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.
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.
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.
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.
Upon moving to our new house, quite a distance from our old location, my wife and I were looking for a new “go to” restaurant that would be close to our new digs.
I did a Google search and found a place that was only a couple miles away and had good reviews. My wife and I went in and it was a quaint little place. The food was good, as expected, but the service was not.
We discussed the lackluster service and decided to go again about a week later hoping it was an isolated incident. On this visit we had a different server (which turned out to be the owner). Long story short, the service was again not good. It took a long time to place our order and receive our food.
I was ready to just write them off but my wife has a very soft and forgiving heart. So against my vote we go a third time. Which turned out to be a carbon copy of the 1st visit. With one great exception, we left after we had been there 25 minutes and our order was not taken. So, now we drive farther to our “old standby” because the service makes the difference to us.
The chart below is representative of reasons business’s lose customers.
Fortunately, EXAIR is a customer centric organization. EXAIR ensures that the staffing is present to handle your needs with the care and quickness you deserve and our culture dictates that we serve you effectively and efficiently! With both a Customer Service and Application Engineering Department we can handle your questions and requests consistently and accurately. Speak with a real person, and learn from over 159 years worth of combined manufacturing experience.
Did you know that most items are available for same day shipping (limits on quantities) with orders that can be processed by 3:00PM Eastern Time for the USA? Last but certainly not least EXAIR offer’s a 30 day money back guarantee on all our catalog items within 30 days of the purchase date!
When you are looking for quiet and efficient point of use compressed air products or static reduction devices, give us a call. Experience the EXAIR difference first hand and receive the great customer service, products and attention you deserve! We would enjoy hearing from you.
When trying to explain or state a number associated with how loud a sound or noise is it can be somewhat confusing or at the very least, ambiguous. This blog will help to make it clear and easy to understand the difference between Sound Power and Sound Pressure.
Sound Power is defined as the speed at which sound energy is radiated or transmitted for a given period of time. The SI unit of sound power is the watt. It is the power of the sound force on a surface of the medium of propagation of the sound wave.
Sound Pressure is the sound we hear and is defined as the atmospheric pressure disturbance that can vary by the conditions that the sound waves encounter such as furnishings in a room or if outdoors trees, buildings, etc. The unit of measurement for Sound Pressure is the decibel and its abbreviation is the dB.
I know, the difference is still clear as mud! Lets consider a simple analogy using a light bulb. A light bulb uses electricity to make light so the power required (stated in Watts) to light the bulb would be the “Sound Power” and the light generated or more specific the brightness is the “Sound Pressure”. Sound just as with the light emitting from the bulb diminishes as the distance increases from the source. Skipping the math to do this, it works out that the sound decreases by 6 dB as the distance from the sound source is doubled. A decrease of 3dB is half as loud (Sound Pressure) as the original source. As an example sound measured at 90 dB @ 36″ from the source would be 87dB at 54″ from the sound source or 84dB at 72″.
We at EXAIR specialize in making quiet and efficient point of use compressed air products, in fact most of our products either meet or exceed OSHA noise standards seen below.
EXAIR also offers the model 9104 Digital Sound Level Meter. It is an easy to use instrument for measuring and monitoring the sound level pressures in and around equipment and other manufacturing processes.
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.
If you would like to discuss quiet, efficient compressed air products, I would enjoy hearing from you…give me a call.
The EXAIRAir 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.
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.
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!
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.
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.
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.
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.
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.
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!