When talking about Air Amplifiers there are two (2) kinds when considering what best fits your needs. An amplifier that is used to increase pressure above your compressor’s ability are also known as air boosters. These boosters are sometimes needed for specific processes which demand much higher pressures. Amplifiers that increases the volume flow rate of your compressed air or nitrogen are the type of amplifier that EXAIR manufactures.
EXAIR’s Super Air Amplifiers will increase the volume of air on to a target or being circulated in an environment. EXAIR’s Air Amplifiers use the Coanda effect pulling in large volumes of surrounding air to produce high volume, high velocity outlet flows up to 25 times their consumption rate.
Air Amplifiers have no moving parts and are basically maintenance free. EXAIR’s amplifiers operate on a source of clean compressed air and do not use electricity. The outlet flows are easily adjusted by opening or closing the air gap. By regulating the supply pressure you can tune in your outlet flow to meet your specific needs. Vacuum and discharge ends of the Air Amplifier can be ducted, making them ideal for drawing fresh air from another area or for moving smoke and fumes away.
EXAIR has 5 standard sized Air Amplifiers ranging from 3/4″ (19mm) to 8″ (203mm) plus an Adjustable Air Amplifier . If you have a specific application EXAIR can manufacture Air Amplifiers to fit your application. If you have a project and think EXAIR’s Air Amplifier or any of our Intelligent Compressed Air Products please contact me or any of our qualified Application Engineers to discuss your project.
EXAIR uses the Coanda effect in many of our products. Henri Coanda is an important figure in the world of fluid dynamics and aerodynamics.
Henri Coanda was a prominent Romanian Inventor and aerodynamics pioneer is known for the creation of the Coanda-1910 experimental plane as well as discovering the Coanda effect. On June 7, 1886 Henri was born in Bucharest Romania to General Constantin Coanda and Aida Danet. In 1899 Henri’s father who desired him to have a military career had him transfer to a Military High School for additional years of schooling, where he graduated with the rank of Sergeant Major. Continuing his studies, he went on to technical school back in Bucharest for Artillery, Military, and Naval Engineering. In 1904 he was sent to an artillery regiment in Germany where he would enroll in Technische Hochshule. Henri did not give up on studying and in 1907 went to Montefiore Institute in Liege, Belgium, where he met Gianni Caproni.
In 1910 Henri and Gianni began a partnership to construct an experimental aircraft which was later called the Coanda-1910. The Coanda-1910 was unlike any other aircraft of its time as it had no propeller; instead it sported an oddly shaped front end with built-in rotary blades arranged in a swirl pattern. These blades were driven by an internal turbine screw that would suck air in through the turbine while exhausting the gases out of the rear, propelling the plane forward. This initial jet engine was quite impressive for the time, but sadly nobody believed it would ever fly and is believed that it never did achieve flight. Coanda is not credited with the invention of the jet engine, but his technology spurred the future of aviation into the future.
During World War 2 Henri spent his time developing the turbo-propeller drive system from his 1910 Biplane. After World War 2 had ended Henri began furthering his research on the Coanda Effect which would become the basis for several investigations into entrained and augmented flow of fluids. Later on in 1969 Henri would spend the last of his days in Romania serving as Director of the Institute for Scientific and Technical Creation. Coanda died on November 25, 1972 in his home town of Bucharest.
Here at EXAIR we have taken Henri Coanda’s, Coanda Effect and applied it to a number of our products to help amplify total airflow and save on compressed air. The most notable product lines are our Air Amplifiers, Air Nozzles, and Air Knives – which are some of the most efficient products of their kind. These products can help lower your compressed air demand.
If you have any questions about compressed air systems or want more information on any of EXAIR’s products, give us a call, we have a team of Application Engineers ready to answer your questions and recommend a solution for your applications.
Cody Biehle Application Engineer EXAIR Corporation Visit us on the Web Follow me on Twitter Like us on Facebook
How did a past inventor help generate efficient compressed air products for EXAIR? In the early 20th century, Henri Coanda who was a Romanian aeronautical engineer that built an experimental Coanda-1910 airplane. There are some debates if the airplane actually flew, but he invented a curved surface for a wing to generate a Coanda effect. The Coanda effect is the “tendency of a fluid jet to stay attached to a convex surface”1. Thus, a moving stream of fluid will follow the curvature of the surface rather than continuing to travel in a straight line. The Wright Brothers who flew the first airplane in the state where EXAIR is located, Ohio, used the Coanda effect to create lift. With a curved profile, the air will adhere to the surface, causing a low pressure which makes the airplane fly.
