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

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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.

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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

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.

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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

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

Super Air Knife Cools Laminated Packaging Material

I recently worked with one of our distributors on a Super Air Knife application for a manufacturer of flexible packaging material. They create the plastic material that is commonly wrapped around the outside of a wide variety of different containers. The material exits the laminating machine at about 129°F (54°C) and must be cooled to close to room temperature before it is able to be rolled without the material sticking together.

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Model 110012, positioned to maximize counter-flow

They performed a test with a Model 110012, recording the temperature after the knife and determined that it would be suitable for them. Prior to using the Super Air Knife, they had been using a series of fans to cool down the material. This worked to some degree, but they had been experiencing quality issues as a result of inadequate levels of cooling and were forced to slow down the laminating machine in order to compensate. By implementing the Super Air Knife, they were able to cool the material down to ambient temperatures without having to slow production. As an added measure, they ordered a second knife to install on the underside to further decrease the temperature of the material.

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Graph showing the effectiveness of a Super Air Knife vs. fans or no cooling method.

The laminar airflow of the Super Air Knife is critical to the success of any cooling application. A fan “slaps” the air which provides random spikes of air at moderate velocities. The uniform, high velocity, laminar sheet of air from the Super Air Knife, in addition to the low compressed air consumption, makes it a much more effective cooling method than fans. The design of the Super Air Knife allows it to entrain ambient air at a rate of 40:1, maximizing the force and flow from the knife while keeping compressed air usage to a minimum.

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The design of the Super Air Knife allows it to entrain air from the top and bottom, creating a 40:1 air amplification ratio.

Super Air Knives are available in a range of different materials and sizes. From stock EXAIR carries knives from 3”-108” in Aluminum, 303 Stainless Steel, 316 Stainless Steel, and 3”-54” in PVDF (Polyvinylidene Fluoride) for superior resistance to highly corrosive materials. In addition to being an excellent tool for cooling, the Super Air Knife can solve a wide range of drying and blowoff applications. If you have an application that would be better served with one of EXAIR’s Super Air Knives, reach out to us today and get yours on order! We ship same day from stock with orders received by 3:00 pm EST, stop wasting time with ineffective cooling or blowoff methods!

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

Super Air Knife Coupling Kit Helps Customer Save Money and Increase Productivity!

I was recently contacted by a manufacturer of specialty food products that was looking to increase productivity on one of their packaging lines. In order to do so, they needed a longer Super Air Knife.

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Model 110012SS-316 Super Air Knife

They manufacture a variety of different products, but this application was involving small snack-size blocks of cheese. They’re placed into individual plastic containers and before they seal the packaging any residual particles must be blown off or it will affect the seal. Any residual particles of cheese around the container would allow air to come into contact with the product and affect shelf-life.

In the current setup, they were using EXAIR’s Model 110012SS-316 a 12” 316 grade Stainless Steel Super Air Knife and the Model 9060 Universal Mounting System. They wanted to add in an additional two rows of cheese to help increase throughput. To do so, he needed an overall width of 18”. We do have an 18” available from stock, but rather than having a spare 12” model lying around he wanted to try and utilize what he had without having to purchase an entirely new knife.

uakmb
Model 9060 Universal Mounting System

Fortunately, EXAIR’s Super Air Knives can be coupled together to create a wide variety of different lengths. From stock, the Super Air Knife is available from 3”-108”. With the help of a Super Air Knife Coupling kit, we can achieve much longer lengths. In this case, although we did have an 18” knife available, we could also couple the existing 110012SS-316 (12”) with our Model 110006SS-316 (6”). This option was a bit cheaper than going with a new knife, and still allowed them to utilize the 12” that they already had.

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Coupling Kit for Aluminum Super Air Knives

While this isn’t the typical place we’d recommend a coupling kit, it was an option that allowed the customer to save a bit of money but still get the same effect that they’d achieve with the 18” single piece knife. We also manufacture a wide variety of custom knives per customer specifications. If you’ve got an odd application that you don’t think is best served by a stock offering, give us a call. An Application Engineer will be happy to take a look at your application and help recommend the most suitable product.

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

Super Air Knife with a Plumbing Kit Removes Gypsum from a Conveyor Belt

Plumbing Kits

A gypsum facility was having issues in losing powder from the tailings in their conveying system.  The conveyor moved gypsum from their processing plant to an outside silo bin location for loading and transportation.  The conveyor that they used was 60” wide.  As the conveyor went around the end to dump the gypsum powder, some of the material would stick to the belt and collect on the floor underneath.  Depending on production rates, they would have to stop the operation to clean up the floor which added additional hours for custodial work.  The customer sent a picture of the problem and wondered if EXAIR could help them with this application.

The facility did an annual cost projection to determine the loss of money from the gypsum material collecting under the conveyor.  The custodial cost to clean up the excess powder was roughly $45,000/year.  The unscheduled downtime was estimated at 115 hours per year.  (They did not share the loss of dollars in production to EXAIR.)  But it was large enough that they needed a solution from EXAIR.  (The photo below is similar to the same application as written by Lee Evans: “EXAIR Super Air Knives Improve Process in an Aluminum Rodding Shop“.)

Powder collecting under conveyor

I suggested a model 110260PKI Super Air Knife Kit for this application.  The Super Air Knife was 60” in length to cover the conveyor belt.  The kit included a filter, a regulator, and a shim set to “dial” in the minimum amount of force to remove the material.  This gives the customer the most flexibility when using an EXAIR Super Air Knife.  The “PKI” suffix at the end of the model number indicates our Plumbing Kit.  This kit which is Installed on the Super Air Knife allows for ease of installation to compressed air connections and it also allows for the proper airflow to get a consistent blow-off across the entire length of the Super Air Knife.

At EXAIR, we pride ourselves in energy efficiency.  Compressed air is expensive to make, so why not use it as efficiently as you can?  The Super Air Knife has a 40:1 amplification ratio which allows 40 parts of ambient “free” air for every 1 part of compressed air.  And, with the “dirty” environment at the gypsum facility, the Super Air Knife would not be affected as they do not require a motor that can fail or a maintenance program to perform.  After installing the model 110260PKI, the gypsum powder was no longer collecting on the floor underneath.  If we look at the cost of removing the hourly rate of the custodian, the Return on Investment, ROI, was only 27 days (and this did not include the increase in production rates).

Spillage is wasteful, costly, and time consuming to cleanup.  If you have excess waste from your conveying system, EXAIR will have the product to help you.  For the gypsum facility above, the Super Air Knife Kit made it possible to increase production efficiencies with a short ROI.  You can contact an Application Engineer to review your application and see if we can improve your conveying operation.

John Ball

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