Month: February 2013

What’s in a Name?

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Do you ever wonder where certain names come from?  Here’s a for instance: Peaches en Regalia.  Well, I know what peaches are.  I’m pretty sure en=in.  But what is regalia?  I have to admit I had to look that one up.  From www.thefreedictionary.com …

re·ga·lia

pl.n. (used with a sing. or pl. verb)

1. The emblems and symbols of royalty, such as the crown and scepter.

2. The rights and privileges of royalty.

3. The distinguishing symbols of a rank, office, order, or society.

4. Magnificent attire; finery.

… and now we know!  Don’t we feel so much smarter now?!?  Strangely, no, because I still couldn’t identify a Peach en Regalia if I saw it on the street.  The only thing I do know for sure is that it’s a catchy little jazz number by Frank Zappa that our @ProfPenurious and @EXAIR_KE can occasionally be found rocking out to.

How about your world?  Are there names, titles or units that you have questions about?  One that we often get at EXAIR is ‘What’s a SCFM?’ The short answer is: Standard Cubic Feet per Minute.  Like Peaches en Regalia, let’s break it down word by word:

Standard – Believe it or not, this is the most complicated word of the whole bunch.  The short answer is that this unit (SCFM) has been standardized or normalized to be able to make a fair comparison of air flow rates of various products at various pressures.  For a more thorough explanation, check out this blog that @EXAIR_JP wrote awhile back.

Cubic – Not flat, not round, but….you guessed it! Cube shaped!  That is to say, a measurement of volume.

Feet –  More than an inch, less than a kilometer.  You know, a foot?  The units we’re using to measure volume.

Minute – Those things that drag on and turn into hours waiting for 5 o’clock.  This tells us that the measurement we are taking occurs over time, or is a rate.  In our case, the volume of feet in one minute’s time.

So there you have it!  SCFM isn’t so scary after all.  Just a unit to make an apples to apples comparison of how much compressed air a product uses. Coincidentally enough…

…if you’d like to learn about reducing the amount of compressed air you use, we just happen to have a LOT of stuff that can help you do that!  Please feel free to give me or any of the Application Engineers here at EXAIR a call, e-mail or tweet!

In the mean time, please enjoy some Peaches en Regalia, whatever it/he/she/they might be…

Dan Preston
Engineer
EXAIR Corporation

I Love Dimensions

Published on by Lee EvansLeave a comment

2006

Late last week I was contacted by an OEM regarding our Air Knives.  They make equipment used in an automated process and had a need for more of our product.

One of the engineers contacted me because she had only so much information about our Air Knives.  She knew they worked well, she knew they needed more, but she was unsure of the part number.  When ordering, her purchasing department uses as coded item number, which was nothing like ours.  She was kind enough to send me a few files showing the process and the EXAIR Air Knives.  Fortunately one of the drawings was a stand-alone exhibit of our knife.

Taking a few dimensions from the file I was able to determine the knife in question was a 6” Standard Air Knife.  I then supplied model number (2006) and pricing, shortly before receiving a purchase order request.

We have CAD and PDF files available for our products through the CAD Library.  If you need any dimensions for EXAIR products they can be found in the CAD Library.  If additional information is needed, contact an Application Engineer.

Lee Evans
Application Engineer
leeevans@exair.com
@EXAIR_LE

Video Blog: Silencing Mufflers

Published on by Russ BowmanLeave a comment

Noise reduction isn’t the only way that EXAIR Silencing Mufflers can help provide a safer, healthier work environment.  Here’s a short video, showing our different styles of mufflers, how they work, and how you might be able to use them.

Russ Bowman
Application Engineer
EXAIR Corporation
(513)671-3322 local
(800)923-9247 toll free
(513)671-3363 fax
Web: www.exair.com
Blog: http://blog.exair.com/
Twitter: twitter.com/exair_rb
Facebook: http://www.facebook.com/exair

Sometimes Back Pressure is Good, Sometimes it is Bad

Published on by Neal RakerLeave a comment

As the title of this blog indicates, I’m going to discuss situations in compressed air applications where a condition that we refer to as back pressure is good and where it is downright problematic.
Back Pressure Good – When we talk about Air Nozzles, Air Knives and Air Amplifiers, we always tell the customer to insure they have proper operating pressure at the inlet of our equipment. To do this, install a pressure gauge on a pipe tee, right to the inlet of our equipment to monitor the actual “working pressure” or as can be termed “back pressure” created by the product connected to the end of the pipe while it is operating. If the “back pressure” remains the same or drops by only a few PSIG, then all is good and the compressed air supply can deliver sufficient volume of air without pressure dropping. In other words, the Air Nozzle is able to create enough restriction to flow that the pipe can manifest enough pressure right behind the nozzle. This is exceptionally important to have good performance from the product connected to the pipe as maintaining proper input pressure and volume flow is what we are concerned with in these cases. The two water photos below represent the difference between no back pressure and back pressure situations with the result shown in the water flows.

garden-hose
A Nozzle with NO back Pressure
finger%20in%20nozzle
A restriction causes back pressure and more force at the nozzle

Back Pressure Bad – The situations where having back pressure is a bad thing is when it is observed in a Vortex Tube. The ideal situation for a Vortex Tube while operating is to have as high a pressure as is reasonable on the inlet (let’s say 100 PSIG), and zero “back pressure” on the outlet. The reason that you want to do this is to enhance the effectiveness of the Vortex Tube’s ability to generate cold air at its outlet. The more extreme the pressure differential across the Vortex Tube, the more extreme the temperature drop becomes.
The following photo shows a set up where by the cold output flow from the vortex tube is being restricted. The customer means well in that they want to measure the output pressure and also divide the cold air out over two areas were the cooling effect is needed. The problem is that the tubing is undersized and the ends, where the cold air hoses are inserted into cooling fixture, are blocked off and do not allow for sufficient flow.

VT

To demonstrate mathematically the effect of back pressure on a vortex tube, I have the following example: Assume a vortex tube has 100 PSIG at the inlet. A pressure gauge inserted into the cold flow measures 15 PSIG “back pressure”. What is the effective input pressure in this condition?
100 psig + 14.7 psia = absolute pressure ratio of 3.86
15 psig + 14.7 psia
Effective input pressure is determined as follows:
X + 14.7 = 3.86            x = 42 psig effective input pressure
14.7
At first glance you would not think the back pressure could have such a devastating effect on inlet pressure, but it does and this affects the performance of the vortex tube negatively as well.
So, what is the point of the discussion? Make sure you have plenty of pressure right at the inlet to all your compressed air equipment. And when operating a Vortex Tube, make sure the exhaust is free and clear to escape for best performance.

Neal Raker, Application Engineer
nealraker@exair.com