h a l f b a k e r ycarpe demi
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Sometimes I want a cold drink, but there is no ice available because the guests took it all; or a drink is too good to dilute it with frozen tap water. In these cases a vacuum chiller could help. It consists of a base plate with a sealing dome. The dome is connected to a rough pump (4 Torr). You place
the glass with the drink on the plate, cover it with the dome and turn on the pump. The decrease in pressure will make the drink boil so it looses heat. The rate of cooling is only limited by the pump capacity and the drink boiling over, so it can be pretty fast.
The worst case scenario would be to cool fresh brewed tea or coffee from boiling to near freezing for ice tea or coffee. If I calculated right you would loose about 16% of the liquid to steam (see links for data). For a drink at room temperature that's cooled to a pleasant 10C losses would be a lot less.
A manufacturer for vacuum cleaners could sell this as an add on, with a somewhat modified vacuum to get the lower pressure and handle the condensing exhaust steam.
Thermal data water 1
http://www.guilford...logy/WaterHeat.html
[kbecker, Oct 04 2004, last modified Oct 21 2004]
Thermal data water 2
http://hyperphysics...kinetic/watvap.html
[kbecker, Oct 04 2004, last modified Oct 21 2004]
Swift Vacuum Cooler
http://myweb.hinet....t_vacuum_cooler.htm
Their grammar is not so swift. [Amos Kito, Oct 04 2004, last modified Oct 21 2004]
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I have had good results with this technique when applied to footwear. On a hot day, put the uncomfortable shoes into the vacuum chamber. A minute later you have a refreshing pair of freeze-dried sneakers. Maybe better to use a different chamber for the drinks. |
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Vacuum is nothing, so whatever the shoes released should be gone. If the vacuum is not so perfect a few purge cycles with fresh air may be advisable though. |
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Carbonated beverages would turn flat, however. |
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And don't do this with anything alcoholic - you'll boil off the alcohol before you get the the water. Elegant idea nonetheless. + |
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[Worldgineer] For that matter, wouldn't any solution (as in mixture, not answer) have that problem? What about suspensions or emulsions? |
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No, only mixtures with liquids with a lower boiling point than water. Alcohol is the only such liquid commonly consumed that I can think of. You'll make solutions more concentrated, but that could be fixed by adding a bit more water. |
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I see. So my vodka and liquid nitrogen cocktail (Russian Glacier, I call it) would suffer doubly. |
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Yummy. No, that would work fine (without the drink cooler). Unless you wanted to drink the liquid nitrogen, which you really shouldn't (-195F would produce quite a brain freeze, though come to think of it so would frozen alcohol). I still want to have a liquid nitrogen ice cream party but just can't seem to get my hands on any. |
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(added later) Had a LN ice cream holloween party - went off very well. Turns out you can get LN at welding shops. |
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I prefer vanilla ice cream, myself. Can't stand those nitrogen chunks. |
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{ceadar park] - that's humor right? (liquid nitrojen is just used to freeze the milk.) |
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// And don't do this with anything alcoholic - you'll boil off the alcohol before you get the the water.// |
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I needed to look it up to be sure, but all the alcohol will not go out first. The drink itself will never go to pure water. Even if you hold it at a pressure where alcohol boils but water doesn't you'd be getting vapor that was only slightly richer in alcohol than the drink is. |
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There'd be some loss, but not enough to worry about. |
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You'd need careful condensation to get alcohol out of the vapor, but that isn't the point. |
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// Turns out you can get LN at welding shops. // |
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At your better class of shops (industrial Saville Row?) you
can also get liquid helium and liquid oxygen, both of which
can be used in fun party tricks. |
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After 13 years in the industry, I still have no idea what a
welder would do with liquid helium. I've used helium in
several welding porcesses, but never encountered it in
liquid form in the workplace, and the only time I asked at
the store, it turned out the guy I was talking to didn't even
know they sold it there. Even the interweb doesn't seem to
know. Maybe it's for keeping my Gatorade cold while I
work. |
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LHe is required for high-integrity welds in Titanium. |
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Aha. Good to know. Never done any Titanium welding, nor
am I likely to. The only process I ever heard of being used
for it is solid sub-arc, but my work is in an entirely
different corner of the field. The high-tech guys can keep
the LHe, then; I sometimes have up to 300 lbs. of LO2 in a
blast hut out
back, which is plenty cold enough for me. |
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