Keeping liquids cold !

[adsl1981]

Hello

 

I am interested to know if there is anyway of keeping a liquid cold constantly with no other method appart from electricity. I do not have enough room for any regfrigeration pumps etc.. but i wondering if there is any simple way of keeping liquids cold using electricity ?

 

Thank you

[sunspot]

I am a little foggy on this but I sort of remember a article many years back of a some type of metallic bilayer. Depending on the polarity of the electricity, it could be used to cool or heat.

[zeropoint]

Hello

 

I am interested to know if there is anyway of keeping a liquid cold constantly with no other method appart from electricity. I do not have enough room for any regfrigeration pumps etc.. but i wondering if there is any simple way of keeping liquids cold using electricity ?

 

Thank you

 

WITH electricity?

Nothing that comes to mind. However, there is a method that was used by some Native Americans and Mexican Indians some time ago (still in use today in some areas) whereby you don't need electricity.

 

Use 2 very large thick clay pottery containers, 1 larger than the other. Put sand in the bottom of the larger one, insert the smaller one into the larger pot and put sand all around the outside of the smaller pot. Preferably the smaller pot allows at least a one-inch space between it and the larger pot. Wet the sand and store perishables in the smaller pot. You'll need a "lid" of sorts for this so the cold is not allowed to escape.

 

If you have ice, you can place a few pieces of ice atop the sand around the perimeter of the smaller pot and let it melt into the sand.

 

Can't get much more primitive than this.

 

zeropoint

[Borek]

Google Peltier effect.

 

Best,

Borek

--

Chemical calculators at www.chembuddy.com

equation balancer and stoichiometry calculator

www.pH-meter.info

[zeropoint]

Google Peltier effect.

 

Best' date='

Borek

--

Chemical calculators at www.chembuddy.com

equation balancer and stoichiometry calculator

www.pH-meter.info

 

Not sure what your ph meter has to do with the question. I used the Nerst equation in neuroscience class in figuring action potentials and certainly the ph does trigger an action potential. However, not much to do with temperature as far as needing to set up a contraption for refrigeration. ???

 

zeropoint

[Klaynos]

A joule thompson process machine would do it, but it would take a little space and would only work for certain liquids/gases depending on the temperature they start...

[The Thing]

You can use a Stirling cycle Cooler. Some small coolers are about the length of a 30cm ruler (so, about 30cm). They don't have a lot of moving parts - just a linear motor driving a piston.

 

It's very efficient and larger ones can cool to cryogenic temperatures. Of course, it takes up a bit of space.

[adsl1981]

Ok well i need something that is reasonably small. What i want to do is use the trapped cold and blow it away with a fan to spread cold air ! would this work with that sand method ?

 

Thanks a lot

[adsl1981]

would i be abled to use any other materials more solid like metals and plastics instead of clay pots ! and also how long will the cold stay inside and will it be damp ?

 

Thanks

[DV8 2XL]

There are all sorts of Peltier coolers on the market. Why re-invent the wheel?

[BhavinB]

There are all sorts of Peltier coolers on the market. Why re-invent the wheel?

 

+1 for Peltier coolers.

I use Melcor as my source

http://www.melcor.com

[Kermit]

Can't you use a Dewar flask or whatever it was called? That thing they use to keep liquid nitrogen cold. Doesn't use electricity, but instead uses a vacuum between two layers of insulating materials.

 

Heck, even a thermos should work. Unless of course it's for a scientific application. What're you trying to keep cold?

[adsl1981]

Well yeh the problem is that i want to keep the liquid cool but i also want to use it for cooling down so it cant be completely sealed...

 

I think its impossible to keep a liquid cold and have access to it

 

Anyone think it can be done ?

 

Thanks a lot

[DV8 2XL]

The Peltier cooler link that BhavinB was kind enough to post for you sells cold plates (like hot plates). Go look at it.

[Caver451]

When you "create cold", you're really just "pumping heat". That is, moving heat from one place to another. Without moving parts, a peltier cooler is about your best bet, but while they are capable of creating quite a wide temperature differential--and some designs can even get to cryogenic temperatures--they can't generally move very much heat. If your intention is to create an air conditioner, it will work, but it won't be able to move enough heat fast enough to chill a room, for example.

 

So, what are you up to? If you can give a few more details, I am sure we can come up with some hints. For example, you can do it without electricity if you only want cold for an hour or two. Dry ice can be used to cool a liquid which can then be pumped through a radiator. If you want really cold air, that is a good option.

 

If on the other hand, you're just trying to make a simple and inexpensive air conditioner for a room, you can do what "they" did before air conditioners were invented: evaporative cooling. Take a regular fan, a pan of water and some strips of thick cloth. Soak the cloth and put the ends in the pan of water. When the fans blow across the cloth, it will cool the air as the water evaporates. It will also help increase humidity, if you live in a dry climate like I do.

 

If you're just interested in cooling a small space, perhaps the size of a soda cooler, peltier is a great choice. Depending on ambient temperature, you can expect to cool a cubic foot or two down to about 45 F or so. I recommend just going to a department store and buying a premade cooler. I believe "Coleman" makes one.

 

So, what is your application? We know you want to cool air, but to what temperature, on what scale, and for what purpose?

 

-Caver

[Borek]

Not sure what your ph meter has to do with the question.

 

Nothing. Answer was above signature, not below

 

And judging from the fact that Peltier coolers were later mentioned twice - it was a good answer.

 

Best,

Borek

--

Chemical calculators at www.chembuddy.com

equation balancer and stoichiometry calculator

www.pH-meter.info

[Alireza]

There are all sorts of Peltier coolers on the market. Why re-invent the wheel?

 

Hi, remember Peltier has very low COP or efficiency; not useful for relatively large volume

 

There are all sorts of Peltier coolers on the market. Why re-invent the wheel?

 

Hi, remember Peltier has very low COP or efficiency; not useful for relatively large volume

 

When you "create cold", you're really just "pumping heat". That is, moving heat from one place to another. Without moving parts, a peltier cooler is about your best bet, but while they are capable of creating quite a wide temperature differential--and some designs can even get to cryogenic temperatures--they can't generally move very much heat. If your intention is to create an air conditioner, it will work, but it won't be able to move enough heat fast enough to chill a room, for example.

 

So, what are you up to? If you can give a few more details, I am sure we can come up with some hints. For example, you can do it without electricity if you only want cold for an hour or two. Dry ice can be used to cool a liquid which can then be pumped through a radiator. If you want really cold air, that is a good option.

 

If on the other hand, you're just trying to make a simple and inexpensive air conditioner for a room, you can do what "they" did before air conditioners were invented: evaporative cooling. Take a regular fan, a pan of water and some strips of thick cloth. Soak the cloth and put the ends in the pan of water. When the fans blow across the cloth, it will cool the air as the water evaporates. It will also help increase humidity, if you live in a dry climate like I do.

 

If you're just interested in cooling a small space, perhaps the size of a soda cooler, peltier is a great choice. Depending on ambient temperature, you can expect to cool a cubic foot or two down to about 45 F or so. I recommend just going to a department store and buying a premade cooler. I believe "Coleman" makes one.

 

So, what is your application? We know you want to cool air, but to what temperature, on what scale, and for what purpose?

 

-Caver

 

 

Hi Cover,

 

Your explanation was really helpful and thorough which i really liked it. I am working on special type of stirling cooler in small size, any idea where to prapare? I already have a medium size one, wonder why small siza of it is not available. I will let you know what is in my mind finally.

 

You can use a Stirling cycle Cooler. Some small coolers are about the length of a 30cm ruler (so, about 30cm). They don't have a lot of moving parts - just a linear motor driving a piston.

 

It's very efficient and larger ones can cool to cryogenic temperatures. Of course, it takes up a bit of space.

 

Please let me know where did you find/buy a small stirling cooler? I have a big size but could not find a small size, thank you.

[CaptainPanic]

Alireza,

 

Both The Thing and Caver451 have not been active on this forum for many years. The last time any of them logged in was in 2007.