Quote:
Originally Posted by Jim Ford  A few years ago, there was on television a programme that showed a drum of petrol and a cylinder of hydrogen, being shot with a rifle bullet. The drum of petrol exploded in a huge fireball, but the hydrogen in the cylinder ignited, but with little luminous flame, and hence not a lot of heat radiated sideways. The burning hydrogen went straight up. It was quite clear that the petrol was far more damaging.
Jim |
it depends on the air mix - a drum full to the brim with petrol wont explode at all - all you will get is a leak or at worst a jet of flame
likewise a drum full of hydrogen shouldnt blow up though it is easier to ignite so you will as you say get a flash flame straight up
a drum which is semi full of petrol will go bang as a result of the vapour igniting - the reason that petrol tanks have to be crash safe
however the issue with hydrogen is that if a non crash safe container ruptures and the gas mixes with the air before igniting you will get one heck of a big bang.
also if it is stored in a compressed state (which petrol isnt but hydrogen is) just rupturing the cylinder will give you an explosive decompression with bits of frag whanging arround even before the gas itself ignites