The Case For The EXAIR Super Air Wipe

If you’ve ever used an air gun to blow something off, you’re familiar with the cleaning ability of compressed air.  If you can get the whole object blown off from where you’re standing, there really is no substitute…but what if you need to get to the other side…or sides?

Even if your product is not on fire, you probably wouldn’t want to “limbo” under it with an air gun…

This is where the EXAIR Super Air Wipe comes in…they allow you to blow a continuous, uniform 360° air stream, all around your product.  Consider their benefits:

*Sizes: the Super Air Wipe’s compact ring design means it won’t take up a lot of room; you just need a few inches, in any direction, to install one.  We stock them in eleven sizes, from 11″, all the way down to our brand-new 3/8″ diameter.

*Durability:  All EXAIR Super Air Wipes are assembled with stainless steel shims and hardware.  Models up to 4″ come with a rugged, stainless steel wire braided hose, connecting the two halves for compressed air supply.

The aluminum Super Air Wipe is available in 11 sizes; the stainless steel Super Air Wipe comes in 5 sizes…all from stock.

*Ease of installation:  Smaller sizes can be supported by the compressed air supply line, if a pipe is used and threaded into the connector hose’s 1/4 NPT port.  Larger sizes can likewise be adequately supported with pipe to both halves. All models have a bolt circle of 1/4″-20 tapped holes for more permanent and rigid mounting.  The split ring design is another key feature:

Simply open the two halves, and clamp them around your product…no threading!

*Corrosion resistance: Depending on the environment in which the Super Air Wipe will be installed, we offer them with aluminum (3/8″ – 11″ sizes) or stainless steel (3/8″ – 4″ sizes) bodies.

*Temperature rating: Aluminum Super Air Wipes are good to 400°F (204°C) and stainless steel models are good to 800°F (427°C.)

*Range of operation: We install a 0.002″ thick shim in all stock Super Air Wipes; this is suitable for a wide range of typical industrial/commercial blow off applications…a Pressure Regulator can then be used to “dial in” the air flow precisely to meet specific needs.  If a job calls for higher force & flow, additional 0.002″ shims can be installed.  Shim Sets come with the Super Air Wipe Kits, or individual shims can be ordered separately.

*Performance: Before the Super Air Wipe, a ring of nozzles was commonly used.  In fact, they still are, but we’re trying to fix that, at every opportunity we come across.  Problem with those is, it’s hard to get an even air flow all around, which leads to inconsistent blow off.  They can also be loud & inefficient, as we’ve found in numerous Efficiency Lab tests and Case Studies, like this one…

These wasteful and loud modular plastic tube blow offs…
…were replaced with EXAIR Super Air Wipes. 24 such replacements netted the customer an annual compressed air cost savings of over $13,000.00.

…and this one…

Implementing a Super Air Wipe salvaged a $30,000 job for this customer. Click on the picture to read all about it in our Case Study Library (registration required.)

Do you have a challenging blow off application that you need help with?  Call us to find out how an EXAIR Super Air Wipe (or another one of our Intelligent Compressed Air Products) can be a simple, quick & easy solution.

Custom Shims – Literally A Breeze For EXAIR

As proud as we are of being able to ship most any catalog product, same day, from stock (99.9831% of the time for on-time shipping in 2017…22 years straight for 99.9% or better,) we take a certain amount of pride in our ability to offer custom solutions for challenging applications as well. Our Engineering and Production teams have a deep well of resources (knowledge, experience, and capability) to draw from, which allows us to meet those challenging applications head-on, in short order.

The one I’m writing about today isn’t exactly one of those challenging ones…

A machine fabricator had a special need for an Air Knife. It had to be Stainless Steel, and it had to be 30″ long. No problem so far…that’s a Model 110030SS 30″ Stainless Steel Air Knife, and it’s on the shelf. Thing is, they only needed 26″ worth of air flow; a full 30″ width was going to disturb, and maybe damage, the edges of the sheet of material that the air was being blown onto.

So we made a custom shim for the Air Knife.  Now, we make these all the time, in all kinds of configurations…hence the term “custom.”  Since this one was blowing onto a web where they didn’t want to disturb the material on the far edges, we made this shim to provide 26″ of flow, on center.  We could just as easily made it to provide 26″ of flow starting at one end or the other, or a specified distance from one end or the other.  Or 13″ of flow on both ends, with 4″ of no flow in the middle, for a total of 26″.

If your application is more challenging than a custom shim, we’ve also made Air Knives with (left to right) curved radius, special material (glass filled PEEK shown here,) flat, double-sided, and even one with end-mount threaded holes.

Regardless of how challenging (or not) your compressed air product application is, we’re here to discuss, any time you’re ready.  Call us.

 

Line Loss: What It Means To Your Compressed Air Supply Pipe, Tubing, And Hose

“Leave the gun. Take the canolli.”

