The Super Air Knife and the Amplification Ratio

Super Air Knife

The EXAIR Super Air Knife has a 40:1 amplification ratio.  So, what does this mean?  The definition of ratio is a relation between two amounts showing the number of times one value is contained within the other.  For the Super Air Knife, it is a value that shows the amount of ambient air that is drawn into the compressed air.  With an amplification ratio of 40:1, that means that there are 40 parts of ambient air for every 1 part of compressed air; which helps make the most efficient air knifes available in the market.

Super Air Knife has 40:1 Amplification Ratio

Most people think that compressed air is free, but it is most certainly not.  Because of the amount of electricity required, compressed air is considered to be the fourth utility for manufacturing plants.  To save on utility costs, it is important to use compressed air very efficiently.  So, the higher the amplification ratio, the more efficient the compressed air product.  Manufacturing plants that use open fittings, copper tubes, and drilled pipes for blowing are not efficiently using their compressed air system.  These types of products generally have between a 5:1 to 10:1 amplification ratio.  When EXAIR began, they knew that there was a better way in saving compressed air by increasing the amplification ratio.

EXAIR initially created a line of air knives called the Standard Air Knife and Full-Flow Air Knife.  They utilize a Coanda effect to blow air at a 30:1 amplification ratio.  These air knives were much more efficient for blowing air than the open fittings, tubes and drilled pipes.  But, EXAIR knew that we could design a more efficient air knife, the Super Air Knife which has a 40:1 amplification ratio.

I like to explain things in every day terms.  For this analogy, the amplification ratio can be represented by gas mileage.  Like your car, you want to get the most distance from a gallon of gas.  With your compressed air system, you want to get the most utilization for blowing.  With an EXAIR Super Air Knife, it has a 40:1 amplification ratio.; or, in other words, you can get 40 mpg.  If you use the EXAIR Standard or Full Flow Air Knife, you can get 30 mpg.  But, if you use drilled pipes, copper tubes, etc. for blowing, then you are only getting 5 to 10 mpg.  If you want to get the most “distance” from your compressed air system, you want to check the “gas mileage” of your blow-off components.

EXAIR can “tune up” your blow-off systems to make them efficient and safe by contacting an Application Engineer.  We will be happy to help you.

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

EXAIR’s Super Air Knife: The Benefits of Laminar Airflow

SSPlumbingKitpr_cheese-559x

When a wide, even, laminar flow is necessary there isn’t a better option available on the market than EXAIR’s Super Air Knife. We’ve been manufacturing Air Knives for over 35 years, with the Super Air Knife making its first appearance back in 1997. Since then, the Super Air Knife has undergone a few enhancements over the years as we’re constantly trying to not only introduce new products but also improve on the ones we have. We’ve added new materials, longer single piece knives, as well as additional accessories. But, by and large, the basic design has remained the same. As the saying goes: “If it ain’t broke, don’t fix it!”.

What really sets EXAIR’s Super Air Knife above the competition is the ability to maintain a consistent laminar flow across the full length of the knife compared to similar compressed air operated knives. This is even more evident when compared against blower operated knives or fans. A fan “slaps” the air, resulting in a turbulent airflow where the airflow particles are irregular and will interfere with each other. A laminar airflow, by contrast, will maintain smooth paths that will never interfere with one another.

turbulent vs laminar
A representation of a turbulent flow on top, and laminar flow on bottom

The effectiveness of a laminar airflow vs turbulent airflow is particularly evident in the case of a cooling application. The chart below shows the time to cool computers to ambient temperatures for an automotive electronics manufacturer. They used a total of (32) 6” axial fans, (16) across the top and (16) across the bottom as the computers traveled along a conveyor. The computers needed to be cooled down before they could begin the testing process. By replacing the fans with just (3) Model 110012 Super Air Knives at a pressure of just 40 psig, the fans were cooled from 194°F down to 81° in just 90 seconds. The fans, even after 300 seconds still couldn’t remove enough heat to allow them to test.

air-knife-cooling
While the fans no doubt made for large volume air movement, the laminar flow of the Super Air Knife resulted in a much faster heat transfer rate.

Utilizing a laminar airflow is also critical when the airflow is being used to carry static eliminating ions further to the surface. Static charges can be both positive or negative. In order to eliminate them, we need to deliver an ion of the opposite charge to neutralize it. Since opposite charges attract, having a product that produces a laminar airflow to carry the ions makes the net effect much more effective. As you can see from the graphic above showing a turbulent airflow pattern vs a laminar one, a turbulent airflow is going to cause these ions to come into contact with one another. This neutralizes them before they’re even delivered to the surface needing to be treated. With a product such as the Super Ion Air Knife, we’re using a laminar airflow pattern to deliver the positive and negative ions. Since the flow is laminar, the total quantity of ions that we’re able to deliver to the surface of the material is greater. This allows the charge to be neutralized quickly, rather than having to sit and “dwell” under the ionized airflow.

