Super Air Knife Shims & How They Affect Performance

To Shim or not to Shim… The Super Air Knife is a fabulous piece of equipment. Between the quiet laminar flow of air, and the intense 40 to 1 ratio of entraining the ambient air around it, this Knife is definitely cutting edge (pun intended). As you look at the front edge of the Super Air Knife, or as we call it “the place where the magic happens“, you will see that there is a very small slit or gap where the air flows. The gap in that metal is caused by the shim that is inside the Super Air Knife. We control the size of this gap with shims. Hark, what light through yonder air gap breaks?… Sorry, I get carried away sometimes.

The shims in the Aluminum Super Air Knives are made of a polyester plastic, the PVDF Super Air Knife Shims are made of PTFE, and I will give you two guesses what the Stainless Steel Super Air Knife Shims are made of, you guessed it… Flubber… Just kidding, they are stainless steel of course.

All of our Super Air Knives, regardless of material, ship standard with a 2 thou shim installed. 2 thou you ask? I did too. That is 2 thousandths of an inch, or 0.002″. This is the height of the gap where the Air Flows out. When you are looking at all of our published numbers in the catalogue or on the website, all of those performance numbers are based on this 2 thou shim. Here is the Super Air Knife performance table:

Pic by Conmongt, licensed by Pixabay

So, what if you need more or less air than what’s on this list? We can adjust the gap. We can add shims up to @ 0.01″ to increase the flow. Or we can go down to 0.001″ (1 thou). This poses the question of, what happens to performance? The good news with the shims is that the Air Consumption is a direct linear proportion to this performance table, and the force is very close to the same. So if you double to a 4 thou shim, you double the air consumption and force. Velocity and sound level will vary, but I do not have data to what degree.

As we size these, generally see people wanting more air, larger gaps (more shims), But conversely, we can decrease the air flow down to a 1 thou shim (1/2 of the published values above). Technically we can go smaller than 1 thou, but there is a limit to where a hole is no longer a hole. Here is a breakdown of our stock shims, with colors and sizes for the Super Air Knives:

The Super Air Knives are in a class of their own. As long as you feed the Super Air Knives enough air (SCFM) you can run them at most any psig to retrieve the desired air flow for you application. As an added means of flexibility, you can change the gap size with shims. I have put in a request to change the name of these to Super Flexible Air Knives, but I’m not holding my breath.

Public Domain Picture Licensed by Pixabay

One more thing about Shims. We can customize your shims!! Now I am not talking about putting your logo on them (but money talks!!), but we can customize your length. Let me give you an example. Let’s say that you need 58″ of airflow, no more no less. Our standard length Super Air Knives are 54″ and 60″. We can make you a custom knife, which is a great option, but for 1 or 2, this is probably not very cost-effective. But we can make you a custom shim. We can have the knife only push 58″ of air with a shim blocking the rest. Furthermore, you can decide if you want 58″ centered on the knife, or all 58″ starting from the left, or right side. It is a very cost-effective way to get a custom flow width.

Please let me know of you have any questions, or would like to discuss any of this further.

Thank you for stopping by,

Brian Wages

Application Engineer

EXAIR Corporation
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1″ And 2″ Flat Super Air Nozzles Overview

In most “general” blowoff applications, the conical airflow pattern from a standard round shaped nozzle is ideal when trying to remove dust or light debris from the surface of a part or material. However in certain applications, a focused, laminar flow of air is required to produce the desired result, such as cleaning peanut butter from a fill nozzle or ejecting parts in a stamping operation.

EXAIR manufactures our 1″ Flat and 2″ Flat Super Air Nozzles, which provide a 1″ and 2″ (respectively) wide, forceful stream of high velocity, laminar airflow while consuming only a small amount of compressed air. Both the 1″ and the 2″ are available in Zinc Aluminum alloy, rated up to 250°F (121°C), or 316 Stainless Steel construction, rated up to 1,000°F (538°C)

1″ Flat Super Air Nozzle

2″ Flat Super Air Nozzle

Their unique design incorporates a specially designed, replaceable shim, to maintain a critical gap between the cap and body, resulting in the focused airflow. They are shipped from stock with a .015″ shim installed.

Using the optional shim kit, the shims can be changed out to .005”, .010” or .020”, which allow you to increase or decrease the force and flow by either opening or closing the gap, providing more or less force and flow to meet the demand of the application.

