Category: Air Knife

Air Knife Shim Adjustment can be Key to Successful Applications

Published on by Brian FarnoLeave a comment

On January 2, 1960 Little Anthony & The Imperials appeared on The Dick Clark Saturday Night Beech-Nut Show to sing Shimmy Shimmy Ko Ko Bop. While I wasn’t around at that time, I have heard the song quite a few times and get it stuck in my head more than I have heard it. What does that song and EXAIR have to do with each other? Well, we shimmy shimmy Super Air Knives to dramatically increase or decrease their flow and force.

The stock shim that is assembled in every Super Air Knife is a .002″ (0.05mm) thick. This sets a continuous opening the full length of the knife that drives the performance of the knife. The shim sets the gap height between the cap and the body of the Super Air Knife. If we evaluate a 24″ Super Air Knife with the stock shim installed we could calculate the airflow opening of the knife as the surface area of a rectangle.  To obtain the surface area we take the length of the air knife times the thickness of the shim.  See the example below.

As you can see with the stock .002″ thick shim installed we are actually operating at a surface area opening of 0.048 square inches.  If we were to install the .004″ thick shim into the knife then we would double the height which in turn doubles the surface area, shown below.

This doubling effect will increase the force out of the Super Air Knife when applications require more power.  Thinning out the shim will have the exact opposite effect, if the shim thickness is reduced to .001″ thick then the air consumption and force will be reduced.

Changing the shims out of the Super Air Knives is a fairly simple task as shown in the video below.  Installing a different thickness of shim is a coarse adjustment to the volumetric flow needed for your application.  Then a pressure regulator can be used to fine tune the needed force and flow for the ideal setting to meet your needs, and operate at maximum efficiency for the application.

If you would like to discuss this further or even see what kind of custom thicknesses we can offer on the shims to truly make a tailor fit Super Air Knife for your application, please contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

Little Anthony & The Imperials “Shimmy Shimmy Ko Ko Bop” – [Merlin] XelonEntertainment, WMG (on behalf of Turntable Recordings LTD); ARESA, LatinAutor, União Brasileira de Compositores, Spirit Music Publishing, UNIAO BRASILEIRA DE EDITORAS DE MUSICA – UBEM, Abramus Digital, BMI – Broadcast Music Inc., and 4 Music Rights Societies – https://www.youtube.com/watch?v=5mLjZRAXRRA

Super Air Knives in Agriculture

Published on by John BallLeave a comment

I spoke with an international agribusiness that specialized in improving processes with cutting-edge technologies in the agricultural sector.  They started a project with a company to improve their drying process for potatoes.   This company was washing 10 tons of potatoes per hour during 16-hour days.  The potatoes would travel along a conveyor that was 90cm (35.4”) wide after the washing system where they had three blower air knives to remove the water from the surface.  Since the project scope was to increase productivity, the agribusiness company targeted their biggest issue, the blower air knives.

They described the two main problems that their customer was experiencing.  First, the conveyor had to run at a slower rate to remove enough water from the surface of the potatoes before packaging.  Thus, the feed rate into the washing system ran intermittently to not overload the drying process.  The main issue was that the blower system was limited with force.  It could not generate a strong enough air stream to properly dry the entire spud at higher speeds.  Thus, the conveyor system was not at an optimal range.

The second issue was premature spoilage of the potatoes which had to be discarded.  I remember when my family would store potatoes in bunkers under the ground to keep them cool.  This would help to slow the bacterial growth which causes spoilage.  Blower systems generate hot air from the electric motors.  Since bacteria growth is enhanced with warmer temperatures, the potato company was noticing poor appearance and early spoilage.  To increase their profits, they wanted to dry the potatoes without heat.

110236SS Super Air Knife Kit

EXAIR has been manufacturing leading-edge technology since 1983, and we could offer a solution.  For removing water from the surface of the potatoes; the EXAIR Super Air Knife would be the perfect instrument.  This compact system is easy to install; and it does not have any moving parts to wear or need shutdowns for maintenance.

I recommended to replace the three blower-air knives with one piece of a model 110236SS Super Air Knife Kit.  The kit includes a 36” (914mm) 303SS Super Air Knife, a filter, a regulator and a shim set.  The regulator and shim set are specifically designed to control the force requirement and air usage to the Super Air Knife.  So, you can fine tune the correct amount of force to blow around the entire potato for effective drying.  For a stock Super Air Knife, the model 110236SS can generate 5.6 pounds of force (2.55 Kilograms) at 80 PSIG (5.5 Bar); a tough target for a blower air knife.  The agribusiness was excited about the concept and wanted to know more.

Another unique feature with the EXAIR Super Air Knife is the engineered design.  We are able to reach a 40:1 amplification ratio.  That means for every 1 part of compressed air, we can entrain 40 parts of ambient air.  What does this mean?  First, the Super Air Knife is very efficient within your compressed air system as we are using mainly free ambient air.  Second, since majority of the air is ambient, the temperature of the air is not heated; thus, a cooler air stream.   And third, by adding the mass of the ambient air, it gives a stronger blowing force.  So, the Super Air Knife was able to meet both of the agribusiness requirements.  In the end, we were able to cut scrap and increase the production rate by almost 10%.

