Reduce Sound Level in your Factory, Improve Worker Safety and Comfort

Checking the sound level in your processes is an important aspect of ensuring a safe working environment for your employees. Loud noises and the exposure time can lead to significant health concerns. Permanent hearing loss, increased stress levels due to the uncomfortable work environment, and potential injury due to lack of concentration or inability to hear the surroundings are all examples of some risks associated with a noisy environment.

The Occupational Safety and Health Administration, known by most simply as OSHA, introduced Standard 29 CFR 1910.95(a) as a means of protecting operators from injury associated with high noise levels. The chart below indicates maximum allowable exposure time based on different noise levels. At just 90 dBA, an operator can operate safely for 8 hours. Open end pipe blowoffs and some air guns fitted with cross drilled relief holes will often result in noise levels in excess of 100 dBA. At 110 dBA, permanent hearing loss can be experienced in just 30 minutes!

OSHA Chart

The first step to lowering your sound level is to take a baseline reading of your various processes and devices that are causing the noise. EXAIR’s Sound Level Meter, Model 9104, is an easy to use instrument that provides a digital readout of the sound level. They come with an NIST traceable calibration certificate and will allow you to determine what processes and areas are causing the most trouble.

SoundMeter_new_nist225

From there, EXAIR has a wide range of Intelligent Compressed Air Products® that are designed to reduce compressed air consumption as well as sound levels. For noisy blowoffs where you’re currently using an open-ended pipe or a loud cross-drilled nozzle, EXAIR’s Super Air Nozzles are the ideal solution. Not only will they pay for themselves over time due to compressed air savings, but your operators will thank you when they’re able to hear later on in life!!

Drilled pipe is another common culprit of high noise levels. Rather than purchasing an engineered solution, the idea is that a simple drilled pipe is just as effective right? Not at all!! Not only does a drilled pipe produce exceptionally high sound levels, but the amount of compressed air used is also very inefficient. EXAIR’s Super Air Knife is available in lengths ranging from 3”-108” and has a sound level of just 69 dBA at 80 PSIG. At this sound level, operators won’t even require hearing protection at all!

SAK vs drilled pipe
EXAIR’s Super Air Knife is the ideal solution for replacing noisy, inefficient drilled pipe

With all of these products available in stock, EXAIR has the tools you need to reduce sound level in your processes. If you’d like to talk to an Application Engineer about any applications that you feel could benefit from a sound reduction, give us a call.

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

Reduce Sound Level with EXAIR’s Flat Super Air Nozzles

2san_blowaway
EXAIR’s Flat Super Air Nozzles have been blowing away the competition since 2003.

The patented design of EXAIR’s 1” and 2” Flat Super Air Nozzles make them a highly efficient option when seeking a powerful, flat airflow. A precise air gap across the width of the nozzle provides a forceful stream of high velocity, laminar airflow without consuming high amounts of compressed air and also resulting in a greatly reduced sound level compared to some of the alternative flat nozzles available in the market.

EXAIR’s Flat Super Air Nozzles are safe, reliable, and efficient. Here on the EXAIR Blog we frequently discuss dead-end pressure as explained in OSHA Standard 1910.242(b). This directive states that the when compressed air is used for cleaning purposes, the dead-ended pressure must not exceed 30 psig. When pressures greater than this occur, there is potential for an air embolism.

EXAIR’s Flat Super Air Nozzles cannot be dead-ended, which allows us to operate at pressures well above the 30 psig limit. Some competition markets their nozzles as “Extremely Quiet”, but a deeper look into their performance specifications shows that the published sound level reading was taken at a pressure of 29 psig. They must use a pressure of 29 psig because the nozzles are not OSHA compliant at pressures exceeding 30 psig. For the same competitive nozzle, there is no path for air to escape if the nozzle were to be dead-ended or pressed up against the skin. At 29 psig, the nozzle simply isn’t very effective as it doesn’t provide enough force for most applications. This very same nozzle, when operated at 80 psig, actually has a sound level of 85 dBA.

2inNozzlehand_800x

EXAIR’s Model 1122 delivers more force, more efficiently, and at a sound level of just 77 dBA at 80 psig. Remember, sound levels are expressed in dBA as a logarithmic function. This represents a decrease in sound level by 60%! If you’re looking for a means of reducing sound level in your plant, EXAIR’s 1” and 2” Flat Super Air Nozzles are just what you need.

