Super Air Knife Plumbing Kits Ensure Proper and Optimum Operation

The EXAIR Super Air Knife is a Highly Engineered and intelligently designed point of use compressed air powered device that delivers a 40:1 air amplification ratio!  This simply means that for every one part compressed air supplied to an EXAIR Super Air Knife it will entrain 40 parts ambient air into the exiting compressed air stream.  Almost as good as “money for nothing”!  Also the EXAIR Super Air Knife is designed to provide an even or “laminar” flow of air.  This is due to it being an intelligent, highly engineered compressed air product.

However if an EXAIR Super Air Knife is not connected to the compressed air supply with the appropriate number of inlet ports being fed, poor and/or erratic performance is likely.  This would manifest itself as uneven air flow and lower performance from the air knife.  In order to make this plumbing easier we offer optional plumbing kits for all Super Air Knives starting with the 24″ length all the way up to the 108″!  The 24″ and longer Super Air Knive’s require that compressed air must be supplied to multiple air inlets along its length for optimal performance.  This will ensure that the air flow is laminar and the force is even across the entire length of the Super Air Knife.  All our products are shipped with an installation guide referencing the proper recommended pipe sizes for various lengths of supply pipe.

The Plumbing Kits for Aluminum Super Air Knives provide properly sized Nitrile/PVC Hoses, Brass Fittings and a Pressure Gauge which monitors the inlet pressure to the air knife.  If the gauge shows a pressure drop when the Super Air Knife is turned on this indicates that there is an air starvation issue.  For the 303SS, 316SS and PVDF Air Knives the Plumbing Kits contain 5/8 OD SS tubing X .034 wall thickness tubing and SS fittings.

AirKnifePlumbing

So when ordering your next Super Air Knife be sure to designate the Plumbing Kit to ease your installation and to ensure top performance.

When you are looking for expert advice on safe, quiet and efficient point of use compressed air products give us a call.   We would enjoy hearing from you!

Steve Harrison
Application Engineer
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Henri Coanda: June 7, 1886 – November 25, 1972

Henri Coanda was a Romanian aeronautical engineer best known for his work on the fluid dynamic principle with his namesake, the Coanda effect. Before this, Henri patented what he labeled as a jet engine.

Jet Engine 1
Jet Engine

Henri’s patent (French patent No. 416,54, dated October 22, 1910) gives more information into how he envisioned the motor working. When air entered the front, it passed through different cavities that caused the air stream to first contract and then expand. In Henri’s opinion this contraction and expansion converted the air’s kinetic energy into potential energy.  The air ultimately was channeled to a diffuser where it was discharged.

Henri stated that the efficiency of this engine could be improved by heating the air in the cavities, Henri’s logic was that this would increase the pressure of the air passing through.

What is obviously lacking in the patent (including identical ones taken out in England and the United States) is any mention of injecting fuel, which in a true jet engine would combust with the incoming air. Judging only by Henri’s patent, it was little more than a large ducted fan and it could not have flown.  Throughout Henri’s career he changed his story many times on whether this plane actually flew or not.

Not to cast too much shade on Henri’s accomplishments he did discover the Coanda effect.  The Coanda effect states that a fluid will adhere to the surface of a curved shape that it is flowing over.  One might think that a stream of fluid would continue in a straight line as it flows over a surface, however the opposite is true.  A moving stream of fluid will follow the curvature of the surface it is flowing over and not continue in a straight line. This effect is what causes an airplane wing to produce lift, and enhance lift when the ailerons are extended while at lower air speeds such as occurs during takeoff and landing.

plane-1043635_1920
Ailerons positioned for cruising speed

EXAIR uses the Coanda effect to offer you highly engineered, intelligent and very efficient compressed air products.  Our designs take a small amount of compressed air and actually entrain the surrounding ambient air with the high velocity exiting compressed air stream to amplify the volume of air hitting a surface.

nozzle_anim_twit800x320
Surrounding Air Captured (Entrained) In Exiting Compressed Air Stream
How Air Knife Works
1). Compressed Air Inlet, 2). Compressed Air Exiting EXAIR Super Air Knife 3). Surrounding Air Being Entrained With Exiting Compressed Air Stream
Super Air Amplifier
EXAIR Super Air Amplifier Entraiment

When you are looking for expert advice on safe, quiet and efficient point of use compressed air products give us a call.   We would enjoy hearing from you.

Steve Harrison
Application Engineer
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Video Blog: Gen4 Super Ion Air Knife Conversion

The video below provides details on the simple conversion to the new Gen4 style Super Ion Air Knife from the previous style or the addition of a Gen4 Ionizing Bar to an existing Super Air Knife to add static elimination to an existing blow off.

If you have questions about the Gen4 Super Ion Air Knife or any of the 16 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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Mounting Options for EXAIR’s Super Air Knife

 

Super Air Knife installed using the Universal Air Knife Mounting system.

