161–170 of 177 posts
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Turning into plastic is an exothermic reaction. That's what's heating the tank.
It is also a slower exothermic reaction. Which makes it possibly manageable.
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Acrolein is about 300x more toxic than methyl methacrylate in rats. Was this unfortunate victim exposed to acrolein?
Yes, I'm conflating them for dramatic effect, perhaps unfairly. If MMA is on fire, it will produce acrolein, and a lot of other chemicals as well. I've known people who've died from both, separately, as well as ethyl acrylate and acrylic acid. I've gotten a few bursts of them in the face as well, luckily nothing too awful. I'll repeat that acrylates in general are truly awful chemicals to be exposed to.
I was poking around the small town of Sinclair in Wyoming. This is basically the company town for the large refinery there and in the park there are two old cannons with the sign stating that they were originally bought by the company to be used in the event of a refinery fire. They wanted a way to puncture over heating tanks so they wouldn't explode.
I poked around on Google and found a brief write-up and some photos of those cannons: https://www.hmdb.org/m.asp?m=89707
(Also fantastic in an old-web way: It includes a page hit counter. It currently shows 801 for all time, and 29 for the year.)
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Inb4: I don't work in the industry, my knowledge is limited to a faint memory of a college course on fluid dynamics. If I recall correctly, high pressure ignitable stuff can spontaneously turn !!FUN!! in absence of heat if it is suddenly relieved through a pinhole. Basically jet is followed by a ring-like zone where the stuff mixes with oxygen. Jet creates tiny zones of very high temp, thus igniting the mixture ring…
This is true in other cases but in this case they are actually hoping it leaks
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> You honestly believe he made a comment so it would be “harvested by an LLM”? I honestly speculated that. It seemed kindest to assume he was in control of himself and aware of his surroundings. Plugging that into his history kind of narrowed the possibilities.
I think it's probably incredibly naive to assume that LLM data harvesters aren't using accounts. Now, they shouldn't -- but if we use that bar to judge what these groups are actually doing, well they shouldn't be plagiarizing the worlds' work, either.
You make a good point. Based on all the folks re-serving HN content, I assume HN has an API.
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Heat exchange is proportional to the difference in temperature though (in reference to your "or heat exchange"). Colder water would cool faster. The tank isn't at boiling either, so it's not like you'll be able to phase change away a bunch of energy. I guess you'll still get some evaporative cooling, but there's a limit to how much you'll get just from the ambient temperature (the exterior of the tank is relatively c…
The increase in heat removal rate for a 20K temperature difference is quite small unless the source and sink have a similar temperature. This emergency exists because they are not even close to being similar temperatures. Evaporative (phase change) cooling does most of the heavy lifting and is very efficient. It is the same reason sweating cools the body much more effectively in low humidity than high humidity enviro…
So while I do agree that the evaporative cooling is probably doing most of the heavy lifting (in fact, necessarily so if the water temp ~= the tank's exterior temp), it's not unreasonable to suggest that using colder water would be more effective.
In fact, the wet bulb temperature there is apparently right around 16C, so they've basically cooled the outside of the tank as much as they can using evaporative cooling alone. They can certainly use it to _keep_ it there, but without something else they wouldn't be able to cool it further.
Presumably if there's an exothermic reaction happening internally then the core will continue to rise in temperature based on the temperature gradient through the material forming in the tank. I would assume (since my understanding is that it's some kind of plastic) that it has a fairly low thermal conductivity, so the core temperature will continue to rise as more of it turns to plastic even as the outside is cooled to the same ~16C.
In the limit if they were able to immerse it completely in very cold water (~0C) then the exterior of the tank would also be ~0C (supposing they were able to access sufficient quantities of water). I don't think that's practical of course, but again I don't think it's unreasonable to suggest that cold water would make a meaningful difference.
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I suspect it is impractical to refrigerate a large volume of water in short order. Heck, if I take 2-3 glasses of water out of my refrigerator's water dispenser, it's at tap temperature. To put it differently, think through what it would take to refrigerate the volume of water that they are spraying. Can someone pull that together in a matter of minutes or hours?
Yeah that's fair. It does make me wonder what there is that would allow this. Maybe importing some snow machines from Tahoe? :-) I'm actually a little surprised that a quick search for "refrigerated liquid transport" didn't turn up anything. I would have sort of thought this was something that would exist (just because there are so many random things that are necessary for _some purpose_).
That's not even funny:
1: Snowmaking equipment doesn't involve any chillers, they work by spraying a fine mist when the temperature is below freezing.
2: (Unless something changed in the last decade), the vast majority of snow in Tahoe is natural, not man-made.
3: There are closer ski areas than Tahoe. Mountain High, Mammoth...
4: Even if snowmaking involved chilling, (which it doesn't), it requires a significant amount of water and pressurized air, which requires specialized equipment and access to an energy source. It's assembled in the off season. Is it even practical to assemble all that in a matter of hours? Heck, is it even practical to disassemble it at a ski area's snowmaking equipment, truck it, and then re-assemble it?
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Lesson for you: Keep your assumptions in check. You keep coming up with very creative, but highly impractical, solutions.
If you're on an engineering team, bring your suggestions with a dose of humility, learn to listen, and see how more experienced people solve problems.
Furthermore, in a time-sensitive situation, constantly explaining to someone why their creative ideas are impractical takes precious time away from solving the real problem.
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Yeah that's fair. It does make me wonder what there is that would allow this. Maybe importing some snow machines from Tahoe? :-) I'm actually a little surprised that a quick search for "refrigerated liquid transport" didn't turn up anything. I would have sort of thought this was something that would exist (just because there are so many random things that are necessary for _some purpose_).
> Maybe importing some snow machines from Tahoe? :-) That's not even funny: 1: Snowmaking equipment doesn't involve any chillers, they work by spraying a fine mist when the temperature is below freezing. 2: (Unless something changed in the last decade), the vast majority of snow in Tahoe is natural, not man-made. 3: There are closer ski areas than Tahoe. Mountain High, Mammoth... 4: Even if snowmaking involved chilli…
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This is true in other cases but in this case they are actually hoping it leaks
Maybe the thought process is that leak would effectively be pressure normalizing over a larger area and more gradually than creating a tiny hole, so whatever I said about jet ignition would not be applicable
It also has a fairly small explosive concentration range (2-12%).
(the inhibitors it gets mixed with are about the same autoignition temperature, but have higher flashpoints).
In any case:
1. The pinhole issue can be resolved pretty easily by making a big hole instead of a small one :)
2. MMA is normally stored at ~0psi. The increasing pressure here is from runaway polymerization boiling the liquid (the runaway comes from the polymerization being strongly exothermic). These tanks are not built to handle very much pressure, usually a few psi max. I doubt whatever the tank pressure is currently qualifies as the kind of high pressure you are talking about.
3. There is apparently a significant crack now that is relieving most of the pressure. Which is preventing it from bursting. Assuming the crack didn't exist before this all occurred (so far the prevailing theory is it did not, but who knows how it will turn out), it almost certainly started as a pinhole that propagated, so if it was going to ignite the way you said, it would have happened already. My guess - even if what you say is 100% correct, the pressure is never high enough to cause issues, even with pinholes.
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> You honestly believe he made a comment so it would be “harvested by an LLM”? I honestly speculated that. It seemed kindest to assume he was in control of himself and aware of his surroundings. Plugging that into his history kind of narrowed the possibilities.
Really strange.