In addition to being very quiet EXAIR’s flat super air nozzles integrate a shim used to adjust the air gap, which changes the maximum airflow and force. Thicker shims will produce more force and flow, while a thinner shim would do just the opposite.Some applications require more force and some require less, which is not always achieved through simple pressure adjustments so the shims provide the flexibility needed for success.

They’re on the shelf in stock. With same day shipping on orders placed by 3:00 ET and an Unconditional 30-Day Guarantee, there’s no excuse to not give them a try!

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

What is Sound and Interesting Facts About Sound

In physics, sound is a wave of pressure. It occurs in a medium, which can be a solid, liquid or gas. Sound cannot travel through a vacuum, such as in space. The wave of pressure reaches our ears and causes the ear drum to vibrate, which then goes through a complex process to ultimately be perceived as audible sound.

There are several characteristics of sound waves that can be measured and help define the sound. A sound wave can be visualized as a repeating sinusoidal wave (see below), and can be described by these properties – frequency and wavelength, amplitude, and speed.

Sound Wave
Sound Wave
  • Frequency is the number of cycles in 1 second, and is measured in Hertz (Hz)
  • Wavelength is the distance over which 1 cycle occurs, and for audible sound is  between 17 m and 17 mm long
  • Amplitude is the measure of its change over a single period, and normally a measure of sound loudness
  • Speed is the distance traveled per unit time

The speed of sound in air can be found using the equation:  a = Sqrt (γ•R•T)

where for air:
γ = ratio of specific heats = 1.4,
R = gas constant = 286 m²/s²/K
T = absolute temperature in °K (273.15 + °C)

At room temperature, 22°C (71.6°F), the speed of sound is 343.8 m/s (760 mph)

Some interesting facts about sound:

  • Sounds generally travels faster in solids and liquids than in gases.
  • You can estimate the distance from a lightning strike by counting the seconds that pass between seeing the lightning flash and hearing the thunder.  Take this duration an divide by 5 to get the distance away, in miles.
  • Humans normally hear sound frequencies between 20 Hz and 20,000 Hz.
  • Sound waves above 20,000 Hz are known as ultrasound, and sound waves below 20 Hz are known as infrasound.
  • Sound travel through water close to 4 times faster then through air.
  • The sound of a cracking whip occurs because the speed of the tip has exceeded the speed of sound.

Sound that is too loud can be a problem. The Occupational Safety and Health Administration (OSHA) has set limits on the noise exposure that an employee can be subjected. Exceeding these values can cause permanent damage to your ears and cause noise induced hearing loss. So, knowing and reducing the sound levels within a manufacturing operation is important.

OSHA Chart

EXAIR has many products that can help reduce the sound levels in your processes.  With products such Air Knives, Air Wipes, Air Amplifiers, Air Nozzles and Jets, and Safety Air Guns, strong, quiet and efficient blowoff, drying, and cooling can be performed.

Quiet Products

If you have questions about sound and keeping your sound levels in check or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
Send me an email
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Twitter: @EXAIR_BB

“Go Green” in 2019 With EXAIR’s Super Air Nozzles & Jets!

If one of your New Year’s resolutions for 2019 is to help improve your impact on the environment, look no further than EXAIR’s Engineered Air Nozzles & Jets. By upgrading your blowoff, cooling, and drying operations to use one of our Super Air Nozzles or Jets you can save as much as 80% of your compressed air usage when compared with an inefficient solution.

open tubes
Example of a manifold of open pipes

An open copper pipe or tube, even if “flattened” as we’ll commonly see, wastes an excessive amount of compressed air. This wasted compressed air can create problems in the facility due to unnecessarily high energy costs and the pressure drop that can be experienced affecting other processes. In addition to simply using too much compressed air, an open pipe or tube will often produce sound levels in excess of 100 dBA. At these sound levels, according to OSHA, permanent hearing damage will occur in just 2 hours of exposure.

