h a l f b a k e r yThis ain't rocket surgery.
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I keep a bottle of water in my trunk (everyone should)
but this time of year it freezes solid. If I ever needed
that bottle of water I would have to thaw it out for an
extended period of time before drinking. People
backpacking or hunting in very cold places might have
the same problem when
packing water. Most
solutions
to this problem involve some way to thaw the water,
but that takes time and energy.
Enter the un-freezable emergency water bottle. A
plastic bottle with a large carbon filter on top,
followed
by a particulate filter. The bottle is filled with a
50/50
mix of H2O and C2H6O2, so it won't freeze. Squeeze
the bottle to force the mixture through the filter and
into your mouth. Don't worry, that sweet taste is
normal.
[link]
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You could always add a bit of salt... |
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wikipedia "Ethylene glycol is moderately toxic, with children having been particularly at risk because of its sweet taste, until it became common to add bitter flavoring to consumer antifreezes containing it." |
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So just add water to a half empty bottle of antifreze ? |
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I don't think a carbon filter will remove anti-freeze from water. Also, drinking sub-zero temperature liquid is probably bad for you. |
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That's also the formula for methoxymethanol, a most interesting
compound ... |
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// Ethylene glycol is moderately toxic, with children having been
particularly at risk because of its sweet taste, until it became common
to add bitter flavoring to consumer antifreezes containing it. // |
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Fortunately, it's still possible to get the pure stuff. And, handily, it's
also extremely toxic to cats. |
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Piezo-electric bottle-top, with little heater and a rechargeable battery, well insulated bottle, and a few fish-scented regurgitant tablets labelled "eat me". As the water heads towards freezing it expands, so pressing on the bottle-top, which makes leccy, which heats the water up. |
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Due to entropy, battery assist would be useful. Battery could also be recharged by sliding magnet/coil wossername, so getting recharged in just day to day driving. |
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Hand me that patent form... |
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If you would just filter the water extremely well, going into the bottle,
it would have no nucleation points around which to freeze. It would
freeze as you pour it out, but so would your idea. |
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I agree with [xaviergisz]. Drinking cold water is bad for you, drinking
super-cold water would be worse. (I don't mean sipping a cold drink
on a hot day, I mean trying to rehydrate with icewater at any time.
(The only thing worse is trying to eat snow to keep alive.)) If you
*need* the water, you need it to not be cold. |
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A thermos is already a pretty good way of keeping water from freezing, especially if you start with boiling water. |
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For long term water storage (i.e. in the trunk of your car) a thermos could be fitted with a switchable thermal conductivity element. When the ambient temperature is above a threshold (e.g. 20ºC) the element becomes thermally conductive, and below the threshold is thermally non-conductive. The element could be as simple as a bi-metallic strip that selectively forms a thermal bridge between the inside and outside of the thermos. |
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Just add an amount of ethanol adjusted for your
expected climate. Somewhere around 60 proof is
adequate to prevent freezing around Boston. |
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Of course if you bump it up a bit further, you have
the advantage of being able to light it on fire for
warmth. |
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//I keep a bottle of water in my trunk (everyone should)// |
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Well, okay. But I'll need your car keys and address first. |
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Munge it into your engine compartment, alongside the exhaust manifold cooking set. |
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How about a week solution of hydrogen peroxide.
