William:
I have done some work with what is probably a similar material, AFFF or "Aqueous Foam Forming Film", a product developed by 3M (I'm not sure that it is still made, as 3M got out of the business). If this is the same sort of material, it is not a foam in the storage tank, but a liquid. Your question: "Can I treat the flowing fluid which is the FOAM as WATER in the calculations using the properties of foam[?]" is misleading, as the properties of the foam will not correlate with those of water. Because it is a foaming material, it will have many properties quite unlike water (such as surface tension); it is likely to be less dense than water. Also, in all of the installations that I have reviewed, the foam forming material is not pumped using a centrifugal pump, but rather an eductor, metering the foam forming material in with the water as it is discharged. I don't know preceisely why, but the shears and other stresses expereinced as the fluid passes through a centrifugal pump might cause problems, particularly cavitation. Because it is an emergency use only system, any cavitation might only present difficulties in adequately metering in the material, and not cause major mechanical problems with the pump.
... Bruce D. Bullough ...
Sebesta Blomberg & Associates, Inc.
2381 Rosegate
Roseville, MN 55113 USA
+ 651-634-7344
www.sebesta.com
-----Original Message-----
From: Paul Bowers [mailto:pbowers@pipingdesign.com]
Sent: Thursday, March 24, 2005 5:32 AM
To: <a href="/group/PipingDesign/post?postID=ymRurJDEJPA8Wy_v1SxCY8w9Fogs0keeaqctcrmJR0CSi-GVg1ALQ7IaPAbzREPTCNnamTx6vgrnseZ9OhT-Ga5o">PipingDesign@yahoogroups.com</a>
Subject: [PipingDesign] [Fwd: The fliud is foam for fire fighting at the
petroleum storagearea.] [bcc][faked-from][mx][spf]
Sir,
I am a Mechanical Engineer attached to our Projects section at the Tema Oil Refinery (TOR) in Ghana.
Currently, I am to rehabilitate our tank farm foam system as a project.
There is a storage tank for the foam to which a single stage centrifugal is attached to send this foam to the tanks in case of a fire outbreak.
Can I treat the flowing fluid which is the FOAM as WATER in the calculations using the properties of foam.
Can you also assist me with relevant notes and information how to go about the whole project?
Thank You.
William.
<a href="http://www.pipingoffice.us/">http://www.pipingoffice.us/</a> =========================================Main site: <a href="http://www.pipingdesign.com">http://www.pipingdesign.com</a>
Yahoo! Groups Links Received on Thu Mar 24 09:16:00 2005
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