Super Air Wipe Helps Shield a Lens

Super Air Wipe Kit

A tier 2 automotive company makes small metal boxes with a process which includes laser welding and a vision inspection system. The machine was programmed to weld different components onto the metal enclosure. During the welding operation, an optical sensor would check the quality of the welds. The vision system used a lens to protect the sensor from welding slag and debris. After a few operations, they started seeing false positives in the welding areas, and the metal enclosure would be flagged for rejection. In investigating the issue, they found that the lens was getting dirty from the welding operation. Because of the sensitivity of the sensor, it would detect the debris and marks on the lens and signal for poor weld. The lens was doing its part in protecting the sensor from damage; but, they needed a way to shield the lens from dirt and slag during the welding operation and visual inspection.

With this process, the machine would weld metal fasteners onto an enclosure by laser. The optical sensor would move along the welded areas to check the quality. In a lead/lag operation, the vision system would check the welds after a few seconds of cooling. So, both operations were occurring at the same time but at different intervals. When they started to see the rejection rate increase, they would have to stop the operation, clean the lens, and verify the integrity of the welds. In some cases, they would have to replace the 1 ¼” diameter lens especially if a piece of welding slag marred the surface. With incorrect rejections and lens cleaning, downtime was hurting their production rates and cost.

This customer wanted to use compressed air because it is a powerful and invisible way to create a shield. Since EXAIR is a leader in efficient and effective ways to use compressed air, they contacted us for help. Initially, I suggested a Super Air Knife to deflect any slag and debris from the lens surface. I showed a prior solution to a very similar issue; “Air Shielding a Laser Lens” (Reference below). But, because of the proximity to the part and the limitation in space, the Super Air Knife  configuration in the solution below would make it impossible to use. They were looking for a product that could be mounted either flush or behind the surface of the lens and still protect it.

Air Shielding a Laser Lens

To accommodate for this request, we had to direct the compressed air stream at an angle. EXAIR manufacturers a product that can do just that, the Super Air Wipe. The design of the Super Air Wipe blows compressed air at a 30-degree angle toward the center in a 360-degree air pattern, just like a cone. It can be placed around the lens and still be able to create a “wall” of air to block any slag or debris from hitting the lens.

I recommended the model 2452SS, 2” Super Air Wipe Kit. This Super Air Wipe has the body, braided hose, hardware, and shims that is made from stainless steel. It can handle the high heat loads from the welding process as well as to allow for easy cleanup after a day of operating. The kit includes a filter, to keep the compressed air clean; a regulator, to finely tune the force requirement; and a shim set. The shim set includes two additional sets of shims that can be added to increase the force of protection if needed. With the kit, the customer can “dial” in the correct amount of force needed to keep the lens clean without using excessive amount of compressed air.

As an added benefit of saving compressed air, the Super Air Wipe uses the Coanda effect to maximize the entrainment of ambient air into the compressed air stream. This makes the unit very efficient and very powerful. The Super Air Wipe was mounted just behind the lens like the customer required (Reference mock picture below), and the sensor could examine the welds without any interference with the metal enclosure.

Laser Lens mock drawing

Visual inspections systems are highly accurate pieces of equipment, and a dirty lens will affect the performance. EXAIR has many ways to keep the lens clean with a non-contact invisible barrier to protect sensors, cameras, and lasers. If you have a similar application, you can contact an Application Engineer to determine the best way to keep the lens clean and your equipment functional. After mounting the Super Air Wipe, the customer above eliminated any false rejections, and dramatically decreased any downtime for cleaning or replacing the lens in his welding machine.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Intelligent Compressed Air: How do Vortex Tubes Work

A vortex tube is an interesting device that has been looked upon with great fascination over the last 89 years since its discovery by George Ranque in 1928. What I’d like to do in this article is to give some insight into some of the physics of what is happening on the inside.

With a Vortex Tube, we apply a high pressure, compressed air stream to a plenum chamber that contains a turbine-looking part that we call a generator to regulate flow and spin the air to create two separate streams. One hot and one cold.

