Sound: What Is It … More Importantly, Weighted Scales of Frequencies

We’ve blogged about sound and what exactly it is before, see the link. Understanding that sound is vibration traveling through the air which it is utilizing as an elastic medium.  Well, rather than me continue to write this out, I found a great video to share that is written in song to better recap how sound is created.

Now that we have that recap and understand better what sound is let’s dig a little deeper to better understand why some sounds may appear louder to a person when they may not appear different on a sound scale that is shown by something like a Digital Sound Level Meter.

Loudness is how a person perceives sound and this is correlated to the sound pressure of the frequency of the sound in question.  The loudness is broken into three different weighing scales that are internationally standardized. Each of these scales, A, C, and Z apply a weight to different frequency levels.

  1. The most commonly observed scale here in the USA is the A scale. A is the OSHA selected scale for industrial environments and discriminates against low frequencies greatly.
  2. Z is the zero weighting scale to keep all frequencies equal, this scale was introduced in 2003 as the international standard.
  3. C scale does not attenuate these lower frequencies as they are carrying the ability to cause vibrations within structures or buildings and carry their own set of risks.

To further the explanation on the A-weighted scale, the range of frequencies correlates to the common human hearing spectrum which is 20 Hz to 20kHz. This is the range of frequencies that are most harmful to a person’s hearing and thus were adopted by OSHA. The OSHA standard, 29 CFR 191.95(a), that corresponds to noise level exposure permissible can be read about here on our blog as well.

When using a handy tool such as the Digital Sound Level Meter to measure sound levels you will select whether to use the dBA or dBC scale.  This is the decibel reading according to the scale selected. Again, for here in the USA you would want to focus your measurements on the dBA scale. It is suggested to use this tool at a 3′ distance or at the known distance an operator’s ears would be from the noise generation point.

Many of EXAIR’s engineered compressed air products have the ability to decrease sound levels in your plant. If you would like to discuss how to best reduce sound levels being produced within your facility, please contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

1 – Fun Science: Sound – @charlieissocoollike – https://youtu.be/xH8mT2IQz7Y

 

OSHA Safety, Efficiency, and Flexibility from Engineered Compressed Air Nozzles

Throughout my years here at EXAIR as well as my years in the metal cutting industry, one of the most common quick fixes I see in production environments for compressed air blowoffs in a process is an open copper pipe that is contorted into a position, pinched at the end, and more often than not kinked from repositioning. I call this a quick fix because it does blow air, more often than not it will get production up and running, but it does not meet or exceed OSHA standards for safety and is an inefficient use of compressed air. [OSHA Standards 29 CFR 1910.242(b) and 29 CFR 1910.95(a)]

EXAIR Super Air Nozzles that are easy replacements for 1/8″ and 1/4″ Copper pipe.

The first engineered solution I could offer to prevent any costly OSHA fines and to lower the ambient noise level caused by these blowoffs is to implement an EXAIR Engineered Air Nozzle. We offer a wide variety of nozzles ranging from a 4mm thread up to a 1-1/4″ NPT thread. With this wide range comes a wide variety of forces and flows as well.

Today, I would like to focus on the common sizes of copper blowoffs which are 1/8″ and 1/4″. To simply adapt a nozzle to copper line a compression fitting can be easily sourced, often from EXAIR, and convert the copper tubing in place to an NPT threaded outlet for easy installation of an EXAIR nozzle. More often than not a compression fitting is how the copper tubing is tied into the machine’s compressed air system.

We have a total of 37 engineered air nozzles from stock that will easily fit a compression fitting which goes to a 1/8″ NPT or 1/4″ NPT thread. Several of these are also adjustable through a gap adjustment or a patented shim adjustment to vary the force and flow out of the nozzle from a forceful blast to a gentle breeze in order to me your application needs. What if you want to eliminate the copper line and compressions fittings?

EXAIR offers a replacement option for the ever-common copper tube that is more robust and does not require a tool to be properly repositioned. We currently offer twenty-four different models of our Stay Set Hoses that can be easily connected to any of the nozzles mentioned above. The lengths that are available are 6″ (152mm), 12″ (305mm), 18″ (457mm), 24″ (610mm), 30″ (762mm) and 36″ (914mm).

These lengths are available with two separate connection options. 1/4″ MNPT x 1/4″ MNPT or 1/4″ MNPT x 1/8″ FNPT. The Stay Set Hoses can easily be bent by hand into position for a precise placement of the air pattern from the engineered nozzle attached to it. This permits operators a tool free adjustment for fast and reliable location to keep production up and running. They can also be paired with Magnetic Bases.