Suck it through a silver catalyst straw and the H2O2
will break down and add to the water plus heat it
up. Probably wouldn't actually work since you'd
need a very weak solution to avoid an effect similar
to trying to drink from a rocket engine. I couldn't
find the freezing point of weak solutions, but a 50%
solution freezes at -51C. |
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Best solution (unavoidable pun) to the problem so
far, scad mientist. From the diagram on wikipedia
on Hydrogen peroxide it appears the melting point
of hydrogen peroxide in water is roughly equal to
the percent in solution, so 10% H2O2 has melting
point of -10ºC, 40% has a melting point of -40ºC. |
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Rather than a straw, it should be a high surface
area element that is plunged into the hydrogen
peroxide water solution. The element is left in until
the hydrogen peroxide is substantially decomposed
and the water heated. |
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Ah, I see. You nearly got it. Simply replace ethylene glycol with
C2H5OH. A 50:50 solution of this with water would not freeze until
things got rather insanely cold. As a bonus, I've heard that C2H5OH Is
readily metabolized and routinely used by cold Russians. |
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//A 50:50 solution of this with water would not
freeze until things got rather insanely cold.//
Google told me about -40C, which is pretty chilly but
not //insanely cold//. |
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why not just keep the bottle of water in the cab where it is presumable not freezing? |
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A simple sleeve containing sodium acetate, a la a skiing handwarmer, would do the trick. But I suppose the land that gave birth to Eddie the Eagle probably doesn't know much about skiing accessories... |
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//Eddie the Eagle probably doesn't know much about skiing
accessories...// |
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Given that nowhere in England is more than 70 miles from
the sea, and nowhere more than 70 yards from a reasonably
well appointed coffee shop, dying of cold and dehydration is
more of a leisure pursuit for us. Robert Falcon Scott was
simply a correspondent for the "Summer Getaway"s column
in The Times. |
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// Rather than a straw, it should be a high surface
area element that is plunged into the hydrogen
peroxide water solution // |
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Yeah, I think that would work better. For
example, I suspect that a 10% solution would have
too much energy, and if that freezes at -10C, it
couldn't be sucked through a straw anyway. If the
catalyst is put in contact with the frozen solution,
assuming a reaction can get started, the heat
should melt more, making more H2O2 available for
reacting until it is all melted. |
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It still might be tricky to get a concentration that
releases enough energy to deal with the phase
change if it is frozen but not get the water too
hot if it starts out at room temperature. I guess
one solution would be to carry a half-full bottle of
water and a half full bottle of H2O2 solution. If
both are liquid, just use the water, or if you want
it a little warmer, add a little H2O2 solution to the
water and stir. If the water is frozen, pour in a
bunch of H2O2 and stir. If they are both frozen,
use the catalyst to melt the H2O2 solution. The
concentration should be chosen so that when the
H2O2 is just barely frozen, the final temperature
will be less than scalding. The nearly scalding
water can be transferred to the bottle with ice
long enough to cool it to the desired temperature.
If it starts out far below freezing temperature, the
final temperature may still be somewhat cold.
There could be a burn hazard if the user puts the
catalyst in the H2O2 solution when it is liquid
without diluting it first, but there can be a
warning label, and hopefully the concentration
would be low enough that it wouldn't vaporize and
cause an explosion hazard. |
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Also, for the catalyst, it might be convenient to
just use some very fine silver powder. Apparently
it's not very toxic and should be fine for occasional
emergency use. Maybe even have it as a
suspension in water (colloidal silver is available as
an alternative medicine) to help get the reaction
going faster when it is frozen. We might need to
make that suspension with a high salt
concentration so it never freezes, but if a small
drop of this is added to a quart of water, the final
salt concentration should not be disagreeable for
drinking. |
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//-40C, which is pretty chilly but not //insanely cold//// |
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Odin's hairy crotch, man. To someone who lives at sea level within 1000km of the equator, -40C certainly suits the definition "insanely cold" to me. |
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Maybehaps the problem is people trying to abide within unrealistically inhospitable climates? Like complaining that your martinis keep evaporating while hollidaying on the surface of the sun? |
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I've calculated that complete decomposition of a 4% hydrogen peroxide water solution will heat the water 50ºC, 8% to heat 100ºC (someone should check the maths), |
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If you needed something to operate below -8ºC (the melting point of 8% concentration) you could have nested chambers of higher concentration H2O2 to do a 'cascading' defrost. |
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Of course we are overthinking this - There are plenty of exothermic reactions that could be initiated in a separate chamber adjacent or within the water bottle to defrost the water. Trying to make the product of the exothermic reaction drinkable water is overkill. |
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//the problem is people trying to abide within unrealistically inhospitable climates?// |
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Water. In a bottle. Under the front seat. Problem solved. |
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bottles: LOx, LH2 - now you can make drinking water instantly, even in Edmonton. |
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Dammit, I was just going to say hydrogen and oxygen... |
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// bottles: LOx, LH2 // LOx? Sure some people
think it's overkill to be prepared for -50C weather,
but you're not really prepared unless you're ready
for a sudden loss of oxygen in the atmosphere. |
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Ignoring the obvious containment issues, carrying
LH2 is very efficient because it is much lighter
than the water that can be produced. My H2O2
idea is actually quite inefficient since all that extra
oxygen is heavy and doesn't add to the final
volume of water. |
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Now you just need to figure out what to do with
the excess heat when you make water. |
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//Ignoring the obvious containment issues,// |
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from original idea: //People backpacking or hunting in
very cold places might have the same problem when
packing water. // |
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I've encountered this while taking my usual Camelbak
water thingy up mountains in winter, the tube freezes
very fast. Eventually the whole thing freezes. Fortunately
I was never up mountains very long, but we solved the
problem by taking vacuum flasks. Perhaps a vacuum flask
would be a good enough insulator that to actually remove
the heat energy to both reduce the temperature and
then freeze the water would take so long that it doesn't
happen, at least between periods of heating, e.g. the car
heater being on and used. |
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