“What we’ve got here is failure to communicate.”

“I’ll get you my pretty, and your little dog too!”

“This EXAIR 42 inch Super Air Knife has ¼ NPT ports, but the Installation and Operation Instructions recommend feeding it with, at a minimum, a ¾ inch pipe…”

If you’re a movie buff like me, you probably recognize 75% of those quotes from famous movies. The OTHER one, dear reader, is from a production that strikes at the heart of this blog, and we’ll watch it soon enough. But first…

It is indeed a common question, especially with our Air Knives: if they have 1/4 NPT ports, why is such a large infeed supply pipe needed?  It all comes down to friction, which slows the velocity of the fluid all by itself, and also causes turbulence, which further hampers the flow.  This means you won’t have as much pressure at the end of the line as you do at the start, and the longer the line, the greater this drop will be.

This is from the Installation & Operation Guide that ships with your Super Air Knife. It’s also available from our PDF Library (registration required.)

If you want to do the math, here’s the empirical formula.  Like all good scientific work, it’s in metric units, so you may have to use some unit conversions, which I’ve put below, in blue (you’re welcome):

dp = 7.57 q1.85 L 104 / (d5 p)

where:

dp = pressure drop (kg/cm2) 1 kg/cm2=14.22psi

q = air volume flow at atmospheric conditions (FAD, or ‘free air delivery’) (m3/min) 1 m3/min = 35.31 CFM

L = length of pipe (m) 1m = 3.28ft

d = inside diameter of pipe (mm) 1mm = 0.039”

p = initial pressure – abs (kg/cm2) 1 kg/cm2=14.22psi

Let’s solve a problem:  What’s the pressure drop going to be from a header @80psig, through 10ft of 1″ pipe, feeding a Model 110084 84″ Aluminum Super Air Knife (243.6 SCFM compressed air consumption @80psig)…so…

q = 243.6 SCFM, or 6.9 m3/min

L = 10ft, or 3.0 m

d = 1″, or 25.6 mm

p = 80psig, or 94.7psia, or 6.7 kg/cm2

1.5 psi is a perfectly acceptable drop…but what if the pipe was actually 50 feet long?

Again, 1.5 psi isn’t bad at all.  8.2 psi, however, is going to be noticeable.  That’s why we’re going to recommend a 1-1/4″ pipe for this length (d=1.25″, or 32.1 mm):

I’m feeling much better now!  Oh, I said we were going to watch a movie earlier…here it is:

If you have questions about compressed air, we’re eager to hear them.   Call us.

Russ Bowman
Application Engineer
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Custom Solution From Stock For A Pick And Place Application

Even if you’re just a casual, infrequent reader of our blogs, you likely know that EXAIR Corporation is proud of our abilities to customize solutions for “out of the box” compressed air product applications. Oftentimes, this is offered as a custom engineered product, developed from a user’s specifications when one of our stock products just won’t work for one reason or another. For instance, when an exotic material of construction is required for heat or corrosion concerns, a special length or size is needed for space constraints, etc.

An Air Amplifier with a PTFE plug (left,) a curved Super Air Knife (center,) and a flanged Line Vac are just a few ways EXAIR has provided custom solutions.

Other times, though, we can use a stock product for something other than what everyone else uses it for.  We’ve sold Air Amplifiers for use in vacuum chucking, and pick-and-place applications – those are normally the realm of our E-Vac Vacuum Generators.  Speaking of E-Vacs, they’ve been used to deflate basketballs.

And speaking of E-Vacs (still,) I had the pleasure of helping a long-time customer solve a new problem in their growing manufacturing business.  They put their consumer products in blister packages, and recently converted one of the lines that picks & places the plastic “blister” onto the cardboard “backer” from two at a time, to six at a time.  They were using a Model 810003M E-Vac High Vacuum Generator, which worked fine, every time, with two Model 900762 1″ x 1/2″ Oval Vacuum Cups, but when they put four more of those Vacuum Cups on, they weren’t able to pick all six “blisters” every time.

These plastic blisters are smooth and non-porous, so this a “textbook” application for a High Vacuum Generator.  They’re also VERY lightweight, and were picked in a horizontal motion, so the 27″Hg that the Model 810003M can generate wasn’t actually necessary.  By replacing it with a Model 800003M E-Vac Low Vacuum Generator, the extra vacuum flow solved the problem, with no increase in compressed air consumption, which was critical for this area of their operation.

EXAIR E-Vac Vacuum Generators and Vacuum Cups are a reliable, low cost solution for most any pick & place application.

EXAIR Intelligent Compressed Air Products can solve many of your industrial/commercial challenges.  Our catalog documents the ones they’re aimed at.  Others need to be addressed by knowledge and experience…and maybe a little theory to practice.  If that’s the case, call an EXAIR Application Engineer.  We’re here to help, and we’re pretty good at it.