EXAIR Magnetic Bases are available in single outlet or dual outlet configurations. Both include a 100 lb. pull magnet that will hold tight to any ferrous metal surface for secure mounting, as well as a quick 1/4 turn miniature valve on each outlet. This permits independent customization of the force our of each output for the dual outlet mag base. Each magnetic base offers a 1/4″ FNPT inlet port and outlet port. We offer these with any of combination of the Stay Set Hoses mentioned above as well as any of the Super Air Nozzles mentioned above.

Mag Bases come with one or two outlets. Stay Set Hoses come in lengths from 6″ to 36″.

The Super Air Nozzles, Stay Set Hoses, and Magnetic Bases can be easily combined before they ship to your facility to make a complete blowoff station that is easily installed and adjusted to fit any of the needs your process may have for a point of use blowoff. If you want help determining how much compressed air you would save by replacing the open pipe blowoffs with an engineered solution like a Stay Set Magnetic Base Blowoff System please contact myself or any Application Engineer here at EXAIR.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

Happy Earth Day 2019!

Today marks the 49th annual Earth Day and it will be observed in over 193 countries.  For EXAIR, this year marks our 36th year helping compressed air users save compressed air energy and electrical resources.

It is also another year that we continue to focus on manufacturing our products with minimal impact and doing our part to help protect our planet. We are proud to manufacture efficient products, implement processes and programs throughout our facility to help use our resources wisely and recycle everything we possibly can. 

First and foremost, we manufacture and sell Intelligent Compressed Air Products that are specifically designed to reduce the use of compressed air throughout facilities.  On top of that, when you purchase an EXAIR product it will arrive in fully recyclable packaging and, in most cases, is made from a material that will be recyclable should it reach a point it is no longer useful.

Over the past years we continually look for improvement opportunities within our systems and processes. Recently we have made improvements to the efficiency of our computers and computer servers which require fewer Kilowatt hours (KWH) per day. We have further reduced our wastewater for reclamation by another 17%, and minimized our own compressed air use by 1 million cubic feet.

We use our very own Chip Trapper Systems in our manufacturing areas to extend the water soluble coolant life from 6 weeks per changeover to 6 months per changeover. Keeping our coolant clean allows us to minimize the total amount of wastewater we recycle each year. 

EXAIR recycles 100% of the metal scrap from our machining processes, which equates to 6.5 tons. Our cardboard and mixed paper products are also recycled 100%. Of the waste we place into our trash dumpsters – 80% is recycled and 20% is sent to the landfill.     

In total over the past year, EXAIR recycled 36.6 tons of paper and cardboard which equates to 80% of the solid waste we produce is recycled.  We focus on more ways to improve this percentage every year.

Another waste reducing factor that has proven to work out well for EXAIR is asking every customer if they accept digital invoices rather than requiring them to be printed and mailed.   Thanks to our wonderful customers we have been able to eliminate 91% of all printed and mailed invoices which helps to reduce our resources used as well as the amount of materials that are possibly turned into solid wastes at their facilities. This also prevents the gas and vehicles necessary to deliver all of these invoices by mail. 

On top of all the efforts above, we also continue to maintain RoHS compliance on all electronic products, as well as actively track our supply chains to ensure no Conflict Minerals are being sourced from the Democratic Republic of Congo.

If you have any questions on how we can help your facility reduce their volume of compressed air or why we continue to reduce our wastes and increase our recycling efforts, contact us.

Happy Earth Day from EXAIR!

 

Image Credit: NASA/NOAA/GSFC/Suomi NPP/VIIRS/Norman Kuring

Six Steps to Optimization, Step 4 – Turn Off Your Compressed Air When Not in Use

Step 4 of the Six Steps To Optimizing Your Compressed Air System is ‘Turn off the compressed air when it isn’t in use.’  Click on the link above for a good summary of the all the steps.

6 Steps from Catalog

Two basic methods to set up a compressed air operation for turning off is the ball valve and the solenoid valve. Of the two, the simplest is the ball valve. It is a quarter turn, manually operated valve that stops the flow of the compressed air when the handle is rotated 90°. It is best for operations where the compressed air is needed for a long duration, and shut off is infrequent, such as at the end of the shift.

manual_valves (2)
Manual Ball Valves, from 1/4 NPT to 1-1/4 NPT

The solenoid valve offers more flexibility. A solenoid valve is an electro-mechanical valve that uses electric current to produce a magnetic field which moves a mechanism to control the flow of air. A solenoid can be wired to simple push button station, for turning the air flow on and off – similar to the manual valve in that relies on a person to remember to turn the air off when not needed.

wa_solvalv
A Wide Array of Solenoid Valve Offerings for Various Flows and Voltage Requirements

Another way to use a solenoid valve is to wire it in conjunction with a PLC or machine control system. Through simple programming, the solenoid can be set to turn on/off whenever certain parameters are met. An example would be to energize the solenoid to supply an air knife when a conveyor is running to blow off parts when they pass under. When the conveyor is stopped, the solenoid would close and the air would stop blowing.

