Super Air Knife Math – When 72 + 72 = 75

The Super Air Knife is the latest generation of EXAIR engineered air knife that dramatically reduces compressed air usage and noise when compared to other blowoffs.

Super Air Knife Data

From the chart above, the Super Air Knife when supplied with 100 PSIG of compressed air has a sound level of just 72 dBA (A-weighted decibel scale) when measured from 3′ away.  72 dBA is a moderate sound level, and some common comparisons are ‘normal speaking voice’ at 70 dBA and ‘living room music’ at 76 dBA.

For many processes, such as a bottling line drying operation, a pair of the air knives delivers the best performance. When asked, “what is the sound level for (2) of the knives,” a little Acoustic Engineering is in order. Because the decibel scale is logarithmic, the result is not as simple as adding 72 + 72 = 144.  144 dBA is in the range of a jet aircraft take off! Thankfully, both the actual sound level and the numerical value are determined another way.  I’ll spare you a lot of the math but the equation is as below.

Capture

… where SL1, SL2, SL3 are the sound levels in dBA of the each sound makers, for as many that are being combined.

In the case of (2) Super Air Knives operated 100 PSIG, the combined sound works out to be a quiet 75.0 dBA — a powerful, efficient and quiet product ideal for many applications and process within the manufacturing environment.

Super Air Knife

Super Air Knife

As a helpful rule of thumb- combining any (2) items will yield an increase of 3 dBA, combining (3) results in a rise of 4.8 dBA, and combining (4) results in a 6 dBA rise over just (1) of the items.

The Super Air Knives have been successfully used in a wide range of applications, including part drying, sheet and conveyor cleaning, web cooling, scrap removal, pre-paint dust blowoff, and many, many more.

To discuss your application and how an EXAIR Intelligent Compressed Air Product can make your process better and quieter, feel free to contact EXAIR and myself or one of our other Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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EXAIR’s Efficiency Lab can Help With your Energy Audit, Quantify Savings and Provide an ROI

I recently received an inquiry from a customer to test their current air guns through our Efficiency Lab service. According to the operators, the handheld blow gun they were purchasing from a commercial retailer was too loud and complaints were rolling in.  They were also hoping to save some compressed air in the process as they were performing an energy audit at the same time.

Commercial Air Gun w/ Cross Cut Hole

Commercial Air Gun w/ Cross Cut Hole

Cross Cut Hole Nozzle

Cross Cut Hole Nozzle

The gun they sent in looked fairly similar to our Precision Safety Air Gun but it did not have an engineered nozzle on the tip of it.   Instead, it was simply a cross cut hole in a piece of material.   The air inlet to the gun was a 1/4″ NPT just like our Precision Safety Air Gun, the extension on the gun was slightly longer, the only significant variance I saw was the tip.

EXAIR Model 1410SS-CS

EXAIR Model 1410SS-CS

The Model 1110SS Nao Super Air Nozzle and Chip Shield

The Model 1110SS Nao Super Air Nozzle and Chip Shield

To try and get as much information as possible I measured the O.D. and I.D. of the extension, the hole size was approximately .140″.  I measured the extension on our Precision Safety Air Gun just to see what is different, it came in at the same size.  So, I flow tested the competitive blow gun with their tip on it and came up with air consumption of 12.69 SCFM, noise level of 92 dBA at 3′ away, and a blowing force of 11.5 oz at 80 psig.   I then measured the same attributes of EXAIR’s model 1410SS-CS Precision Safety Air Gun at 80 psig inlet pressure.  The model 1410SS-CS measured 8.3 SCFM, gave 8.1 ozs of working force, and only produced a 75 dBA sound level from 3′ away.

The sound level reduction was a total of 17 dBA which is below the OSHA standard for allowable noise level exposure, as well as reduced their air consumption by 4.39 SCFM.  That is almost a 35% reduction in their compressed air usage per gun replaced.  After seeing these levels of reduction the customer had more than enough information to provide management with in order to replace the blow guns not just for noise level reduction but also because it will reduce air use and save money. A clear supportive role in their energy audit.

If you would like to discuss how EXAIR can provide some free force, flow, and noise level testing for your facility, please contact an Application Engineer or check out the Efficiency Lab page on our site.

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF

Use The Force…Or Not…It’s Up To You, Really

The month of May, in 1977, was a great time to be ten years old. I was finishing up my fifth grade year, a pivotal one, thanks to Miss Walker, who ended up being my favorite teacher ever. She had a pet rat named A.J. that we took turns taking home for the weekend. She rewarded us for class performance by taking us outside to play softball on warm & sunny spring afternoons. I trace my love for math (and hence, my inspiration for a career in engineering) to the excitement she instilled in me for the subject…I was among the first to master the multiplication tables.

