The Victory is in Solving the Problem, No Matter the Size

I had an engineer from a welding company contact me about his application.  He was already using three EXAIR Super Air Knives for a cooling application.  He had the Super Air Knives mounted in a linear fashion, two model 110018 18″ Super Air Knives and a model 110012 12″ Super Air Knife. His system was designed to operate the different Super Air Knives to cool the corresponding tubes length after a welding operation.  (He purchased the EXAIR Super Air Knives because he wanted the best air cooling capacity with the highest efficiency.)

Super Air Knife

Because it was an automated system, timing was critical.  The system was designed to operate one 18″ Super Air Knife for an 18″ welded tube.  For a 36″ long tube, they would turn on both the model 110018 Super Air Knives.  For their longest tube, they would activate all three Super Air Knives to cool the 48″ welded seam.  The engineer was extremely happy with the effectiveness and the consistency of the Super Air Knives that he was able to create a timing sequence in his automated operation for a repeatable and reliable cooldown of the welds.

So, why did he decide to contact EXAIR? I was thinking the same thing when he was giving high praises about the EXAIR Super Air Knives.  It was because of their compressed air system.  In another section of the plant, they would use large air vibrators to break loose powder from a hopper.  These vibrating devices would use a large quantity of compressed air when they were turned on.  During this time, the compressed air system would drop in pressure throughout the plant. This would change the amount of compressed air available for his application; affecting his timing sequence to get adequate cooling.

EXAIR Digital Flowmeter

Since that the engineer was happy with the efficiency and quality of our Super Air Knives, it was an easy decision for him to contact EXAIR about the Digital Flowmeters. He wanted to measure the amount of air flow to each Super Air Knife and continuously monitor the system for any low-flow conditions.  Since he was supplying the Super Air Knives with ½” NPT piping, he requested the model 9090 ½” Digital Flowmeter for each Super Air Knife.  I explained that the EXAIR Digital Flowmeters are very accurate and easy to install.  They have different ways to monitor the compressed air flow; 4 – 20 mA analog output, serial connection, or a Datalogger.  Since his PLC system had an analog reader, our Digital Flowmeters could supply the analog signal for flow measurements.   Currently the PLC was operating the solenoids to turn on and off sections of the Super Air Knives to cool the desired length of welds.  Now, he was looking to measure the amount of air flow with the PLC to verify that they did have adequate compressed air flow to the Super Air Knives.  If the flow was not sufficient, then he could trigger an alarm to delay the welding operation.  So, when the vibrators went offline, then they could restart their operation.

EXAIR routinely maximizes compressed air efficiency in an effective manner and I recommended, as an alternative, that he could use one 1½” Digital Flowmeter, model 9094, to monitor the air flow to all three Super Air Knives.  This would save him a lot of cost for his project in purchasing one larger Digital Flowmeter instead of three smaller ones.  Also, with the resolution of the flow meter and his ability to utilize the 4 – 20 mA analog signal, he could easily determine the required flow to one Super Air Knife, two Super Air Knives, or all three.  In the end, he was quite impressed with my recommendation to keep his system operating, even during times of depletion in his compressed air system.

At EXAIR, our first priority is to help the customer to correct their compressed air issues.  For this engineer, he was able to mount one Digital Flowmeter to monitor the compressed air flow to all three Super Air Knives. If you need real solutions to your compressed air applications, you can contact an Application Engineer at EXAIR, and perhaps we can also reduce your project cost in the process.

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

Proper Plumbing Means Proper Performance

36″ Aluminum Super Air Knife being used in a monofilament extrusion line

An EXAIR customer recently contacted me about the application shown above, using an aluminum Super Air Knife model 110036 as a component to a blow off application in a monofilament extrusion line.  The extrusions from this line are used in one of the end user’s main product lines, a personal health device used by over a billion people around the world.

The original problem of drying the extrusions can certainly be solved with the setup shown, but the output force from the knife was less than what the customer expected, and below the EXAIR published data.  We take great care in the collection and verification of our performance data, so this prompted a deeper dive into the application to determine what could be the cause.

Immediately upon seeing the application photos, there were two things which stood out.  The first was the angle of attack of the knife, and the second was the compressed air plumbing.  The angle of attack in the original setup was ~90°, nearly perpendicular to the extrusions passing through the airstream from the knife.  EXAIR always recommends an angle of attack of ~45° to increase time in contact between the airstream from the knife and the materials passing through the airstream.  Although a small adjustment, this angle significantly contributes to overall blow off performance.

