[Superbman]

Hello all,

I'm totally green in the subject of chemistry and I come to you-passionate professionals for help.

I would like to contruct (for a needs of my catering objects) some kind of device/refrigerator/freezer to very very quick cooling drinks in glass bottles.

Do You have any ideas ?

As I read, cooling mixtures(ethylene glycol/ethanol/dry ice mixtures) can be helped in this.

What do You think about this ?



Thank for your *delete me*
Best regards !
Peter

[enahs]

How fast do you want?

Is 15 min fast enough?

If it is, a plastic cooler filled with really salty water and ice will get drinks to 40 F in 15 minutes or left.

[Superbman]

I want to cooling it in about 1 min, max few minutes.

Maybe I should use ultra freezer(-86°C) and put in cooling mixture in it to keep low temperature ?

[enahs]

You do not just want low temperature, but low temperature of something with a high specific heat.

To be honest, 1 min, while possible is NOT by any means economical. Is it really worth $50 per bottle/can to cool it in one minute when you could just plan and do it in advanced?


The cheapest to fastest I could think of would be a 70% ethylene glycol (anti freeze) and 30 % water, and a little bit of dry ice in the solution at a time. But it is going to form a liquid/glass like solution at that low of a temperature and be sticky. And antifreeze is toxic so you would have to really clean the bottles and cans off well before serving. Not sure if you are even legally allowed to do this.

[fledarmus]

There are two major factors controlling the rate of cooling the bottles that you need to consider. One is the difference in temperature between the fluid outside the bottle and the fluid inside the bottle, and the other is how quickly heat moves through the fluids. You can increase the rate of cooling to a point by decreasing the temperature of the outside fluid,  by increasing movement in the outside fluid, and by using a fluid that is a good conductor. Salt water and ice, as suggested by enahs, is more than sufficient, especially if you have a pump moving it around in your cooler. That keeps you from forming successive layers of slightly warmer water around the bottles and allows you to use convection to cool the bottles faster.

Unfortunately, you're still limited by how quickly you can transfer heat in the fluid inside the bottles. The glass will get nice and cold and will start to cool the innermost layer of the fluid, but the temperature will drop slower as you go to the center of the bottles. You will get some convection just because the fluid will get more dense as it gets colder next to the glass and will start to sink, bringing warmer fluid in contact with the glass, but this isn't as efficient as the forced convection you can use in the outside fluid. Having a mechanical system to rotate the bottles might help even more. If the outside of the bottle is too cold, however, the layer of fluid adjacent to the glass on the inside of the bottle will freeze before the convection currents can thoroughly mix it, and you will end up with frozen layers against the glass while the middle still isn't as cold as you would like it. I suspect the antifreeze system proposed in enahs second post would rapidly freeze the fluid inside before it was really cool.