Intelligent Compressed Air: Distribution Piping

air compressor

An important component of your compressed air system is the distribution piping. The piping will be the “veins” that connect your entire facility to the compressor. Before installing pipe, it is important to consider how the compressed air will be consumed at the point of use. Some end use devices must have adequate ventilation. For example, a paint booth will need to be installed near an outside wall to exhaust fumes. Depending on the layout of your facility, this may require long piping runs.  You’ll need to consider the types of fittings you’ll use, the size of the distribution piping, and whether you plan to add additional equipment in the next few years. If so, it is important that the system is designed to accommodate any potential expansion. This also helps to compensate for potential scale build-up (depending on the material of construction) that will restrict airflow through the pipe.

The first thing you’ll need to do is determine your air compressor’s maximum CFM and the necessary operating pressure for your point of use products. Keep in mind, operating at a lower pressure can dramatically reduce overall operating costs. Depending on a variety of factors (elevation, temperature, relative humidity) this can be different than what is listed on directly on the compressor. (For a discussion of how this impacts the capacity of your compressor, check out one of my previous blogs – Intelligent Compressed Air: SCFM, ACFM, ICFM, CFM – What do these terms mean?) Once you’ve determined your compressor’s maximum CFM, draw a schematic of the necessary piping and list out the length of each straight pipe run. Determine the total length of pipe needed for the system. Using a graph or chart, such as this one from Engineering Toolbox. Locate your compressor’s capacity on the y-axis and the required operating pressure along the x-axis. The point at which these values meet will be the recommended MINIMUM pipe size. If you plan on future expansion, now is a good time to move up to the next pipe size to avoid any potential headache.

Once you’ve determined the appropriate pipe size, you’ll need to consider how everything will begin to fit together. According to the “Best Practices for Compressed Air Systems” from the Compressed Air Challenge, the air should enter the compressed air header at a 45° angle, in the direction of flow and always through wide-radius elbows. A sharp angle anywhere in the piping system will result in an unnecessary pressure drop. When the air must make a sharp turn, it is forced to slow down. This causes turbulence within the pipe as the air slams into the insides of the pipe and wastes energy. A 90° bend can cause as much as 3-5 psi of pressure loss. Replacing 90° bends with 45° bends instead eliminates unnecessary pressure loss across the system.

Pressure drop through the pipe is caused by the friction of the air mass making contact with the inside walls of the pipe. This is a function of the volume of flow through the pipe. Larger diameter pipes will result in a lower pressure drop, and vice versa for smaller diameter pipes. The chart below from the “Compressed Air and Gas Institute Handbook” provides the pressure drop that can be expected at varying CFM for 2”, 3”, and 4” ID pipe.

pressure drop in pipe

You’ll then need to consider the different materials that are available. Some different materials that you’ll find are: steel piping (Schedule 40) both with or without galvanizing, stainless steel, copper, aluminum, and even some plastic piping systems are available.

While some companies do make plastic piping systems, plastic piping is not recommended to be used for compressed air. Some lubricants that are present in the air can act as a solvent and degrade the pipe over time. PVC should NEVER be used as a compressed air distribution pipe. While PVC piping is inexpensive and versatile, serious risk can occur when using with compressed air. PVC can become brittle with age and will eventually rupture due to the stress. Take a look at this inspection report –  an automotive supply store received fines totaling $13,200 as a result of an injury caused by shrapnel from a PVC pipe bursting.

Steel pipe is a traditional material used in many compressed air distribution systems.  It has a relatively low price compared to other materials and due to its familiarity is easy to install. It’s strong and durable on the outside. Its strength comes at a price, steel pipe is very heavy and requires anchors to properly suspend it. Steel pipe (not galvanized) is also susceptible to corrosion. This corrosion ends up in your supply air and can wreak havoc on your point-of-use products and can even contaminate your product. While galvanized steel pipe does reduce the potential for corrosion, this galvanizing coating can flake off over time and result in the exact same potential issues. Stainless Steel pipe eliminates the corrosion and rusting concerns while still maintaining the strength and durability of steel pipe. They can be more difficult to install as stainless steel pipe threads can be difficult to work with.

Copper piping is another potential option. Copper pipe is corrosion-free, easy to cut, and lightweight making it easy to suspend. These factors come at a significant increase in costs, however, which can prevent it from being a suitable solution for longer runs or larger ID pipe installations. Soldering of the connecting joints can be time consuming and does require a skilled laborer to do so, making copper piping a mid-level solution for your compressed air system.

Another lightweight material that is becoming increasingly more common in industry is aluminum piping. Like copper, aluminum is lightweight and anti-corrosion. They’re easy to connect with push-to-lock connectors and are ideal for clean air applications. Aluminum pipe remains leak-free over time and can dramatically reduce compressed air costs. While the initial cost can be high, eliminating potential leaks can help to recoup some of the initial investment. Aluminum pipe is also coated on the inside to prevent corrosion. While an aluminum piping system may be the most expensive, its easy installation and adaptability make it an excellent choice.