With lengths from 3”-108” and (4) four different materials all available from stock, EXAIR has the right Super Air Knife for your application. In addition to shipping from stock, it’ll also come backed up by our unconditional 30-day guarantee. Test one out for yourself to see just how effective the Super Air Knife is on a wide variety of cooling, cleaning, or drying applications.

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

Super Air Knives Provide Dry Surface for Printing

I’ve always liked Halloween.  My friends and I got to go trick-or-treating together around the neighborhood, under the supervision of a parent or two, until one year when we were deemed old enough to go around the immediate neighborhood (gasp) by OURSELVES!!!

You need to know that, for any of our Moms, that was a HUGE investment in trust they were putting in us. One that, I’m afraid was undeserved. See, we’d all heard rumors of “tricks” from some cool older kids, and were eager to try our hands at it. Now, we were a relatively mild mannered bunch. We certainly weren’t going to break anything or hurt anyone. But the tales of soaping windows had an irresistible appeal…so, after we donned our costumes that evening, we all sneaked a bar of hand soap out of the house, and set about on our great adventure. Which was not so great, for a couple of reasons:

First, Halloween that year fell on a particularly drizzly night.  We weren’t in danger of a rain-out, but there was a layer of “wet” on everything…especially the windows on which we planned to display our art. That didn’t stop us from trying, though…it just wasn’t near as effective, or fun, as we’d hoped.  Basically, we got some weak smudges here and there.

Second, our parents & neighbors were a lot more savvy than we’d expected. I’m not even sure what happened first…the discovery of the missing bars of soap, or the neighbors calling our parents to tell them what we were up to. We were all punished according to our respective families’ customs, and the next year, we were the oldest trick-or-treaters out there under adult supervision.

I think about that night whenever I see one of those “World’s Dumbest Criminals” shows, but it popped into my head recently while discussing a Super Air Knife application with a customer.  The caller worked in facility that produced pizza dough, and had recently implemented a quality tracking system that applied a temporary code to the rims of the plastic trays that carried the loaves of dough along a conveyor.   Thing is, the trays could still be wet from the wash/rinse cycle, and the ink (which is water soluble and is supposed to be removed by the washer anyway) really, really needs a pretty dry surface, or it’s just going to be a weak, smudgy mess, much like the great Window Soap Fail of 1970-something.

They purchased two Model 110003SS 3″ Stainless Steel Super Air Knives and installed one on each side of the conveyor, just after the rinse tunnel.  The Super Air Knives blow off the rims of the trays, leaving a clean, dry surface for the printer.

EXAIR Super Air Knives come in a wide variety of lengths to suit a wide range of applications.

EXAIR Super Air Knives come in a variety of materials, lengths from 3 inches to 9 feet, and are the quietest & most efficient compressed air operated blow off products on the market today.  If you’d like to find out more about they can help you, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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EXAIR Standard Air Knife Overview

EXAIR manufactures a variety of different air knives in several different materials of construction. For the purposes of this blog, I’ll be discussing the Standard Air Knife. EXAIR’s Standard Air Knife was the first rendition of the Air Knife family. The Standard Air Knife utilizes what’s known as the Coanda Effect, or the propensity of a fluid to adhere to a curved surface. The airflow from the Standard Air Knife exits the nozzle outlet and ends up perpendicular to the outlet. This air motion that is created also allows the knife to entrain ambient air at a rate of 30:1, 30 parts ambient air to one part compressed air, which maximizes the force while minimizing compressed air consumption.

gh_Standard Air Knife 750x696
Standard Air Knife

Due to this air entrainment, air savings of 40%-90% are possible when replacing homemade blowoff devices such as drilled or slotted pipe. Return on your investment is seen typically within weeks rather than months or years.

In addition to significant air savings, the Standard Air Knife also dramatically reduces “wind shear” by gradually introducing the entrained air into the primary airstream. The exiting air is also laminar, not turbulent. These two features help cut noise levels in HALF! With drilled pipes or open tube jets, there’s little to no air amplification and the sound levels are extremely high. These sound levels typically will be far outside of OSHA’s acceptable level of noise for operators. Fines can be handed out by OSHA under directive 29 CFR 1910.95.

