Month: March 2010

6 Reasons to Keep Using Open Blow Offs

Published on by Kirk EdwardsLeave a comment

An open blow off is often copper tube or pipe without an air nozzle. It could also be an open pipe fitting or a pipe with drilled holes along its length. Generally they provide a cleaning or cooling function as well as keeping product moving down the production line.

These types of blow offs are very inefficient, loud and dangerous. They can be easily retrofitted to gain efficiency, lower noise an provide safety by outfitting them with engineered air nozzles. But we understand why you have them, here are 6 reasons why you should keep using them.

1. You continually see a reduction in your electricity costs from your utility provider. They are saving money for you, there is no need for you to be proactive.

2. You have never heard of an embolism and are unaware of the danger an open blow off over 30 PSIG may be to someone.

3. You blew out your eardrums at that concert in ’88 and the loud noise doesn’t bother you, why would it bother anyone else?

4. The initial investment is too high – forget about the rapid ROI (often days or weeks) which pays for the engineered nozzles or Super Air Knives. 

5. You are not responsible for lowering the cost of production, that is someone elses job, let them worry about it.

6. You enjoy visits from OSHA and paying fines. After all you have that extra money from your utility provider.

Enjoy your day,
Kirk Edwards
Application Engineer
kirkedwards@exair.com

Understanding Compressed Air

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In my job as an application engineer, I spend a lot of time explaining the principles of compressed air. When my clients run into trouble operating an air device, they overlook the flow requirements and focus mainly on pressure. The two are interrelated.

Let me offer a simple comparison to electricity. Air pressure is equivalent to voltage and air volume to amperage. Most people recognize that larger amperage draw, the larger gauge wire is required. Also the longer the wire, the larger wire gauge is required.

The same applies to compressed air. The more CFM required by the tool the larger the air line required. Also the longer the air line, the larger diameter pipe is required.

With electricity, if you pull more amps than what the wires can carry the lights dim because you are experiencing a voltage drop. With compressed air, if the air tool is demanding more air than the hose can carry, you get a pressure drop.

So you see pressure and volume are interrelated. On the EXAIR website in our knowledge base  we have a table of pressure drops for various sizes of pipe against the SCFM of draw.

In situations experiencing pressure drops with correct sized plumbing, you have to consider the capacity of your compressor as well as to how many other operations are drawing air from it. Again going back to the electricity analogy, you would not expect to run your entire house and your neighbor’s on a small portable generator. The same applies to the size of your compressor.

So many times when I ask a client the size of their compressor they will state the size of their receiver tank. Here again is another misconception. The receiver tank is only a reservoir to store air when demand is down. If the air device demand is greater than the capacity of the compressor, then it has to be idled for a period of time for the compressor to catch up. The length of this time depends on the differential of the air demand vs. compressor capacity. The size of the receiver tank will determine how long the demand can be on before you get ahead of the compressor.

The following equation enables one to calculate the air receiver volume in terms of gallons necessary to power an air operated components for a specified length of time, given an undersized compressor:

V = T(C-S)P0/ (P1-P2)

Where:

V is the receiver capacity in cubic feet
T is time in minutes the air component will operate
C is the air requirement of the air components (scfm)
S is the air being delivered to the receiver from a compressor (scfm)
P0 is the atmospheric pressure, psia (refer to table below)
P1 is the initial receiver pressure, psig
P2 is the workable pressure receiver is allowed to drop to, psig

 Joe Panfalone
Application Engineer
jopanfalone@exair.com

 

Benefits of Measuring Compressed Air Flow

Published on by Kirk EdwardsLeave a comment

I will now attempt to compare compressed air flow measurement to my recent endeavor to shed a few pounds, wish me luck…

Over the years EXAIR has grown and added to our in-house compressed air system. Little by little the length of compressed air pipe has increased, the diameters have increased, the number of fittings have increased and the number of connections have increased. Simply adding a new pipe drop from the header or another tool to the compressed air system seems harmless.

Needless to say, if everything about the compressed air system was working fine, we paid little attention.

In the same way, over the years I have grown, little by little a pound here a pound there. I am still able to get the job done, keeping up with my kids (they are still young) and generally move around OK so there is really no issue. As long as I was doing alright, I paid little attention.

Then the doctor told me to lose weight, eat better, exercise etc… So I started counting my calories using a nifty app on an I Touch. It provides feedback about the number of calories in foods and has given me a target caloric intake per day in order to lose weight. What I found was I had no problem eating twice what this app recommended for someone my size and age. I was shocked, but the simple feedback set me down the right path.

Much is the same about gathering feedback from our compressed air system. Once  EXAIR installed some digital flow meters we were provided with good feedback about our air consumption habits. We first learned that when we stopped working, the compressed air system was still consuming air!? Realizing it was leaks in the system, we began to identify and fix them.

Flow meters can also help you identify the largest air consuming processes in the plant when they are installed at multiple branches of the system. They will also help to identify the air savings once the process has been optimized with efficient blow off products, leaks are fixed and pressure is reduced.

Flow meters can also keep general awareness of the compressed air consumption at the forefront. If air flow values change significantly from one day to the next it may point to a broken component or leaking valve etc…

It is the feedback provided by the flow mater which allows you to have a starting point to reduce air consumption, it also allows you to put a value on the air you have saved after you have put forth the efforts necessary. A flow meter keeps the subject of air consumption relative to the process on an ongoing basis and helps people understand the importance of keeping the system efficient.

That is also the case with the my feedback about calories – It helps keep me in line, know where I stand, and pay attention to an important subject which is easily overlooked.

Kirk Edwards
Application Engineer
kirkedwards@exair.com

Prevent Hearing Loss

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The latest buzz (sic) of  TV commercials is for a drug to treat tinnitus which is a ringing in the ear. Tinnitus can be caused by various events one of which is loud noise. Pete Townshend of “The Who” rock band is an example how debilitating this condition can be. The band’s planned spring 2010 tour was ditched when Townshend’s tinnitus returned. 

Hearing conservation is serious business. OSHA has specific directives governing noise exposure (Standards -29 CFR) which persons in the workplace can be exposed to. When noise exposures average 85 dB or greater during an 8 hour workday, monitoring is required.

EXAIR has an economical  digital sound level meter   that can  help monitor the sound levels around your facility. The source of loud noises can be quickly identified and isolated so corrective measures can be taken to reduce or eliminate the problem. For compressed air noise, it is often as simple as replacing the existing inefficient blow-offs with EXAIR’s engineered compressed air products such as the super air knife, super air amplifier, or super air nozzles.

Feel welcome to contact me if you have any questions

Joe Panfalone
Application Engineer
joepanfalone@exair.com