The key towards a successful Super Air Knife  application is making sure it’s installed properly. Using the chart on the installation & maintenance guide to ensure your plumbing is properly sized is the first step. This ensures that an adequate volume of compressed air is able to reach the knife, without causing an unnecessary pressure drop.

super air knife pipe size

Once you’ve planned out the distribution of compressed air to the Super Air Knife you must consider how to mount it in your application. Across the bottom of the knife are ¼-20 tapped holes spaced out evenly every 2” along the knife. A 30” Model 110030 will have (15) holes, a 60” 110060 (30), and so on. These holes are tapped through to allow you to mount the knife to best suit the application.

If you’d rather have a more “out of the box” solution, EXAIR offers our Universal Mounting System. It gives you the ability to mount onto a conveyor rail or machine frame and provide precise positioning for all of EXAIR’s Super Air Knives, Standard Air Knives, Full-Flow Air Knives, as well as the Standard and Super Ion Air Knives. Each system comes with (2) 1/2-13 x 5” long bolts, 2’ long stainless steel rod, mounting hardware, angle bracket, and adjustable swivel clamps. Check out the video below for a demonstration of the adjustability you can achieve with the Model 9060 Universal Mounting System.

Another critical factor to consider is the mounting position of the knife. If the material is moving along a conveyor, the knife should be positioned as closely as possible with the airflow oriented against the direction of travel of the material. By doing so, we increase the amount of time that the material is in contact with the airflow. We call this term counter-flow. Maximizing the time in contact with the laminar airflow from the Super Air Knife gives us the best chance at a successful result. Whether we’re talking about cooling, drying, or cleaning, the longer that the material is in contact with the laminar airflow the better the results will be.

air knife counter flow

In this photo, the Super Air Knife is positioned upside down at an angle above a conveyor belt, against the direction of travel. We recommend installing the Super Air Knife in this orientation as it allows the airflow to get closest to the material being blown off. They’ve used their own brackets to allow the knife to be adjusted when blowing residual dust off of a conveyor for a mining application. The dust on the belt would build up over time and was difficult to remove. By installing a Super Air Knife, they’re able to continuously remove the dust from the conveyor belt before it becomes a problem.

If you have an application that would be better served with one of EXAIR’s Super Air Knives, give us a call. An Application Engineer is ready to assist you in selecting the proper material, length, and mounting method.

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

Where Can’t I Use An EXAIR Super Air Knife?

Considering the material options available, there are very few places you CAN’T use a Super Air Knife. Most often, we find those to be due to extreme elevated temperature, like this one:

A caller from a glass manufacturing company wanted to replace a drilled pipe in a cooling application. Thing is, glass makers deal with their product in molten form, which is HOT…the ambient temperature that this drilled pipe is exposed to reaches 800°C, or 1,472°F.  Because of the temperature, and corrosive atmospheric elements (SO2 is also present, as if the heat wasn’t bad enough,) they have to replace the drilled pipe every so often, and wanted to explore other solutions.

Now, this was a rare case where a Super Air Knife would not have necessarily offered an improvement over a drilled pipe:

  • The air flow from the drilled pipe is primarily straight from their compressed air system.  Since the Super Air Knife entrains air from the surrounding environment at a rate of 40:1, the resultant flow would be very close to the 800°C ambient temperature…and not as effective at cooling as the much cooler compressed air supply temperature.  It wouldn’t have helped to reduce consumption if it simply didn’t work.
The Super Air Knife takes a supply of compressed air (1), discharges it through a gap that runs the length of the Air Knife (2,) and entrains an enormous amount of “free” air from the surrounding environment (3.)
  • Another great thing about the Super Air Knife is that it’s dramatically quieter than any other method of compressed air blowing.  Of course, if you find yourself in a 800°C sulfur dioxide environment, hearing protection is the least of your concerns.

    When supplied at 80psig, the EXAIR Super Air Knife produces a hard hitting, powerful curtain of air, with a sound level of only 69dBA.
  • EXAIR Super Air Knives (and all of our Intelligent Compressed Air Products) are compliant with OSHA Standard 1910.242(b) which limits the outlet pressure of a compressed air blowing device used for cleaning to 30psi…this protects personnel from high velocity debris and air embolisms.  Again, not a concern in an unoccupied (and uninhabitable) space.

