So Many Holes

I remember the book and movie about a young teenager who gets sent to a prison/ work camp that all they do is dig holes. Yeah, there’s a much deeper story line there and that isn’t the point of this blog. The point is, that movie is all I thought of when I encountered this customer’s nozzle solution. Their ejector nozzle on a recycling conveyor was using too much air and was too noisy.

Upon receiving the nozzle to do a free EXAIR Efficiency Lab, we were absolutely amazed at the level of care taken to make something like this. The nozzle was purpose built and definitely got the job done, it also drained their compressed air system at times and made a lot of noise while it did the work. So what did this nozzle look like, now keep in mind, this was not the customer’s design, it was a solution from the machine manufacturer.

For an idea, the customer nozzle was a 3″ overall length, and had a total of 162 holes in it. There were two inlets for 3/8″ push to connect tubing. The holes were very cleanly drilled and we used a discharge through orifice chart to estimate the consumption before testing. Operating pressure were tested at 80 psig inlet pressure.

Discharge through an orifice table.

Our estimations were taken from the table above. We used a pin gauge to determine the hole size and it came close to a 1/32″ diameter. With the table below we selected the 1.34 CFM per hole and used a 0.61 multiplier as the holes appeared to have crisp edges.

Estimation Calculation

Then, we went to our lab and tested. The volumetric flow came out to be measured at 130.71 SCFM. This reassured us that our level of estimation is correct. We then measured the noise level at 95.3 dBA from 3′ away. Lastly, we tested what could replace the nozzle and came up with a 3″ Super Air Knife with a .004″ thick shim installed. To reach this solution we actually tested in a similar setup to the customer’s for functionality as they sent us some of their material.

Now for the savings, since this customer was focused on air savings, that’s what we focused on. The 3″ Super Air Knife w/ .004″ thick shim installed utilizes 5.8 SCFM per inch of knife length when operated at 80 psig inlet pressure. So the consumption looks like below

That’s an astounding amount of air saved for each nozzle that is replaced on this line. The line has 4 nozzles that they want to immediately change out. For a single nozzle, the savings and simple ROI looks like the table below.

Air Savings / Simple ROI

That’s right, they will save 115.02 SCFM per minute of operation. These units operate for seconds at a time so the amount of actual savings is still to be determined after a time study. In videos shared, there was not many seconds out of a minute where one of the four nozzles was not activated. Once the final operation per minute is received we can rework our calculations and see how many hours of line operation it will take to pay back each knife purchase.

If you have any point of use blowoff or part ejection and even have a “nice looking” blowoff in place, don’t hesitate to reach out. These are still very different from our Engineered Solutions. We will help you as much as we can and provide test data, pictures, and even video of testing when possible.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

Bed Coffee and the Coanda Profile

Photo by Stocksnap and licensed by Pixabay

Every weekend my wife craves her “bed coffee”. I do my best to bring her some coffee in bed at least one, if not both weekend days. It makes her happy, and when she’s happy… The only thing I truly despise about this act of kindness is the actual pouring of the coffee. Now, I’m a decently smart guy but pouring this weekend coffee is a mess. Every time I end up with coffee on the counter, and many times on the mug. And when it gets on the mug it’s over, because it goes to the bottom of the mug and if I forget to wipe that off? Well, it gets on the sheets, because she inevitably rests her coffee on the sheets, and somehow this is my fault, and now she’s not happy anymore… (in fairness, she is still happy and just busts my chops about this part). But why does this happen to me?

It is a little refreshing to realize that I am just a victim of this scientific phenomenon called the Coanda profile. When I start to pour the coffee, the stream adheres to the outer wall of the coffee pot. This causes the coffee to run down the pot and onto the counter, where the cups are sitting (getting that mug bottom soaked in coffee). This is partially caused by the Coanda effect, and partially caused by me not being awake enough to outsmart a coffee pot. The simple solution is to simply increase the flow rate, right? This is correct however, this does not eliminate the Coanda Effect. In fact, even if you are smarter than me you will notice, after you pour the coffee, there is liquid on the side of the pot. That liquid may only be in the form of steam but it’s there, just to a lesser degree. The solution to avoid the mess, is to adjust the pot so that the pour angle is such that gravity overpowers the majority of the Coanda effect. Many times, in my case, this adjustment is too late…

The Coanda phenomena closely depends on several factors, the speed of the jet flow (pouring at a steeper angel), the flow rate (pouring more or less volume over time), and the profile of the container. I believe that a mad scientist invented my particular coffee pot with full intention of messing up countertops all over the world. In fact, he may be a super villain.

At EXAIR, we utilize the Coanda Profile to our benefit on most products. Here are 2 products that are perfect examples of how we use the Coanda Profile to maximize the performance of our products.

Air Amplifiers use the Coanda Effect to generate high flow with low consumption.
Compressed air flows through the inlet (1) to the Full Flow (left) or Standard (right) Air Knife, into the internal plenum. It then discharges through a thin gap (2), adhering to the Coanda profile (3) which directs it down the face of the Air Knife. The precision engineered & finished surfaces optimize entrainment of air (4) from the surrounding environment.

