EXAIR Corporation’s Research & Development team often finds themselves at odds with our Marketing department, who thinks R&D, through their constant introduction of new ideas & products, is trying to turn our catalog into something resembling a phone book.
I do not believe that is their aim or intention, though (and to be fair, Marketing doesn’t either.) Honestly, we just want to help folks in a wide range of industries solve problems. And a diverse range of engineered compressed air products is our tried-and-true, successful method for doing so.
EXAIR’s Atomizing Spray Nozzles are used to atomize fluids in a wide range of different spray patterns. They utilize a small amount of compressed air which mixes with the liquid supply to create a fine mist of atomized liquid. EXAIR manufactures Atomizing Spray Nozzles in (3) different varieties: Internal Mix, External Mix, and Siphon Fed. For this blog, I’m going to focus on just the External Mix variety.
On all External Mix Atomizing Nozzles the volume of liquid is easily adjusted by adjusting the valve stem on the standard Atomizing Nozzle, or by regulating the liquid pressure (the only option with the No-Drip style). Increasing the liquid pressure will result in an increased liquid flow rate.
The External Mix nozzles have the highest flow rates and can be used with liquids with a viscosity greater than 300 centipoise (cP). Since the air and liquid are mixing just outside of the nozzle, thicker liquids have a lesser chance of clogging in the nozzle. Both the liquid stream and the air stream will come into contact with each other just outside both the air and liquid caps. The compressed air breaks the liquid up into very small particles, allowing you to use much less liquid than a liquid only nozzle.
This makes them very effective in applications that utilize expensive paints, oils, or other liquids. Rather than wasting the expensive materials, the nozzle can be set to precisely dispense only what is necessary to achieve a successful application. The External Mix Atomizing Nozzle is available in the standard configuration as well as the No-Drip style.
The No-Drip Atomizing Nozzle is used in a variety of applications where any liquid dripping from the nozzle after the air supply has shut off would cause a problem. This is common in painting applications where any paint dripping would affect the quality.
The External Mix Atomizing Nozzle is available in (3) different sizes: 1/8” NPT, ¼” NPT, and ½” NPT. If your application could benefit from utilizing the fine atomized spray of liquid look no further than EXAIR’s Atomizing Nozzles. With all sizes and configurations available from stock, we can get one out to you quickly!
For today’s topic we will focus on EXAIR’s Siphon Fed No Drip Atomizing Nozzle. They provide the same great performance as the standard atomizing nozzles with the added benefit of positive liquid flow stoppage when the compressed air supply is shut off.
The No Drip option eliminates post spray liquid flow that can result in unwanted drips that can ruin the finish on painted or coated surfaces. Also, liquid loss due to post spraying cycle drips is eliminated saving you money on expensive materials such as chemicals or coatings. When the compressed air is turned-off, the No Drip nozzle positively seals off the liquid flow, eliminating the chance for drips or wasted liquids. Only one compressed air line is required, as this single line that is used to create the atomized liquid flow also operates the no drip feature.
No Drip Atomizing Nozzles require a minimum air pressure of 20 PSI for the 1/8 NPT models and 30 PSI for the larger 1/4 & 1/2 NPT sizes to turn on. This is similar to a check valve and the pressure required to open the valve which can be referred to as the “cracking pressure”.
The Siphon Fed Atomizing Nozzles require no liquid pressure to operate and can be used with either gravity or siphon feeds. The 1/8 NPT & 1/4 NPT can draw liquid up to 36″ vertically and the 1/2 NPT size up to 24″ vertically! They are designed to be used with liquids up to 200 cP and can spray either a round or flat fan pattern for the 1/8 NPT & 1/4 NPT. The 1/2 NPT nozzle is available in the round spraying pattern only.
Centipoise is defined as a dynamic viscosity measurement unit. A Centipoise (cP) is a non-SI (non-System International) measurement unit of dynamic viscosity in the centimeter gram second (CGS) system of units.
Don’t forget the optional Mounting Bracket that is available. Naturally there are (3) sizes available to fit the size nozzle you are using (1/8, 1/4 or 1/2 NPT). They are constructed from 301 SS and allow any Atomizing Spray Nozzle to be easily attached to a wall, frame or other surface.
Some key points to consider when determining which Atomizing Spray Nozzle will work best in your application are:
Today, I would like to focus on 2 specific Atomizing Nozzles – our No Drip Internal Mix Deflected Fan Nozzle and our Internal Mix 360° Hollow Circular Pattern Nozzle.
