Tag: Frequently Asked Questions

Benefits of Atomized Liquid Nozzles vs. Liquid Nozzles

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There are a great many applications that require a spray (as opposed to a stream) of liquid. Certain droplet sizes, and flow rates, are beneficial for certain applications. For example, if you’re fighting a fire, you want as high of a flow rate as possible – the more water you douse the fire with, the quicker it goes out.  You also want a fairly large droplet size, since a mist would tend to evaporate instead of extinguishing the flames.

Pressure washers also benefit from higher (though not near as high as fire hose) flow rates, and droplet sizes.  You want an appreciable flow rate, because that means high velocity, and good sized droplets combine that velocity with their relative mass to “blast” away dirt and detritus from the surface.

Medicine delivery devices, like asthma inhalers, are designed to produce mid-sized droplets, but pretty low (and controlled) flows.  The droplets need to be small enough to efficiently spread the medicine through the breathing passages, but large enough to where they won’t evaporate before they ‘plant’ on the nasal & bronchial membranes to get absorbed.

These are examples of “liquid-only” nozzles…no other media or means of force are used to effect the spraying action.  Most of the time, the droplet sizes in these applications are measured in hundreds of microns, which “liquid-only” nozzles are ideally suited to generate.  Other applications, however, call for much smaller droplet sizes…such as those only attainable through atomization.

EXAIR Atomizing Spray Nozzles use compressed air to create a fine mist of liquid, with droplet sizes as low as 22 microns.

A typical “liquid-only” nozzle is capable of producing droplet sizes of 300-4,000 microns. Atomizing Nozzles’ droplet sizes are consistently under 100 microns, and can be as small as 20 microns!

Small droplet size is key to cost effectiveness in many applications:

  • Think about expensive coatings…the smaller the droplet size, the better and more even the coverage, and the less you have to spray (and pay) out.
  • Or humidification…smaller droplet size means more stays airborne, for longer, and in a larger space.
  • Petroleum based lubricants, by their nature, only require a thin layer for best results.  Smaller droplets make as even and thin of a layer as possible.
  • Dust control is much more effective with smaller droplet sizes, since the longer the mist lingers in the air, the more dust particles the individual droplets will adhere to…and then drop with them to the surface.  This also prevents getting the surface of the material any wetter than it has to be.
142 distinct models. 8 different patterns. Liquid flow rates from 0.1 to 303 gallons per hour. If you’ve got a spraying application, EXAIR has an Atomizing Nozzle for you!

If you’d like to discuss a liquid spraying application, I’d love to hear from you.  Call me.

Russ Bowman
Application Engineer
EXAIR Corporation
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Adjustable Air Amplifiers Aren’t Just About Adjustability

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Adjustability is a key feature for a great many devices:

  • An adjustable wrench – or as I like to call it, the trusty “all 16ths” – is my go-to for work around the house involving anything with a hex…fittings under the sink when I’m cleaning out a drain, nuts & bolts on furniture or household items needing some tightening (or loosening,) etc.  I don’t get out my combination-end wrenches for much except automobile maintenance.
  • Speaking of sinks, my kitchen faucet lets me adjust water flow (and temperature) which is important because I use different flow rates (and temperatures) if I’m getting a tablespoon of water, or if I’m rinsing my hands, or if I’m filling the sink to do dishes.
  • Speaking of tablespoons, I’ve even got an adjustable measuring spoon that lets me get a full tablespoon, a half a teaspoon, or anywhere in between, by moving a lever block back & forth in the spoon head.

Adjustability is a key feature for several EXAIR Intelligent Compressed Air Products too…like our Adjustable Air Amplifiers.  The ‘adjustable’ part has to do with setting the air flow:

Just loosen the locking ring, and you can thread the plug out of, or in to, the body to increase, or decrease the flow and force of the developed flow.  There’s a hole in the plug (opposite the “EXAIR.com” stamp) so you can use a spanner wrench (another adjustable tool!) to thread the plug in or out.

You can get an amazing range of flow from a little twist*:

These are the performance values for a Model 6042 2″ Aluminum Adjustable Air Amplifier with a compressed air supply pressure of 80psig. Regulating the pressure can give you even lower…or higher…flows.                                              *0.002″ to 0.010″ is about 1/4 turn of the plug.