OSHA Chart

By simply replacing the open tubes and pipe with an EXAIR Super Air Nozzle, you can quickly reduce air consumption AND reduce the sound level. Sound level isn’t the only thing an OSHA inspector is going to be concerned about regarding an open pipe blowoff, in addition OSHA 1910.242(b) states that a compressed air nozzle used for blowoff or cleaning purposes cannot be dead-ended when using with pressures in excess of 30 psig. I don’t know if you’ve ever tried to use an air gun with 30 psig fed to it, but the effectiveness of it is dramatically reduced. This is why there needs to be a device installed that’ll prevent it from being dead-ended so that you can operate at a higher pressure.

nozzle_anim_twit800x320
EXAIR Super Air Nozzle entrainment

EXAIR’s Super Air Nozzles are designed with fins that serve two purposes. They help to entrain ambient air from the environment, allowing us to maximize the force and flow from the nozzle but keeping the compressed air consumption minimal. In addition, these fins are what prevents the nozzle openings from being completely blocked off. Using an OSHA compliant compressed air nozzle for all points where a blowoff operation is being performed should be a priority. Each individual infraction will result in a fine if you’re subject to an OSHA inspection. Inspections are typically unannounced, so it’s important to take a look around your shop and make sure you’re using approved products.

sag-osha-compliant
The fins along the outside of the Super Air Nozzle prevent it from being dead-ended

So, go ahead and make 2019 the year of energy savings, increased efficiency, and improving worker safety. You’ll find all of the tools you need in EXAIR’s 32nd edition of the catalog. Click here if you’d like a hard copy sent directly to you! Or, get in touch with us today to find out how you can get saving with an Intelligent Compressed Air Product.

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

 

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

Safety, Efficiency, and Production Improvements

Last week, I received an email from a satisfied customer, after he had already purchased our product.  Come to find out this customer had not spoken to an application engineer during the planning stage to make their purchase. With our excellent resources listed at EXAIR.com, the customer was able to fulfill his application without even speaking to us. After his initial email of thanks, he also shared with me some details of his application that I want to share with you today.

The customer works as a machinist at a large aircraft part manufacturer. The parts require a very tight tolerance. A sample of each part needed to be gauged and measured in an automatic thread gauging machine or a coordinate-measuring machine (CMM). Their machining process required a water based flood coolant, so each part would be coated in water based coolant and chips, which needed to be remove before gauging. Before visiting EXAIR’s site, the company used a variety of homemade and commercial blow offs, as safety air gun tips. Here is a photo of (20) of the (25) nozzles the customer was using.

Aircraft manufacturer's obsolete nozzles

As you can see, the nozzles vary in design purpose, flow and safety. Most of the nozzles feature a cross drilled hole or a secondary escape path, but not all of the nozzles do. Any nozzle without a secondary relief port violates OSHA standard CFR 1910.242(b), so replacing some of the nozzles increased the safety in the plant. Secondly, these nozzles are wasteful in their use of compressed air because some were designed as liquid nozzles and have large exit holes. A hole that is 1/8″ in diameter at the nozzle outlet can consume up to 21.4 SCFM of compressed air at 80 PSIG. For comparison, the model 1103 Mini Super Air Nozzle with a 1/8″ NPT inlet will flow 10 SCFM at 80 PSIG, which would be a 53% compressed air savings. In 24 running hours, the 1103 nozzle will save 16,416 Standard Cubic Feet, which the plant spent $4.10 for a standard industrial compressor to produce (The standard for compressed air cost is $0.25 per 1,000 SCF). Replacing just one 1/8″ drilled hole with 1103 Mini Super Air Nozzle saves the aircraft company $1,026 over 250 working days running 24 hours a day.

Neither of these were the real reason that the customer emailed to thank us though. He was actually an office employee just entering the work force.  Starting in June until after the company finally acquiesced to his request to buy a better, quieter nozzle near the end of July, he had left work needing an aspirin to relieve the headache he acquired due to the noise from these other nozzles. The nozzles the machining center had been using would create noise levels between 88-100 dBA at 80 PSIG of inlet pressure. For reference OSHA mandates that employees are required to wear hearing protection, if they are exposed to noise levels over 90 dBA over an 8 hour work day.  The employees doing the machining wear hearing protection, but the employees in the office were still exposed and affected by the noise level.  This is just one anecdotal example, but everyday more and more research shows that noise exposure has a negative effect on our health and productivity in the workplace.  If you are interested in more information here are some links to a number of studies/research – please read this, here or this.

