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Engineering the Perfect Coffee Mug
Nerval's Lobster writes "From the annals of Really Important Science comes word that a research assistant who picked up his B.S. just seven months ago has invented a coffee mug designed to keep java at just the right piping-hot temperature for hours. Logan Maxwell, who got his undergraduate degree in chemical engineering from North Carolina State University in May, created the "Temperfect" mug as part of his senior design project for the College of Engineering. Most insulated mugs have two walls separated by a soft vacuum that insulates the temperature of a liquid inside from the temperature of the air outside. Maxwell's design has a third layer of insulation in a third wall wrapped around the inner basin of the mug. Inside is a chemical insulator that is solid at room temperature but melts into a liquid at 140 degrees Fahrenheit. The insulator – which Maxwell won't identify but swears is non-toxic – turns to liquid as it absorbs the extra heat of coffee poured into the mug at temperatures higher than 140 F, cooling it to a drinkable temperature quickly. As the heat of the coffee escapes, the insulating material releases heat through the inner wall of the mug to keep it hot as long as possible; a graph mapping the performance of a prototype shows it could keep a cup of coffee at between 128 F and 145 F for as long as 90 minutes. "Phase-change" coffee-mug insulation was patented during the 1960s, but has never been marketed because they are difficult and expensive to manufacture compared to simpler forms of insulation. While working on the Temperfect design, Maxwell met Belgian-born industrial designer Dean Verhoeven, president of consulting form Ancona Research, Inc., who had been working on a similar design and had already worked out how to manufacture a three-walled insulated mug cost effectively. The two co-founded a company called Joevo to manufacture the mugs." According to the Joevo Kickstarter page, you can get one starting at $40. For that much, I'd like a clever lid like this Contigo has.
This is just the same approach as Coffee Joulies, which is a former Kickstarter project. I have a bunch of these, they work well. No need for a custom mug.
The insulator – which Maxwell won't identify but swears is non-toxic
I think this is a case where it most certainly needs to be disclosed in an MSDS and/or patent filing (though more likely in the MSDS, as the patent filing is allowed to be vague).
It holds 800ml.
If you need insulation, you are drinking it too slow.
perhaps the ability to add an iv-drip
A feeling of having made the same mistake before: Deja Foobar
It's too tall and thin; it will tip over easily (not that it matters if it has a spill-proof lid, but still...).
A $40 coffee mug. Come here and let me slap you.
This is just the same approach as Coffee Joulies, which is a former Kickstarter project. I have a bunch of these, they work well. No need for a custom mug.
Well, it's not quite the same as coffee joulies, for a number of reasons.
... you won't lose the integrated joulies. ... different name.
... but it's not breaking new ground.
First, it's integrated/built in.
Second, well
Third... uh
Seriously though, this is just an improvement on the thermos. A fancy improvement, and it might even be more effective
- Nec Impar Pluribus, or so I'm told.
It'll never sell to me. There are sunk costs involved. I have too much engineering invested in non-linear coffee consumption as cheap mugs and paper cups lose heat. Slowly at first, with much intake of the aroma. Then cautious sips, then normal sips, then fairly heavy consumption somewhere between 1/2 and 2/3rd of the way down. It ain't broke. I'm not fixing it. It works anywhere. No need to buy an expensive mug, take it with me everywhere, wash it, and worry about losing it.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
Wait, what does the time of day have to do with thermodynamics? If the coffee and insulating material are both heated to the same temperature then there is no way it would cool things down *more* quickly than if there were no insulation at all. Especially if you rinse the mug out with some hot water first to add some heat to the system before putting the coffee in. There is no disadvantage to this system...
The unnamed insulator is Spam. Not sure if that makes it toxic or non-toxic, though.
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All good, except; gallium is hella expensive. And very very dense, therefore very heavy.
My money is on good old-fashioned paraffin wax, which (at least in the bulk candle variety that I bought in my hippie candle-making days) melts at exactly 140F.