If you need to dry your agricultural items with cutting-edge technology, EXAIR would be the manufacturer for you.   We are staffed with Application Engineers to find solutions and improvements, and we will be happy to discuss your application.  For this agribusiness company, they were excited to work with EXAIR to get a great result for the company above in the potato arena.

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

Proper Plumbing Prevents Poor Performance

Published on by Tyler DanielLeave a comment

There’s nothing quite like an ice-cold Coke from McDonald’s. While there’s many reasons for this, one of the reasons for the unique experience of a McDonald’s Coke lies in the straw itself. In their drinks, they provide wider straws that are designed to help enhance the taste of Coca-Cola, or so they claim. Another impact of this is it allows you to drink significantly faster. The wider the opening for liquid to pass through, the more volume you’re able to drink. Imagine trying to drink your Coke, or any other beverage, through a coffee stirrer. I imagine you’re going to have a difficult time and a dry mouth as you try and force what little amount of liquid you can through the small I.D. of a coffee stirrer. Try that with a milkshake and the problems compound…..

The same is true when it comes to plumbing of your point-of-use compressed air products. I recently assisted a customer that was experiencing lackluster performance from the Super Air Knife they purchased. The application was fairly straightforward, they were hoping to reduce the rate of rejected material on their production line of plastic sheets. The sheet goes through a washing process to remove any residual contaminants, then would air dry as it made its way down the line. As the material dried, there were water spots left on the material that would have to then be cleaned off. In the hopes of speeding up the drying process, they purchased a Model 110060 60” Super Air Knife to provide a wide laminar sheet of air to dry the material.

WhatsApp Image 2018-12-13 at 15.49.45 (2)

When they hooked everything up, the flow from the knife seemed far less than they were expecting. They were supplying full line pressure (just over 90 PSIG), so in theory they should feel a strong blast of air from the knife. When they installed a pipe tee and pressure gauge directly at the inlet, they noticed the pressure was dropping to 35 PSIG while the knife was in operation. When this occurs, it’s indicative of a lack of volume of air. This can be caused by undersized compressor,  or improper plumbing. In their case, they were only plumbing compressed air to one center inlet of the knife. For a 60” knife, EXAIR recommends a minimum of (4) air inlets to ensure adequate volume.

SAK plumbingh

The size of these lines is also critical. You can’t force greater volumes of air through a smaller hose or pipe, just like you can hardly drink through a coffee stirrer with any great success. A 60” knife requires a supply pipe size of 1-1/2” for up to a 50’ run, if you’re trying to supply a knife of this length with a 100’long, ¼” ID hose, you’re not going to get the performance you expect. If you’re experiencing less than optimal performance from any of your EXAIR Intelligent Compressed Air Products, there’s a good chance air supply is the culprit. The first step is determining what the actual inlet pressure is, install a pipe tee and pressure gauge right at the inlet. Then, give us a call and we’ll help work through the proper line sizes and ensure that you’re getting the most out of our products.

I hope I didn’t make you hungry or thirsty… But I think I know where and what I’m having for lunch 😊!

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

How to Install A Super Air Knife – From the Basic to the Creative

Published on by Russ BowmanLeave a comment

Occasionally, a caller will ask if we offer installation services for our products. They’re usually very pleased to learn that there’s not all that much to it.

Any of our Super Air Knives can use our Model 9060 Universal Air Knife Mounting Systems (shown below; one on a 12″, and four on a 108″ length) for easy installation and precise aiming.

The 9060 Universal Air Knife Mounting Systems are perfect for simple, fast installation and positioning.

Shorter lengths, like the Model 110006 6″ Aluminum Super Air Knife (below, left,) can be adequately supported by air supply piping.  We don’t recommend that with longer lengths (due to overhung load concerns) but even a Model 110018 18″ Aluminum Super Air Knife (below, middle,) can be supported by the supply pipe in a vertical position.  We even stock our 3″ Aluminum Super Air Knives with Stay Set Hoses & Magnetic Bases (below, right.)

Just a few more popular ways to install a Super Air Knife.

The Super Air Knife also has a series of 1/4″-20 tapped holes, 2″ apart, along the bottom of the body.  These are often used for installation & mounting as well, and we’ve seen some creative methods, for sure:

Yes, that’s a door hinge. No, it wasn’t my idea, but I kind of wish it was.

EXAIR Super Air Knives come in lengths from 3 inches to 9 feet long.  We stock them in aluminum, 303SS, 316SS, and PVDF.  If you need a custom length or material, though, we do those too.  We can even talk about the best way to mount it.  Call me.

Russ Bowman
Application Engineer
EXAIR Corporation
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