The Standard Air Knife is available in lengths from 3”-48” in both aluminum and Type 303SS. They’re an excellent choice for applications such as blowing or removing debris, drying or cooling parts, or environmental separation. ¼ NPT female ports are located at either end of the knife and the force and flow through the knife is adjustable. For gross adjustments to the airflow, we offer shim sets that contain a .001”, .003”, and .004” shim for aluminum or (3) .002” shims for the stainless steel knives. Shims can be stacked together to create even more flow, or in the case of the aluminum knives the .001” shim can be installed to cut the flow and force in half. In addition to offering the shim sets, a pressure regulator can be installed right at the point of use to “dial in” the exact pressure that you need for the application.

Standard Air Knife Kit
Standard Air Knife Kit

If you have drilled or slotted pipe blowoffs in your facility, you’re simply leaving money on the table through high energy costs. Take advantage of the unconditional 30 day guarantee for all stock products and see just how much you can save with EXAIR’s Standard Air Knife.

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

Is It Safe To Use Compressed Air?

Think about it…compressed air is, by definition, gas under pressure: potential (stored) energy.  This energy is intended to do work, like operation of pneumatic tools, actuation of pneumatic cylinders, debris removal with an air gun or blow off device, and (even though I haven’t done it in a while) my personal favorite:

High pressure compressed air is meticulously made, prepared, and stored to ensure the number of surfaces equals the number of dives.

Uncontrolled, unplanned, or accidental releases of stored energy (regardless of the source) are inherently dangerous, and great care must be taken to guard against such incidents.  This is accomplished, primarily, in three areas:

*Operation.  This might be the most prevalent, because it involves the greatest number of personnel (e.g., everyone) as well as the ways compressed air is used (e.g., all of them.)  It’s also the area where the most involved people (the operators) have the most control:

  • Personal protection.  Don’t even think about operating a compressed air device without eye protection.  Ever.  Hard stop.  Also, if the operation involves flying debris, a full face shield, long sleeves, gloves, etc. might be called for.  Hearing protection may be required as well…keep in mind, even if an engineered device (like any of EXAIR’s Intelligent Compressed Air Products) generates a relatively low sound level, the impingement noise of the air flow hitting the object can reach dangerous levels.
  •  Personnel cleaning is prohibited.  The risk of injury to the eyes, respiratory system, and other parts is just too great to rely on personal protective equipment that’s designed for use while discharging compressed air AWAY from the body.  While this is expressly prohibited in certain situations, OSHA has long recognized it as good practice for all industries.
  • No horseplay.  ’nuff said.  Plenty of better ways to have fun at work.

*Design.  This one usually has the advantage of being traceable to a small number of people, and is also the one that’s most likely to be documented.  This is where it starts…if the system is designed to fail, it doesn’t matter how much care the operators take:

  • Supply lines, fittings, and hoses must be rated for use with compressed air, up to and exceeding the maximum discharge pressure of the air compressor.
  • This goes for any tools, blow off devices, components, etc., serviced by the air system.  The only thing worse than a component failing is a component failing in your hand.
  • Shut off valves should be located as close as practical to point(s) of operation.  This allows you to quickly secure the flow of compressed air to a failed component, hose, etc., and prevent further damage or risk of injury.
  • Hoses shouldn’t be run across the floor, where they can become a trip hazard or subject to damage from stepping on them.   This is a surefire way to find out the value of shut off valves (see above.)

*Product specification.  Or, more simply put, using the right tool for the job.  A broader discussion could include efficiency and performance, but we’ll stay within the confines of safety for the purposes of this blog:

  • Be mindful of dead end pressure.  Blow off devices, especially hand held ones like air guns, are oftentimes fitted with a simple open-end discharge.  If this is pushed into a part of the body, the pressurized air can break the skin and cause an air embolism.  This is a serious injury, and can be fatal if it reaches the heart, lungs, or brain.
    • This is a key consideration to OSHA Standard 1910.242(b), which limits the downstream pressure when compressed air is used for cleaning to 30psi.
    • EXAIR products are compliant with this Standard by design…there’s always a relief path for the air pressure; they can’t be dead ended.
Because the compressed air exits through a series of holes, recessed between a ring of fins, any attempt to block the air flow will simply send it in another direction.
  • Harmful sound levels are a consideration as well.  As stated above, hearing protection is required in many cases, but sound levels can be mitigated through the use of engineered products.  EXAIR Intelligent Compressed Air Products, as a result of their high entrainment, generate a boundary layer of air flow that leads to dramatically lower sound levels than a similar-sized open end blow off device.

If you’d like to explore ways to make your compressed air system safer, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Compressed Air Uses In Industry

Air Compressor

There are so many uses for compressed air in industry that it would be difficult to list every one of them as the list would be exhaustive.  Some of the uses are the tools used in production lines, assembly & robotic cells, painting, chemical processing, hospitals, construction, woodworking and aerospace.

