It is popular now to use the term “engineered”air nozzle for compressed air nozzles used for blow off applications. But what really is an engineered nozzle? The original compressed air operated engineered nozzle is basically a cone shape that draws in surrounding air utilizing the “Coanda” effect and converts pressure to flow by drawing in atmospheric air along with the compressed air existing the nozzle. Copies and different physical sizes abound in the market place but are they really engineered? The size, angle of hole and even how the air flows inside and out of the air nozzle are important. It can be easily proven by taking two similar looking cone shaped nozzles from differnet manufacturers and testing them side by side. Even if they look similar on the outside, they may perform dramatically different, with one perhaps being louder (or more quiet) and the other more (or less) powerful. A truly engineered version will take both inside and outside flow characteristics into account. But in general, these cone shaped designs provide the most “flow” amplification.
For most applications however, force is more important so a high ratio of force/air consumption (CFM) is important. The “bullet” shaped finned nozzles with holes in between the fins seem to provide this optimum force/cfm better than the cone shaped versions. The bullet shape still entertains the Coanda effect to accelerate outside air to produce more flow as well. As with the older designs, the number of holes, their size, overall shape, and fin design is important but also the way the air flows on the inside. Copies of these bullet shaped nozzles have also appeared but rarely perform even close to the original designs because they are poorly copied and not really engineered. As with the cone shaped styles, this can be easily confirmed by taking two similar looking nozzles from two different manufacturers and comparing the force each produces at the same line pressure. The copy rarely does as well.
A few years back so-called laval effect nozzles which has the compressed air exiting the nozzle using an hour glass shaped exit to accelerate the exiting compressed air appeared on the market. However it is questionable that they are any more effective for a higher force/cfm ratio than nozzles using the Coanda effect, especially if not close to the target of the blow off. Noise is another factor with this style of nozzle.
A bullet shaped nozzle developed by Nex Flow Air Mag nozzle series is patent pending where the air exit nozzles are oriented in such a way as to increase the force/cfm over the best competitive nozzle found by about 10% and actually make it more effective at a greater distance. This is truly an engineered nozzle and all factors both inside and out are taken into account. At the time of this writing the available Nex Flow Air Mag sizes are 1/4″, 1/2″ but, 4, 5 and 6 mm small nozzles are pending. A 1/8″ adaptor for the 6 mm nozzles will also be available.
So when looking at engineered nozzles, carefully research the actual force/CFM, at what distance and line pressure the specifications are taken and the distance of their effectiveness to make sure it is truly engineered and will be suitable for your application. Stay with brand names like Nex Flow to assure quality and be wary of copies.
Nex Flow Air Products Corp. manufacturers compressed air technology for blow off, drying, cleaning, cooling, and moving and constantly strives to improve their products’ performance and quality.