Great Stuff About Jets

There are a number of fascinating facts about jets…both the aircraft engines and the EXAIR Intelligent Compressed Air Products:

  • Because they don’t require dense air to engage spinning blades (like their propeller driven counterparts,) they can operate at much higher altitudes. (Jet aircraft engines only)
  • They provide a high thrust, directed airstream, which makes them great for part ejection, chip removal, and part drying. (EXAIR Air Jets only)
  • With few or no moving parts, they are extremely reliable, durable, and safe. (Both jet aircraft engines and EXAIR Air Jets)
  • They use the Coanda effect (a principle of fluidics whereby a fluid flow tends to attach itself to a nearby surface, and follow that surface regardless of the flow’s initial direction) to do what they do.
    • EXAIR Air Jets use this principle to generate a vacuum in their throat, pulling in a large amount of “free” air from the surround environment, making their use of compressed air very, very efficient.
    • Jet (and propeller driven) aircraft wings employ the Coanda effect to create aerodynamic lift, enabling the plane to fly.

Now, since I’m not a pilot, nor do I particularly like to fly, but I AM a fluid dynamics nerd, the rest of this blog will be about the Air Jets that EXAIR makes.

All of our Air Jet products operate on the same principle…using the Coanda effect (as described above) to generate a high volume air flow while minimizing compressed air consumption:

(1) Compressed air enters and is distributed through an annular ring, and directed towards the discharge via the Coanda effect.
(2) This causes entrainment of surrounding air, both through the throat, and at the discharge.
(3) The total developed flow has tremendous force and velocity, for a minimal consumption of valuable compressed air.(1) Compressed air enters and is distributed through an annular ring, and directed towards the discharge via the Coanda effect.
(2) This causes entrainment of surrounding air, both through the throat, and at the discharge.
(3) The total developed flow has tremendous force and velocity, for a minimal consumption of valuable compressed air.

There are four distinct models of the EXAIR Air Jet:

  • Model 6013 High Velocity Air Jet is made of brass for economy and durability.  The annular ring gap (see 1, above) is fixed by a 0.015″ thick shim.  Performance can be modified by changing to a 0.006″ or 0.009″ thick shim, which come in the Model 6313 Shim Set.
  • Model 6013SS is a Type 303 Stainless Steel version, for higher temperatures – good to 400°F (204°C) – and superior corrosion resistance.
  • Model 6019 Adjustable Air Jet is brass construction, and dimensionally identical to the Model 6103.  Instead of a shim that sets the annular ring gap, though, it has a threaded plug, with a micrometer-style indicator, to “fine tune” the gap.
  • Model 6019SS is the Type 303 Stainless Steel version…fine tuning adjustability, good for high heat and/or corrosive elements.
Four distinct models to meet the needs of your air blowing application.

If you’d like to find out more about EXAIR’s quiet, efficient, and safe Air Jets, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Video Blog: How To Calculate Air Consumption At A Pressure Other Than Published Values

The below video shows how to calculate the air consumption when operating at any pressure.

If you want to discuss efficient compressed air use or any of EXAIR’s engineered compressed air products, give us a call or email.  We would enjoy hearing from you!

Steve Harrison
Application Engineer
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How to Calculate SCFM (Volume) When Operating at Any Pressure

If you need to operate at a different pressure because you require less or more force or simply operate at a different line pressure, this formula will allow you to determine the volume of air being consumed by any device.

Volume Formula

Using the EXAIR 1100 Super Air Nozzle as our example:

1100

Lets first consider the volume of the 1100 Super Air Nozzle at a higher than published pressure.  As shown in the formula and calculations it is simply the ratio of gauge pressure + atmospheric divided by the published pressure + atmospheric and then multiply the dividend by the published volume.  So as we do the math we solve for 17.69 SCFM @ 105 PSIG from a device that was  shown consume 14 SCFM @ 80 PSIG.

higher

Now lets consider the volume at a lower than published pressure.  As shown it is simply the ratio of gauge pressure + atmospheric divided by the published pressure + atmospheric and then multiply the dividend by the published volume.  So as we do the math we solve for 11.04 SCFM @ 60 PSIG from a device that was shown to consume 14 SCFM @ 80 PSIG.

lower

When you are looking for expert advice on safe, quiet and efficient point of use compressed air products give us a call.  Experience the EXAIR difference first hand and receive the great customer service, products and attention you deserve!  We would enjoy hearing from you.

Steve Harrison
Application Engineer
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Super Air Knives Provide Dry Surface for Printing

I’ve always liked Halloween.  My friends and I got to go trick-or-treating together around the neighborhood, under the supervision of a parent or two, until one year when we were deemed old enough to go around the immediate neighborhood (gasp) by OURSELVES!!!

