Compressed Air Pressure Regulators Conserve And Protect

Imagine you’re enjoying a nice shower. A cascade of warm water is soothing your body – and spirit – then, someone starts the dishwasher. Or a load of laundry. Or flushes the toilet. Suddenly, the “soothe” turns to “scald” or “freeze,” depending on whether you’ve been robbed of hot, or cold water.  So, what happened?

What happened is, all of those “loads” on your house’s water supply that can ruin your shower experience are controlled by simple on/off valves…they open to permit a certain amount of water FLOW to pass.  When the dishwasher starts, or someone decides to wash a load of whites, the HOT water from your nice warm shower is diverted, leaving a stream of cold water.  When a toilet flushes, or it’s a load of colors, the COLD water is diverted…and that’s not just unpleasant, but downright painful.  Either way, (in my house anyway,) a teenager is getting read the riot act.

The same phenomenon can apply in a compressed air system, if simple flow control valves are used to throttle the appropriate supply of air to a pneumatic device.  If someone, for example, hooks up an air gun to blow off their tools or parts, the valves on EVERYTHING else will need to be opened up some to keep those devices working the same.  In the case of an air gun like this, it usually happens too quick to make the necessary adjustments (by hand) and you’re probably left with a machine tripped off-line, or a ruined part.

Pressure Regulators can prevent this by keeping (or regulating) their downstream pressure to a set value.  If a load elsewhere in the system is activated, the Pressure Regulator opens up, automatically, to keep its output constant.  When that load is secured, the Pressure Regulator closes back down accordingly.  Either way, no single load affects the operation of any others.

That’s only half the value of the use of Pressure Regulators, though.  The other half is, well…the value.  Just looking at a typical function of many EXAIR Intelligent Compressed Air Products – blow off – they’ll all pretty much accomplish the task if you run them, unrestricted, straight off your header.  That’ll give you a good, strong blast of air flow…and it may be more than what’s required, and a waste of good air.  Pressure Regulators will prevent this by allowing you to “dial in” the supply pressure to whatever it takes to get the job done, and no more.

EXAIR offers a range of Pressure Regulators capable of handling air flow of up to 700 SCFM.

Compressed air isn’t free.  Heck, it isn’t even cheap.  Don’t use any more than you have to, and get the most out of what you do use.  Pressure Regulators are one important step in doing this.  If you’d like to talk about optimizing your use of your compressed air system, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Benefits of Atomized Liquid Nozzles vs. Liquid Nozzles

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

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

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, herehere, 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

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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Where Can’t I Use An EXAIR Super Air Knife?

Considering the material options available, there are very few places you CAN’T use a Super Air Knife. Most often, we find those to be due to extreme elevated temperature, like this one:

A caller from a glass manufacturing company wanted to replace a drilled pipe in a cooling application. Thing is, glass makers deal with their product in molten form, which is HOT…the ambient temperature that this drilled pipe is exposed to reaches 800°C, or 1,472°F.  Because of the temperature, and corrosive atmospheric elements (SO2 is also present, as if the heat wasn’t bad enough,) they have to replace the drilled pipe every so often, and wanted to explore other solutions.

Now, this was a rare case where a Super Air Knife would not have necessarily offered an improvement over a drilled pipe:

  • The air flow from the drilled pipe is primarily straight from their compressed air system.  Since the Super Air Knife entrains air from the surrounding environment at a rate of 40:1, the resultant flow would be very close to the 800°C ambient temperature…and not as effective at cooling as the much cooler compressed air supply temperature.  It wouldn’t have helped to reduce consumption if it simply didn’t work.

The Super Air Knife takes a supply of compressed air (1), discharges it through a gap that runs the length of the Air Knife (2,) and entrains an enormous amount of “free” air from the surrounding environment (3.)

  • Another great thing about the Super Air Knife is that it’s dramatically quieter than any other method of compressed air blowing.  Of course, if you find yourself in a 800°C sulfur dioxide environment, hearing protection is the least of your concerns.

    When supplied at 80psig, the EXAIR Super Air Knife produces a hard hitting, powerful curtain of air, with a sound level of only 69dBA.
  • EXAIR Super Air Knives (and all of our Intelligent Compressed Air Products) are compliant with OSHA Standard 1910.242(b) which limits the outlet pressure of a compressed air blowing device used for cleaning to 30psi…this protects personnel from high velocity debris and air embolisms.  Again, not a concern in an unoccupied (and uninhabitable) space.