It can be easy to become overwhelmed with the variety of options at your disposal. Your facility layout, overall budget, and compressed air requirements will allow you to make the best choice. Once you’ve selected and installed your distribution piping, look to the EXAIR website for all of your point-of-use compressed air needs!

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

When Efficiency And Practicality Collide

Even if you’re a casual reader of our blogs, you already know that EXAIR Application Engineers LOVE to preach efficiency in the use of compressed air…it’s our “bread and butter;” the very nature of our business. This year, we’re celebrating thirty-five years of leading the way in the development of efficient, safe, and quiet compressed air products. Our track record of success as a solutions provider across a diverse range of industrial and commercial applications is well documented in our blogs, as well as Knowledge Base and Case Study Libraries.  We devote considerable resources (engineering, research & development, product testing, etc.) to making certain that EXAIR Intelligent Compressed Air Products cost less to operate, and perform better, than whatever you’re using right now.

Strange as it may seem, though, sometimes our products are EXTREMELY popular in cases where they INCREASE a facility’s consumption of compressed air…by replacing something that DOESN’T use compressed air at all:

*I’ve written before about how our Large Maximum Cold Temperature Vortex Tubes have replaced liquid nitrogen rigs in freeze sealing operations.  Now, a Vortex Tube directs a portion of its air supply to (usually) unusable hot exhaust, in order to generate the usable flow of cold air.  When compared to the costs of liquid nitrogen and the resources involved to get it where it needs to be, though, the cost of the compressed air needed to operate the Vortex Tube is indeed the practical solution.

A 1/4 ton of refrigeration from a product that fits in the palm of your hand, and all you need is a supply or compressed air!

*Line Vacs are probably THE prime example of the value of using compressed air where it wasn’t used before…replacing a “bucket and ladder” operation:

Straight from our Catalog, a perfect example of using valuable compressed air to save even more valuable resources.

*Then there are the situations that just come down to time.  In large spaces, our Super Blast Safety Air Guns can be used to “sweep” the floor in a fraction of the time it takes an operator with a push broom.

Super Blast Safety Air Gun makes short work of large area cleanup.

To make a long story just a little bit longer…if you’re using compressed air, you can use it better with EXAIR’s engineered compressed air products.  And there are plenty of practical applications where you’re not using compressed air right now too.  If you’d like to find out more about either one, give me a call.

Russ Bowman
Application Engineer
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Super Air Knife Reduces Defects and Lowers Freight Costs

The EXAIR Super Air Knife – high force with precision flow

An Argentine food manufacturer recently reached out to our distributor in Buenos Aires (AYRFUL) to discuss a potential application for EXAIR products.  The need became clear when a packaging line for soon-to-be-frozen food began experiencing problems with excessive water on the surface of the packages.  In this process, the packages are rinsed to remove any unwanted debris, and then sent into a large freezer before distribution to local groceries.

The excessive water on the packages would become ice, which would fuse the packages together when stacked in boxes for transporting to retail centers.  This fusing caused rips in the packaging when they were separated, thereby creating unsellable goods, ultimately leading to returns for this manufacturer.  And, the residual water also increased the total weight of the packed packages, enough to increase the actual weight when bulk packed.  This increase in actual weight led to an increase in freight costs from their courier.  So, this manufacturer needed a way to remove the residual water, reduce defects and returns, and simultaneously lessen the freight cost.

Model 110048 Super Air Knife (inside red box) blowing off residual water after rinsing and before freezing. See note on plumbing below.

The solution they found was a 48” EXAIR Super Air Knife, model 110048, mounted using (2) Universal Air Knife Mounting Kits.  The Super Air Knife in this application provided a precision airflow to blow off the water from the top of the packages, after rinsing and before freezing.  Removing the water at this stage, as shown above, eliminated the problem of fused packages, rejected products, returns, and increased freight.  And, the Super Air Knife was able to do this at a low operating pressure, fed from a single compressed air inlet.

(Note – EXAIR recommends plumbing multiple compressed air inlets for Air Knives longer than 18”.  For this model, 110048, we recommend compressed air be supplied to (3) compressed air inlets.  Plumbing less inlets will reduce the compressed air flow into the knife, which reduces possible operating pressure.  In this case, the lower operating pressure was acceptable, however, we still recommend to plumb (3) compressed air inlets on a 48” Super Air Knife.)

Plumbing specifics aside, this solution still brought tremendous value for the customer.  They were able to solve the root cause of a multi-faceted problem with an engineered solution.  If you have an application in need of an engineered solution, contact an EXAIR Application Engineer.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com