Tag: coanda

Super Air Amplifier Overview – Vent, Exhaust, Cool, Dry, Clean

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Vent, exhaust, cool, dry, clean -with no moving parts!  That tag line from the catalog section pretty much says it all about the EXAIR Air Amplifiers, both the Super Air Amplifier and the Adjustable Air Amplifiers. I want to share some more information about the Super Air Amplifiers.

In general, the air amplifiers employ the Coanda effect – a basic principle of fluid flow – to create air motion in their surrounding.  Through intelligent design, this surrounding fluid flow can be manipulated and exploited, creating an amplification of a small amount of compressed air.

AirAmplifiers
Super Air Amplifier

How do they work? In the figure below – a small amount of compressed air flows into the unit (1) to an annular chamber (2). The air is then throttled through a small ring nozzle (3) at high velocity. This primary air stream adheres to the Coanda profile (4), which directs it towards the outlet. A low pressure area is created at the center (5), inducing a high volume flow of the surrounding air into the primary stream. At the exit, you have the combination of flows, resulting in a high volume, high velocity flow.

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How Air Amplifiers Work
Super Air Amplifier Coanda Profile
Close Up of the Coanda Profile

The amplification ratio – the outlet airflow compared to the compressed air flow is dependent upon the cross sectional area of the inlet, and the 3/4″ Super Air Amplifiers have 12:1 amplification ratios all the way up to the 4″ and 8″ Super Air Amplifiers with 25:1 amplification ratios! That is a lot of ‘free air’ to use for cooling, drying and cleaning.  And a lot of air or smoke that can be drawn at the inlet and vented away from the area. For more on the amplification ratios, see this -blog-

Each Super Air Amplifier has a patented shim (patent#5402938) that precisely sets the compressed air flow, and shim sets are available to install to increase the force and flow as needed.

Super Air Amplifier Shims
Patented Shims for the Super Air Amplifier

The balanced outflow of air minimizes wind shear to produce a very quiet, powerful flow at sound levels up to three (3) times quieter than other air movers.  A 4″ Super Air Amplifier operated at 80 PSIG will have a Sound Level of just 73 dBA.

The video below shows the power of the Super Air Amplifier in inducing a high volume flow of surrounding air (for venting) into the primary air stream (for cooling/drying/cleaning)

Typical applications include venting weld smoke, cooling hot parts, drying wet parts, cleaning machined parts, distributing heat in mold & ovens, dust collection, and exhausting vent fumes.

If you have questions about the Super Air Amplifier or any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
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Henri Coanda: June 7, 1886 – November 25, 1972

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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.

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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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Great Stuff About Jets

Published on by Russ BowmanLeave a comment

There are a number of fascinating facts about jets…both the aircraft engines and the EXAIR Intelligent Compressed Air Products:

  • Because they don’t require dense air to engage spinning blades (like their propeller driven counterparts,) they can operate at much higher altitudes. (Jet aircraft engines only)
  • They provide a high thrust, directed airstream, which makes them great for part ejection, chip removal, and part drying. (EXAIR Air Jets only)
  • With few or no moving parts, they are extremely reliable, durable, and safe. (Both jet aircraft engines and EXAIR Air Jets)
  • They use the Coanda effect (a principle of fluidics whereby a fluid flow tends to attach itself to a nearby surface, and follow that surface regardless of the flow’s initial direction) to do what they do.
    • EXAIR Air Jets use this principle to generate a vacuum in their throat, pulling in a large amount of “free” air from the surround environment, making their use of compressed air very, very efficient.
    • Jet (and propeller driven) aircraft wings employ the Coanda effect to create aerodynamic lift, enabling the plane to fly.

Now, since I’m not a pilot, nor do I particularly like to fly, but I AM a fluid dynamics nerd, the rest of this blog will be about the Air Jets that EXAIR makes.

All of our Air Jet products operate on the same principle…using the Coanda effect (as described above) to generate a high volume air flow while minimizing compressed air consumption:

(1) Compressed air enters and is distributed through an annular ring, and directed towards the discharge via the Coanda effect.
(2) This causes entrainment of surrounding air, both through the throat, and at the discharge.
(3) The total developed flow has tremendous force and velocity, for a minimal consumption of valuable compressed air.(1) Compressed air enters and is distributed through an annular ring, and directed towards the discharge via the Coanda effect.
(2) This causes entrainment of surrounding air, both through the throat, and at the discharge.
(3) The total developed flow has tremendous force and velocity, for a minimal consumption of valuable compressed air.

There are four distinct models of the EXAIR Air Jet:

  • Model 6013 High Velocity Air Jet is made of brass for economy and durability.  The annular ring gap (see 1, above) is fixed by a 0.015″ thick shim.  Performance can be modified by changing to a 0.006″ or 0.009″ thick shim, which come in the Model 6313 Shim Set.
  • Model 6013SS is a Type 303 Stainless Steel version, for higher temperatures – good to 400°F (204°C) – and superior corrosion resistance.
  • Model 6019 Adjustable Air Jet is brass construction, and dimensionally identical to the Model 6103.  Instead of a shim that sets the annular ring gap, though, it has a threaded plug, with a micrometer-style indicator, to “fine tune” the gap.
  • Model 6019SS is the Type 303 Stainless Steel version…fine tuning adjustability, good for high heat and/or corrosive elements.
Four distinct models to meet the needs of your air blowing application.

If you’d like to find out more about EXAIR’s quiet, efficient, and safe Air Jets, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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People of Interest: Henri Coanda June 7, 1886 – November 25, 1972

Published on by Tyler DanielLeave a comment

Henri Coanda was born in Bucharest, Romania on June 7 1886 in a large family with five brothers and two sisters. His father, Constantin M. Coanda, was a decorated Romanian soldier and following in his footsteps he also enlisted in the military. He finished his military education with high honors, but his keen interest in flying and his desire to achieve this sent him down a much different path.

Coanda attended a technical university in Germany and also attended the Superior Aeronautical School in Paris where he graduated at the top of his class with the highest of honors. In less than a year, he had partnered with Gianni Caproni, another known aviator, to construct what was called the Coanda-1910. This aircraft was displayed in Paris at the Second International Aeronautical Exhibition. But, unlike other planes of this time, Coanda’s aircraft did not have a propeller. The plane had an oddly shaped front with built-in rotary blades arranged in a swirling pattern. It was driven by an internal turbine screw that would suck air in through the turbine while the exhausting gases exited from the rear, driving the plane forward by propulsion.

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As impressive as this jet engine was, no one believed that it could fly. It is not believed that it ever did achieve flight, despite some contradictory claims by Coanda himself, but was instead struck by disaster. It is rumored that as Coanda injected more fuel into the engine, he was surrounded by flames, thrown from the craft and was lucky to make it out alive. Coanda is not credited as the inventor of the first jet plane, but it is his technology that sky rocketed future aviation research and provided perspective into how jet engines should be built.

Coanda is most known today for his research into what is now known as the Coanda Effect, or propensity of a fluid to adhere to the walls of a convex surface. It is this principle that creates lift on an airplane wing and is also the driving force behind many of EXAIR’s Intelligent Compressed Air Products. If you’d like to discuss how the Coanda effect is utilized in a Super Air Knife, Super Air Amplifier, or Super Air Nozzle give us a call!

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

 

Jet Engine image courtesy of Luke Healy via Creative Commons License