Air entrainment is a term that we bring up quite often here at EXAIR. It’s this concept that allows many of our products to dramatically reduce compressed air consumption. The energy costs associated with producing compressed air make it an expensive utility for manufacturers. Utilizing engineered compressed air products that will entrain ambient air from the environment allow you to reduce the compressed air consumption without sacrificing force or flow.
Products such as the Super Air Knife, Super Air Nozzle, Air Amplifier, and Super Air Wipe all take advantage of “free” air that is entrained into the primary supplied airstream. This air entrainment occurs due to what is known as the Coanda effect. Named after renowned Romanian physicist, Henri Coanda, the Coanda effect is used in the design of airplane wings to produce lift. As air comes across the convex surface on the top, it slows down creating a higher pressure on the underside of the wing. This creates lift and is what allows an airplane to fly.
This is also the same principle which is allowing us to entrain ambient air. As the compressed air is ejected through a small orifice, a low-pressure area is created that draws in additional air. Our products are engineered to maximize this entrained air, creating greater force and flow without additional compressed air. Super Air Amplifiers and Super Air Nozzles are capable of up to a 25:1 air entrainment ratio, with just 1 part being the supplied air and up to 25 times entrained air for free!! The greatest air entrainment is achieved with the Super Air Knife at an incredible ratio of 40:1!
This air entrainment principle allows you to utilize any of these products efficiently for a wide variety of cooling, drying, cleaning, or general blowoff applications. In addition to reducing your compressed air consumption, replacing inefficient devices with engineered products will also dramatically lower your sound level in the plant. Sound level in some applications can even be reduced down to a point that would eliminate the need for hearing protection with the OSHA maximum allowable exposure limits set at 90 dBA for an 8-hour shift.
If you have inefficient blowoff devices in your facility, give us a call. An Application Engineer will be happy to help you select a product that will “quietly” reduce your compressed air consumption!
Air Amplifiers are amazing tools that pack a punch (if the punch is a ton of air flow). Imagine an amplification rate up to 25 times. You supply 29 SCFM and yield 730 SCFM coming out? It’s incredible. These little beauties work by flowing compressed air (80psig) through the inlet to the annular chamber. It is then throttled through a small ring nozzle at a high velocity. This Airstream employs the Coanda profile directing all this air to the outlet. Although you should never blow air at a person, a little bit of air input, would easily produce the results to the right!
Why would you use these? See below for starters:
Although we have many options to choose from, sometimes you may need something outside the box. Maybe it’s a different size? A different Material? A different fitting? Ask us we do have many ways to customize this product. Here are 3 examples of things we have done in the past.
The High Temp Air Amplifier (right) was developed for moving hot air to surface needing uniform heating while in a furnace or oven. This is designed for temps up to 700°F, and is now a standard offering in 1 1/4″.
Another example of a “Special” Air Amplifier is a stainless steel version with a flange mount (left). This was designed for exhausting flue gases from a furnace. If there were a power failure, this Special Air Amplifier will quickly evacuate harmful fumes, prior to affecting the workers.
A third “Special” was made when we were brought an application that required a sticky material to be pulled through the Air Amplifier, and it was unable to stick to the inside of the Amplifier. So we developed an Adjustable Air Amplifier with e PTFE Plug (Right), so the material would not stick.
If you have an application that requires a tool that is not quite in line with what we offer, don’t hesitate to reach out. I can’t promise you that we will be able to make it for you, but I can promise you that we will look at it and give it our best shot.
Thank you for stopping by,
Application Engineer EXAIR Corporation Visit us on the Web Follow me on Twitter
EXAIR’s product line contains many products that can be used for cooling. The focus of this blog will be Super Air Amplifiers. These often times get placed in a head-to-head competition with an electric fan. The best part, they easily come out on top.
When looking at the benefits other than performance and rate of cooling due to air entrainment, many customers prefer the Super Air Amplifier due to the fact there are no moving parts. This comes into play when cooling within in a hard-to-reach area or within a harsh process is needed. Placing an electric motor with a blade held on by fasteners may not be desirable from a maintenance standpoint. The Super Air Amplifiers do not require electricity and there is not a motor or bearings that would need to be replaced or inspected.
Another benefit is the small footprint of the Super Air Amplifier. This can also be seen within the video below where the Air Amplifier is shown is able to produce 341 SCFM (9,650 SLPM) in amplified airflow. Compared to the fan in the video, the amplifier is less than a 1/4 of the size but outperforms the fan in cooling the metal block! This allows users to place a small unit inside a tight area or chamber that requires large volumes of air. For instance, a rotomolded part that has a large chamber, and it needs surfaces to be cooled in order for the part to hold its shape from the mold rather than warp. This can also be coupled with the fact that a Super Air Amplifier can be ducted on either the suction or discharge side in order to retrieve cool air or move the warm air out of the area.
Speaking of warm, the Super Air Amplifiers are also manufactured to withstand up to 275 °F (135 °C) from stock. Stainless Steel and High-temperature models go well beyond that temp, up to 700 °F (374 °C). Custom-designed (flanges and different materials are common) versions are also available with short lead-times.
If you would like to discuss the benefits to a Super Air Amplifier further, feel free to contact us.
OSHA Standard 1910.242(b) discusses the use of compressed air for cleaning and blowoff. It states that the use of compressed air for cleaning purposes is prohibited if the dead-ended pressure exceeds 30 psig. This phrase means the downstream pressure of the air nozzle or gun, used for cleaning purposes, will remain at a pressure level below 30 psig for all static conditions. In the event that dead ending occurs, the static pressure at the main orifice shall not exceed 30 psi. If it does exceed this pressure, there is a very high potential for it to create an air embolism. An air embolism, left untreated, can quickly impede the flow of blood throughout the body. This can lead to stroke, heart attack, and sometimes death.
So making sure you are in compliance with 1910.242(b) is truly a life and death situation. Most people believe that lowering the pressure to the blow off device is the only method to keep their operators safe from an air embolism. However this can become a problem when you really need the force of greater than 30 PSIG to complete your operation. We at EXAIR want to give you the flexibility to run at any pressure with out the risk of building that 30 PSI of dead-end pressure! We do this with our line of Intelligent Compressed Air® nozzles! All of EXAIR’s Air Nozzles are designed so that the flow cannot be dead-ended. The fins on the Super Air Nozzles are not only useful in amplifying the force by drawing in ambient air, but they also prevent an operator from completely obstructing the airflow.
Another great example of this is our 2″ Flat super air nozzle. The design not only allows the nozzle to amplify the air flow in the blast of air, the over hang will not let the dead end pressure build as it can escape around the edges and bottom!
If you’ve got questions about compressed air safety or have an existing blowoff in place that does not adhere to this OSHA directive, give us a call. We’ll be sure to recommend a solution that will keep your operators and wallets safe!