As you can see above, using the Coanda Profile correctly, dramatically increases the efficiency and the entrainment of air in our products. Between the Coanda effect, and the air entrainment, some of our products like the Super Air Amplifiers can output up to 25 times the amount of air that they consume.

Please contact us at anytime to see how the intelligent compressed air products of EXAIR can assist you in your application. And, don’t forget about bed coffee, it’s a win win for you and your spouse…

Thank you for stopping by,

Brian Wages

Application Engineer

EXAIR Corporation
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Cover Photo by monileoni and licensed by Pixabay

Villain image by chrismaguirang and licensed by Pixabay

Quick Disconnects and Push In Fittings are not Ideal for Peak Performance

In order to achieve the best performance of your EXAIR Intelligent Compressed Air® product, a steady flow of compressed air must be supplied at the optimal pressure. Compressor output pressure, air flow rate, piping ID (inner diameter), the smoothness of the inside of the pipe and connector type all contribute to the performance.

Especially for manufacturing uses, it is important to consider both the air pressure and air flow being produced by the air compressor providing the supply for all tooling. It is possible for an air compressor to produce sufficient supply pressure for an EXAIR product while not having adequate air flow to use the product for very long.

The optimal air pressure for most EXAIR products is 80 PSIG, with the exception of Vortex Tube based products, which are rated at 100 PSIG. Operating EXAIR products at air pressures less than 80 PSIG may lead to lower performance, but EXAIR encourages operating any blow-off product at as low a pressure as possible to achieve your desired result. A simple pressure regulator can lower your pressure and save energy. As a general rule near the 100 PSIG level, lowering air pressure by 2 PSIG will save 1% of energy used by an air compressor. Operating the product at pressures greater than 80 PSIG may produce slightly higher performance, but will require more energy to produce only a small gain.

Make sure that connectors and fittings do not restrict compressed air flow in any manner. Quick connectors can be especially problematic in this area. Because of their construction, quick connections that are rated at the same size as the incoming pipe or hose may actually have a much smaller inner diameter than that associated pipe or hose. This will significantly restrict the amount of air that is being supplied to the tool, starving it of the air flow it needs for best performance. In some cases, if the fitting is too small, the tool may not work at all!

EXAIR products are designed to improve the overall efficiency of your operations. If you need help and have questions please contact any of the Application Engineers. There is no risk to trying our products as we have a 5 year warranty and also a 30 Day Guarantee to all of our US and Canadian customers.

Eric Kuhnash
Application Engineer
E-mail: EricKuhnash@exair.com
Twitter: Twitter: @EXAIR_EK

EXAIR Super Air Knives Improve Efficiency For Beer Bottling Application

As summer begins to wind down, we’re seeing some “slight” reprieve (at least this week) from the intensely hot summer we’ve had thus far in 2022. Fall will be here before we know it, which for me means a return to weekends on the couch watching football! What goes better with football than an ice cold beer?

In a recent application, I worked alongside a beverage manufacturer to help improve on the efficiency of their beer bottling process. You know the saying, “you get what you pay for”. For this customer it was made quite evident as we replaced some rather inefficient nozzles they were using in the facility with our Super Air Knives.

In the process, the customer had (4) sets of inefficient nozzles to dry the bottles off. (2) sets were located just after their wash/rinse cycle, with another two placed just prior to labeling. After washing, the bottles are taken to the fill station where they perform a cold fill process. Their location is hot and humid year-round, so immediately after filling condensation would form on the outside of the bottle.

Once filled, they need to apply a label to the outside of the bottle. If there’s any condensation present, this leads to many of the labels not adhering properly. The issue they were having was that when all of the nozzles were running simultaneously, they were experiencing a pressure drop that led to insufficient drying of the bottles in both stages of the process. Their solution was a rather expensive one: (8) operators were staged at the end of the line to inspect, dry, and fix any of the labels that didn’t adhere well while boxing them up.

Since we knew compressed air consumption was a critical aspect of this application, we offered (2) of our Model 110006-.001 6” Super Air Knives with a .001” thick shim installed. Super Air Knives are shipped directly from stock with a .002” shim, so this thinner shim helped to further reduce the air consumption from the knife. The knives produce a laminar curtain of air that’s far more effective at drying than the turbulent airflow from these flat nozzles. Rather than having (4) sets of knives, they were able to use just (2) effectively eliminating two of the blowoff stations they were using with the cheap nozzles.

With the knives in place the pressure in their system was no longer dropping and the laminar airflow from the Super Air Knives was much more effective at drying the bottles. Now, at the end of the conveyor they only needed (2) operators to unload the bottles and begin to box them. This dramatically reduced their labor costs for this operation as they were able to utilize those employees for other tasks instead of tying them up standing around, drying bottles, and fixing labels.

If you’re tired of experiencing issues with an inefficient blowoff device, EXAIR has a solution that can ship out today from stock. Contact an Application Engineer today and we’ll be happy to help you to determine the best solution based on your application.

Tyler Daniel, CCASS

Application Engineer
E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD

beer image courtesy of RawPixel Ltd via Flickr Creative Commons License