EXAIR uses this Coanda profile to make some of our Intelligent Compressed Air Products™. Like the airplane wing, our curved surface will also create a low pressure. How does this help? Well, high pressure will always travel to low pressure. Instead of lift, we use the low air pressure to entrain ambient air. This ratio is what we call the amplification ratio. The higher the amplification ratio, the higher the efficiency for a blowing device. Two main compressed air products that EXAIR manufactures use this type of profile; Air Knives and Air Amplifiers. I will cover both below.
The Air Knives that use the Coanda profile blows air along the length of the knife at a 90o angle from the exit. We offer two types; the Standard Air Knife and the Full Flow Air Knife. The Standard Air Knives are made in Aluminum or Stainless Steel with blowing widths up to 48” (1219mm). The inlet ports are at each end; so, the overall length is 1” (25mm) longer. The Full Flow Air Knives have the port or ports on the back. The air blows out the entire length of the air knife. The maximum length is 36” (914mm).
Both types of air knives use the Coanda profile to generate a low pressure as the air exits the gap and “hugs” the curve (reference photo above). This low pressure draws ambient air into the air stream at a 30:1 amplification ratio for both the Standard Air Knife and Full Flow Air Knife. So, for every one part of compressed air, we entrain 30 parts of ambient air. Besides efficiency, it also adds mass to the air stream for a hard-hitting force. With this engineered profile, the air stream is laminar which gives a consistent force across the entire length and reduces noise levels. Not only will they save you money, but they are also OSHA safe.
The Air Amplifiers use the Coanda profile in a circular form to pull in dramatic amounts of free surrounding air. The Coanda effect is able to generate a low pressure to blow air for cooling, cleaning or removing smoke and debris efficiently and quietly. The Air Knives above blow a flat stream of air while the Air Amplifiers will blow a conical air stream. They can reach amplification ratios up to 25:1. The Super Air Amplifiers use a patented shim to increase efficiency.
Unlike fans, they blow a laminar air stream for quick cooling. They do not have any moving parts or motors to wear, so they are very quiet. EXAIR manufactures five different sizes from ¾” (19mm) to 8” (203mm). The Adjustable Air Amplifiers have a plug that can be adjusted to control the blowing force from a breeze to a blast. For cleaning surfaces, this is a nice feature to “dial” in to exactly what you need. We also manufacture five different sizes in aluminum and stainless steel ranging from ¾” (19mm) to 4” (102mm). Both Air Amplifiers can be attached to ducts to remove debris, heat or smoke from the area.
Utilizing the Coanda effect allows for massive compressed air savings. Whether it is a flat or round air stream, EXAIR can do this with high amplification ratios. If you would like to discuss further how our Air Knives or Air Amplifiers can help you in your applications, please contact us. An Application Engineer will be happy to help you. History has shown us a way to increase efficiency when using compressed air. And you can take advantage of it with the Coanda profile. Thank you Mr. Henri Coanda.
In 1983, EXAIR Corporation was founded with the goal of engineering & manufacturing quiet, safe, and efficient compressed air products for industry. By 1988, the EXAIR-Knife (now known as the Standard Air Knife) was quickly becoming the preferred choice for replacing loud and inefficient drilled pipes, long nozzle manifolds…anywhere an even, high velocity curtain of air was required.
The EXAIR Standard Air Knife’s design takes advantage of a fascinating principle of fluidics to achieve quiet and efficient operation: the Coanda Effect, which is the tendency of a fluid jet to stay attached to a convex surface. If you want to see it for yourself, hold the back of a spoon, handle up, under the kitchen faucet. Those who haven’t seen it before may assume that gravity will take over and the water will fall from the bottom of the spoon’s ‘bowl’ – but it doesn’t:
Likewise, the air flow (which is just another example of a fluid jet) exiting the Standard Air Knife’s shim gap follows a convex surface (which we call the “Coanda profile”) causing it to entrain large amounts of air from the surrounding environment:
This entrainment does two things for us:
First, because we’ve engineered the design for maximum entrainment, it’s very efficient – creating a high flow rate, while minimizing air consumption. In the case of the Standard Air Knife, the entrainment ratio is 30:1.
Secondly, this entrainment forms an attenuating boundary layer for the air flow, resulting in a high velocity, high volume airflow that is also incredibly quiet.
If you need a hard hitting curtain of air for blow off, drying, cleaning, cooling, environmental separation, etc., the EXAIR Standard Air Knife is an easy and economical solution. If you’d like to discuss your application and/or product selection, give me a call.
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