61–69 of 69 posts
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That person consumed actual liquid nitrogen. The cardinal rule of culinary liquid nitrogen: don't ever serve a guest liquid nitrogen. The nitro-muddling technique in L.I. is designed in multiple stages to prevent that from ever happening; for instance, if you shake a drink with LN still in it, you'll hurt yourself before you manage to serve a guest LN. You're not wrong, though. You need to know what you're doing or y…
I was at a tiki bar last week that served drinks with dry ice in it, with a straw! So, so bad. I don't think you should ever give people dry ice, especially when they've been drinking. But if you did, the theory behind its safety is that it sinks to the bottom, so the drinker couldn't really consume it. But with a straw, if it got to a small enough size you could easily suck a pebble in, and the results would be at b…
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Also remember - any dewar itself, improperly handled, can be a bomb! One professor I worked for hammered this concept into us when we started work in his lab. Yet my PhD adviser did not. Sometime after I graduated, one of my fellow grad students blew up a dewar!! (Luckily no one got hurt). He obtained an old dewar from another lab, and went through the usual cool-down procedure - evacuate the Outer Vacuum Chamber, fi…
The dewar I bought from Amazon isn't pressurized. It is literally a big thermos. I assume it loses more LN to the atmosphere than a pressurized dewar; on the other hand, the explosion risk isn't big.
The dewars I was talking about above hold several hundred liters, are about 5-8 feet tall, and primarily for liquid helium (where evaporation is way more of a factor.
The pressure relief valves were built in to the storage dewar's we would get from LN2 and LHe suppliers, but I don't think the cryostats in our lab had them built in, you needed to add them separately by connecting onto the dewar's main flange. The one my colleague exploded didn't have the extra valve hardware attached, and he just capped it and walked away.
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The dewar I bought from Amazon isn't pressurized. It is literally a big thermos. I assume it loses more LN to the atmosphere than a pressurized dewar; on the other hand, the explosion risk isn't big.
Hmm, does the cap screw on tight like a normal thermos? Maybe it's designed to always have a loose cap for venting. The dewars I was talking about above hold several hundred liters, are about 5-8 feet tall, and primarily for liquid helium (where evaporation is way more of a factor. The pressure relief valves were built in to the storage dewar's we would get from LN2 and LHe suppliers, but I don't think the cryostats…
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The dewar I bought from Amazon isn't pressurized. It is literally a big thermos. I assume it loses more LN to the atmosphere than a pressurized dewar; on the other hand, the explosion risk isn't big.
Hmm, does the cap screw on tight like a normal thermos? Maybe it's designed to always have a loose cap for venting. The dewars I was talking about above hold several hundred liters, are about 5-8 feet tall, and primarily for liquid helium (where evaporation is way more of a factor. The pressure relief valves were built in to the storage dewar's we would get from LN2 and LHe suppliers, but I don't think the cryostats…
They could easily preserve LN for days. Dewars are impressive.
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Hmm, does the cap screw on tight like a normal thermos? Maybe it's designed to always have a loose cap for venting. The dewars I was talking about above hold several hundred liters, are about 5-8 feet tall, and primarily for liquid helium (where evaporation is way more of a factor. The pressure relief valves were built in to the storage dewar's we would get from LN2 and LHe suppliers, but I don't think the cryostats…
The non-pressurized LN dewars I've seen had a "plug" that was just a cylinder of foam that slid into the neck of the dewar, with a light plastic cap on top. It was lightweight enough to bob upward at the slightest pressure, releasing gas. It probably had a design with channels such that the lip never sealed completely anyway. They could easily preserve LN for days. Dewars are impressive.
:)
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The non-pressurized LN dewars I've seen had a "plug" that was just a cylinder of foam that slid into the neck of the dewar, with a light plastic cap on top. It was lightweight enough to bob upward at the slightest pressure, releasing gas. It probably had a design with channels such that the lip never sealed completely anyway. They could easily preserve LN for days. Dewars are impressive.
Static hold time: 100 days. Evaporation rate: 0.20 liters/ per day. 2.25" Necktube inside diameter. 15" Outside diameter. 25.50" Overall height. Empty weight: 23 lbs. Full weight: 60 lbs. :)
$500, eh? Hmmmmmmmmmmmmm.
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Static hold time: 100 days. Evaporation rate: 0.20 liters/ per day. 2.25" Necktube inside diameter. 15" Outside diameter. 25.50" Overall height. Empty weight: 23 lbs. Full weight: 60 lbs. :)
Wow, I forgot just how many days that was, I see. Though I now remember that one of my labs had a storage dewar full of precious biological samples that was a bigger version of this design, and we only refilled it a couple times a month. $500, eh? Hmmmmmmmmmmmmm.