence, noise levels can become very loud.  With a centrifugal fan or blower, the air is forced to move at a right angle and pushed out through an exhaust port.  This creates a very turbulent air flow.  The axial fan has less turbulence than its counterpart, but the blades still “slap” the air to push it forward.  This disruption in the flow pattern for both fans create turbulence and disarray.  The EXAIR Super Air Amplifier draws the air into the device to generate very little turbulence on the exhaust end.  The flow pattern is consistent, working together in the same direction.  This will allow for more air to reach the target.

Static pressure is important as it relates to the amount of resistance or blockage.  When blowing air through or around products, this resistance will determine the effectiveness and distance for efficient blowing.  To find the maximum resistance, this would be considered at the dead-end pressure.  When the exhaust is totally blocked, the maximum pressure is created.  In an application, the higher the resistance, the less air that can flow through and around to be utilized.  With fans, it is dependent on the blade types, motor size, and RPM.  Since the EXAIR Super Air Amplifiers do not have motors or blades, it is determined by the inlet air pressure.  So, the higher amount of static pressure, the more resistance that the blowing device can handle.

In comparison, I created a table below to show a model 120024 4” Super Air Amplifier against two different types of fans.  The first thing that you notice is the small package area of the model 120024 as compared to the fans that create similar air flows.  The centrifugal fan requires an addition electrical motor which increases the cost and generates a larger footprint.  The reason for the smaller flow area is the laminar air flow that the Super Air Amplifiers generate.  As stated above, the velocity pattern works together in the same direction.  So, a smaller profile can produce a lot more air movement.  In addition, this helps to create a larger static pressure.  Also referenced above, it will move the air much further to do more work.  With high turbulence, the air movement works against itself causing inefficiencies and louder noise levels.

Specification Table

In physics, it is much easier to pull than it is to push.  The same goes for moving air.  Fans are designed to “push” the air and the Super Air Amplifiers are designed to “pull” the air.  This method of pulling makes it simple to create a laminar flow in a small package which is more efficient, effective, and quiet.  Being powered by compressed air, there is no need for electric motors or blades to “push” the air ineffectively.  With the patented shims inside the Super Air Amplifiers, they maximize the amplification by “pulling” in large amounts of ambient air while using less compressed air.  If you want to move away from blower systems or axial fan systems to get better cooling, drying, cleaning, and conveying; you can contact an Application Engineer for more details.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Super Air Amplifier Increases Airflow In Vaccum Hood For Fume Extraction

A couple days ago I  took a call from an extrusion company who was looking to increase the airflow in their plating operation. They manufacture several different shapes and styles of aluminum extrusions by the way of 8 large extrusion presses. On one of the presses they make a specialty line of products that are sent to a finishing operation to be anodized.

Above the anodizing process tanks they use a vacuum hood to capture fumes and send them to a scrubber system so the air can be cleaned before being exhausted. They were starting to see an increase in the level of VOC (Volatile Organic Compound) gases in the area and, after some internal testing, determined the existing system wasn’t moving enough air through the system for the gases to be adequately delivered to the scrubber tank.

Example of a scrubber system

After further discussion, the customer ordered our Model # 120022 2″ Super Air Amplifier to test under our Unconditional 30 Day Guarantee.  Air Amplifiers are one of the most efficient products in the EXAIR catalog. Using a patented internal shim, they use a small amount of compressed air that passes through an internal chamber where it is exhausted through a thin gap at high velocity. This directed airflow creates a lower pressure at the intake side which draws in a large amount of free air. The 2 combining air flows result in a large volume of “amplified”, high velocity exhausting airflow, making them ideal for increased air movement.

Air Amplifiers entrain enormous amounts of “free” air, at ratios of up to 25:1!

If you have an application where you need to increase airflow or if you’re looking to vent or exhaust noxious fumes, an Air Amplifier is the ideal choice. For help selecting the best Model or to discuss a particular process, please contact an application engineer for assistance.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

Pueblo Chemical Agent-Destruction Pilot Plant Agent Processing Building courtesy of PEO ACWA via creative common license.

