EXAIR manufactures three different styles of Air Knives; Super, Standard, and the Full Flow. In this excerpt, I am going to discuss the Standard Air Knives.
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 fluid phenomenon. He stated that “a jet of fluid emerging from an orifice to follow an adjacent flat or curved surface and to entrain fluid from the surroundings so that a region of lower pressure develops” (1). Being that air is a fluid, it will react in the same manner.
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? It will use less compressed air to save you money. For the Standard Air Knife, it has an amplification ratio of 30:1. (For every 1 part of compressed air, 30 parts of ambient air is drawn into the stream). This design makes the product very efficient. We can use less compressed air and bring in more of the free ambient air to create a strong blowing force.
We make the Standard Air Knife in various lengths from 3” to 48” (76mm to 1219mm). We make the air knives in two different materials, aluminum and stainless steel. The unique design is very compact; so, it can fit into tight places for blowing and cooling. The aluminum version uses plastic shims to set the gap. They come standard with a 0.002” shim installed. We have additional shims to make the Standard Air Knife more versatile. The shim set includes a 0.001”, 0.003”, and a 0.004” thickness shim for applications that may require a small breeze up to a strong blast of air. The shims are color coded for easy verification. The stainless steel Standard Air Knife comes with a stainless steel shim for higher temperatures or chemical resistance.
We do offer the Standard Air Knives in kits for a more complete package. It comes with a filter, regulator and the above mentioned shim kit. The filter removes the debris and water from the compressed air line to optimize the performance of the air knife as well as keeping your product clean. The regulator is used to make “fine” adjustments to the blowing force. The shim set is used as 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 kit is used to position your air knife securely and precisely. It comes with a bracket and an articulated arm that can reach up to 30” (762mm). You can orient the Standard Air Knife in any position to maximize the effectiveness.
With the 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 for removing debris, drying parts, or cooling objects without using a large amount of compressed air. As an additional feature, the Standard Air Knife only has a sound level of 83 dBA at 80 psig (5.5 bar). So, in 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.
(1) from Wikipedia