A gap of about 0.010″ is about the max for 80psig supply pressure.  Above that, the air flow overwhelms the Coanda profile, creating a turbulent ‘storm’ in the throat, hampering the efficiency and effectiveness.  The proper “adjustment” for that is to select the next larger Air Amplifier!

While the range of air flow is certainly impressive, their versatility is another major factor in their selection.  I reviewed our Application Database (registration required) for real-life details on Adjustable Air Amplifiers “in the field” and found a litany of other benefits that made them better suited to particular installations than a Super Air Amplifier:

  • A customer who builds automated equipment incorporates the Model 6031 1-1/4″ SS Adjustable Air Amplifier to blow open bags with a puff of air as they move into position on an automated filling machine. They use it because it’s available in stainless steel construction, and it’s still compact & lightweight.
  • A mattress manufacturer uses Model 6043 3″ Aluminum Adjustable Air Amplifiers to  cool mattress springs.  They’re lightweight, the perfect size to match the springs’ profile, and they can “dial them out” for high heat removal before putting springs on a rubber conveyor.
  • A tier 1 automotive supplier has Model 6234 4″ SS Adjustable Air Amplifier Kits installed on their robotic paint line to blow off moisture from parts to prevent water spotting between the wash cycle and the oven.  They use them because the stainless steel construction holds up to high heat due to the proximity to the ovens.
  • A food plant uses Model 6031 1-1/4″ SS Adjustable Air Amplifiers to improve the drying time of 3,000 liter mixers that must be washed between batches of different products.  The stainless steel construction holds up to the rigors of the frequent washdown in this area.
  • A bedding manufacturer replaced a regenerative blower with a Model 6041 1-1/4″ Aluminum Adjustable Air Amplifier for trim removal on stitched fabric at bedding manufacturer.  The blower was prone to failure from lint & dust; the Air Amplifier, with no moving parts, is not.  It’s also compact, lightweight, and virtually maintenance free.
  • A light bulb manufacturer installed Model 6030 3/4″ SS Adjustable Air Amplifiers on the ends of open pipes that were used to cool mercury lamp wicks.  This reduced noise levels significantly while providing the same cooling rate, and the stainless steel construction holds up to the heat of the operation.

Because of the simplicity of their design, Adjustable Air Amplifiers are also extremely adaptable to custom applications.  We’ve added threads or flanges to the inlets and outlets of several different sizes, to accommodate ease of mounting & installation:

Among other custom Air Amplifiers, we’ve put (left to right) threads on the outlet, ANSI flanges on the inlet/outlet, Sanitary flanges on the inlet/outlet, and Sanitary on the inlet/ANSI on the outlet. How are you installing your Air Amplifier?

Adjustable Air Amplifiers are available in both aluminum and 303SS construction, to meet most any environmental requirements…except extreme high heat.  In those cases, the Model 121021 High Temperature Air Amplifier is rated to 700°F (374°C) – significantly higher than the Aluminum – 275°F (135°C) or the Stainless Steel – 400°F (204°C).  They’re commonly used to circulate hot air inside furnaces, ovens, refractories, etc.

A Model 121021 1-1/4″ High Temp Air Amplifier directs hot air to a rotational mold cavity for uniform wall thickness of the plastic part.

Adjustability.  Versatility.  Durability.  If you’d like to know more about the Adjustable Air Amplifier, or any of EXAIR’s Intelligent Compressed Air Products, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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How It’s Made: Static Charge

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For me, one of the first signs that winter is here takes place at the grocery store. I’ll stop on the way home to pick up a thing or two, and proceed to the automated self-scan…not because I don’t like people, but because they’re the closest to the exit and, while I DO actually like a LOT of people, I REALLY like dinner. Anyway, the drop in humidity that comes with colder temperatures outside leads to what the buried-wire pet containment folks call a “mild correction” when I touch the self-scan terminal.

I won’t rehash my disdain of cold weather (like I did here, here, here, or here) and while those nuisance static shocks aren’t at the top of the list of reasons why, they actually can be quite severe in other cases.  For example, the minor jolt you get from touching a grounded terminal after pushing a rubber-wheeled shopping cart over the vinyl-tiled floor of the produce aisle isn’t near as bad as the shock that a plastic extrusion machine operator gets when he touches a conveyor duct carrying hundreds of pounds of plastic pellets per hour.