Below is an animation of how a Vortex Tube works:

Function of a Vortex Tube

 

The generator is a critical feature within a vortex tube that not only regulates flow and creates the vortex spinning action, it also aligns the inner vortex to allow its escape from the hot end of the vortex tube. Note the center hole on the photo below. This is where the cooled “inner vortex” passes through the generator to escape on the cold air outlet.

Vortex generator

Once the compressed air has processed through the generator, we have two spinning streams, the outer vortex and the inner vortex as mentioned above.  As the spinning air reaches the end of the hot tube a portion of the air escapes past the control valve; and the remaining air is forced back through the center of the outer vortex.  This is what we call a “forced” vortex.

If we look at the inner vortex, this is where it gets interesting.  As the air turns back into the center, two things occur.  The two vortices are spinning at the same angular velocity and in the same rotational direction.  So, they are locked together.  But we have energy change as the air processes from the outer vortex to the inner vortex.

If we look at a particle that is spinning in the outer vortex and another particle spinning in the inner vortex, they will be rotating at the same speed.  But, because we lost some mass of air through the control valve on the hot end exhaust and the radius is decreased, the inner vortex loses angular momentum.

Angular momentum is expressed in Equation 1 as:

L = I * ω

L – angular momentum
I – inertia
ω – angular velocity

Where the inertia is calculated by Equation 2:

I = m * r2

m – mass
r – radius

So, if we estimate the inner vortex to have a radius that is 1/3 the size of the outer vortex,  the calculated change in inertia will be 1/9 of its original value.  With less mass and  a smaller radius, the Inertia is much smaller.  The energy that is lost for this change in momentum is given off as heat to the outside vortex.

Adjustments in output temperatures for a Vortex Tube are made by changing the cold fraction and the input pressure.  The cold fraction is a term that we use to show the percentage of air that will come out the cold end.  The remaining amount will be exhausted through the hot end. You can call this the “hot fraction”, but since it is usually the smaller of the two flows and is rarely used, we tend to focus on the cold end flow with the “cold fraction”.  The “Cold Fraction”  is determined by the control valve on the hot end of the Vortex Tube. The “Cold Fraction” chart below can be used to predict the difference in temperature drop in the cold air flow as well as the temperature rise in the hot air flow.

Vortex Tube Cold Fraction

By combining the temperature drops expressed above with the various flow rates in which Vortex Tubes are available, we can vary the amount of cooling power produced for an application. The above cold fraction chart was developed through much testing of the above described theory of operation. The cold fraction chart is a very useful tool that allows us to perform calculations to predict vortex tube performance under various conditions of input pressure and cold fraction settings.

The most interesting and useful part about vortex tube theory is that we have been able to harness this physical energy exchange inside a tube that can fit in the palm of your hand and which has a multitude of industrial uses from spot cooling sewing needles to freezing large pipes in marine applications to enable maintenance operations on valves to be performed.

We would love to entertain any questions you might have about vortex tubes, their uses and how EXAIR can help you.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

Video Blog: Which EXAIR Air Knife Is Right For You?

The following short video explains the differences between the 3 styles of Air Knives offered by EXAIR – The Super, Standard and Full-Flow. All of these Models are IN STOCK, ready to ship, with orders received by 3:00 PM Eastern.

If you need additional assistance choosing your EXAIR Air Knife, please contact an application engineer at 800-903-9247.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

 

Many Ways to $ave on Compressed Air Costs

Using compressed air in the plant is common for many types of processes.  Typical uses are drying, cooling, cleaning and conveying. Compressed air does have a cost to consider, and there are many ways to keep the usage and the costs as low as possible.  The first step is to use an EXAIR Intelligent Compressed Air Product, which has been engineered to provide the most performance while using the least amount of compressed air. The next step is to control the use of the air, to only have it on when needed.