The EXAIR EFC (Electronic Flow Control) is a stand alone solenoid control system. The EFC combines a photoelectric sensor with a timer control that turns the air on and off based on the presence (or lack of presence) of an object in front of the sensor. There are 8 programmable on/off modes for different process requirements. The use of the EFC provides the highest level of compressed air usage control. The air is turned on only when an object is present and turned off when the object has passed by.

efcapp
EFC Used To Control Bin Blow Off Operation

By turning off the air when not needed, whether by a manual ball valve, a solenoid valve integrated into the PLC machine control or the EXAIR EFC, compressed air usage will be minimized and operation costs reduced.

If you have questions about the EFC, solenoid valves, ball valves 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
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The Value Of A Pressure Regulator At Every Point Of Use

regulator
EXAIR Pressure Regulator

To understand the value of a having a Pressure Regulator at every point of use we should start with identifying the two types of Pressure Regulators, Direct Acting & Pilot Operated.  Direct Acting are the least expensive and most common (as shown above), however they may provide less control over the outlet pressure, especially if they are not sized properly.  However when sized properly they do an outstanding job.  Pilot Operated Regulators incorporate a smaller auxiliary regulator to supply the required system pressure to a large diaphragm located on the main valve that in turn regulates the pressure.  The Pilot Operated Regulators are more accurate and more expensive making them less attractive to purchase.  The focus of this Blog will be on the Direct Acting Pressure Regulator.

The Direct Acting Pressure Regulator is designed to maintain a constant and steady air pressure downstream to ensure whatever device is attached to it is operated at the minimum pressure required to achieve efficient operation.  If the end use is operated without a regulator or at a higher pressure than required, it result’s in increased air demand and energy use. To clarify this point, if you operate your compressed air system at 102 PSI it will cost you 1% more in electric costs than if the system was set to run at 100 PSI! Also noteworthy is that unregulated air demands consume about 1% more flow for every PSI of additional pressure.  Higher pressure levels can also increase equipment wear which results in higher maintenance costs and shorter equipment life.

Sizing of the Air Regulator is crucial, if it is too small to deliver the air volume required by the point of use it can cause a pressure drop in that line which is called “droop”.  Droop is defined as “the drop in pressure at the outlet of a pressure regulator, when a demand for compressed air occurs”.  One commonly used practice is to slightly oversize the pressure regulator to minimize droop.  Fortunately we at EXAIR specify the correct sized Air Regulator required to operate our devices so you will not experience the dreaded “droop”!

Standard Air Knife Kit
EXAIR Standard Air Knife Kit Which Incudes Shims, Properly Sized Pressure Regulator & Filter Separator

Another advantage to having a Pressure Regulator at every point of use is the flexibilty of making pressure adjustments to quickly change to varying production requirements.  Not every application will require a strong blast sometimes a gentle breeze will accomplish the task.  As an example one user of the EXAIR Super Air Knife employs it as an air curtain to prevent product contamination (strong blast) and another to dry different size parts (gentle breeze) coming down their conveyor.

EXAIR products are highly engineered and are so efficient that they can be operated at lower pressures and still provide exceptional performance!  This save’s you money considering compressed air on the average cost’s .25 cents per 1000 SCFM.

Super Air Knife Performance
EXAIR Super Air Knife Performance Specifications At 5 Different Pressures.

If you would like to discuss Air Regulators or quiet and efficient compressed air devices, I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer
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Estimating the Cost of Compressed Air Systems Leaks

Leaks in a compressed air system can waste thousands of dollars of electricity per year. In fact, in many plants, the leakage can account for up to 30% of the total operational cost of the compressor. Some of the most common areas where you might find a leak would be at connection joints like valves, unions, couplings, fittings, etc. This not only wastes energy but it can also cause the compressed air system to lose pressure which reduces the end use product’s performance, like an air operated actuator being unable to close a valve, for instance.

One way to estimate how much leakage a system has is to turn off all of the point-of-use devices / pneumatic tools, then start the compressor and record the average time it takes for the compressor to cycle on and off. The total percentage of leakage can be calculated as follows:

Percentage = [(T x 100) / (T + t)]

T = on time in minutes
t = off time in minutes

The percentage of compressor capacity that is lost should be under 10% for a system that is properly maintained.

