Originally published at: https://boingboing.net/2020/07/15/make-this-tool-to-chill-a-beve.html
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I remember Mythbusters had an episode on this! They determined that, if you can afford it (not cheap) a carbon dioxide fire extinguisher could cool a six pack in 3 minutes. Next best was icy salt water in 5 minutes.
https://mythresults.com/episode29
90 seconds is even better though.
I walk to the deli & pick up a cold one.
hnnn… so barely recalling from 12,000 years ago my class in thermodynamics heat transfer rate is just kA(ΔT/Δx) where the “k/Δx” is determined by the separating material and how thick it is. Now, why wouldn’t we assume that circulating the bulk coolant (the icy water) would work even better (faster) than just setting up a nearby vortex, whose ΔT wouldn’t change as fast?
Sadly, no one will make a video about your ingenious hack.
Why bother? I just use the “reverse” setting on my microwave.
This is basically the same as just stirring the water around the can, which is already accomplished by the spinning can.
From the heat transfer perspective, there are three sources of heat resistance from the ice to the soda:
- The thermal boundary layer from the bulk ice water to the surface of the can
- The can itself
- The thermal boundary layer from the inside surface of the can to the bulk of the soda in the can
For boundary layers in fluid, the best way to reduce the thermal resistance is simply by stirring or agitating the fluid. When the fluid is perfectly still, the water near the can will start to warm up (and the soda near the inner wall will start to cool down) which will slow down the overall heat transfer into the can. Stirring overcomes this by continually replacing the fluid near the can with ‘fresh’ cold water (or warm soda on the inside) so the overall heat transfer is faster.
For the outside this is easily done on the outside by stirring the ice water. However its not so simple to stir the liquid inside of the can. This is where the rapid spinning of the can comes in: mostly the liquid will simply be spinning in place, but a secondary flow also occurs where the soda inside the can will flow from the center to the edge in a donut-like shape. This secondary flow is much slower than the spinning can velocity, but is still enough to cause good mixing of the fluid on the inside. This reduces the thermal boundary layer on the inside and the outside, causing the soda to cool much faster.
At an end-of-week celebration during a shoot (we call them Frosty Fridays) my wife plunged her head into a ice water filled cooler and retrieved a beer with her teeth - and bobbing for brown pops was born. I love her very much.
Perfect editing to get all the info in without wasting any time. This could have been a 25 minute video in the long winded style of other maker videos.
Never, NEVER, reverse the polarity!
Bit of a long winded explanation but that’s exactly what I’d figured – you’re not just stirring the ice bath, you’re stirring the can contents as well! Very clever IMO.
The best way I’ve tried to date is the aforementioned saltwater ice bath. I have a surfeit of power tools and I’m real curious to give this one a try! But first, how to cheaply get a 1/4" hex shank on there so I can also use it with my quick change tools? Hmmm
[Edit – aaaaand someone’s done it for me already and it’s a commercial product, because of course it is]
Am I the only one who doesn’t really want ice cold drinks? I mean cooler than air temperature would be nice but whenever I grab something out of the fridge at a shop I feel like it tastes of nothing because it’s chilled too deeply. It would have to be a really hot day (like 35°+) where I would want a drink chilled to the 5° he is going for.
This reminds me of those water baths they have in wine sections at the fancy grocery. Now I get it!
Must say though, when the camera switched to inside the cooler I squealed in delight.
Yeah, but what do you do when you leave it in for too long and wind up having a beverage at 99.99999999% of absolute zero.
So… you’re not American, right?
While mixing the fluids on either side of the can will prevent thermal gradients from developing and hindering the flow of thermal energy via conduction, I believe the primary source of cooling in this case would be via convection, as the fluids are flowing over the can’s surfaces instead of being largely static.
90 seconds of cordless electric drill battery life. I’m thinking you’ll get maybe 3-4 drinks before you gotta switch out the battery.
And if they’re these crappy Ryobi 18V ONE+ batteries, they might just decide to crap out in the middle of your picnic. I swear these things have circuitry that cuts out after a certain amount of use, after which they’ll no longer take a charge.
Why didn’t the can spew all it’s contents out when he opened it?