Again, that’s a rare case…a very specific exception to a broadly inclusive rule, in light of the options EXAIR offers.  Consider:

  • Aluminum Super Air Knives are durable, lightweight, and suitable for most any installation in a typical industrial/commercial environment.  They’re good to 180°F (82°C) and are fitted with stainless steel fasteners to eliminate corrosion in damp environments.  The polyester shim can be replaced with a custom stainless steel shim, increasing the temperature rating to 400°F (204°C) if needed.
  • Type 303 Stainless Steel Super Air Knives offer higher tensile strength, and are good to 800°F (427°C.)  They are popular in applications with factors like high heat, corrosive environments, frequent spray down cleaning, outdoor installations, etc.
  • Type 316 Stainless Steel Super Air Knives are often specified in food and pharmaceutical applications, due to their even higher resistance to chemical attack and pitting.  They’re also rated to 800°F (427°C) and have the same high tensile strength as the Type 303 Stainless Steel models.
  • Some situations call for better corrosion resistance than these high grades of austenitic stainless steels – and that’s where EXAIR’s PVDF Super Air Knife comes in.  Fitted with PTFE shims and Hastelloy© C-276 hardware, they are especially well suited for processes involving the harshest of corrosive agents, such as electroplating, solar cell manufacturing, and lithium ion battery production, just to mention a few.  They would, in fact, be ideal for the SOenvironment at the glass factory, if it weren’t for the temperature…they’re rated to 275°F (135°C.)

Performance is identical, regardless of construction materials, and all EXAIR Super Air Knives come in lengths from 3″ to 108″ (except PVDF…those go up to 54″ lengths) and ship quickly from our well maintained inventory.  Aluminum and Stainless Steel models can be coupled together for even longer flow lengths.  Plumbing Kits and Universal Air Knife Mounting Systems make for easy and quick installation, and all Super Air Knife Kits come with an Automatic Drain Filter Separator, a Pressure Regulator, and a Shim Set for reliability, clean air flow, and total performance control.

If you need a reliable, cost effective, safe, quiet, and efficient curtain of air, EXAIR’s Super Air Knives are what you’re looking for.  If you’d like to discuss a particular application and/or product selection, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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What’s In My Air, And Why Is It Important?

Everyone knows there’s oxygen in our air – if there wasn’t oxygen in the air you’re breathing right now, reading this blog would be the least of your concerns. Most people know that oxygen, in fact, makes up about 20% of the earth’s atmosphere at sea level, and that almost all the rest is nitrogen. There’s an impressive list of other gases in the air we breathe, but what’s more impressive (to me, anyway) is the technology behind the instrumentation needed to measure some of these values:

Reference: CRC Handbook of Chemistry and Physics, edited by David R. Lide, 1997.

We can consider, for practical purposes, that air is made up of five gases: nitrogen, oxygen, argon, carbon dioxide, and water vapor (more on that in a minute.)  The other gases are so low in concentration that there is over 10 times as much carbon dioxide as all the others below it, combined.

About the water vapor: because it’s a variable, this table omits it, water vapor generally makes up 1-3% of atmospheric air, by volume, and can be as high as 5%.  Which means that, even on a ‘dry’ day, it pushes argon out of the #3 slot.

There are numerous reasons why the volumetric concentrations of these gases are important.  If oxygen level drops in the air we’re breathing, human activity is impaired.  Exhaustion without physical exertion will occur at 12-15%.  Your lips turn blue at 10%.  Exposure to oxygen levels of 8% or below are fatal within minutes.

Likewise, too much of other gases can be bad.  Carbon monoxide, for example, is a lethal poison.  It’ll kill you at concentrations as low as 0.04%…about the normal amount of carbon dioxide in the atmosphere.

For the purposes of this blog, and how the makeup of our air is important to the function of EXAIR Intelligent Compressed Air Products, we’re going to stick with the top three: nitrogen, oxygen, and water vapor.

Any of our products are capable of discharging a fluid, but they’re specifically designed for use with compressed air – in basic grade school science terms, they convert the potential energy of air under compression into kinetic energy in such a way as to entrain a large amount of air from the surrounding environment.  This is important to consider for a couple of reasons:

  • Anything that’s in your compressed air supply is going to get on the part you’re blowing off with that Super Air Nozzle, the material you’re conveying with that Line Vac, or the electronics you’re cooling with that Cabinet Cooler System.  That includes water…which can condense from the water vapor at several points along the way from your compressor’s intake, through its filtration and drying systems, to the discharge from the product itself.
  • Sometimes, a user is interested in blowing a purge gas (commonly nitrogen or argon) –  but unless it’s in a isolated environment (like a closed chamber) purged with the same gas, most of the developed flow will simply be room air.

Another consideration of air make up involves EXAIR Gen4 Static Eliminators.  They work on the Corona discharge principle: a high voltage is applied to a sharp point, and any gas in the vicinity of that point is subject to ionization – loss or gain of electrons in their molecules’ outer valences, resulting in a charged particle.  The charge is positive if they lose an electron, and negative if they gain one.  Of the two gases that make up almost all of our air, oxygen has the lowest ionization energy in its outer valence, making it the easier of the two to ionize.  You can certainly supply a Gen4 Static Eliminator with pure nitrogen if you wish, but the static dissipation rate may be hampered to a finite (although probably very small) degree.

At EXAIR Corporation, we want to be the ones you think of when you think of compressed air.  If you’ve got questions about it, give us a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Air photo courtesy of Bruno Creative Commons License