And then there was Star Wars. There were commercials for the movie and the toys and the merchandise on TV; I swear they ran every five minutes. A fast food chain released a series of posters (free with purchase) and every time a new one came out, Miss Walker promptly hung it on the classroom wall. None of us, her included, could hardly wait until the premiere. I could go on (and on and on and on,) but suffice it to say (for the purposes of this blog,) I’ve been a BIG fan ever since.

Which brings us to today…opening day for “Star Wars, Episode VII: The Force Awakens.” The first time, by the way, a Star Wars movie hasn’t premiered in the month of May, but I digress. The 10 year old inside me wants to go see it RIGHT NOW, but the grownup I have to be has a company Christmas party, two Boy Scout events, and a pre-holiday “honey-do” list to attend to first.

Of course, the “other” epic space movie series couldn’t resist launching THEIR new trailer this week…

All this talk about The Force (capital “F”) and the fact that I write this blog on company time has me thinking about compressed air applications that involve force (lower case “f”) and how using force (unlike “The Force”) is not always prudent.

This is the case in just about any blow off application that uses air under pressure. Open ended copper tubing, drilled pipes, etc., are common and easy ways to discharge compressed air for debris removal, drying, or cooling a part. But the fact is, they waste a LOT of the energy devoted to compressing the air by simply turning it into brute force and noise.

This is where EXAIR Intelligent Compressed Air Products(r) come in: by using the energy of the compressed air to entrain air from the surrounding environment, the total air flow is amplified, resulting in a high velocity blast, at minimal consumption. No; it doesn’t have the same amount of force as an open ended discharge device, but most blow off applications don’t need all that much force anyway.

Of course, there ARE situations where you need to use the force, and we’ve got efficient and OSHA compliant ways to do that too: additional shims in Air Knives, Air Wipes & Air Amplifiers, or larger Super Air Nozzles.

“A long time ago, in a galaxy far, far away,” the continuing theme of the Star Wars saga is to use The Force properly. For the past 32 years, the continuing theme at EXAIR is to help you use the force (of your compressed air) properly. Let me know how we can help.

May The Force be with us all…this weekend, and always.

Russ Bowman
Application Engineer
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Video Blog: Features and Positioning of EXAIR’s Digital Sound Level Meter

This video explains a few of the features on the EXAIR Digital Sound Level Meter. It also illustrates proper positioning of the meter when taking sound level readings. This sound level meter is an important tool to quantify noise exposure of employees and identifying the sources of noise.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Reduce Noise Exposure with Super Air Nozzles

News from the CDC that those of us involved with industrial safety are paying close attention to is the release of their NIOSH (National Institute for Occupational Safety and Health) division’s Hazard Evaluation Program Noise Measurement Database, which contains data obtained through Health Hazard Evaluation surveys performed between 1996 and 2012. It includes hundreds of personal noise exposure measurements (how much noise was received by individuals) and almost as many area noise measurements (how much noise was made.) A comparison of these measurements, of course, is valuable in determining if appropriate measures are being taken to abate the exposure, which is key: there are an awful lot of industrial processes where there’s nothing that can be done about the generation of noise…they’re just simply LOUD. So, they focus on what they can do to limit exposure: Use engineering controls (retrofit open line with engineered nozzles, build sound barriers) , use administrative controls (relocating personnel away from the sound), use personal protective equipment, and spending as little time as possible near the source.

Regardless of what people can get used to, the area noise associated with compressed air use CAN be reduced, while still maintaining the efficiency of the operation. Here’s the deal:

*The most basic form of air blow off is a piece of pipe, tubing, or hose connected to a source of compressed air. When it’s opened to the atmosphere, the compressed air exits with a great deal of force. This makes quite a racket, and the only way to quiet it down is to reduce the air supply pressure. Then you get less force, however, and it might not get the job done.

*Engineered air nozzles, such as EXAIR’s Super Air Nozzles, solve this problem by design:

air nozzle flow

The compressed air supply (black arrow) uses the Coanda effect when it exits the series of holes recessed in the array of fins (dark blue arrows.) This serves to entrain an enormous amount of air from the surrounding environment (light blue arrows,) which not only results in a high volume flow rate at minimal consumption, but also makes the resultant air flow very quiet.

EXAIR Super Air Nozzles are quiet, efficient, and easy to get…we maintain inventory of anything you see in the Catalog, all available for same day shipment. If you’d like to know how EXAIR products can be easy on your ears…and your wallet…give me a call!