 

Intelligent Compressed Air: Utilization of the Coanda Effect

Henri Coanda was a Romanian aeronautical engineer most known for his work developing what is today known as the Coanda effect. The Coanda effect is the propensity of a fluid to adhere to the walls of a curved surface. A moving stream of fluid will follow the curvature of the surface rather than continuing to travel in a straight line.  This effect is used in the design of an airplane wing to produce lift. The top of the wing is curved whereas the bottom of the wing remains straight. As the air comes across the wing, it adheres to the curved surface, causing it to slow down and create a higher pressure on the underside of the wing. This  is referred to as lift and is what allows an airplane to fly.

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The Coanda effect is also the driving force behind many of EXAIR’s Intelligent Compressed Air Products. Throughout the catalog you’ll see us talking about air amplification ratios. EXAIR products are designed to take advantage of this phenomenon and entrain ambient air into the primary air stream. Compressed air is ejected through the small orifices creating air motion in their surroundings. Using just a small amount of compressed air as the power source, Super Air Knives, Air Nozzles, and Air Amplifiers all draw in “free” ambient air amplifying both the force and the volume of airflow.

Entrainment
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.

Super Air Knives provide the greatest amount of air amplification at a rate of 40:1, one part being the compressed air supply and 40 parts ambient air from the environment. The design of the Super Air Knife allows air to be entrained at the top and bottom of the knife, maximizing the overall volume of air. Super Air Nozzles and Super Air Amplifiers also use this effect to provide air amplification ratios of up to 25:1, depending on the model.

HowItWorks
Air Amplifiers use the Coanda Effect to generate high flow with low consumption.

The patented shim design of the Super Air Amplifier allows it to pull in dramatic amounts of free surrounding air while keeping sound levels as low as 69 dBA at 80 psig! The compressed air adheres to the Coanda profile of the plug and is directed at a high velocity through a ring-shaped nozzle. It adheres to the inside of the plug and is directed towards the outlet, inducing a high volume of surrounding air into the primary air stream. Take a look at this video below that demonstrates the air entrainment of a Super Air Amplifier with dry ice:

Utilizing the Coanda effect allows for massive compressed air savings. If you would like to discuss further how this effect is applied to our Super Air Knives, Air Amplifiers, and Air Nozzles give us a call. We’d be happy to help you replace an inefficient solution with an Engineered Intelligent Compressed Air Product.

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

Image courtesy of ionutscriparu via Pixabay Creative Commons License

Adjustable Air Amplifier Keeps Sensor Cool

Our distributor in China has a customer who visited the United States, while their customer was in the US they saw an EXAIR product installed and wanted to replicate the setup in China. He saw the EXAIR label and reached out to our distributor for help in identifying the part. Taking a quick measurement of the inlet side of the Adjustable Air Amplifier led us to discern it was a Model 6041 1-1/4” Adjustable Air Amplifier.

adjustable air amplifier sensor cooling
EXAIR Model 6041

The product was installed on a baghouse monitoring system. The sensor is used to detect minor leaks within the dust collection system before the leaks create a major problem. The environment in which the sensor was installed results in temperatures that are just above the normal operating temperatures during warmer months and can result in erroneous readings. When this occurs, production is shutdown to prevent a failure of the dust collection system while the filters can be inspected. By installing the Adjustable Air Amplifier to provide a large volume of air and a low level of compressed air consumption, the temperature is able to be maintained within typical operating range for the sensor. This alleviates the need for unnecessary shutdowns (or unnecessary filter replacement), while ensuring that the working environment remains dust-free.

EXAIR’s Adjustable Air Amplifiers are available in both Stainless Steel and Aluminum from sizes ranging from ¾”-4” on the air outlet. The outlet can be ducted as seen in this application, or it can be used as-is. The air gap of the Adjustable Air Amplifier is infinitely adjustable, allowing you to regulate both the air consumption and outlet flow from a “breeze” to a “blast”. In addition to the standard Adjustable Air Amplifiers, we also have a Model 121021 High Temperature Air Amplifier available that is capable of withstanding temperatures as high as 700°F.

Air Amplifiers can be used in a variety of different applications. Not only can they be used in applications requiring cooling, but the air entrainment properties of the amplifier can be used to exhaust smoke as discussed in this application at a foundry. An Adjustable Amplifier can also be used for drying or cleaning parts as well as for conveying light materials.

Regardless of the application, EXAIR has a suitably sized Air Amplifier to fit your needs. If you need an efficient and reliable way to vent, cool, clean, or dry parts give us a call. An Application Engineer would be happy to take a look at your application and provide the best recommendation.

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