It is considered as important as water, electricity, petroleum based fuels and often referred to as the fourth utility in industry. The great advantage of compressed air is the high ratio of power to weight or power to volume. In comparison to an electric motor compressed air powered equipment is smoother.  Also compressed air powered equipment generally requires less maintenance, is more reliable and economical than electric motor powered tools.  In addition they are considered on the whole as safer than electric powered devices.

Even amusement parks have used compressed air in some capacity in the operation of thrill rides like roller coasters or to enhance the “wow factor” of certain attractions. Compressed air can be found in your dentist’s office where it is used to operate drills and other equipment. You will find compressed air in the tires on your car, motorcycle and bicycles. Essentially, if you think about it, compressed air is being used nearly everywhere.

Here at EXAIR, we manufacture Intelligent Compressed Air Products to help improve the efficiency in a wide variety of industrial operations. Whether you are looking to coat a surface with an atomized mist of liquid, conserve compressed air use and energy, cool an electrical enclosure, convey parts or bulk material from one location to another or clean a conveyor belt or web, chances are we have a product that will fit your specific need.

Atomizing nozzle
Atomizing Nozzles Can Apply Even Coatings
Super Air Amplifier
Air Amplifiers pull in a large volume of ambient air to increase air flow volume and are great for cooling applications!
Heavy Duty Threaded Line Vac
For conveying heavy or abrasive products the Heavy Duty Threaded Line Vacs have male NPT Threads to make permanent and rigid installation into a piping system a breeze.

If you would like to discuss quiet, efficient compressed air products, I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer
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Cleaning Glass After a Cutting Machine, Super Air Knives to the Rescue

Glass cutting machine

A glass cutting facility was having issues with small shards of glass leaving the cutting machine.  After scribing and breaking individual panes, small pieces of glass would come apart from the edges of the glass.  These glass fragments would go downstream causing cuts on transport wheels as well as creating blemishes in the surface of the glass.  They needed a non-contact way to clean the glass as the panes left the cutting machine.

Their operation started with a 156” (3.96m) wide sheet of glass placed at the front of the cutting machine.  The glass was moved into the machine where it would scribe different dimensions and sizes to minimize any scrap.  As the machine was scribing, a protective separator would close off the cutting machine to protect the operators.  Once finished, the protective separator would open, allowing the glass sheet to exit on the other side of the machine.  As the glass was coming out, a break device would “crack” the glass panes on the scribed lines.  They wanted to clean the surface as the glass sheet was coming out to keep the fragments in the machine.

EXAIR Super Air Knife model 1100108

EXAIR has always been the leader in manufacturing the longest air knives in the industry.  The EXAIR Super Air Knives can be manufactured up to 108” (2.74m) long in one continuous length.  But, for this application, we had to tackle it in a different manner to reach across the entire width of 156” (3.96m).  EXAIR had a solution, the model 110900 Coupling Bracket Kit.  This can combine aluminum Super Air Knives for additional length.  It has all the hardware to securely attach the Super Air Knives end-to-end to get a continuous air flow along the entire length.  With the Coupling Bracket Kit, I recommended a model 110072, 72” (1.83m) long aluminum Super Air Knife with a model 110084, 84” (2.13m) aluminum Super Air Knife.  The customer was now able to clean the entire section of glass just in front of the exit of the cutting machine.  With the air knives directed to blow at a slight angle in the counter-flow direction, this non-contact form of cleaning was able to keep the shards inside the machine without scratching the surfaces.

Air Knife Coupling Bracket Kit

The Super Air Knives are designed to be the most efficient air knives in the market place.  It has a 40:1 amplification ratio which entrains 40 parts of ambient air to every 1 part of compressed air.  So, it will save you compressed air which in turn, will save you money.  Here at EXAIR, we like to go one step further for our customers.  EXAIR offers an Optimization product line to save the customer even more money, to reduce even more waste, and to become even more energy efficient.  For this customer above, I recommended an Electronic Flow Control, EFC.  This uses a photoelectric sensor to turn on a system only when compressed air is needed.  It is a small PLC unit with a timer control.  I recommended the model 9064-2 which has two solenoid valves to operate each Super Air Knife.  The photoelectric sensor can be adjusted for light and dark object, but for glass, we had to look for an alternative way.  I was able to have the customer place it on the protective separator.  Now, the Super Air Knives will remain turned off until after the scribing was completed. When the separator moved up, it would trigger the timing operation of the EFC.  By adding the EFC to their system, they were able to reduce the amount of compressed air by one-half.

click on picture for mor information

If you have a wide area that needs to be blown off, cooled, or dried; EXAIR may have a solution for you.  For the customer above, EXAIR was able to combine Super Air Knives with optimization for an efficient and effective way to clean a wide surface.  If you would like to discuss a solution for your “wide” application, you can contact an Application Engineer at EXAIR to discuss.

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