Cheap and food-grade (it coats many candy items) and pretty light.
Any quantity over one is plural, including 1.5 hours. For that matter, while fractions between zero and one are generally written in the singular form (1/2 hour), the equivalent decimal forms are typically plural (0.5 hours). Zero is always plural. Really, the only quantity guaranteed to use the singular form is exactly one.
That said, you're correct that the quantity-free "hours" would generally imply at least two hours, regardless of the fact that 90 minutes converted to hours would be written with a plural. That's because it doesn't include potential fractions of an hour, only whole numbers.
"The state is that great fiction by which everyone tries to live at the expense of everyone else." - Bastiat
My guess is the mystery insulator material is beeswax. At least, the temperatures are about right, it's non-toxic, and doesn't oxidize AFAIK.
The road to tyranny has always been paved with claims of necessity.
Sorry, but a melting point of 30C is entirely too low. That's about 85F and that is the temperature that the cup of coffee would be soon brought down to until all of the gallium melted. The 140F ( 60C) temperature mentioned points towards paraffin wax which is commonly used as a phase change material for maintaining temperatures http://en.wikipedia.org/wiki/Paraffin_wax#Properties
As others have pointed you - you missed the point.
It cools to 140, and then holds near 140 for as long as possible, because 140 is the optimal coffee temperature -- or so sayeth the coffee gods.
That said, I spent a lot of time explaining to people with the "new aluminum beer bottles" that "gets cold faster!" also means "gets warm faster" for all the same reasons.
What a piker.
Just line your coffee mug with plutonium. That'll keep it warm.
I called it.
Is it just my observation, or are there way too many stupid people in the world?
Urine coming out at over 140 degrees may be a health concern.
I just set my ceramic mug on top of my Apple Airport, that seems to keep it warm.
"If any question why we died, Tell them because our fathers lied."
This is precisely one thing that irks me about living in the US. People get the coffee culture completely wrong, they even say things like "let's grab a coffee". In civilized countries, you never *walk* around with a coffee. You sit down, spend 10 focused minutes on an espresso and maybe conversation and then go on doing things with both hands. Walking around holding some significant fraction of gallon of coffee is just pointless - you get gorilla arm, you never enjoy coffee and you never enjoy a real break.
A slightly more subtle than glaringly obvious example of the No True Scotsman fallacy.
It's listed as a material that is in food so I'd say not.
Heavily salted bacon grease? Coconut oil/Copha? Any ideas for something that's going to last and melts at 60C?
As for basic thermo - look for a binary phase diagram for an alloy between two metals of different melting points. There will be some compositions where the melting point is higher than that of the one with the lower melting points. Tin-Lead is a good one to look for, you'll notice that with a lot of tin the melting point is higher than that of Lead.
Gallium has a molar heat of fusion of 5.59 kJ/mol and a mass of 69.723 g/mol. Paraffin (we're going with C31H64, or, hentriacontane here) has a median molar heat of fusion of 21 kJ/mol, and a mass of ((12.017 * 31) + (1.00794 * 64)) = 437.04 g/mol. If we take 437.04 / 69.723 = 6.2682, we see that we can have 6.2682 moles of Gallium for the same mass as paraffin. This leaves us with 5.59 * 6.2682 = 35.0 kJ of energy absorbed for the same mass of ~437g versus 21 kJ for paraffin. Gallium has a density of 5.904 g/cm^3, and Paraffin has a density of 0.781g/cm^3, therefore the gallium will not only absorb more heat, but also be substantially denser, to the tune of about 7.5x denser than paraffin. So, for 437g of gallium, we'll occupy 74 cm^3, and for 437g of paraffin, we'll occupy 559.5 cm^3.
It's been around 7 years since I took a chemistry course; I'd appreciate corrections on mistakes.
Wait, what does the time of day have to do with thermodynamics?
Thermodynamics is already being blamed for the heat death of the universe, even though that hasn't happened yet. It tends to drink a lot, which can leave it hung over in the morning sometimes.