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#61520 01/28/06 12:44 AM
Joined: Feb 2005
Posts: 693
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Boiling Liquid/Expanding Vapor Explosion


Larry Fine
Fine Electric Co.
fineelectricco.com
#61521 01/28/06 08:51 AM
Joined: Nov 2000
Posts: 2,148
R
Member
while Larry has the correct defintion of BLEVE. I like: Blast Leveling Everything Very Effectively
Don


Don(resqcapt19)
#61522 01/28/06 08:54 AM
Joined: Nov 2000
Posts: 2,148
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Member
John,
Quote
So, yes, an electrical fire can easily become an explosion.
In most cases the explosion at an electrical accident is not very very rapid combustion as with normal explosions. It is the result of the rapidly expaning vapor from the vaporized conductors and other materials as well as the expansion of the air as a result of the extreme heating.
Don


Don(resqcapt19)
#61523 01/28/06 09:07 AM
Joined: Nov 2000
Posts: 2,148
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Member
stamcon,
Please note that the link you provided is not completely correct. While the most commonly occurring BLEVEs do occur in vessels containing flammable liquids, that is not a requirement for a BLEVE to occur. The BLEVE can still occur where the liquid is not flammable. Actually the explosive force of a BLEVE in a water container is greater than that in a LP gas container. However the total damage is normally greater when the product is flammable because of the resulting fires.
The only requirements for a BLEVE are:
1) closed container, 2) liquid heated above its atmospheric boiling point, 3) rupture in container that releases the pressure.
When the pressure is released, the product is now instantaneously flashed into vapor. The explosive force is a function of the relative area of the liquid and the relative area of the vapor. For most flammable products this is 300 to 500 volumes of vapor for one volume of liquid. For water this is ~1700 volumes of vapor for one volume of liquid The explosive force is a result of this volume change and not of the type of product involved.
Don


Don(resqcapt19)
#61524 01/28/06 04:09 PM
Joined: May 2004
Posts: 73
R
Member
A motion detecting camera caught this arc blast on tape. http://www.mikeholt.com/files/movies/Accident-live.wmv
Sorry, but that link doesn't work. This one should. http://www.mikeholt.com/files/movies/Accident-%20live.wmv

[This message has been edited by Ralpha494 (edited 01-28-2006).]

#61525 01/28/06 05:01 PM
Joined: Oct 2004
Posts: 806
Member
In freakin credible!! That was one of the most effective illustrations of arc flash hazard I've ever seen!!

The good news, it appears that the worker's PPE did it's job, as he was able to walk away and remove his burning PPE without major injury.


Stupid should be painful.
#61526 01/28/06 06:56 PM
Joined: Feb 2005
Posts: 693
L
Member
I get "request not found" page with the first linkm and a blank download with the second. Should the "%20" be replaced with something else.


Larry Fine
Fine Electric Co.
fineelectricco.com
#61527 01/29/06 12:18 AM
Joined: Feb 2005
Posts: 693
L
Member
Still doesn't work for me. Is it a pop-up issue? I can see other WMVs.


Larry Fine
Fine Electric Co.
fineelectricco.com
#61528 01/29/06 12:29 AM
Joined: Feb 2005
Posts: 693
L
Member
Okay, I got it to work by opening WMV, and then pasting the URL into "open url...". Big pop!


Larry Fine
Fine Electric Co.
fineelectricco.com
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