EXAIR Standard Air Knives™: Overview

From left to right: Super, Standard, and Full Flow Air Knives.

EXAIR manufactures three different styles of Air Knives; Super, Standard, and the Full FlowStandard Air Knives are the first model of air knives EXAIR began to manufacture.

Standard Air Knife

The Standard Air Knife uses a Coanda profile for blowing.  The Coanda effect was named after a Romanian aerodynamic pioneer, Henri Coanda, where he found a phenomenon with fluid flow.  He stated that a jet of fluid emerging from an orifice will follow an adjacent flat or curved surface to entrain fluid from the surrounding.  Being that air is a fluid, it will react in the same way.

Compressed air flows through the inlet (1) to the Standard Air Knife, into the internal plenum. It then discharges through a thin gap (2), adhering to the Coanda profile (3) which directs it down the face of the Air Knife. The precision engineered & finished surfaces optimize entrainment of air (4) from the surrounding environment.

The EXAIR Standard Air Knife creates a high velocity air stream along an engineered profile.  So, as the air “hugs” the profile, a low pressure is created which will draw in ambient air.  What does this mean for you?  If we bring in “free” ambient air into the compressed air stream, we add mass to the blowing force.  So, we can use less compressed air which will save you money.  We call this the amplification ratio.  For our Standard Air Knife, it has an amplification ratio of 30:1.  (As in, for every 1 part of compressed air, 30 parts of ambient air is drawn into the stream).  This design makes this product very efficient.

We stock the Standard Air Knives in various lengths from 3” to 48” (76mm to 1219mm) in two types of material; aluminum and 303 stainless steel.  This unique design is very compact; so, it can fit into tight places for blowing and cooling.  The aluminum version uses a plastic shim to set the gap.  They come standard with a 0.002” (0.05mm) shim installed.  We have additional shims to make the Standard Air Knife more versatile.  The Shim Set will include a 0.001”, 0.003”, and a 0.004” thickness shim (.03mm, .08mm, and 0.1mm respectively) for controlling the air flow from a small breeze to a blast.  The shims are color coded for easy verification.  The stainless steel Standard Air Knife comes with a stainless steel shim for higher temperatures and chemical resistance.

Standard Air Knife Kit

We do offer the Standard Air Knives in kits for a more complete package.  The kit will include the Air Knife, a Filter Separator, a Pressure Regulator and the above-mentioned Shim Set.  The Filter Separator will remove the debris and liquid water from the compressed air line to optimize the air knife as well as keeping your products clean.  The Pressure Regulator is used to make “fine” adjustments to the blowing force while the shims are used for a “coarse” adjustment to the blowing force.  Together, you can “dial” in the right amount of air required to do the job without wasting compressed air.

For easy mounting, we do offer a Universal Air Knife Mounting System.  This system is used to position your air knife securely and precisely.  It comes with a bracket to mount to the Air Knife and can be articulated in any position with a reach up to 30” (762mm).  You can direct the Standard Air Knife to maximize the effectiveness.  It is easy to use as seen in this video: CLICK HERE.

With today’s cost to make compressed air, it is important to do it as efficiently as possible.  The Standard Air Knife has the ability to give you the effective blowing to remove debris, dry parts, or cool objects without using a large amount of compressed air.  As another feature, the Standard Air Knife is quiet.  It only has a sound level of 83 dBA at 80 psig (5.5 bar).  So, by using this EXAIR product, you are not creating a noise nuisance in the work environment.  If you have any questions about the Standard Air Knife or if you would like to discuss an application, you can contact an Application Engineer at EXAIR.  We will be happy to help. 

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

A Super Air Knife Benefits Aerospace Manufacturing

The aerospace industry has a high demand for high quality materials and can often be the leading users of high-quality materials. Since these sort of materials are typically very expensive it should be no surprise that manufacturers of aerospace parts are always looking for ways to gain efficiency within their processes. Today’s blog offers insight into how one aerospace company optimized its performance.

1 – Airplane Interior

A manufacturer of passenger plane interiors contacted us looking to improve their feed of material in and out of presses. They manufactured aircraft plywood and struggled with a hands-free way to help “float” the sheets during loading and unloading. They also spent a good amount of time waiting for the sheet to cool enough to handle for removal. These presses opened a minimal amount and were pressing the layers of the sheet together and then needed to be slid out of the press and moved on to the next process. The operators would use a handheld blowgun to try and blow under the sheet to move and adjust its positioning however they were then left with only one hand to do the positioning which became cumbersome. After the sheet was pressed they would blow with the same gun again and attempt to cool down the handling location and then drag it back out of the press. This was not a safe or efficient method to handle these sheets.

To improve the process this manufacturer installed a Super Air Knife. The opening on the press was 6′ wide, so they used a 72″ Super Air Knife w/ Plumbing Kit Installed Kit on one press as a test run. The knife was fed from a line that was outfitted with a solenoid valve that tied into a sensor already existing on their press so the air would only be fired when called for by the operator. While the knife did consume more air per minute of operation they were able to reduce the overall time air was being used for loading because the operator now had both hands to work with the sheet.

A 72″ Super Air Knife w/ Plumbing Kit Installed blowing debris off a part being laser cut.

Once the process was completed and the press opened the knife would turn on again to cool the sheet, then within a few seconds, the operator would reach in and again be able to easily float the sheet out. This was all made possible by the low profile design of the Super Air Knife not inhibiting the range of motion the operators had and not having to block the limited work envelope they had at the machine.

With this test machine improving production time, operator satisfaction, and enabling safer machine operation the company elected to implement a program installing the 72″ Super Air Knives on each one of their presses. If you would like to discuss any point of use compressed air application that needs improvement or isn’t as safe or efficient as you would like in your facility, contact an Application Engineer.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

1 – Timofejev, Aleksandrs – Turkish Airlines, TK015, Instanbul- Sao Paulo- Buenos Aires – 16 June 2013, retrieved from commons.wikimedia.org/wiki/File:Turkish_Airlines,TK015,_Istanbul-_Sao_Paulo-_Buenos_Aires-_panoramio.jpg

EXAIR’s Super Air Knife Replaces Blower-Driven Slotted Pipe

EXAIR’s Super Air Knives are the ideal fit for any application requiring a laminar “curtain” of air for blowoff purposes. The high-velocity airflow does an excellent job of cleaning off surfaces, cooling, and drying in a wide variety of applications throughout industry. These products are engineered to provide a consistent and reliable force across the full length of the knife, ensuring repeatable performance in any application.

I recently worked with a customer who manufactures a variety of bread products. In one application, they were using slotted pipes connected to a blower to clean sesame seeds off of trays after baking. The cut pipes seemed like a simple and economical solution since they had the materials there in the facility already, but the homemade blower-knives were lacking in force necessary to clean the trays.

Slotted pipes operating off of a blower didn’t quite pack the “punch” necessary to clean the trays.

When the tray wasn’t fully cleaned, residual seeds would stick to the bottom of the next loaves and burn leaving an unacceptable product for their customers. The solution was to implement a manual step of scraping off the trays which required a dedicated operator to perform this single operation. The plant runs 24/7, leading the customer to hire 3 new personnel strictly for cleaning the trays all day long.

Recent staffing difficulties due to COVID-19 led management to seek out areas where they could enhance their production efficiency and identified an opportunity in this application. EXAIR’s compressed air operated Super Air Knives provide a hard-hitting curtain of air that is very effective at cleaning. The (2) slotted pipes were replaced with (2) Model 110024SS stainless steel Super Air Knives and plumbed into their existing compressed air system.

Immediately, the higher force provided by the Super Air Knives displayed the ability to completely clean the trays and eliminate the need for dedicated operators for this part of the process. This allowed them to shift personnel to areas in the facility in desperate need of help, while still solving the problem of rejected bread loaves due to residual seeds.

If you have an application in your facility that is in need of an efficiency makeover, give us a call. Our team of experienced Application Engineers is ready to help evaluate your process and make any necessary recommendations.

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

Save Compressed Air with the EXAIR Electronic Flow Control

The best way to save compressed air is to simply turn it off when it’s not being used. This might seem pretty simple, but there may be processes in your facility where this couldn’t be achieved by just turning a valve. In applications where product is traveling along a conveyor, and must be dried, cooled, or blown off, there is likely some spacing in between the parts. It isn’t necessary to keep the blowoff running constantly if there’s periods of intermittent spacing. To help reduce the overall load on the air compressor, implementing a solution to shut the air off in between each part can have a dramatic impact. EXAIR’s Electronic Flow Control, or EFC, is designed to improve efficiency by reducing overall compressed air usage. It utilizes a photoelectric sensor that detects when the part is present. When it’s not, it triggers a solenoid valve to close and shut off the compressed air supply.

efcapp
EXAIR EFC

One way to use the Electronic Flow Control would be for Turning a Atomizing Spray nozzle on to coat your product.  For example see the photo below where you could use the EFC to sense the pants coming down the line. Then turn the air supply on to spray a bleach solution to get the weathered look you are after. Once the pants pass the EFC will turn the nozzle off, replacing a manual operation awhile saving compressed air and your liquid solution!

Another use would be to tell when a hopper that is being filled by a Line Vac is empty or over filled.  You can adjust the sensor and the control module to sense that the hopper is empty and it will turn the compressed air on to the Line Vac to then feed the hopper.  Then set the timer module so it will run for the length of time it takes to fill the hopper.  The other way would be to place the sensor at the top of the hopper and have it sense when the pile of media has reached the full level.

The EFC models available from stock can accommodate flows up to 350 SCFM. For applications requiring more compressed air, EFCs with dual solenoids are also available. If you have an application in one or more of your processes where intermittent compressed air use could help save you money, give us a call. We’d be happy to take a look at the application and help determine just how quickly the EFC could start paying YOU

Jordan Shouse
Application Engineer

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