0
$\begingroup$

I got this from the internet - “Ignition of the flammable vapor cloud must be delayed until a cloud of sufficient size has formed. If ignition occurs as the flammable material is escaping, a large fire, jet flame, or fireball might occur, but a VCE is unlikely.”

Am I right to say that there is a delay because the flammable range of the explosion is not met yet ? For example, the vol content % of the flammable gas mixture in the vapor cloud is not sufficient enough to cause an explosion when ignited ?

$\endgroup$
1
  • $\begingroup$ Even the small "cloud" from a butane lighter will ignite. Can you give a bit more context (e.g., a link) to the information posted in the question? $\endgroup$ – David White Oct 24 '19 at 4:58
1
$\begingroup$

No, the issue is the percent of oxygen (from the air) that is blended in with the fuel. For the fuel to explode instead of burn, it must first be mixed with enough air for the entire fuel charge to in essence burn everywhere at once. This will happen as the jet of fuel entrains air as the fuel cloud expands.

If the jet of fuel is ignited before a mixed cloud has enough time to form, it burns with a huge flame and a violent explosion is prevented. If the mixed cloud is given enough time to form and then ignited, a violent explosion occurs and a huge flame is prevented.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.