5mm ID x 8mm OD tubing used to supply compressed air to the knife

But, the real issue with this application was in the compressed air supply.  The tubing for this knife was shown as having a 5mm ID and an 8mm OD, which will allow a compressed air flow of ~40 SCFM at 80 PSIG, maximum, without consideration to pipe length from the compressor.  The 36” aluminum Super Air Knife will require 104.4 SCFM at 80 PSIG operating pressure.  So, it was clear that there was a significant plumbing problem, leading to the reduced performance from the knife.

In order to prove this out, we first had to take a pressure reading directly at the knife.  When this was done, the operating pressure dropped from ~85 PSIG at the main header to less than 20 PSIG at the knife.  By taking this pressure reading directly at the knife we were able to gain valuable information as to the true operating pressure of the knife, which was far below what the customer expected, but which made perfect sense given the performance output.

The remedy in this case was to increase the size of the supply line to at least 15mm ID (approximately equivalent to a ½” schedule 40 line), and preferably to something in the range of 19-20mm (~a ¾” schedule 40 line).  Once this was done the knife operated flawlessly, and after adjusting the angle of attack this application was optimized for the best possible results.

Being able to find the source of the problem for this application was a great service to the customer.  Our engineers are well-versed in compressed air system requirements, and we’re available for help in your application if needed.  If you’d like to contact an EXAIR Application Engineer we can be reached by email, phone (1-800-903-9247), or Twitter.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

EXAIR Super Air Knives Provide more Benefit than Blower Air Knives for Green Bean Processing

A customer who was experiencing some issues with a blow off process in their facility contacted EXAIR for a solution. This customer performs post-harvest processing operations on green beans and other vegetables after they’ve been picked. They were having a problem being able to remove excess moisture after the beans had been washed in cold water and keep additional moisture from forming once packaged. The process involved green beans exiting a wash cycle and moving along a belt conveyor. From there, they are dried by a series of blower style air knives. Shortly after being blown off, the beans are weighed and bagged. Once bagged, it was determined that there was too much moisture inside the package and they could not be shipped.

One common issue with blower style knives, and the fundamental issue in this application, is that the air is heated as it moves through the blower. Depending on the type of blower, outlet air temperatures in excess of 180°F are normal. The effect, in this case, was similar to a convection oven where hot air is circulated over the food to cook it. While the beans were not exposed for a long enough time to actually cook, the high temperature air exiting the blower was enough to raise the temperature of the beans. This caused additional moisture to come out from inside the beans after they were bagged and sealed. This is a condition that the customer wanted to avoid because it would lead to the beans drying out and losing their freshness which is a quality issue for the customer.

A second problem was the turbulent airflow from the blower knives causing the beans to be blown all around on the conveyor. The customer effectively had no control over how forcefully the airflow from the blower powered air knives impacted his product. They were either full-on or full-off. This resulted in less than desirable results from a dryness perspective and also caused damage to the product from the high impact disturbance of the blower air knives.

After talking it over with the customer and learning the specifics of the application, we determined that EXAIR’s Super Air Knife Kit Model 110212SS is able to address both of these issues. The airflow would be at ambient temperature, keeping the product at a desired colder temperature. The blowing force could be precisely adjusted with a pressure regulator so as not to cause damage to the product and provide a laminar airflow to strip the water from the product.

EXAIR’s Super Air Knives are available in 303 or 316 grade Stainless Steel to meet the more stringent requirements of many food grade applications. They also operate at a far lower sound level than blower powered air knives, are more compact for easier mounting, and do not involve the purchase of a blower package and associated ducting.

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Model 11006SS Stainless Steel Super Air Knife

Our Application Engineers can work closely with you to resolve any issues you may be having, even if compressed air isn’t currently a part of the process. If your process involves washing, drying, conveying, or packaging food or other products and you can relate to any of the issues above, please keep EXAIR Corporation in mind as a viable solutions provider. Contact an Application Engineer today and we’ll do our best to help you solve your application problems.

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

Super Air Knife Math – When 72 + 72 = 75

The Super Air Knife is the latest generation of EXAIR engineered air knife that dramatically reduces compressed air usage and noise when compared to other blowoffs.