You need to know that, for any of our Moms, that was a HUGE investment in trust they were putting in us. One that, I’m afraid was undeserved. See, we’d all heard rumors of “tricks” from some cool older kids, and were eager to try our hands at it. Now, we were a relatively mild mannered bunch. We certainly weren’t going to break anything or hurt anyone. But the tales of soaping windows had an irresistible appeal…so, after we donned our costumes that evening, we all sneaked a bar of hand soap out of the house, and set about on our great adventure. Which was not so great, for a couple of reasons:

First, Halloween that year fell on a particularly drizzly night.  We weren’t in danger of a rain-out, but there was a layer of “wet” on everything…especially the windows on which we planned to display our art. That didn’t stop us from trying, though…it just wasn’t near as effective, or fun, as we’d hoped.  Basically, we got some weak smudges here and there.

Second, our parents & neighbors were a lot more savvy than we’d expected. I’m not even sure what happened first…the discovery of the missing bars of soap, or the neighbors calling our parents to tell them what we were up to. We were all punished according to our respective families’ customs, and the next year, we were the oldest trick-or-treaters out there under adult supervision.

I think about that night whenever I see one of those “World’s Dumbest Criminals” shows, but it popped into my head recently while discussing a Super Air Knife application with a customer.  The caller worked in facility that produced pizza dough, and had recently implemented a quality tracking system that applied a temporary code to the rims of the plastic trays that carried the loaves of dough along a conveyor.   Thing is, the trays could still be wet from the wash/rinse cycle, and the ink (which is water soluble and is supposed to be removed by the washer anyway) really, really needs a pretty dry surface, or it’s just going to be a weak, smudgy mess, much like the great Window Soap Fail of 1970-something.

They purchased two Model 110003SS 3″ Stainless Steel Super Air Knives and installed one on each side of the conveyor, just after the rinse tunnel.  The Super Air Knives blow off the rims of the trays, leaving a clean, dry surface for the printer.

EXAIR Super Air Knives come in a wide variety of lengths to suit a wide range of applications.

EXAIR Super Air Knives come in a variety of materials, lengths from 3 inches to 9 feet, and are the quietest & most efficient compressed air operated blow off products on the market today.  If you’d like to find out more about they can help you, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Experience The EXAIR Difference For Yourself!

The other day I received a call from the Corporate Director of a manufacturing company with multiple locations across the country.  He had grown frustrated with the service and quality he was receiving from his current Air Gun & Nozzle supplier.  He explained that he was unable to buy the individual components to make repairs to the air guns and described the overall quality as “disposable”.

I asked him for model air gun he had been purchasing so that I could make an accurate comparison and recommendation for the equivalent or better EXAIR offering.  As I researched this competitive air gun I was surprised to find out that the specifications were vague at best.  What I mean by that is EXAIR clearly publishes air consumption @ 80 PSI, force which is specified @ 12″ from the nozzle and the sound level in dBA @ 3′ from the nozzle.

I recommended the EXAIR 1699-24 (1699-12 pictured) which is the VariBlast Compact Safety Air Gun, 24″ Extension Pipe & the 1102 Mini Super Air Nozzle.

Final Image
1699-12

The 1699-24 (supplied with the 1102 Mini Super Air Nozzle) specifications are: 10 SCFM @ 80 PSI compressed air consumption, 9 ounces force @ 12″ from nozzle and 71 dBA @ 3′ from the nozzle.  The 1102 1/8 FNPT is available in Zinc Aluminum, 316 SS or PEEK plastic.

1102 Mini Super Air Nozzle

The customer reported an average noise reduction of over 15 dBA which looks considerable, however it is a greater gain than the number would indicate. An increase of 10 dB is required before sound is perceived to be twice as loud, therefore EXAIR lowered the perceived sound by over 150%!

While this customer did not add the optional EXAIR Chip Shield you certainly can.  Simply add -CS to the end of any Safety Air Gun part number.  The part number for the featured VariBlast Safety Air Gun would become 1699-24-CS.  Chip Shields are made from durable poly-carbonate that protect operators from flying debris often associated with blowing chips off machined parts.  Chip Shields are also great for keeping coolant from spreading everywhere during drying operations.  They are available for the VariBlast Safety Air Gun, Soft Grip Safety Air Gun and Heavy Duty Safety Air Gun.  Also Chip Shields can be used on Safety Air Guns with or without the aluminum extension!

When you are looking for OSHA safe, quiet and efficient point of use compressed air products give us a call.  Experience the EXAIR difference first hand and receive the great customer service, products and attention you deserve!  We would enjoy hearing from you.

Steve Harrison
Application Engineer
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Is It Safe To Use Compressed Air?

Think about it…compressed air is, by definition, gas under pressure: potential (stored) energy.  This energy is intended to do work, like operation of pneumatic tools, actuation of pneumatic cylinders, debris removal with an air gun or blow off device, and (even though I haven’t done it in a while) my personal favorite:

High pressure compressed air is meticulously made, prepared, and stored to ensure the number of surfaces equals the number of dives.