Russ Bowman
Application Engineer
(513)671-3322 local
(800)923-9247 toll free
(513)671-3363 fax
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Award Winning Compressed Air Nozzle Saves Hundreds of Dollars Annually

awards2013_1126_400wide

 

EXAIR’s 1 Inch Flat Super Air Nozzle won the Gold Award for Compressed Air from Plant Engineering in 2014. We won the award for the immense savings that our customers reap by using this nozzle to replace open blow offs. While saving compressed air, we also reduce noise level and comply with an OSHA regulation 192.242(b).  Do not leave that blow off open. It is costing you everyday in dollars; it may cost you more in OSHA fines later, and it will cost your employees hearing later.

A 1/4″ copper tube can use 33 SCFM at 80 PSIG of inlet pressure. This homemade blow off will use 1,980 standard cubic feet per hour. Typical industrial compressed air cost $0.25 per 1,000 standard cubic feet.  That 1/4 copper tube is costing you $0.50 every hour to run. Each year, one 1/4″ copper tube costs $2,970*.

The 1 inch Flat Super Air Nozzle, model 1126, uses 10.5 SCFM or 22.5 SCFM less than 1/4″ Copper tube.  Saving your company 22.5 SCFM, is the same as saving $0.34 every hour or $2,025 every year.*  Saving 22.5 SCFM also, means that your compressor system doesn’t have to work as hard.  A 5 HP compressor will put out 20 SCFM, so replacing one 1/4″ Copper Tube with a model 1126 will save you from upgrading compressor system as your company expands.

Regardless of the $2,025 you just saved by replacing the homemade blow offs with engineered nozzle, it is also an industry best practice because it can lower the noise exposure for personnel and prevent any harm from dead end pressure.  OSHA standard 29 CFR – 1910.95(a) requires that if an employee is exposed to greater than 100 dBA for 2 hours, he or she needs to wear hearing protection.  A 1/4″ copper tube will easily exceed 100 dBA.  The model 1126 will lower the noise level to 77 decibel, 13 dBA lower than the OSHA requirements for an 8 hour day.

Finally, the 1″ Flat Super Air Nozzle cannot be dead ended, which protects your employees from serious injury. In the event, that a compressed air orifice is blocked with no means of escape, air may enter the bloodstream from an open cut or wound in the skin. Compressed air must be kept below 30 PSIG to eliminate this danger when using an open pipe, tube or many commercial air nozzles. With EXAIR nozzles, pressure to the nozzle  can remain at line pressure and produce the maximum velocity and force for a successful application.

*Assuming 24 hours a day and 250 working days

Dave Woerner
Application Engineer
Davewoerner@EXAIR.com
@EXAIR_DW

How can you protect people that don’t protect themselves?

My sister-in-law and my nephews are traveling from Columbus to Cincinnati for a visit this weekend. My nephews are 18 months and 3 years old, and they will find any sharp, fragile, or flammable object within walking, crawling or climbing distance. Of course they don’t consider these things dangerous. All they see are fun new toys. Yesterday, I battened down the hatches for the nephew hurricane that will be barreling down Interstate 71 this weekend, and there were more dangerous or scary items in the house that the nephews will want to use than I could hide.

At EXAIR, we strive to provide products that intelligently use compressed air, but everyday we have customers who are using compressed air in unsafe manner. We try to educate many of our customers and the industry as whole of the dangers and that can be associated with compressed air. The chief concern is that compressed air may cause an embolism by forcing air into the bloodstream through a break in the skin or body opening. Because of this risk, OSHA has laid down several rules for using compressed air for cleaning purposes inside the work place. To quote the OSHA Instruction STD 1-13.1, “The requirements for dynamic flow are such that in the case when dead ending occurs a static pressure at the main orifice shall not exceed 30 psi. This requirement is necessary in order to prevent a back pressure buildup in case the nozzle is obstructed or dead ended.

An open pipe used for cleaning violates this rule. Yet everyday I speak to a customer who are using open pipes to remove chips, dust or water from parts. If a employees hand is trapped against the open tube, serious injury will result. EXAIR’s Super Air Nozzles are designed with multiple openings and fins to protect those openings, so that air always has a path to escape.

 

Nozzle Lineup

 

The other safety concern with an open pipe is the noise level.  Open pipes can produce noise levels over 100 dBA which violates OSHA’s standard for maximum Allowable Noise Exposure for even 2 hours per day.  EXAIR Super Air Nozzles will reduce noise levels to create a safer more productive work environment.

Dave Woerner
Application Engineer
Davewoerner@EXAIR.com
@EXAIR_DW

 

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