Air Knife Shim Adjustment can be Key to Successful Applications

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

Many Air Knife Materials and Shim Options to Suit Your Application

The EXAIR Super Air Knives are used in many applications ranging from part drying, to web cleaning, to conveyor blowoff, and many other uses. For most processes, the aluminum models provide the performance required and withstand the environmental conditions present.

Ambient temperature limits for the aluminum models is 180°F (82°C). EXAIR also offers the air knives in types 303 and 316 Stainless Steel, which increase the temperature limit to 800°F (427°C) and provides a great degree of corrosion resistance. For the harshest, most corrosive environments, an air knife constructed of Polyvinylidene Fluoride (PVDF) with a temperature limit to 275°F (135°C) is available.

Super Air Knives
Aluminum, Stainless Steel and PVDF Super Air Knives

But what can we do about those applications where the increased corrosion resistance isn’t needed and the temperatures do not approach anywhere near to 800°F (427°C)?

The solution to this situation is an aluminum air knife with a custom stainless steel shim. The aluminum material is rated to 400°F (204°C) and the shim is good to 800°F (427°C) so this knife can be used in those hotter environments up to 400°F (204°C). This option helps to keep the cost of the knife low, by utilizing the lower cost aluminum for the body and cap.

The table below details the materials of construction options for the Super Air Knife – a wide array of material offerings to suit even the hottest, harshest conditions.

Air Knife Temperature Table

We recommend consulting with an Application Engineer to review the application, process, and environmental conditions, and we can present best options.

And don’t forget, the shims can be further customized for special blowoff requirements. See the blog that my colleague, Russ Bowman, posted here.

If you have questions about Super Air Knives or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
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Super and Adjustable Type Air Amplifiers

The EXAIR Air Amplifiers are a powerful, efficient and quiet air mover, whose power can be harnessed for blowoff, cooling and ventilation applications. Using a small amount of compressed air, air amplifiers pull in large amounts of surrounding air to produce a high volume, high velocity outlet flow.  Quiet and efficient, output flows with amplification ratios of up to 25 times are possible. There are two types, the Super Air Amplifier and the Adjustable Air Amplifier.

The Super Air Amplifier, with sizes ranging from 3/4″ to 8″, has a patented design (patent #5402938) that uses a special shim to maintain critical position of the components parts. It is through this critical gap setting that a precise amount of compressed air is passed at exact intervals controlled by the shim toward the center of the of the Super Air Amplifier.  The jets of air create a high velocity flow across the entire cross sectional area, which in turn pulls in large amounts surrounding air, resulting in the amplified outlet flow.  Because the outlet flow remains balanced and minimizes wind shear, sound levels are typically three times lower than other types of air movers. The shims are available in thicknesses of 0.003″ (supplied as standard), 0.006″ and 0.009″, and changing to a larger shim will increase the force and flow of the outlet air. The 8″ Super Air Amplifier is supplied with a 0.009″ shim, with a 0.015″ shim available.

2″ Super Air Amplifier and Patented Shim Design

For high temperature applications (up to 700°F/374°C) a special 1-1/4″ High Temperature Air Amplifier is available, with performance equal to the 1-1/4″ Super Air Amplifier. Its surfaces are protected from heat stress by a mil-spec coating process. The High Temperature Air Amplifier is highly effective at pushing large amounts of hot air to areas that typically remain cool.

The Adjustable Air Amplifier, with sizes ranging from 3/4″ to 4″, does not use a shim, and has an infinitely adjustable air gap, which regulates the air consumption and outlet flow from a light breeze to a powerful blast. A highly effective air mover, it can be tailored to meet the exact air flow and force of your specific application. They are available in aluminum and in stainless steel (Type 303) for food service, higher temperatures (400°F/204°C) and corrosive environments.

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2″ Adjustable Air Amplifier, in Aluminum or Stainless Steel

Force and flow of the Adjustable Air Amplifier is changed by loosening the knurled lock ring and turning the exhaust end to open or close the gap.  Once the desired force and flow is achieved, the knurled ring can be tightened to lock the device at the current setting. Typically, an air gap of 0.002″ to 0.004″ provides the required performance.

The table below summarizes the key features of the Super Air Amplifier and Adjustable Air Amplifier.  Please contact an Application Engineer if you need assistance in making a selection.

Air Amp Selection Chart

Note that EXAIR can manufacture special Air Amplifiers to your specification including special flanged mounting style or with a PTFE plug to avoid sticky material build up.

To discuss your application and how a Super or Adjustable Air Amplifier or any EXAIR Intelligent Compressed Air Product can improve your process, feel free to contact EXAIR, myself, or one of our other Application Engineers. We can help you determine the best solution!

Brian Bergmann
Application Engineer

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EXAIR Flat Super Air Nozzles – Adjustable, Flexible and Powerful

As an Application Engineer here at EXAIR, we get calls from customers looking for an air knife, but shorter than our typical 3″ stocked size.  We can make an air knife to any length needed, but we will look at the 1″ and 2″ Flat Super Air Nozzles as a possible solution.

Like an air knife, the Flat Nozzles provide a wedge shaped pattern of air that maintains the width of the nozzle, to create a concentrated, powerful air flow.  Thus, a 1″ Flat Super Air Nozzle has air stream 1″ wide, and the 2″ Flat Super Air Nozzle has one 2″ wide.

The Flat Super Air Nozzles are available in zinc aluminum alloy or type 316 stainless steel construction, to meet environmental conditions of the process.  Both the 1″ and 2″ nozzles contain a changeable, patented shim that maintains the critical air gap, which allows the release of a precise amount of air through the thin slot, across a flat surface. The result is a wide, forceful stream of high velocity, laminar airflow, with minimal air consumption and noise.

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1″ and 2″ Flat Nozzles, in Zinc aluminum Alloy and Type 316 Stainless Steel

Shims are available in thicknesses of 0.005″, 0.010″, 0.015″, 0.020″, 0.025″, and 0.030″.  Shim Sets with either 2 or 3 shims are available for both sizes to allow for adjustment of the performance to best meet the application need.

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Patented, Interchangeable Shims

Table below shows the stock offerings of 1″ and 2″ Flat Super Air Nozzles, along with Air Consumption, Force and Sound Level data for your review.

Flat Nozzle Table

If you have any questions about the Flat Super Air Nozzles, or any EXAIR nozzle or other compressed air product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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