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

Stories From The Field: Automotive Plant Tour

Throughout my years I have been in many manufacturing facilities. Oddly enough, I have seen nearly every part of a passenger car manufactured and then fully assembled. The amount of compressed air applications in automotive supplier and manufacturing facilities are tremendous. Here are some stories from just a few we have encountered over the years, and all of them can be found in our Application Database.

Air Wipe – How it works
  1. A component manufacturer, specifically a steering and transmission component manufacturer was having issues with machined parts coming out of a CNC machine with too much oil based cutting fluid on them and not passing inspection process because the oil would throw off the automated measuring system. The part was a splined shaft that the high surface tension oil stayed in the splines. The part was removed from the machine via robotic loader and set onto a fixture. The path to the fixture was outfitted with a Super Air Wipe so the robotic loader could move the part into and out of the air wipes’s airflow and remove the oil. The converging airflow of the Super Air Wipe was ideal to keep the peaks and valleys of the shaft clean of oil and they were able to direct oil back into the cutting machine so no separate collection system was needed.
Robotic Welder fitted with EXAIR Super Air Wipe

2. A seat bracket manufacturer had issues protecting the lenses on their vision systems from welding spatter. They were again able to reduce the replacement / repair downtime by installing a 9″ Super Air Wipe in front of the robotic mounted lens and keep the spatter / fumes from ever making it to the lens, resulting in expanded run times between repair / downtime.

Cooling with Air Amplifiers

3. A forging company manufacturing the pistons was having issues reducing the temperature of the pistons as they were assembled to the connecting rods. The solution for them was to install a series of Super Air Amplifiers over the fixtured, indexing line and at each dwell station a Super Air Amplifier would activate and cool down the assembly by moving large volumes of ambient air mixed with small amounts of compressed air onto the surfaces.

4. An automotive manufacturer had issues with stamping shavings and welding debris staying on the surface of parts and fixtures resulting in rework and defective parts. Implementing a series of Super Air Nozzles, and Super Air Knives resulted in debris removal that saved tooling rework as well as production reject parts.

5. Another automotive / recreational vehicle manufacturer needed help with their torture test machine for suspension components. They were utilizing fans to try and keep shock sensors cool and replicate air movement. electric fans were not able to provide a focused airflow and so enter the Super Air Amplifiers. These have also been utilized on engine torture test machines.

1 – Chevrolet Corvette C7 2014 – LT1 Engine Testing on Dyno

These are just a select few of the actual applications that I have actually help with over the course of the years. As a whole, we have helped endless number of automotive industry applications. It doesn’t matter if you are in the automotive industry or just a garage tinkerer, contact and Application Engineer and let us help you with your point of use compressed air application today.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

1 – Autoblog_gr; Chevrolet Corvette C7 2014 – LT1 Engine Testing on Dyno – retrieved from https://www.youtube.com/watch?v=N3h8imnOPwU on 8/31/2022

3-1/2 EXAIR Pro Tips for Compressed Air Use

EXAIR offers industry leading Intelligent Compresses Air Products. Our products are engineered to comply with all relevant OSHA standards and are CE certified. When you purchase an EXAIR product, be it a Super Air Knife or a brass bulkhead fitting, you are expecting to receive a high quality and high performing product, and you will. If the product is not performing there is a very high probability that the problem is not the product.

So whatever could it be? And how can we fix the issue? Air supply going to the product is a common issue, so first we need to insure that there is a steady flow of the appropriate pressure and volume of air. Even though you may have a 100HP compressor, the distance form the product, the size of the pipes delivering the air, the smoothness of the inside of the pipes (is there internal rust and buildup), leaks and other restrictions of air flow rate all contribute to the overall performance.

A large majority of the product performance issues that are brought to us are caused by insufficient air supply in one form or another. Sometimes this is due to the overall size of the system, but many times it is at the point of use. Let’s assume that you have the right sized compressor to power all features in the shop. These next items are where we would want to focus and correct.

