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How are you going to create a vacuum while camping out in the wilderness? |
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These would be pre-vacuum sealed. You pop the top off and air rushes into the cube. |
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How 'bout making it regenerative? There must be a convenient way to make a heating device using friction supplied by the user, which then heats up said liquid/food/mush. |
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I propose: 3-cylindered mug/vessel -- outside ring is for insulation. The interface between the middle and inner ring generates friction heat when the inner ring is spun. Plus, the spinning of the inner ring should at least stir the contents. |
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Attach the inner cylinder to a crank, not unlike that used in the old hand-cranked egg beaters.
The only trick will be to use a material that can generate a lot of friction heat, but will not degenerate that much over repeated usages. |
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This doesn't exactly fit your idea, but it gets the same job done. |
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Maybe add some sodium, lithium, or potassium? Not sure how best to prevent premature deployment (which could be a BAD thing), but sodium should be able to self-start the reaction. |
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I think a little thermite cube in your coffee might evaporate it before you even realize what happened.. |
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[link] baked if you like your drinks tepid, though making it hotter shouldnt be too difficult for the manufacturer |
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Ah, but this is a new method for heating meals. Its a subtle distinction. |
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The method. The method is different. |
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The hotpack uses a magnesium and iron alloy, sodium chloride, and silica, in a psecial pouch. The reaction begins when water is added. |
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The cube uses aluminium and iron-oxide, and the reaction begins when it comes into contact with air. |
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These two methods use different chemicals, have different catalytic agents, and as such have a different method. |
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Its the difference between using two sticks, and using steel wool and a battery. |
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You'll have to ask the author that one, methinks. |
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// Maybe add some sodium, lithium, or potassium? // |
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Phosphorous would be better. |
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The "Thermite" reaction is just a little too vigorous, and there are quite a few gaseous and particulate by-products - irritant, but not specially toxic. |
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How about a USB powered cup heater.
Wherever your computer is, you always get hot coffee. (While programming in Java) |
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Just to comment of some of the other comments. Which are great by the way, I did propose just using a little iron oxide, to keep the thermite reaction small. I wanted to use a waterless system so it could be used in subzero environments. The vacuum sealing was proposed instead of CO2/N2 purge so it would be self starting, but I suppose one could add a tube to blow air in. I also chose the thermite reaction because this is meant to boil water, possibly provide warmth when all else is lost. Thanks for the comments. |
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//How about a USB powered cup heater. Wherever your computer is, you always get hot coffee.// |
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Let's suppose you have 46ml of water at 30C and you wish to heat it to 80C (which would be heating a pitifully small amount of water to a temperature which isn't really hot enough to make coffee). This will take 2,300 calories of energy, or 10,000 joules. A USB port is limitted to 500mA at 5 volts, i.e. 2.5 watts or 2.5 joules/second. Assuming no thermal losses, the pitifully-small quantity of water mentioned above would take 2500 seconds to reach a temperature which isn't really hot enough to make coffee. |
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