(Here’s a short video showing how easy it is to change out the shims)

We also offer our High Power versions of these nozzles which feature a thicker shim installed (0.025″) for applications requiring higher thrust and velocity.

If you have an application you would like to discuss or to see how the Flat Super Air Nozzles might improve your process, give me a call, I’d be happy to help.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

More Power? I DO Think So…

We occasionally get calls from folks who are looking for “more power” – and it always brings that classic 1990’s sitcom “Home Improvement’s” Tim “the Tool Man” Taylor to mind. Well, not so much Tim’s “more power” mantra, but the ubiquitous response from his long-suffering sidekick, Al Borland:

Al knows it.  George Foreman knows it. Lisa knows it.  Even Tim knows it, this time.

Sometimes, they’re looking for a product to replace what they’re currently using…something they’re not getting desirable results from. Other times, they have an EXAIR product in place, and it’s just not getting the job done.

Our first response is, of course, to make sure they’re getting a sufficient supply of air to their product, no matter whether it’s ours or not. If you’re familiar at all with our blogs, you know we write about this frequently:

The Importance of Proper Compressed Air Supply Lines

Video Blog: Proper Supply Plumbing for Compressed Air Products

Improper Installation and Associated Problems

3 Common Mistakes in Your Compressed Air System

Once we’ve made sure that the product is indeed receiving appropriate air supply, we can look at adding to the flow rate and force of the air stream. We’ve made it easy to do that with a variety of blow off products by designing them with a replaceable shim.

All of our Air Knife products (Super, Standard, and Full Flow) will ship with a 0.002” thick shim installed. These will perform superbly in a wide variety of general industrial blow off applications. If this doesn’t provide the force needed for your application, we carry Shim Sets for any Air Knife that will allow you to double, triple, or even quadruple the air flow for amplified thrust. Some common examples are stubborn debris in tight spaces (like the fins of a fin-and-tube heat exchanger) or removing oil from a corrugated surface.

From left to right: Super, Standard, and Full Flow Air Knives.

 

Like the Air Knives, our Air Wipes (Super and Standard) are built with 0.002” thick shims, which can be easily replaced for additional flow and force. Like when the Air Wipe is getting all the coolant off an extruded & machined part, but some stubborn, hair-like fibers need a little more “oomph” to remove.

 

Super (left) and Standard (right) Air Wipes come in sizes from 1/2" to 11".
Super (left) and Standard (right) Air Wipes come in sizes from 1/2″ to 11″.

Yes, those were real calls I took. Yes, they had sufficient air flow. Yes, the extra shims worked like a champ.

Similar to our Air Knife products, our Flat Super Air Nozzles also incorporate a replaceable shim. In fact, you have your choice of standard Models with a 0.015” thick shim installed, or High Power Models with a 0.025” thick shim. Shim Sets with a variety of thicknesses from 0.005” to 0.030” are available for either of these.

Model 1126 (Zinc Aluminum) or 1126SS (316SS) 1" Flat Super Air Nozzles (left) have replaceable shims (middle), same as Model 1122 (Zinc Aluminum or Model 1122SS 2" Flat Super Air Nozzles (right.)
Model 1126 (Zinc Aluminum) or 1126SS (316SS) 1″ Flat Super Air Nozzles (left) have replaceable shims (middle), same as Model 1122 (Zinc Aluminum or Model 1122SS 2″ Flat Super Air Nozzles (right.)  High Power versions of both are also available from stock.

Our Super Air Amplifiers and High Velocity Air Jets incorporate patented shims that make for the highest amplification flows available, anywhere. These are available, from stock, in Shim Sets or individually.

High Velocity Air Jets and Super Air Amplifiers use patented shims for optimum performance and efficiency.
High Velocity Air Jets and Super Air Amplifiers use patented shims for optimum performance and efficiency.

If you have an air blowing application that you’d like to get a little (or a lot) more out of, give us a call. Prepare for a discussion on proper air supply first (of course,) but we’ll be more than happy to help in any way that we can.

Russ Bowman
Application Engineer
(513)671-3322 local
(800)923-9247 toll free
(513)671-3363 fax
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Video Blog: Changing Shims in Flat Super Air Nozzles

A brief video explaining just a few of the benefits to utilizing the EXAIR Flat Super Air Nozzles and how to change the shims which change the force and volume of flow out of the nozzle. Our shims and the adjustable air gap mean you can increase or decrease the volume of air flow and force without adjusting the inlet air pressure.

 

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF