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Hydrogen explosion

Hydrogen explosion

Hydrogen explosion


I am a physical security consultant, i have a client who is concerned about a hydrogen / air explosion in his factory. I would like to know the pressures that could be attained using the following scenario

room size - 40m3
explosive - equivalent to 5kg TNT (is that possible for calculations)

what would pressure and impulse be on the walls of the room?


RE: Hydrogen explosion


I worked on a project a long time ago to do with a Hydrogen Lab. I can't recall exactly but I believe it was the civil engineers who dealt with this problem as they designed the doors and blow out panels to handle an explosive situation. I know that the company I worked for hired an consultant whose expertise it was to calculate the reactionary forces.

You may have an easier time finding an answer if you post it in the civil/structural discussion board or perhaps the chemical forums?

There is a post (link below) that sort of talks about calculating the build up of gas pressure in a building. It may provide some guidance as to what you are looking for.

Best of luck,

RE: Hydrogen explosion

You have to know the hydrogen concentration in conjunction with the air (oxygen).  Too little hydrogen and the mixture is not explosive.  Too much hydrogen, same result.   

RE: Hydrogen explosion


If you are in the US, and are looking for information regarding nuclear plants, you should realize that the Nuclear Regulatory Commission considers such information to be safeguards, such that it would not be readily available. If you have a legitimate work-related reason to have this information, then you might want to call the NRC's Nuclear Security and Incident Response Group.  Your client's licensing group should be able to arrange for such a call.

Patricia Lougheed


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RE: Hydrogen explosion

See, you've almost bounded the problem too much:  You have specified a weight of explosion equal to the amount of H2 you are predicting inside a fixed room volume.   The rest is (as mentioned above) is (almost) a "simple" civil engineering problem of dynamic pressure loads.

But, the H2 buildup rate and concentration w/r to time is critical to determining that "equivalent explosive" mass.  (For example, are you assuming the H2 is evenly mixed with the O2 in the room, or is it concentrated in a "bubble" near the ceiling where only the edges of the bubble can burn?)

Further, solid or plastic mixed explosives "blow up" drastically different than the relatively low "burning flame" of a H2+O2 filled room.  So your peak pressure and press rise with respect to time is significantly different between almost every explosive and H2-O2 mix..

As mentioned by VPL above, I'd not recommend venting explosive topics on an open forum concerning nuclear plants.  Creates concern in areas you don't (probably) want to open.

RE: Hydrogen explosion

Pay no attention to the silent black helicopters.


Mike Halloran
Pembroke Pines, FL, USA

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