Why one is so much worse than the other?  To fully understand the answer to that question, we’ll need to better understand how static charge is generated.  Scientists have been studying the phenomenon since at least the 17th Century, and studies continue to this day of its creation (mainly at universities) and control (right here at EXAIR Corporation.)  Simply put, when two solid surfaces touch each other, the contact can result in electrons in the outer valences of atoms on one surface to “jump ship” and end up in the outer valences of atoms on the other surface.

It’s called the triboelectric effect.  The prefix “tribo” comes from the Greek word “to rub,” and while many common demonstrations of static charge involve rubbing…for example, rubbing a balloon on a wool sweater sleeve and ‘sticking’ it to the wall…mere contact is all it takes – and that’s where we’ll start:

Static charge from simple contact between this injection molded plastic part & the mold caused defects in a subsequent metallic coating process (left,) which were eliminated after an EXAIR Super Ion Air Knife was installed (right.)

Separation of material – lifting the top sheet from a stack, peeling off a protective layer,  or unrolling plastic film, for example – can also cause those weaker-held electrons to leave one surface for another.

Separation of contacting surfaces can generate a considerable static charge. The 16.9kV charge on this roll of film (left) shortened the life of print heads in a downstream process until EXAIR Ionizing Bars (center) dissipated the charge to an inconsequential 0.4kV (right.)

Some processes involve surface contact, and separation.  And more contact, and separation.  And oftentimes, one surface is in relative motion with the other…and that’s what REALLY puts the “tribo” (“to rub,” remember?) in “triboelectric effect.

The constant motion of these plastic jugs on the conveyor (left,) generated (and multiplied) a static charge so great, it resulted in adhesive labels folding or wrinkling while being applied. A pair of EXAIR Super Ion Air Knives (right) solved the problem.

These are just a few examples of the mechanisms behind, and the solutions for, static charge.  For more details, I encourage you to read EXAIR’s Basics Of Static whitepaper (registration required) or watch our recorded Webinar: Understanding Static Electricity.  If you have a static problem you’d like help with, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Ultrasonic Leak Detector: Because Leaks Won’t Find (Or Fix) Themselves

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I once worked in an equipment repair shop with a small and simple compressed air system…just a 5HP single acting piston compressor that sat atop a 50 gallon tank, in the corner by “The Big Truck”. The majority of our work was field service, and management was big on maintaining our service trucks, so we checked tire pressures every Monday morning as we rolled out, and kept a tire chuck handy to ensure proper inflation. It was also used to supply a couple of air guns that were used at our drill press and soldering/assembly station. One morning, I noticed the air compressor was running when I arrived…I thought it was odd, because I knew for a fact it hadn’t been used in at least 16 hours, but that compressed air went someplace, right? We had a leak. Well, at least one.

This was mid-December, and the week between Christmas and New Year’s Day was characteristically slow, and typically devoted to a thorough shop cleaning. We also took the opportunity to get some bottles of soapy water and check for leaks at the handful of pipe fittings that comprised the system…for the uninitiated, if you have a leaky fitting, the escaping air blows bubbles in the soapy water (a cheap, messy way in other words). We found some bubbling, undid those fittings, cleaned them, and applied fresh pipe thread sealant (I don’t want to start any arguments, but I was taught that tape is more of a thread protectant than an effective sealing agent) and, in addition to replacing a couple of well-worn hoses, we were up and running.  And we never heard the compressor running first thing in the morning again.

Not all compressed air systems are as simple as that, though.  Many go from a room with several large & sophisticated air compressors, to corners of every building on the grounds.  Through valves & manifolds, to cylinders, machinery and blow offs, with more connections than you could soap-and-water check in a month.

In those cases, the EXAIR Model 9061 Ultrasonic Leak Detector makes short(er) work of finding the leaks.  With both visual (LED’s on the face) and audible (headphones) indications, even very small leaks are easy to detect with the parabola installed.  The precise location can then be found with the tubular extension.

EXAIR Ultrasonic Leak Detector “hones in” on the exact location of a leak in a compressed air line.

You’ll still have to fix the leaks yourself, but finding them is oftentimes more than half the battle.  And, once fixed, it can be worth a million (cubic feet of compressed air, that is.)

EXAIR’s Ultrasonic Leak Detectors are not only useful for finding compressed air leaks; they’re popular in a variety of other areas:

Additionally, they can be used to identify faulty bearings, brake systems, tire & tube leaks, engine seals, radiators, electrical relay arcing…anything that generates an ultrasonic sound wave.  If you’d like to find out more, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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