Super Air Knife Data

From the chart above, the Super Air Knife when supplied with 100 PSIG of compressed air has a sound level of just 72 dBA (A-weighted decibel scale) when measured from 3′ away.  72 dBA is a moderate sound level, and some common comparisons are ‘normal speaking voice’ at 70 dBA and ‘living room music’ at 76 dBA.

For many processes, such as a bottling line drying operation, a pair of the air knives delivers the best performance. When asked, “what is the sound level for (2) of the knives,” a little Acoustic Engineering is in order. Because the decibel scale is logarithmic, the result is not as simple as adding 72 + 72 = 144.  144 dBA is in the range of a jet aircraft take off! Thankfully, both the actual sound level and the numerical value are determined another way.  I’ll spare you a lot of the math but the equation is as below.

Capture

… where SL1, SL2, SL3 are the sound levels in dBA of the each sound makers, for as many that are being combined.

In the case of (2) Super Air Knives operated 100 PSIG, the combined sound works out to be a quiet 75.0 dBA — a powerful, efficient and quiet product ideal for many applications and process within the manufacturing environment.

Super Air Knife

Super Air Knife

As a helpful rule of thumb- combining any (2) items will yield an increase of 3 dBA, combining (3) results in a rise of 4.8 dBA, and combining (4) results in a 6 dBA rise over just (1) of the items.

The Super Air Knives have been successfully used in a wide range of applications, including part drying, sheet and conveyor cleaning, web cooling, scrap removal, pre-paint dust blowoff, and many, many more.

To discuss your application and how an EXAIR Intelligent Compressed Air Product can make your process better and quieter, 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

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Twitter: @EXAIR_BB

 

Another Label Problem, Another Super Air Knife Solution

Last week, I used this space to brag on our Super Air Knives, and how they solve a common problem in bottling applications: label adhesion. This week, I have another opportunity to brag on the Super Air Knife. AND it’s another solution to a labeling problem.

Self-adhesive labels are commonly applied to goods are they travel on high speed conveyors. If they’re going onto a flat, smooth surface (like a box,) it’s pretty easy…they come right off a timed roller with a wheel that presses them in place. This can even work with round containers (like drums, jars, or bottles) by putting an idler on the wheel to take up the slack as it rolls over the rounded surface.

Sometimes, the label needs to go around the corner of a box. This requires the roller to turn that corner. Or two rollers to pull the old “one-two” on the label. Either way, that’s going to slow down the speed at which the conveyor can be run. And time is money.

Enter the Super Air Knife…mount it so it’s blowing at the corner. The laminar, high velocity air flow will then press the label in place on each adjacent surface.

With a laminar curtain of air traveling as fast as 13,500 feet per minute, an EXAIR Super Air Knife is the ideal solution for corner labels.

Another benefit: when supplied with clean, dry air, the Super Air Knife will run darn near indefinitely, maintenance-free. Those rollers get dirty, and the bearings will fail eventually. Same with the idlers, and they’ll need adjusted from time to time.

Super Air Knife Kits include a Shim Set, Filter Separator, and Pressure Regulator…everything you need for long term operation & performance.

The Super Air Knives come in lengths from 3″ to 108″ – if you’d like to discuss how these, or any of our Intelligent Compressed Air Products, can make a difference in your processes, give us a call.

Russ Bowman
Application Engineer
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Super Air Knives Make Beer Bottle Labels Stick; EFC Optimizes Efficiency

The Super Air Knife has been featured as the cover photo of every EXAIR Compressed Air Products catalog since I got here in 2011…except for Catalog #26 in 2013, which featured the Super Ion Air Knife. BIG difference, right there.

The highlighted application photos may change from catalog to catalog, but one that always remains is the iconic (I think, anyway) image of the Super Air Knives blowing off the orange soda bottles:

This is a darn-near ‘textbook’ application for the Super Air Knives…the even, laminar flow wraps around the bottles, stripping moisture away. Among other reason why this is important, it improves the next step in the process – the labels stick better.

One of the many simple and effective ways an EXAIR Super Air Knife is commonly used.

In my younger, intemperate days, I’d join my friends at a popular watering hole to celebrate special occasions like…well, Tuesday, for example. Sometimes, there’d be a ballgame on the TV, or lively conversation, to entertain us. Other times, we’d make a game out of trying to separate the labels from the beer bottles, in one piece.