Anyway, that’s enough of my soapbox. The company purchased 25 of EXAIR’s 1103 Mini Super Air Nozzles and utilizing the same guns they were currently using saw between a 10-15 dBA decrease in noise levels near the work stations. Here is a photo of one of their setups with the model 1103 installed on one of their current air guns.

Nozzle Replacement
The 1103 Super Air Nozzle is an engineered solution to replace a plethora of commercial nozzles. It was a simple and cost effective retrofit which increased the comfort of employees.

 

We know that every time they squeeze that air gun trigger they will be using less compressed air than before, and we know they are now in compliance with OSHA. But the best benefit for EXAIR is we know that the engineer took the time to email us to thank us for taking away his headache everyday.  That’s enough for me.

Dave Woerner
Application Engineer
DaveWoerner@EXAIR.com
@EXAIR_DW

 

 

EXAIR Super Air Knife: Reduce Cost, Reduce Noise, Increase Safety

This question from end user’s comes up again and again:

“I know EXAIR makes Air Knives. Do you have one for this application?”

We can answer, almost unequivocally, with a resounding “YES!” Whether we can meet the needs of the application with a stock product, or through manufacturing a specially made unit, we make every effort to provide the needed solution.

Super Air Knife Replaces Drilled Pipe Blow Off

Case in point, in the application above, a specific length Air Knife was desired to remove debris from material as it goes into a processing chamber. The current setup (outlined in red)  uses drilled holes in a section of pipe which are costly, loud, and unsafe.

How costly, you ask? Our customer stated this knife was 100″ long with 3/32″ holes on 2″ centers (50 holes). EXAIR test results on 3/32″ drilled holes confirm 15 SCFM per hole at 80 PSIG inlet pressure. The customer also estimates this drilled pipe operates for a total of 1 hour every day, 250 days per year. Using $0.25 per 1000 SCFM we can calculate the following:

  • 50 holes x 15 SCFM = 750 SCFM at 80 PSIG
  • 750 SCFM x 60 minutes per day = 45,000 SCF per day
  • 45,000 SCF x 250 days = 11,250,000 SCF per year
  • 11,250,000/1000 x $0.25 = $2812.50 cost per year

How loud, you ask? Our customer confirmed all personnel near the application were require to wear ear protection at all times. Though they were unable to provide a decibel (dBA) level, the need for hearing protection would indicate this pipe was operating in excess of 100 dBA.

How unsafe, you ask? Air can be dangerous when the outlet pressure of a hole is greater than 30 PSIG. In the event any of the holes were blocked by a hand or other body part, air may enter the bloodstream through the skin, resulting in serious injury. All of the Air Knives manufactured by EXAIR have been engineered for safety. They are all safe to be supplied with higher pressure compressed air and meet OSHA standard CFR 1910.242(b). Drilled holes in a pipe DO NOT MEET this OSHA standard.

Initially, discussions with this end user focused on a custom length, custom built Super Air Knife. Given the dimensions of the processing environment, we determined the desired length and the end user was thrilled we could not only make to their specifications, but offer 3 day delivery as well.

As the discussion carried on, we realized that the special length Super Air Knife, while applicable, was not a critical requirement for the application. With this new consideration, a stock length knife was chosen, and just like any stock EXAIR product, we had it on the shelf, ready to ship the same day.

This application highlights several benefits of the EXAIR Super Air Knife solution – compressed air savings, noise reduction, providing safety, and quick delivery. EXAIR Super Air Knives solve multiple problems for end users and OEM’s in a variety of applications.

Compressed Air Savings: 

  • 96″ knife with 2.9 SCFM per inch consumption at 80 PSIG = 278.4 SCFM at 80 PSIG
  • 278.4 x 60 minutes per day = 16,704 SCF per day
  • 16,704 SCF x 250 days = 4,176,000 SCF per year
  • 4,176,000/1000 x $0.25 = $1044 cost per year
  • $2812.50 (drilled pipe annual air cost) – $1044 (EXAIR 96″ Super Air Knife air cost) = $1768.50 SAVINGS the first year!

Noise levels reduced to under 80 dBA. 

SAFETY: EXAIR Super Air Knives meet the OSHA standard CFR 1910.242(b).

Switching this customer over to an engineered solution provided a win in these three important areas of any operation. If assistance is needed determining which Super Air Knife best suits your application, contact an Application Engineer.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE