Armed Polite Society
Main Forums => The Roundtable => Topic started by: kgbsquirrel on December 11, 2016, 12:36:15 PM
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I'm looking for a material that fits the following criteria, I suspect probably a ceramic of some sort, but I'd like to get a second (and hopefully more exact) opinion on the matter.
Material must:
Be inert in a molten NaCl, molten post-transition metal, and/or molten alkaline metal environment.
Be nonconductive.
Be dimensionally stable across the specified temperature range.
Quiescent temp: -50° to +125°F
Operating temp: +1,500° to +1,700°F
Tne ( =D ): +1,900°F
(I really do love the malleable nature of forum threads.)
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quartz or SiC or graphite
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You going to try to make sodium metal by electrolysis?
Depends how long it needs to be stable, and will you be applying heat? First thing that comes to mind is wood. ;/ (seriously, it will hold up for a while, and it won't fail suddenly)
How about PyroCeram? (old Corningware) or borosilicate glass? Borosilicate glass will soften at some point (it doesn't really melt), but I think it's usable to about 1300F or so.
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Crap, forgot a very important criteria!
I am not attempting to make sodium metal. Needs to remain stable on a protracted time scale.
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Seems to me we used to use ordinary laboratory porcelain crucibles for pyrolysis at those temps. And even higher.
1000°F is just getting into the dull red range. Comparison: a burning cigarette is about 1100°F if I recall correctly. MP of sodium chloride is around 1500°F.
What do you mean by "dimensionally stable?" Porcelain's linear expansion coefficient is 3.6 X 10-6, less than half of most stainless steels.
So whatcha up to? You casting copper bullets or sumthin'? It would be helpful to know, and if it's proprietary, you can PM me and I'll keep your seekrits.
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Seems to me we used to use ordinary laboratory porcelain crucibles for pyrolysis at those temps.
1000°F is just getting into the dull red range. Comparison: a cigarette is about 1100°F if I recall correctly. MP of sodium chloride is around 1500°F.
So whatcha up to?
*checks his paper notes* Nuts, I typo'd myself, thanks for that catch.
Let me go check some other stuff to make sure I didn't make any more...
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Okay, I fixed my OP.
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"must be nonconductive"
Eliminates charred wood, stainless steel, and graphite.
Added to my own previous post --you might not have seen it:
So whatcha up to? You casting copper bullets or sumthin'? It would be helpful to know, and if it's proprietary, you can PM me and I'll keep your seekrits.
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"must be nonconductive"
Eliminates charred wood, stainless steel, and graphite.
Added to my own previous post --you might not have seen it:
Well I sent you a PM. ;)
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You might try contacting Coors Porcelain division here in Golden Colorado. They make more than beer out here.
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I'd look at fused quartz. https://en.wikipedia.org/wiki/Fused_quartz#Physical_properties (https://en.wikipedia.org/wiki/Fused_quartz#Physical_properties)
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Try stupidity.
Low chance of success, but it's plentiful, and tossing imbeciles into molten salt is always worth a try.
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You haven't said a size yet...
You're just beyond what pyroceram can handle.
You need some kind of refractory. Firebricks would work. There's also castable refractory (looks like portland cement mixed with vermiculite) that would probably work if you bring the temperature up slowly the first time.
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About thermos sized for an initial test article.
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Working on the product line?
(https://armedpolitesociety.com/proxy.php?request=http%3A%2F%2Fsites.psu.edu%2Fsiowfa14%2Fwp-content%2Fuploads%2Fsites%2F13467%2F2014%2F11%2Fbluemeth.jpg&hash=9610812c2b856e52d60109981858867da23607b1)
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Working on the product line?
(https://armedpolitesociety.com/proxy.php?request=http%3A%2F%2Fsites.psu.edu%2Fsiowfa14%2Fwp-content%2Fuploads%2Fsites%2F13467%2F2014%2F11%2Fbluemeth.jpg&hash=9610812c2b856e52d60109981858867da23607b1)
I suppose it could be as lucrative. I suppose this wouldn't hurt: I'm sketching out some ideas for a proof of concept molten metal battery.
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Just take a regular battery and overcharge it. I hear you can get the Samsung Note 7 batteries pretty cheap. =D
Or just get a regular Boeing 787 battery.
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http://news.mit.edu/2016/battery-molten-metals-0112
Brad
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So you're still not tossing Hillary voters into molten salt?
I mean, come on; even if it delays the rest of the project, the YouTube ad revenue alone could pay for someone to do whatever you're wanting to do.
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Well, hey, mercury's molten at ordinary temps. Wood's metal melts below BP of water (at STP).
But hey, I read somewhere that in general, electrical resistance increases with temperature.
So, without fully understanding it, are they just trying to eliminate battery polarization because of the mechanical mobility of the molten metals?
Also, what about the NRG required to keep the stuff molten. Is that included in the energy budget?
Interesting, though.
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So you're still not tossing Hillary voters into molten salt?
I mean, come on; even if it delays the rest of the project, the YouTube ad revenue alone could pay for someone to do whatever you're wanting to do.
Screaming-Alpha class fire. (https://youtu.be/7Xu2YZzufTM) >:D
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Well, hey, mercury's molten at ordinary temps. Wood's metal melts below BP of water (at STP).
But hey, I read somewhere that in general, electrical resistance increases with temperature.
So, without fully understanding it, are they just trying to eliminate battery polarization because of the mechanical mobility of the molten metals?
Also, what about the NRG required to keep the stuff molten. Is that included in the energy budget?
Interesting, though.
More like trying to eliminate the mechanical breakdown of most rechargeable batteries by liquefying the materials thus obviating issues like material anode cracking and electrolyte loss to solid material formations, crystalization etc. Another major intent is to take a significant problem, thermal runaway, and instead turn it around into something useful/desired.
There are a few ways to achieve the initial molten state but for my initial test article I think I will be using an induction coil.
I'm starting to seriously consider prototyping this thing rather than keeping it my usual mental project.
Stage 1: Paper and mind. (Free.)
Stage 2: Test crucible to see if the desired battery chemistry is even feasible. (Cheap'ish.)
Stage 3: Experimental test article. (Expensive.)
Stage 4: Instrumented prototype. (Very expensive.)
Stage 5: Production model. (Pricey.)
I think if S1 doesn't reveal any show stoppers I will continue on through S2 on my own dime, and then if things look good I may hit up some of my more entrepreneurial family members.
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My science knowledge is limited to making coffee, so humor me here.
What can you do with a molten battery? You can't install it an anything. And it won't stay molten very long.
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My science knowledge is limited to making coffee, so humor me here.
What can you do with a molten battery? You can't install it an anything. And it won't stay molten very long.
>:D
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My science knowledge is limited to making coffee, so humor me here.
What can you do with a molten battery? You can't install it an anything. And it won't stay molten very long.
I was thinking it might be suitable for in situ storage use for alternative energy sites, as in large power facilities or "off the grid" homesteads.
It might not be necessary to keep it molten all the time, just fire it up when the alternative energy source starts to decline. As in when the rain starts or the wind stops.
I gotta look into it some more.
Terry
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But won't more energy be used to make the battery molten hot than what the battery puts out?
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You can maintain a high thermal gradient with fairly minimal input with appropriate insulation.
Consider something the size of a 55 gallon barrel. 32ft2 of surface area.
Ambient temp, 70F. Battery temp, 600F. Thermal difference of 530F
Assuming R11 insulation:
U value = (1/11) = 0.0909 BTU/(hr °F ft2) * 32 ft2 * 530 °F = 1541 BTU/hr * (1 watt / 3.414 BTU) = 451 Watts/hour
Assuming R-50 insulation:
U value = (1/11) = 0.0200 BTU/(hr °F ft2) * 32 ft2 * 530 °F = 339 BTU/hr * (1 watt / 3.414 BTU) = 99 Watts/hour
In the context of a battery that large, it's not bad.
That said, this is a function square-cube law - it won't scale down well, but it will scale up even better.
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In the context of a battery that large, it's not bad.
And easily provided by a simple gas burner. Storing potential heat (and making it into actual heat) is easier than getting electricity to stay in a can.
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And easily provided by a simple gas burner. Storing potential heat (and making it into actual heat) is easier than getting electricity to stay in a can.
Eh, I wouldn't. You'll need heat exchange between an open flame and the battery, which is by definition uninsulated space.
Plus, I imagine there would be pushback from the green culture surrounding products like this to using gas burners.
No, I think it makes far more sense to use electric resistance heating for this.
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You can maintain a high thermal gradient with fairly minimal input with appropriate insulation.
Consider something the size of a 55 gallon barrel. 32ft2 of surface area.
Ambient temp, 70F. Battery temp, 600F. Thermal difference of 530F
Assuming R11 insulation:
U value = (1/11) = 0.0909 BTU/(hr °F ft2) * 32 ft2 * 530 °F = 1541 BTU/hr * (1 watt / 3.414 BTU) = 451 Watts/hour
Assuming R-50 insulation:
U value = (1/11) = 0.0200 BTU/(hr °F ft2) * 32 ft2 * 530 °F = 339 BTU/hr * (1 watt / 3.414 BTU) = 99 Watts/hour
In the context of a battery that large, it's not bad.
That said, this is a function square-cube law - it won't scale down well, but it will scale up even better.
Ding ding ding!!!
I'm basically putting this sucker in a glorified dewar. God it's good to have easy access to vacuum pumps and stuff... >:D
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To clarify, the molten battery will be chillin' in a fused quartz vessel, which itself will be housed inside a cobalt steel pressure vessel which is then itself housed inside a stainless steel vacuum chamber. Under vacuum.
In other news I think I'm going to source the glass locally. I can't wait to see the look of terror in their eyes when I utter the words "fused quartz". :lol:
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. . . I can't wait to see the look of terror in their eyes when I utter the words "fused quartz". :lol:
Bet it won't match the look of terror we got from our safety people when were were loading optical fiber with H2 in a device we called a hydrogen bomb.
And then we decided to try it with deuterium . . . =D
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Bet it won't match the look of terror we got from our safety people when were were loading optical fiber with H2 in a device we called a hydrogen bomb.
And then we decided to try it with deuterium . . . =D
What, you think you're special or something over there Mr. Q? =D
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I'm basically putting this sucker in a glorified dewar. God it's good to have easy access to vacuum pumps and stuff...
Oooh...Democrats in molten salt in a hard vacuum...this just keeps getting better.
You are testing stupidity for viability as the magic element in this, right?
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Oooh...Democrats in molten salt in a hard vacuum...this just keeps getting better.
You are testing stupidity for viability as the magic element in this, right?
It seems worth a try. I'm thinking pureed, boiled down, foamed, injected into the interstitial space and freeze dried in place. Do you think the Stupid(tm) will be concentrated enough?
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It seems worth a try. I'm thinking pureed, boiled down, foamed, injected into the interstitial space and freeze dried in place. Do you think the Stupid(tm) will be concentrated enough?
Go for the Sanders crowd. That's about as dense as it gets.