Coandă Profiles & Effect

Here at EXAIR, Coandă is a household name that can be heard on any given day multiple times throughout the day. The Coandă effect is fairly easy to visualize with a ligthweight ball and some high velocity airflow. Take the video below for example. This 2″ Super Air Amplifier on a stand powered at 40 psig at the inlet easily lifts this hollow plastic ball and then suspends the ball due to the Coandă effect.

If you were able to see the airflow, you would see it impacting the surface of the sphere at all different points then following the profile of the sphere until it colides with itself and is forced to separate off the surface. The turbulent flow on the top is creating a downward pressure as well. The science behind this was all found and showcased by Henri Coandă. He showcased this with a propulsion device which used a domed hood with airflow to follow the curvature of the dome then exit off the sharp edge or where the separate air streams began to recombine causing a turbulent / low pressure area depending on the angle.

This stream of air following a surface begins to pull in all surrounding and impacted air molecules from around the stream which is called entrainment. This is a key factor for EXAIR products and one reason the Coandă profiles are a key characteristic to obtaining the peak performance and efficiency out of a compressed air product.

As the high velocity air stream exits the EXAIR model 1100 Super Air Nozzle the ambient air is entrained around the fins and angled surfaces of the nozzle.

Many EXAIR products utilize the Coandă principle to improve their efficiencies and performance. Below you can see the EXAIR product families containing Coandă profiles within their design which increases the ambient air entrainment resulting in an amplified air blowoff.

Super Air Wipes, Super Air Knives, Super Air Nozzles and Super Air Amplifiers use the Coanda principle to become some of the most efficient compressed air blowoff products available.

If you would like to discuss how the Coandă profile and EXAIR Intelligent Compressed Air Products® can help your process, please give us a call.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

Is PVC Pipe Alright to Use with Compressed Air?

A question arises every now and then on whether or not PVC pipe, yes the stuff from your local hardware store that says it is rated for 200 psi, is safe to use as compressed air supply line.   The answer is always the same,  NO! OSHA agrees – see their statement here.

Schedule 40 PVC pipe is not designed nor rated for use with compressed air or other gases.  PVC pipe will explode under pressure, it is impacted significantly by temperature and can be difficult to get airtight.

PVC pipe was originally designed and tested for conveyance of liquids or products that cannot be compressed, rather they can be pressurized.   The largest concern is the failure method of the piping itself.   When being used with a liquid that cannot be compressed, if there is a failure (crack or hole) then the piping will spring a leak and not shatter.   When introducing a compressed gas, such as compressed air, if there is a failure the method ends up being shrapnel.  This YouTube video does a good job of illustrating how the pipe shatters.

While it may seem that it takes a good amount of pressure to cause a failure in the pipe, that is often not the case.  I have chatted with some local shop owners who decided to run PVC as a quick and cheap alternative to get their machines up and running.

They each experienced the same failures at different points in time as well.  The worst one was a section of PVC pipe installed over a workbench failed where an operator would normally be standing. Luckily the failure happened at night when no one was there.  Even though no one got injured this still caused a considerable expense to the company because the compressor ran overnight trying to pressurize a ruptured line.

Temperature will impact the PVC as well. Schedule 40 PVC is generally rated for use between 70°F and 140°F (21°-60°C). Pipes that are installed outside or in non temperature controlled buildings can freeze the pipes and make them brittle.

If you haven’t worked with PVC before or do not let the sealant set, it can be hard to get a good seal, leading to leaks and a weak spot in the system.

The point of this is the cheapest, quick, and easy solutions are more often , the ones that will cost the most in the long run.

If you would like to discuss proper compressed air piping and how to save compressed air on your systems, please contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

Image courtesy of: Dennis Hill, Creative Commons License

Video Blog: EXAIR Efficiency Lab

The video below is a brief introduction to the EXAIR Efficiency Lab, a free service provided by EXAIR for customers within the USA and Canada.

If you have a single point blowoff that does not have an engineered nozzle, or if you have a wider format blowoff, manifold or home-made drilled pipe, contact an Application Engineer with EXAIR and let us help you to reduce your energy waste. Following are some examples of product where we have helped to save some serious air and reduced noise levels which heightens employee comfort.

Non-engineered blowoffs

Drilled and soldered copper pipe.

Custom manufactured inefficient pipe blowoff

 

The EXAIR Efficiency Lab

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF

EXAIR Won’t Keep You Waiting For Anything

Have you ever sent an email, or left a voice mail message for someone without knowing they were out of the office? It can be pretty frustrating to not hear back from someone, especially if your needs are urgent.

At EXAIR, we make sure this doesn’t happen:

*For starters, we don’t have an automated attendant…if you call EXAIR during normal business hours, you’re going to talk to a real live human being.

*What’s more, that real live human being is going to be one of our Customer Service Representatives, and they can answer any questions you might have about price and availability of any of our Engineered Compressed Air Products.

*If you need detailed technical information, they’ll transfer you to an Application Engineer…and they are always keenly aware of who’s available & who’s not.  You won’t get anyone’s voice mail unless you specifically ask for it, and if one of us is on vacation (and won’t be able to return your call for a number of days,) you’ll know that before you’re transferred to leave that message.