The No Drip Internal Mix Deflected Fan Atomizing Nozzle produces a flat fan of atomized liquid at a right angle to the nozzle’s orientation and is designed for use in pressured fed applications where the liquid doesn’t need to be controlled independently from the pressurized air. This nozzle is the perfect choice in processes where mounting space is limited like spraying solvent on conveyed parts inside a small chamber or coating the inside of an enclosure. The patented No Drip feature positively stops the liquid flow when the supply air pressure drops below 30 PSIG, eliminating the need for any additional valves or supply lines. This is especially beneficial in applications using expensive fluids or where drips can ruin a finished product. This nozzle is available with 1/4″ NPT inlets and flows as high as 6.9 gallons per hour.
Our Internal Mix 360° Hollow Circular Pattern Atomizing Nozzles produce a circular spray pattern, the ideal solution when trying to coat the inside of ductwork or where a broad mist of atomized liquid is necessary, like dust suppression or humidification. Available in 1/4″ NPT with flows as high as 14.7 GPH and spray diameters up to 53″ in diameter depending on air and liquid supply pressures. With the 1/2″ NPT, we can achieve up to 150 GPH with a spray diameter up to 156″. Our standard Atomizing Nozzles also feature an adjustment valve to provide control of the flow rate, making them easy to adapt to a specific requirement.
If you have an application requiring a fine mist of atomized liquid, please contact one of our application engineers and let us know how we can help in making the best product selection to fit your need.
Recently, I was working with a customer that has purchased several of the EXAIR Atomizing Spray Nozzles, specifically the model Aw5020SS. The customer had another project coming up and needed two more nozzles. I inquired about the application and we discussed at length the way the nozzles are being used.
When a concrete road is being poured, several sample forms are poured during the process. The local Department of Transportation takes the samples and cures them in a wet room for 30 days, and then performs tensile testing, to confirm the concrete meets the strength requirements. The wet room must be kept at 23°C (73.4°F) and 100% Humidity during this time frame. The EXAIR model AW5020SS Atomizing Nozzles are used to provide the moisture that ensures the room humidity conditions are met and maintained. Because the droplets are very fine, the effect of a fog is achieved, with the water droplets suspended in the air, keeping the humidity at 100%.
Atomizing spray nozzles are capable of producing very fine droplet sizes. A typical rain drop is 6000 microns in diameter, standard liquid nozzles produce droplets ranging from 300-4000 microns. The EXAIR Atomizing Nozzles produce droplets from 20-100 microns!
Droplet sizes can be adjusted by varying either the liquid pressure or air pressure. Increasing the air or decreasing the liquid pressure will generally produce a smaller droplet size.
EXAIR manufactures (3) types of Atomizing Nozzles – Internal Mix, External Mix, and Siphon Fed, in both 1/4 NPT and 1/2 NPT sizes. Maximum liquid viscosity is 800 cP. Flow rates range from 0.6 GPH up to 303 GPH, so we’ll be able to find one that meets your flow requirements.
To discuss your application and how an EXAIR Atomizing Nozzle can benefit your process, feel free to contact EXAIR and myself or one of our other Application Engineers can help you determine the best solution.
In this summer of 2016, we are nearing the beginning of one of the largest sporting events on the planet, The 2016 Summer Olympics. At the heart of this celebration will be sporting events of all kinds. And in the tradition of the Olympics there is always a gold, silver and bronze winner to award the top three athletes in each event.
EXAIR is participating in a competition as well. It isn’t one of a sporting nature, but rather, one of ingenuity and innovation. Flow Control Magazine holds an annual competition for innovations in new products available in industry and we have entered the No Drip Atomizing Nozzle into the competition.
In general, Atomizing Nozzles are used for the application of high value fluids within industrial processes. In some cases where the Atomizing Nozzles are mounted above the target, residual fluid that is left inside the nozzle body can drip out when de-energized and cause un-wanted blemishes on the target surface.
EXAIR No Drip Atomizing Nozzles allow for external adjustment of compressed air and liquid inputs to adjust the liquid spray flow rate as well as droplet size for a wide range of applications. That’s pretty common amongst atomizing nozzles in general. So what is so innovative about the No-Drip Atomizing Nozzles?
We have found a way to control the on/off function of the atomizing spray which supports the no-drip feature as well as the atomizing flow with only one compressed air supply. Most other manufacturers require a nozzle that has a separate control for the small valve within the nozzle and another for the airflow that atomizes the fluid coming through. It is this innovation that dramatically improves the simplicity with which these nozzles can be installed into an application and controlled through typical air automation techniques. It was innovative enough that the US Patent Office granted EXAIR a patent on the design (Patent # 9156045). So, we’ve made the No-Drip Atomizing Nozzle available with 3 different spray patterns and 14 different liquid volume options to suit a wide variety of application need. Operating pressures can fall anywhere between 30 – 250 PSIG to atomize fluids up to 300 centipoise.
If you agree with the US Patent Office on the innovation and think that EXAIR’s No Drip Atomizing Nozzles should be a winner in this competition, we would appreciate your official vote.