Some years later, I tried to teach my young sons this game…except with root beer bottles. It didn’t work near as well, because these labels adhered much tighter to the root beer bottles in my dining room than the ones on the beer bottles at the bar.

Some years after that (those boys are teenagers now,) I became an Application Engineer at EXAIR, and found out that this drying-the-bottles-to-make-the-labels-stick-better thing was for real, because I got to talk to folks in the bottling business who told me that the Super Air Knives had made all the difference in the world for their operation.

Just the other day, I had the pleasure of helping a caller who operates a micro-brewery, and had just installed a set of 110009 9″ Aluminum Super Air Knives for the express purpose of (you guessed it, I hope…) making their labels stick better. The only thing that could make it better, according to them, was if they could use less compressed air, and they were interested in what the EFC Electronic Flow Control could do for them.

Click here to calculate how much you can save with an EXAIR EFC Electronic Flow Control.

As a micro-brewery, their production lines don’t run near as fast…nor do they want them to…as some of the Big Names in the business. As such, there’s some space between the bottles on the filling lines, and they thought that turning the air off, if even for a fraction of a second, so they weren’t blowing air into those empty spaces, would make a difference. And they’re right…it’s a simple matter of math:

Two 9″ Super Air Knives, supplied at 80psig, will consume 26.1 SCFM each (52.2 SCFM total). This microbrew was running two 8 hour shifts, 5 days per week. That equates to:

52.2 SCFM X 60 minutes/hour X 16 hours/day X 5 days/week X 52 weeks/yr = 13,029,120 standard cubic feet of compressed air, annually.  Using a Department of Energy thumbrule which estimates compressed air cost at $0.25 per 1,000 SCF, that’s an annual cost of $3257.00*

Let’s say, though, that the micro-brewery finds that it takes one second to blow off the bottle, and there’s 1/2 second between the bottles.  The EFC is actually adjustable to 1/10th of a second, so it can be quite precisely set.  But, using these relatively round numbers of 1 second on/0.5 seconds off, that’s going to save 1/3 of the air usage…and the cost…which brings the annual cost down to $2171.00*

*As a friendly reminder that the deadline to file our USA income tax returns is closing fast, I’ve rounded down to the nearest dollar.  You’re welcome.

That means that the Model 9055 EFC Electronic Flow Control (1/4 NPT Solenoid Valve; 40 SCFM) with a current 2017 List Price of $1,078.00 (that’s exact, so you know) will have paid for itself just short of one year. After that, it’s all savings in their pocket.

If you’d like to find out how much you can save with EXAIR Intelligent Compressed Air Products, give me a call.

Russ Bowman
Application Engineer
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Super Air Knife Cleans Rotary Mesh Screen

Last week I worked with an OEM who was looking for a more effective method of cleaning the wire mesh on the rotary screeners they manufacturer. Rotary screens, also know as trammel screens (think of a washing machine drum), separate solid materials by passing the parts through a rotating perforated cylinder, typically elevated on the feed side, to help keep the material moving through to the exit side. With the spiraling motion of the cylinder, the smaller parts begin to pass through the mesh screen, where they are commonly recovered in some type of hopper or fed onto a conveyor system.

Example of a screener/trammel used to separate gravel and sand.

In this particular application, their proprietary machine design features a non-vibratory system used in separating pet foods. The screener is working as far as separation but the problem they were having was as the pet food passes through the rotating mesh cylinder, it leaves an oily residue on the screen. Due to this being a food application, they are unable to use any type of cleaning brush over concerns that some of the fibers may break loose, contaminating the finished product, so they were looking at using air as an alternative solution.

I recommended they incorporate our 48″ Stainless Steel Super Air Knife in the application. The Super Air Knife is our most efficient unit, as far as compressed air usage, using only 2.9 SCFM per inch of knife when operated at 80 PSIG supply. The end to end, high velocity airflow produced by the unit would span the 48″ width of the screen. The top of their machine is removable, so I suggested they also incorporate our Model # 9060 Universal Mounting System. The Model # 9060 provides for an easy installation as well as a simple way to change the distance and direction of the knife to provide the most effective blowoff. With the cover off, they could easily move the knife into position to perform the cleaning.

Super Air Knife mounted to Universal Mounting System. (note: longer knives require multiple systems)

If you are considering an Air Knife to use in your process and would like to discuss the application, please give us a call at 800-903-9247.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

Trommel and sluicebox image courtesy of Roy Luck via Creative Common License

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