*Not only that, but we’ve got a system in place to monitor each other’s emails.  Which brings me to the success story that inspired this blog:

It’s vacation season, and another of us took off for some well deserved R&R with the family.  According to The System, I get to check those incoming emails while this co-worker is out.  And he (like the rest of us) gets a LOT of emails.  Some are new requests for application/performance data, and some are continuing conversations of the details of (sometimes) complex applications.  Like the project he was working on with a customer who wanted to use Air Knives to blow off a continuous strip of material exiting a wash/rinse vessel.  After a discussion of the details of the application, they had decided to try (2) Model 110003 3″ Aluminum Super Air Knives, one mounted on either side, to “strip the strip.”  And it worked perfectly.  They just wanted to run the details of this first installation by us before doing the other seven.  Part of my process was to go back through the chain of emails…while this looked pretty straight forward, the devil is indeed in the details, and I hate that guy.  But, try as I might (sorry; I’m an engineer,) I could not find fault, or room to improve, with the setup they designed…it was most pleasantly devil-free.

Compact, efficient and quiet, the EXAIR 3″ Super Air Knife is an ideal blow off solution for a variety of applications.

Anyway, with my agreement that their installation was indeed optimal (it’s exactly what I would have done too, for the record,) they placed an order for the (14) Super Air Knives to outfit the other (7) wash/rinse operations.

If we were keeping score, it would be coworker-2, Russ-14.  But we’re not.  Lest my record suffer when I “break for the Lake” in June.  By then, it’ll be Cabinet Cooler Season, and I almost hate to miss a week of that.  Almost.

Man, I don’t even take long pants with me to the Lake.

If you have questions about compressed air products or applications, we’ve got answers.  Live and in real time, every day.  Call us; let’s talk.

Russ Bowman
Application Engineer
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Glass Filled PEEK Super Air Knife w/ Brass Hardware & PTFE Shim? No Problem!

That’s right folks, we’ve gone and done it again.  When a customer calls for custom product because their environment calls for it or due to dimensional requirements, EXAIR has the ability and flexibility to meet those needs!

This time around it was a customer with specific material requirements due to their environment. I had a customer contact me recently that was using an aluminum Super Air Knife near a high voltage operation and was getting ground interference due to the aluminum air knife.  They asked if it was possible to make them a custom knife out of PEEK plastic.  After some light discussions about the form of the knife and what other materials are safe for their environment we settled on a 30% glass filled PEEK plastic for the knife, brass bolts and pipe plugs, with a PTFE shim installed.   The form factor of the knife would follow the same shape as our PVDF Super Air Knives that are available from stock.   The customer could not use PVDF due to high temperature and potential off-gassing in the process.

The results are shown below.

IMG_6590
EXAIR 6″ Super Air Knife in 30% Glass Filled PEEK Plastic w/ Brass Hardware and PTFE Shim

End View – 6″ Super Air Knife in 30% Glass Filled PEEK Plastic w/ Brass Hardware & PTFE Shim

Whether you are looking for a one off product that is tailor made to your application or want to have a simple feature like hardware material changed in a stock EXAIR product that you are incorporating into thousands of machines, we have the solution for you.

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF

 

 

 

 

Super Sized Is Not A Problem At EXAIR

For many years we as Americans wanted to biggie size, super size, or mega size anything and everything we could.   For myself that mainly meant the fries and drink I used to get at any local fast food joint.   Now that I have hit my mid-30s and all of that has started to catch up to me, I don’t always want the large fry or any fries at all, instead I might try a new salad and trying to eat healthy.  Here at EXAIR, we don’t always associate bigger with better but we do always fill the need when we don’t have something off the shelf.

However, there are still occasions where going super size is necessary and this week, we did just that.   We had a customer ask if we can go bigger on our Super Air Wipes.   We simply asked how big they needed to go and what the reasoning is for it.  Turns out, the reasoning for the larger Super Air Wipe was a newly designed automated cell in a pipe manufacturing facility.   The stock 11″ was too small to fit the 11″ max. diameter piece through to blow off debris so they requested a 12″ Super Air Wipe.   To top off the customization, they were also in need of BP threaded air inlets.

Catalog 30 Stock Air Wipe Sizes

Within a matter of weeks our customer has gone from a product they didn’t know was possible, to shipping out to their site.  This is a one off, custom machined, Super Air Wipe that has a 12″ Throat Diameter.   The only parts on this that are from our standard stock are the bolts, stickers, and the connecting / hinge plates(The clam shell design requires these.).

If you have an application where you don’t think we have exactly what you need or maybe you need to go bigger, or smaller, than what we show in the catalog don’t move on and try to find something else.   Give an Application Engineer a call and we will see how we can tailor our products to your exact needs.

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF

Video Blog: The EXAIR Ultrasonic Leak Detector Works for Vacuum Leaks?

 

A brief video showcasing the EXAIR model 9061, Ultrasonic Leak Detector’s, performance on vacuum leaks.  For more information or questions on what else the ULD can be used for, contact an Application Engineer!

 

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF