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

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