Large explosion in Beirut
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Honestly, it’s somewhat amazing that this kind of thing doesn’t happen far more often than the ~1 incident per year, globally.
[0]https://www.aljazeera.com/news/2020/08/huge-explosion-rocks-...
But large amounts of grain and oxygen are often found together in confined spaces so that makes it more explosive in practice than most things that people who work in offices and don't deal in bulk goods come into contact with.
Also I don't understnd how it could be explosive at all, sudden oxidation of large (that is, low surface area to volume), non-dry particles seems unlikely. Flour etc. may be another matter, but a blast like this... flour?
concentration of the fuel in otherwise normal atmospheric air required to go whoosh (or bang, which is basically just a really fast woosh or one that's constrained by something).
Too much fuel, too rich, no woosh.
Too little fuel, too lean, no woosh.
Lower and upper explosive limits are generally used to refer to gas mixtures though you can use them for solids but the units will be different. Solids we think of as explosive when not fishing around for virtue points on the internet generally contain their own oxygen supply so lower and upper explosive limit doesn't apply.
>sudden oxidation of large (that is, low surface area to volume), non-dry particles seems unlikely. Flour etc. may be another matter, but a blast like this... flour?
Yeah, no way that secondary explosion is flour or grain. I'd put my money on some sort of industrial chemical that contains its own oxidizer. Explosions that use atmospheric oxygen look different and rarely manage to be able to build up that kind of shock-wave if not constrained by something (like a building). There should be videos of natural gas explosions on YouTube that illustrate the difference.
If it's too dry, there's a risk of static/friction/electrical ignition.
If it gets wet, you can have anaerobic bacteria build up heat in a compartment that, when exposed to oxygen, ignites.
Grew up on a farm, have a fair bit of experience messing around with grain bins. Our local elevator had a fire due to the former condition, and our neighbor's barn burned down due to the latter.
A single frame of the fireball shows a large spherical fireball whose edge maybe reaches the edge of the grain silos. The next frame looks to my untrained eyes more like the edge of the fireball is having some reflection from the wall of the grain silos, followed by a dark cloud obscuring details, and then the vapor cloud really obscuring everything, and finally the photographer falling over.
It seems pretty clear to me that grain played no role in the big explosion.
They were in a tough spot already before this happened :-/
If one find it interesting one shouldn't flag it just because "we use to flag stuff like that".
[0] https://www.bing.com/maps?osid=e851aed9-b5df-495a-89e8-5c53d...
[1] https://twitter.com/JeonggukJeon__/status/129068971722728243...
https://twitter.com/N_Waters89/status/1290681231693275136
See also this tweet:
"In November 2018, I was away from Beirut, briefly, for work. One morning I woke up to find a deluge of WhatsApp messages from various friends and relatives, all forwarding the same few videos. There had been a terrible storm. At one point, hail the size of fists had fallen. In one of the videos, shoppers run screaming as it smashes into the courtyard of a fancy mall. In another, a woman holds up a plastic chair on her balcony, so punched through with holes it looks like Swiss cheese. There are brutalized cars, felled trees and electricity poles, a man water-skiing on the northern coastal highway, mudslides in the quarries. The last was of the boulevard overlooking Ramlet el-Baida beach. The water was almost hip-deep, if the drowned cars parked on the side of the road were anything to measure by.
But it wasn’t water: it was shit. Exploding so forcefully up from the depths that the sewer covers danced atop the flumes, like in a cartoon. Yes, Eden Bay, and all its enablers, had caused a literal shitstorm."
The form of the explosion here points in my mind to something significantly more explosive than fireworks (fireworks result in white smoke too, no?) - if nitrates are involved, that might certainly point in a better direction.
This kind of unnerves me a little.
Seemingly, a couple of tons of this not-entirely-impossible-to-get-ahold-of-chemical could seriously screw up national infrastructure.
We've had decades of fairly organised terrorism here in the UK, so perhaps I should know better, but it's a bit of a shock to realise that a 'manageable' quantity of otherwise fairly standard chemical stock is capable of producing something as dramatic as this.
The nitrates in question here apparently ended up in Lebanon after coming from Brazil via Mozambique.
If the reports are correct that the explosion is 2,750 tons of ammonium nitrate, the orange is probably nitrogen dioxide. A high concentration of nitrogen dioxide indicates that the explosion was very oxygen-rich, likely pointing to it being accidental.
Ammonium nitrate is normally very very stable. Even mixed optimally with fuel oil, ammonium nitrate prills (pellets) won't reliably detonate with a No. 8 blasting cap, and in mining a small "booster" charge of TNT is used to get the ANFO going. However, very large piles of ammonium nitrate have caught fire and exploded, such as the Texas City disaster where a tanker full of ammonium nitrate burned for a long time, and then levelled a good portion of the town when it exploded.