Again, that’s a rare case…a very specific exception to a broadly inclusive rule, in light of the options EXAIR offers.  Consider:

  • Aluminum Super Air Knives are durable, lightweight, and suitable for most any installation in a typical industrial/commercial environment.  They’re good to 180°F (82°C) and are fitted with stainless steel fasteners to eliminate corrosion in damp environments.  The polyester shim can be replaced with a custom stainless steel shim, increasing the temperature rating to 400°F (204°C) if needed.
  • Type 303 Stainless Steel Super Air Knives offer higher tensile strength, and are good to 800°F (427°C.)  They are popular in applications with factors like high heat, corrosive environments, frequent spray down cleaning, outdoor installations, etc.
  • Type 316 Stainless Steel Super Air Knives are often specified in food and pharmaceutical applications, due to their even higher resistance to chemical attack and pitting.  They’re also rated to 800°F (427°C) and have the same high tensile strength as the Type 303 Stainless Steel models.
  • Some situations call for better corrosion resistance than these high grades of austenitic stainless steels – and that’s where EXAIR’s PVDF Super Air Knife comes in.  Fitted with PTFE shims and Hastelloy© C-276 hardware, they are especially well suited for processes involving the harshest of corrosive agents, such as electroplating, solar cell manufacturing, and lithium ion battery production, just to mention a few.  They would, in fact, be ideal for the SOenvironment at the glass factory, if it weren’t for the temperature…they’re rated to 275°F (135°C.)

Performance is identical, regardless of construction materials, and all EXAIR Super Air Knives come in lengths from 3″ to 108″ (except PVDF…those go up to 54″ lengths) and ship quickly from our well maintained inventory.  Aluminum and Stainless Steel models can be coupled together for even longer flow lengths.  Plumbing Kits and Universal Air Knife Mounting Systems make for easy and quick installation, and all Super Air Knife Kits come with an Automatic Drain Filter Separator, a Pressure Regulator, and a Shim Set for reliability, clean air flow, and total performance control.

If you need a reliable, cost effective, safe, quiet, and efficient curtain of air, EXAIR’s Super Air Knives are what you’re looking for.  If you’d like to discuss a particular application and/or product selection, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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The Super Air Knife Vs. a Homemade Drilled Pipe Solution

A drilled pipe has been used for many years to blow compressed air across a span for cleaning, cooling, and drying.  They are a simple tool that was created from spare parts and many holes.  The cost to make this type of product is not expensive, but to use this product in your application is very expensive.  Similarly, an incandescent lightbulb is inexpensive to purchase, but it will cost you much more in electricity than a LED light bulb.  Since 1983, EXAIR has been innovating safe and efficient products to be used in compressed air systems.  In this blog, I will compare the drilled pipe with the Super Air Knife.

Even though you can find the components relatively easily to design your own drilled pipe, this blow-off design is very costly and stressful to your compressed air system.  Typically, the holes along the pipe are in a row next to each other.  As the airstream leaves from each hole, it will hit the airstream from the one next to it.  This will cause turbulent air flows which has inconsistent forces and loud noises.  Also, with turbulent air flows, the ability to entrain the surrounding ambient air is very small.  We call this the amplification ratio.  The higher the amplification ratio, the more efficient the blow-off device is.  For a drilled pipe, the amplification ratio is near 3:1 (3 parts ambient air to 1 part compressed air).

A colleague, Brian Bergmann, wrote a blog about the amplification ratio of the EXAIR Super Air Knife.  (Read it HERE.)  This blog demonstrates how EXAIR was able to engineer an efficient way to blow air across a span.  The unique design of the Super Air Knife creates an amplification ratio of 40:1 which is the highest in the market.   Unlike the drilled pipe, the gap opening runs along the entire knife for precise blowing.  This engineered gap allows for laminar air flow which has a low noise level, a consistent blowing force, and maximum amplification ratio.  With these benefits, the Super Air Knife can reduce the amount of compressed air required, which will save you money and save your compressed air system.

In comparing the drilled pipe to the Super Air Knife, I will relate both products in a simple cooling application.   Thermodynamics expresses the basics of cooling with an air temperature and an air mass.  Since both products are represented in the same application, the air temperature will be the same.   Thus, the comparison will be with the amount of air mass.  In this example, the customer did some calculations, and they needed 450 Lbs. of air to cool the product to the desired temperature.  At standard conditions, air has a density of 0.0749 lbs/ft3.  To convert to a volume of air, we will divide the weight by the density:

450 lbs. / (0.0749 lbs./ft3) = 6,008 ft3 of air

To meet this requirement, reference Table 1 below.  It shows the volume of air required by your compressed air system to meet this demand.  As you can see, your compressor has to work 13X harder to cool the same product when using a drilled pipe.  Just like the LED light bulbs, the Super Air Knife has more efficiency, more innovation, and uses less compressed air.  In turn, the Super Air Knife will save you a lot of money in electrical costs.  If you would like to see how much the Super Air Knife can save compared to the drilled pipe, we have that information in this blog.  (Read it HERE.)  For my reference, it will reduce the stress of your compressed air system.

if you would like to compare any of your current blow-off devices with an innovative EXAIR product, you can contact an Application Engineer.  We can do an Efficiency Lab to shine an LED light on saving energy and money with your compressed air.

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

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