Talk:Boiling liquid expanding vapor explosion

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Toronto. Aug 10 2008. A BLEVE?

—Preceding unsigned comment added by 71.61.75.205 (talk) 07:26, 26 August 2008 (UTC)[reply]

"Pronounced Blevy" - does that rhyme with Bevy? Or is it Blee-vee?

It rhymes with 'bevy'.

Mechanism of the explosion?

I do not understand how, after initial rupture, boiling liquid manages to produce pressures HIGHER that the initial pressure in the intact container. This seems to be impossible. Boiling releases more gas. Pressure is rising, and this should be reducing the intensity of boiling. Because at original pressure there were no boiling at all. Moreover, boiling COOLS the liquid.

Something is wrong here. The most simple explanation might be that pressure is not in fact increased so much during BLEVE and it doesn't exceed the original pressure. Just the large amount of produced gas and its significant venting speed at the rupture make BLEVE violent, incorrectly hinting at "high pressure". Does anyone know better? 89.102.37.40 (talk) 19:09, 25 September 2008 (UTC)[reply]

Question on the thermodynamics after initial rupture - for a non-flammable fluid (say, steam) how can the pressure *increase* over the pre-event vessel pressure.

Clearly before the event, the liquid and vapor were in equilibrium; unless heat is added, then there's no additional energy available and therefore the pressure can only fall (if the fluid is supercritical, such as for supercritical cryogenics) or stay constant (as for "conventional" fluids, like water or liquified CO2). So, how can the pressure inside the vessel _increase_?

Is there a cite that clears this up? —The preceding unsigned comment was added by 137.203.128.30 (talk) 18:15, August 23, 2007 (UTC)

The system does not remain in equillibrium. An open bottle of soda is near equillibrium and atmospheric pressure. Shake the bottle and it departs further from equillibrium; the pressure increases.- Ac44ck (talk) 15:50, 11 October 2009 (UTC)[reply]

Simple question needs answering in the article: Does the pressure at any point exceed the original pressure, or not, and if so then why? Surely data on this must exist. E.g., is the problem that any agitation of the vessel (such as boiling causes) will temporarily raise the pressure uniformly (exactly like a soda bottle shaken until the lid blows off)? Or is it that the initial leak grows bigger due to accelerated local deterioration caused by the high velocity flow (probably even supersonic converging-diverging nozzle and cavitation effects) around its edges? In only one of those two cases might one expect to detonate a tank just by suddenly turning open a good-conditioned valve. Or is it just that when an old tank completely fails (at a given pressure), any additional vaporisable-liquid contributes a weightier explosion/wave-of-gas compared to if the same tank had contained only vapour to begin with (in which case, regardless of whether liquid was present, the tank still would have completely failed anyway)? Or is there some highly non-equilibrium dynamic process, where a wave of low-pressure from the leak triggers a pulse of extremely high pressure from the liquid, placing non-uniform force over the vessel walls (which in some places may rupture before the whole vessel has a moment to adopt to any uniform pressure temporarily even)? Cesiumfrog (talk) 04:01, 16 February 2010 (UTC)[reply]

First, I believe it is a myth that a closed bottle of soda can be "shaken until the lid blows off" unless the shaking added enough energy to create a temperature rise in the bottle.

As to the question about detonating a tank just by suddenly turning open a valve. It probably depends on the size of the valve and how quickly it is opened. Other issues may become problems before the tank explodes:

http://industrialmechanical.doodig.com/2010/02/11/how-to-use-oxy-fuel-oxygen-acetylene-cutting-torch-equipment-safely/

Always open oxygen cylinders very slowly. Opening them quickly is very dangerous and can cause the regulator to explode.

Not said, but I imagine that if the valve is large and open far enough, explosion of the regulator might be followed by explosion of the tank. -Ac44ck (talk) 17:39, 20 November 2010 (UTC)[reply]

Explosions of oxygen regulators are caused by the presence of organic material (grease, dirt) combusting. An air regulator may contain rubber or grease. Venting gas through a valve causes a drop in temperature which can in more extreme cases lead to brittle fracture of some component. Neither of these are specific to BLEVEs.Chemical Engineer (talk) 22:18, 20 November 2010 (UTC)[reply]

Texas City, TX doesn't belong in this article

The disaster in Texas City in 1947 was caused by exploding ammonium nitrate so I don't think that it should be included in this article. See Texas City Disaster for more information.

wysiwyg 21:25, 19 January 2007 (UTC)[reply]

Someone "corrected" the date from 1978 to 1947, so yes, while the 1947 explosion was not a BLEVE, the one in 1978 was. I guess they get lots of explosions in Texas City. --Bob Mellish 08:00, 30 May 2007 (UTC)[reply]

Steam explosion not a BLEVE

These two statemetns contradict each other: "When the liquid is water, the explosion is usually called a steam explosion.", and "A BLEVE can occur in a vessel that stores a substance that is usually a gas at atmospheric pressure but is a liquid when pressurized (for example, liquefied petroleum gas)." In my experience, the term BLEVE is restricted to the latter sentance. Fireproeng 07:09, 8 November 2007 (UTC)[reply]