Uncontrolled, unplanned, or accidental releases of stored energy (regardless of the source) are inherently dangerous, and great care must be taken to guard against such incidents.  This is accomplished, primarily, in three areas:

*Operation.  This might be the most prevalent, because it involves the greatest number of personnel (e.g., everyone) as well as the ways compressed air is used (e.g., all of them.)  It’s also the area where the most involved people (the operators) have the most control:

  • Personal protection.  Don’t even think about operating a compressed air device without eye protection.  Ever.  Hard stop.  Also, if the operation involves flying debris, a full face shield, long sleeves, gloves, etc. might be called for.  Hearing protection may be required as well…keep in mind, even if an engineered device (like any of EXAIR’s Intelligent Compressed Air Products) generates a relatively low sound level, the impingement noise of the air flow hitting the object can reach dangerous levels.
  •  Personnel cleaning is prohibited.  The risk of injury to the eyes, respiratory system, and other parts is just too great to rely on personal protective equipment that’s designed for use while discharging compressed air AWAY from the body.  While this is expressly prohibited in certain situations, OSHA has long recognized it as good practice for all industries.
  • No horseplay.  ’nuff said.  Plenty of better ways to have fun at work.

*Design.  This one usually has the advantage of being traceable to a small number of people, and is also the one that’s most likely to be documented.  This is where it starts…if the system is designed to fail, it doesn’t matter how much care the operators take:

  • Supply lines, fittings, and hoses must be rated for use with compressed air, up to and exceeding the maximum discharge pressure of the air compressor.
  • This goes for any tools, blow off devices, components, etc., serviced by the air system.  The only thing worse than a component failing is a component failing in your hand.
  • Shut off valves should be located as close as practical to point(s) of operation.  This allows you to quickly secure the flow of compressed air to a failed component, hose, etc., and prevent further damage or risk of injury.
  • Hoses shouldn’t be run across the floor, where they can become a trip hazard or subject to damage from stepping on them.   This is a surefire way to find out the value of shut off valves (see above.)

*Product specification.  Or, more simply put, using the right tool for the job.  A broader discussion could include efficiency and performance, but we’ll stay within the confines of safety for the purposes of this blog:

  • Be mindful of dead end pressure.  Blow off devices, especially hand held ones like air guns, are oftentimes fitted with a simple open-end discharge.  If this is pushed into a part of the body, the pressurized air can break the skin and cause an air embolism.  This is a serious injury, and can be fatal if it reaches the heart, lungs, or brain.
    • This is a key consideration to OSHA Standard 1910.242(b), which limits the downstream pressure when compressed air is used for cleaning to 30psi.
    • EXAIR products are compliant with this Standard by design…there’s always a relief path for the air pressure; they can’t be dead ended.
Because the compressed air exits through a series of holes, recessed between a ring of fins, any attempt to block the air flow will simply send it in another direction.
  • Harmful sound levels are a consideration as well.  As stated above, hearing protection is required in many cases, but sound levels can be mitigated through the use of engineered products.  EXAIR Intelligent Compressed Air Products, as a result of their high entrainment, generate a boundary layer of air flow that leads to dramatically lower sound levels than a similar-sized open end blow off device.

If you’d like to explore ways to make your compressed air system safer, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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OSHA 29 CFR 1910.15(a) – Occupational Noise Exposure Limits

Hearing loss due to high noise levels is a common problem in many industrial facilities. Without the use of proper PPE, hearing loss can occur quickly. This is a serious concern as hearing loss is permanent and once the damage is done there’s no way to reverse it. Due to this risk, OSHA strictly enforces standard 29 CFR-1910.95(a).

This directive discusses the effects of noise and limits exposure based on the dBA. The table below indicates the maximum allowable exposure time to different noise levels. Sound levels that exceed these levels should first be addressed by proper engineering controls such as isolating the source of the sound from personnel or replacing the cause of the sound with something like an engineered compressed air nozzle. When such controls aren’t feasible, proper PPE must be worn to protect the operator.

OSHA Chart

Hearing loss can occur in as little as 30 minutes when exposed to sound levels 110 dBA or greater. Operators have a tendency not to use PPE as directed, if an OSHA inspector comes to your facility and notices that the sound levels exceed the maximum allowable level without protection hefty fines will be soon to follow. In this example from the United States Department of Labor, a company was fined a total of $143,000 for failing to protect their employees.

SoundMeter_new_nist225
Model 9104 Digital Sound Level Meter

In order to identify the places or processes in your facility that are causing the problems, you’ll need a tool to measure the sound level. EXAIR’s easy to use Digital Sound Level Meter allows you to measure and monitor the sound level pressure in a wide variety of industrial environments. The source of the loud noise can then be identified and isolated so that corrective action can be taken. For compressed air related noise, EXAIR manufactures a wide variety of engineered compressed air products that can reduce the sound level dramatically. In many cases, EXAIR products are capable of reducing noise levels by as much as 10 dBA. Since the dBA scale is logarithmic, this equates to cutting the sound level in half!

sound-level-comparison
Drilled pipes and open ended tubes are the common culprit for excessive noise levels. Replacing them with an engineered solution often eliminates the need for hearing protection.

If there’s processes within your facility that are above these limits and you’d like to eliminate relying on proper PPE, give an Application Engineer a call. We’ll help walk you through the selection process and make sure that when the OSHA inspector comes knocking you’re prepared!

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@exair.com
Twitter: @EXAIR_TD