EXAIR Digital Flowmeter

Pro tip #1 – Use EXAIR Digital Flowmeters to monitor your air consumption. You should have a log of how much each compressed air tool / machine uses, and compare that to how much air is traveling down that leg of your facility. Leaks, corrosion, rust, and accidents happen. By monitoring and logging your SCFM in each major leg of your system, you will easily be able to narrow down root problems, and track leaks. You will also have solid answer when asked – “Do you have enough air for this?”.

Pressure Regulators “dial in” performance to get the job done without using more air than necessary.

Pro Tip #2 – Use a Tee Fitting and install a Pressure Regulator with Gauge at the point of use. This allows you to see, and control the pressure for each product. This removes all questions of air pressure at the point of use. Although your system seems large enough, many times the pressure is less at the point of use, due to restrictions, unknown leaks etc… Having the information from tip #1 and #2, you will easily be able to identify if your issue is the system, or the tool.

Pro Tip #2.5 – Turn it down (the pressure) if you can… Operate each compressed air application at a pressure just high enough for your desired result – not necessarily full line pressure. We have discussed in many other blogs how compressed air is your 3rd or 4th highest utility. If you optimize the pressure per application, you can save dollars. As a rule of thumb, if your system is operating at the 100 psig level, lowering the pressure by 2 psig will save 1% of energy used by the air compressor. A great example of this would be our Super Air Knives. Optimal use is at 80 psig, and “X” SCFM (based upon length of the Super Air Knife). At 80 psig and the proper SCFM, this flow will feel like having your hand out the window of your car when you are driving about 50 MPH. Your application may not need that much air flow, to get the job done. Turn it down and test it. Start at 80 psig and using the tools from tip #2, turn it up or down until your needs are met. Many of our products do not need to be used at full pressure to effectively solve your process problem.

Pro tip #3 – Use the proper sized lines, connectors and fittings. Pipe restriction can kill performance. Quick connects can be very problematic. Most quick connects are rated at the same size as the incoming pipe, tube or hose, but may actually have a much smaller inner diameter. As you can imagine, this oversight can cause significant performance issues, and end up costing more lack of production or defective product. Be it a quick connect, or any other connector or fitting, it is imperative not to restrict the air. This will result in problems, and lack of performance.

Please do not hesitate to reach to discuss any performance issues, or find out how we can help.

Thank you for stopping by,

Brian Wages

Application Engineer

EXAIR Corporation
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Air Amplifiers to Increase Volume of Airflow Aid in Cooling, Cleaning, Circulation, Venting

Air Amplifiers are a perfect solutions for utilizing air for Venting, Exhausting, Cooling, Drying, or Cleaning with no moving parts. As the name implies, these tools produce a high volume and a high velocity of outlet flow. These are very quiet, efficient and can amplify your air consumption up to 25 times… Here is a great diagram and description of exactly how these work:

Air Amplifiers use the Coanda Effect to generate high flow with low consumption.

As you can see, these fine pieces of engineering genius have no moving parts, and require no electricity. You can easily control the flow, force and velocity by opening or closing the air gap (fixed with a shim) and regulating the the supply air. These can also be ducted on each end to either pull in or remove air or fumes from one room or area to another.

SUPER?? What makes our Super Air Amplifier super? I’m glad you asked. The Super Air Amplifier has a patented design that uses a special shim to maintain critical position of the component parts. This results in a precise amount of compressed air to be released at exact intervals towards the center of the Super Air Amplifier. These jets of air create a constant, high velocity outlet flow across the entire cross-sectional area. This balances out the airflow to maximum performance, this simultaneously minimizes wind shear, causing sound levels up to 3 x’s quieter than other comparable air movers. To completely understand how much air this Super Air Amplifier amplifies (try saying that fast 5 times), please see the below chart.

As you can see, the amplification ratio is between 12 and 25 x the amount of air consumed. For the right applications, these are game changers… Pro tip – notice that even the highest level still falls under OSHA guidelines for noise!!

If you have any questions, or would like to discuss your application directly, please reach out today. We would love to speak with you, and help wherever we can.

Thank you for stopping by,

Brian Wages

Application Engineer

EXAIR Corporation
Visit us on the Web
Follow me on Twitter