Another method to calculate the amount of leakage in a system is by using a downstream pressure gauge from a receiver tank. You would need to know the total volume in the system at this point though to accurately estimate the leakage. As the compressor starts to cycle on,  you want to allow the system to reach the nominal operating pressure for the process and record the length of time it takes for the pressure to drop to a lower level. As stated above, any leakage more than 10% shows that improvements could be made in the system.

Formula:

(V x (P1 – P2) / T x 14.7) x 1.25

V= Volumetric Flow (CFM)
P1 = Operating Pressure (PSIG)
P2 =  Lower Pressure (PSIG)
T = Time (minutes)
14.7 = Atmospheric Pressure
1.25 = correction factor to figure the amount of leakage as the pressure drops in the system

Now that we’ve covered how to estimate the amount of leakage there might be in a system, we can now look at the cost of a leak. For this example, we will consider a leak point to be the equivalent to a 1/16″ diameter hole.

A 1/16″ diameter hole is going to flow close to 3.8 SCFM @ 80 PSIG supply pressure. An industrial sized air compressor uses about 1 horsepower of energy to make roughly 4 SCFM of compressed air. Many plants know their actual energy costs but if not, a reasonable average to use is $0.25/1,000 SCF generated.

Calculation :

3.8 SCFM (consumed) x 60 minutes x $ 0.25 divided by 1,000 SCF

= $ 0.06 per hour
= $ 0.48 per 8 hour work shift
= $ 2.40 per 5-day work week
= $ 124.80 per year (based on 52 weeks)

As you can see, that’s a lot of money and energy being lost to just one small leak. More than likely, this wouldn’t be the only leak in the system so it wouldn’t take long for the cost to quickly add up for several leaks of this size.

If you’d like to discuss how EXAIR products can help identify and locate costly leaks in your compressed air system, please contact one of our application engineers at 800-903-9247.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

 

 

 

 

What Is A Btu?

A Btu, or British Thermal Unit, is a traditional unit of energy and is a measure of the heat content of fuels.

Originally, the Btu was the amount of energy needed to increase the temperature of 1 pound of liquid water by 1 degree Fahrenheit.  The term became common among engineers in the late 1800’s.

A single Btu is insignificant in terms of the amount of energy used by a single household or by an entire country. In 2013, the United States used about 98 quadrillion (written out, 1 quadrillion is a 1 followed by 15 zeros) Btu of energy.

One Btu is approximately equal to the energy released by burning a match.

Match

Interesting Energy Conversion Factors

Energy source Physical units and Btu (averages,¹ 2012)
Electricity 1 kilowatt hour = 3,412 Btu
Natural gas 1 cubic foot = 1,025 Btu
Motor gasoline (10% ethanol) 1 gallon = 120,524 Btu
Diesel fuel 1 gallon = 138,690 Btu
Heating oil 1 gallon = 138,690 Btu
Propane 1 gallon = 91,333 Btu
Wood 1 cord = 20,000,000 Btu (Estimated)

1Weighted averages across different contexts of each fuel such as imports, exports, production, and consumption. Source:  www.eia.gov/EnergyExplained by the U.S . Energy Information Administration

EXAIR manufactures the Cabinet Cooler System.  The Cabinet Cooler System is a low cost, reliable way to cool and purge electronic control panels.  They incorporate a vortex tube to produce cold air from compressed air – with no moving parts! EXAIR Cabinet Cooler Systems are available for NEMA 12, 4, and 4X type enclosures.  For the most efficient way to operate Cabinet cooler, a thermostat control system would be utilized. The standard thermostat control systems include an adjustable thermostat factory set at 95F.  Also, available is the ETC Electronic Temperature Control, providing precise control with easy adjustability and a digital readout.

Cabinet Cooler Family
EXAIR Cabinet Cooler Systems

In the United States, the power of HVAC (Heating Ventilating and Air Conditioning) systems is often expressed in BTU/hr.

The EXAIR Cabinet Cooler Systems are available with cooling capacities ranging from 275 to 5,600 Btu/hr.  To cool the down the equivalent of 98 quadrillion Btu’s of energy used by the US in 2013, it would take 17.5 trillion of our largest Cabinet Cooler Systems!

If you would like to find out how many Btu’s of cooling your electrical cabinet needs, please fill out and send in the Cabinet Cooler Sizing Guide and we can let you know.

Brian Bergmann
Application Engineer
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Match Photo courtesy of Samuel M. Livingston via Creative Commons License