EXAIR offers the EFC – Electronic Flow Control.  It offers the most comprehensive method to maximize the efficiency of compressed air usage.  It combines a photoelectric sensor with a timing control that operates a solenoid valve to turn on and off the air as required. With 8 different program types, an on/off mode that works with any process can be programmed ensuring that the minimum amount of compressed air is used.  You can use the online EFC Savings Calculator to see how quickly the savings add up!

EFCp4

EFC – Electronic Flow Control

Another method would be to use a solenoid valve with some other method of control. Depending on the process, the solenoid could be energized via a machine control output, or as simple as an electrical push button station. EXAIR offers solenoid valves in a variety of flow rates (from 40 to 350 SCFM) and voltages (24 VDC, 120 VAC and 240 VAC) to match the air flow requirements of the products we provide, while integrating into the facility and available supply voltages.

For control of the Cabinet Cooler Systems, the ETC – Electronic Temperature Control, uses a thermocouple to measure cabinet temperature and cycle the system on and off to maintain a precise cabinet temperature, and provides a digital readout of the internal temperatures and on the fly adjustment.  Also available is the Thermostat Control models, which utilize an adjustable bimetallic thermostat to control the solenoid valve, also cycling the unit on and off as needed to maintain a set cabinet temperature.

ETC CC

ETC – Electronic Temperature Control

There are several manual methods that can be used to control the compressed air.  A simple valve can be used to turn the air off when not needed, whether at the end of the work day, at break time, or whenever the air isn’t required.  We offer several options, from a foot controlled valve, to a magnetic base with on/off valve, to a simple quarter turn ball valve.

footpedalvalve (2)dualstand (2) manual_valves (2)

 

To discuss your processes and how an EXAIR Intelligent Compressed Air Product can control the air supply and save you money, feel free to contact EXAIR and myself or one of our other Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

Send me an email
Find us on the Web
Like us on Facebook
Twitter: @EXAIR_BB

 

 

Thank You For The Video Ideas

Over the past month or so I have been doing some update projects at home.  Tearing out wood paneling, drywalling, and even tearing out some old tile to install new inside of an entryway.  While I have helped with drywall before it was when I was 16 and let’s just say that the details are a little fuzzy on the right way to do quality drywalling.  Instead of calling a professional in, I looked to my readily available options on where to find information.  I reached out to friends and family that I knew had experience with it and then I turned to the internet.

One simple search for “How to tape and mud drywall” or any combination of those words and I was spoon fed hundreds of videos that showcase how many different people go about the process. (Some professional, some not so professional.)   I never like to watch just one so I checked out a dozen or so and decided to give it a go.  The point is, I didn’t spend time reading through instructions or finding books on the matter,  I went to people that I knew had the knowledge then straight to videos for help.  This is why I want to thank all of our customers who have ever asked the question “do you have a video on that?”.

Customer inquiries and FAQs are where a good number of our video topics on our blog and YouTube channel are generated.   A simple search on our blog for video will show all of the tips and tricks videos that the EXAIR Application Engineers have released over the past handful of years.   This count continues to go up as a new video is released every month since 2011. We currently have 54 EXAIR product related videos on our blog. Our YouTube channel features additional videos for product categories and some humorous (subjective, we know) videos from Professor Penurious.

Blog Search.PNG

Click on the image above to see all of our “Video Blog” entries. 

If you have a topic you would like to discuss or something you think would make a good how to video for us, contact us and tell us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

 

A Ride Down Memory Lane

The past few weeks been very busy, both here at EXAIR and at home.    Last night was the first night in quite some time where I arrived home to a quiet house and which afforded me some time to decompress and process. I had roughly one hour of time before my wife and daughters got home and so I sat down and just stopped thinking about everything.   I turned the TV on and my Home Theater PC was going through all the pictures that we have stored on it as a slide show.

The pictures ranged from family gatherings before we had kids to my first daughter’s birth (wow, there are a lot of pictures of that first kid!), through time and up to the present which finds me with a 4 year old and a 16 month old.  You can even see our two dogs growing older in the pictures from every month.

In no time at all the hour was up and I heard the garage door opening up.  Then got to see the three women that make my life awesome come through the door – and its a great event to have young kids who still celebrate seeing their dad for the first time in a day.

Many of us have such busy lives that I’m sure you can appreciate some down time at home which allows you to refocus. It certainly helped me to bring everything here at EXAIR right back into focus.  EXAIR keeps pushing forward (in case you haven’t noticed) with expanded product lines, new products, new people and new services.  We’ve come a long way since we began in 1983.  Instead of a single product sheet for a catalog we now have a 164 page catalog and every single product line has grown to encompass more and more models.   Our product lines aren’t the only thing that have grown also.  You can see just how much we have grown by the many co-ops, Professor Penurious has enlisted, I mean employed. He’s had so many co-ops he has a slide show of his own.

Coop2coop3coop4coop5

So if you haven’t seen our newest items or are still rocking the timeless Catalog 99 because you like vintage items – give us a call or visit our website at EXAIR.com, a lot has changed but our top notch service remains.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

Free Safety Air Guns and Beards

Last week, Brian introduced Movember to the EXAIR blog this year.  I’m pretty sure Movember was started as a flimsy excuse for some Aussies to grow their facial hair and not have their bosses and wives give them a hard time.  I fully support this plan.  Having said that, it is very difficult to talk about men’s health with other men.  One of the difficulties is it is impossible to feel manly, while mentioning a prostate exam, but if women can go through breast examinations and child birth, we can deal with going to the doctor every year.  Do you know the one thing that makes you feel manly? Outrageous facial hair.  So I’m hoping by the end of the month, I will be able to pull off talking about testicular cancer, prostate exams, and mental health without making awful of jokes about the subject matter.  I wouldn’t bet on my growing up that much by growing a beard, but it is worth a shot.  *Note: I had a very funny joke here that made my editor spit his coffee from laughter, unfortunately, this a family friendly blog, so we had to cut it.*

On Halloween, I had my last full face shave until December 1st, but I have been trimming my neck.  Here are the results so far.

IMG_3445

1 week beard – not weak, but week.

I have reached the stage in beard growing, where I now need to do some trimming to keep it neat, and it itches like crazy.

(Alas, complaining about facial hair being itchy is distinctly unmanly, so I will stop that.  Joe is photobombing me in this picture to keep me from posting a selfie, which is also distinctly unmanly.)

Speaking of health issues.  According to Michigan’s OSHA Five Minute Safety Talk No. 13, “Air pressure in excess of 30 lbs. can drive chips, as well as scale from inside the piping, into your face and eyes with the force of shrapnel. Such air driven missiles still do damage when they bounce off a surface, spinning much like a high speed cutting head. Air pressure against the skin may penetrate deeply to cause internal hemorrhage and intense pain.”

When using compressed air, please ensure that you use an engineered solution to prevent accidentally dead ending over 30 PSIG against human skin and be sure to wear all PPE and ensure that proper shielding is in place to prevent flying chips from creating and unsafe situation.

This month EXAIR is running a promo on two products that will conserve compressed air and comply with OSHA’s standards.  Please take advantage of our month long Super Air Gun promotion for a free Super Air Gun with a purchase of any Super Air Knife.

Super Air Knife Promo

The Soft Grip Super Air Gun will conserve compressed air, while providing a strong blow off with up to 3.3 pounds of force.  By replacing open tubes and cheap air guns with EXAIR’s line of Safety Air Guns,  you will reduce the noise level in your facility and prevent dead ending over 30 PSIG of compressed air against human skin, which is a distinct threat to Men’s (and Women’s) health in the work place.

The Super Air Knife creates a laminar sheet of air which will cool, dry, blow off, open, float or separate your parts.  All of this process can be done while keeping the noise level below 69 dBA and providing up to 15 ounces of force with a 6″ long air knife, when it is supplied with 80 PSIG.

Dave Woerner
Application Engineer
davewoerner@exair.com
@EXAIR_DW

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