This is sourced from a "how to" blog site for plumbers. I believe it is wrong and that it only applies to flammable materials. Citations are available to this effect. I too suggest deletion. --Old Moonraker (talk) 07:08, 11 October 2009 (UTC)[reply]

How does the flammability of the material enter into the mechanics of an expanding vapor explosion that is driven by a boiling liquid? If the flame front was within the vessel and had oxygen available to it, that would seem to be a deflagration. Such an explosion is due to burning vapor, without regard for the presence of liquid. This page talks about a water-based BLEVE:

http://www.kirsner.org/pages/forensicResAlt.html

Although normally associated with accidents involving flammable liquids like propane, a BLEVE can occur in a pressurized hot water tank in which only hot water and steam are released. A BLEVE occurs when superheated water (at elevated temperature and pressure compared to atmospheric conditions) is released through what may start as a relatively small fracture in the vessel.

The characterization of the source in the article as a "'how to' blog site for plumbers" may be read as disparaging. It contains information that explains why building codes contain certain requirements: they embody good judgement which was obtained by bad experience. -Ac44ck (talk) 15:13, 11 October 2009 (UTC)[reply]

Apparently also known as Blast Leveling Everything Very Efficiently. --Kizor 15:10, 4 February 2008 (UTC)[reply]

I've added an external link about propane BLEVE's. They are the most common pressure vessel ruptures we hear about and I felt some facts instead of videos might be appropriate. Mtt124 (talk) 03:47, 28 February 2008 (UTC)[reply]

Information is incorrect

Information in this article is incorrect. Please note that Bleve can happen with any liquid in a container. Because the container or vessel is holding water, as compared to LPG or Propane, it can still BLEVE. Tanks used in the industry are now required to have pressure relief valves that will open from excess pressure.

A BLEVE can occur when a vessel containing a liquid explodes or ruptures from being exposed to heat. Such explosions can be extremely hazardous. A vessel holding a liquid will build pressure as it is heated and the liquid expands. The liquid will expand exerting force to the container. Unless this pressure is released or heat is removed, an explosion can occur. A vessel that is already venting, can BLEVE if the pressure is not reducing from this venting action. A tell tail to this is the increase of pitch to the venting noise. Also a vessel can BLEVE quicker if the heat weakens the container to the point of failure. 198.50.63.15 (talk) 14:52, 24 June 2008 (UTC) —Preceding unsigned comment added by 198.50.63.15 (talk) 02:05, 10 June 2008 (UTC)[reply]

Fire in new image

The new image looks good, but it may give undue weight to the presence of an external fire.

How does the rate of heat transfer to the liquid from the external fire compare with the rate at which internal energy is released from liquid in the tank?

Perhaps an external fire may create an overpressure to cause the initial rupture, and it may make the situation worse by igniting the escaping vapor. A gas explosion may be a secondary effect of a BLEVE.

If an LPG tank falls over and ruptures, couldn't a BLEVE happen even in the absence of an external fire? - Ac44ck (talk) 03:14, 26 January 2009 (UTC)[reply]

Water heater

A water heater with hot water is a pressurized container. When the pressure is dropped do to a leak that can cause the water to boil. water boils at different temperatures depending on pressure.

Apollo 13

Was the LOX explosion of the Apollo 13 Service Module an example of this. Was this mechanism involved in that incident?

Basesurge (talk) 09:27, 1 December 2009 (UTC)[reply]

Blast leveling everything very effectively...

Lets gets some talk on this one. Why is this not a valid thing to include in an article on the subject? This is a nearly-universal backronym; i got to this page a long time ago by way of it. Wikipedia is not a paper encyclopedia, it doesn't need to be shipped or stored or flipped through endlessly searching for the right word... Sniper1rfa (talk) 23:23, 13 May 2010 (UTC)[reply]

It needs a citation. Some sort of Cite that would prove firefighters use this as a a backronym. BTW, I don't believe http://www.acronymgeek.com/ counts on this one. Exit2DOS ^{• Ctrl • Alt • Del} 12:07, 14 May 2010 (UTC)[reply]

Compressed gas not required

The reason I reverted the edits of Chemical Engineer is that the wording, "Gases such as propane may be stored in a more compact form by compressing them into a liquid ...." implies that BELVEs are confined to compressed gases, which is incorrect. Please discuss before reverting again with no explanation.Kilmer-san (talk) 16:07, 25 October 2010 (UTC)[reply]

But you have stated:

"If a vessel partly filled with liquid with vapour above filling the remainder of the container, is ruptured — for example, due to corrosion, or failure under pressure — the vapour portion may rapidly leak, lowering the pressure inside the container." You have omitted the critical fact that the pressure inside has to be higher than the outside, which is why I reverted. As this is an encyclopedia I include some explanation as to how the situation may arise to allow a BLEVE. I quote Kletz "A BLEVE occurs when vessel containing liquid under pressure, above its normal boiling point, bursts, releasing the contents with explosive violence."Chemical Engineer (talk) 23:14, 25 October 2010 (UTC)[reply]