half baked idea, frozen can cooler

George Herold wrote in news:73416d2f-9d34- snipped-for-privacy@googlegroups.com:

For folks above the arctic circle?

Frozen water beer can > USB charger?

I go the other way. Hot exhaust > peltier > USB charge circuit. Probably work better in a cold clime.

Oh great, 1k seconds? Why not just stand there and breathe on it?

Winfield Hill wrote in news:qe1lj401rt6 @drn.newsguy.com:

Use a phaser on it. That'll heat it up almost immediately.

Have to set it somewhere between stun and kill.

The big problem I see is clamping a beer can to anything. I would make a water cooled heat sink and use ice water if you need a lot of heat removed.

Dan

You may break your can when it gets frozen. Here in the far North (60 degrees N) I have seen too many frozen water pipes ...

Well when cooling with the hot plate air cooled, the hot side of the TEC is ~35- 40 C... and that limits the minimum temperature of the cool side.

To get to lower temperatures I was thinking ice cooling.

George H.

Oh dear... OK well that's much better. I can dump a Watt for 100k sec.. ~30 hours (with perfect insulation around the can)

GH

Huh, I was thinking that cans are pretty uniform in size. I was picturing some half moon clamps from the side.. but there are other options. (I could take the heat out through the bottom of the can...?)

I was more worried about the condensation.

George H.

Oh well that's the great part. First I drink the beer, :^) and then fill with water and freeze.. I don't think that would cause the can to expand.. I better go do an experiment.

GH (60 deg N? Finland?)

There's a more serious issue: why would anyone buy beer in cans?

Same reason I get Shiraz in a box. The 'cork-and-glass' packaging of traditional wine merchandising is (nowadays) an affectation. Neither plastic corks nor twist-off caps make any significant effect on the taste, that I can perceive.

Steel cans weren't innocuous, but aluminum can/aluminum lid seems to be a technology that is very close to inert, and there's no plastic disk in the cap like in a bottled beer.

Like the boxed Shiraz, the cans fit in the fridge better.

they make free low performance heatsinks. Just cut your metal with scissors & tie it on. I do that for parts that get too hot in existing equipment. The upside is you can cut them to any shape to fit anywhere.

NT

Yep - southern tip. The far north here is 70 deg N.

What are you trying to do?

The only time I contemplated ice (and dry ice) was for a crazy science demo with TEC run to generate voltage from a candle flame to light a high power white LED. In the end I gave up even though it worked the thing ended up so hot that solder melted on the first stage and the third stage cold side was capable of inflicting severe cold burns.

The usual approach is forced air cooling of the final stage heatsink and fans intended for PCs are remarkably cheap. The trick is to cool the smallest possible volume to the target temperature and then use a two stage system to pump the heat away with a finned heatsink and a fan.

Insulation around the place you are trying to cool is the key. Amateur astronomy cooled CCD devices are the canonical thing to beat.

Well, we've been crazy busy here, building and testing. But I look to be caught up soon, and I'm thinking again of my spad thing. (cooled single photon detector.)

A single TEC stage needs a little more umph (cooling power). Double stages get a bit more, but are trickier, (and I've never used one.) and also want to live in vacuum... which is a complication. I might gain another ~20C in cooling with ice on the cold plate.

I am worried about the whole condensation issue though.

George H.

es

Liquid nitrogen is handy - if you've got it.

Boil off as much of it as you need with a little resistive heater, and the stream of cold gas is absolutely dry. Nasty time delay in the control loop though - the cold gas takes time to get from the dewar to the detector you are, cooling, and the less cooling you need, the slower the transfer.

Are you going to force those poor physics students to empty beer cans?

How about some gas expansion thing instead of the TEC?

Propane makes a great expansion cooler, between explosions.

mandag den 17. juni 2019 kl. 17.12.41 UTC+2 skrev John Larkin:

here most if not all refrigerators use propane aka R290 as refrigerant