Cold Gases

[qwerty123]

Hello,

 

I am wondering if anyone can help me with this ! I need a gas which can be sprayed onto a surface that can rapidly cool it to a low temperature and sustain that tempertature for a reasonable amount of time such as 30 mins . Does anyone have any ideas ? I will be spraying this onto glass

 

Thanks any help would be great !!!

[YT2095]

30 mins after "atomisation" is alot to ask for!

to be so volatile as to disperse so easily and yet maintain its cooling effect (down to exaporation) is a difficult task!

an alcohol gel may work, but it wouldn`t deploy as a Spray, more like a shaving cream.

it also depends on the temps you`re after too!

you`ll not accomplish this effect with Any Gas.

[qwerty123]

These liquid gels , how cold can u get them im esuming you got to keep the gel in a freezer type thing to keep it cool ?

 

Thanks

[YT2095]

you`de have to make them, Im not aware of Any available on the market (there Might be some though).

[qwerty123]

Hello,

 

Ok then well maybe something that can freeze water very quickly like a cylinder of Liquid nitrogen . Out of cylinders dose liquid nitrogen come out as a gas or liquid :S ?

 

Cheers ur helps appreciated

[jdurg]

In a cylinder the nitrogen comes out as a gas because the cylinders are filled with compressed gas.

 

In a large cryogenic flask, like a dewar flask, the nitrogen comes out as a liquid because the gas is simply cooled down to a liquid and is not under pressure.

[woelen]

What you ask is probably is not possible. What is possible though, is to use a gas tank and slowly drip the liquid gas on the surface, at a controlled rate. One can buy those small gas cylinders, for cooling electronics components (used for detecting failures). Such a container of gas contains enough to keep a surface cold for a few hours, but you need a mechanism to slowly release the cold gas (which btw. comes out as liquid). Another option is to use liquid butane gas. This can be found as cigarette lighter refill, and has a boiling point of -1 C or something like that. When this is allowed to evaporate, then temperatures of -20 C are reached easily. Again, here you have the same problem of finding a way to slowly drip the gas on the surface.

With both solutions, you have to be careful. The gases are non-toxic, but highly flammable. A spark may ignite all gas and cause a violent explosion or a big fire, if this is not done in a well-ventilated room!

[SmallIsPower]

If there is a magnet in the glass and the gas is magnetic, maybe. Is there a such thing as a magnetic gas? Can you aerosolise mercury, and if so is it magnetic?

[woelen]

Some gases are slightly magnetic. E.g. when you have a flame, and a very strong magnet, then you can see that the flame is slightly attracted by the magnet. IIRC, oxygen also is very slightly magnetic. If you have a thin stream of liquid oxygen, then it is attracted by a magnet. But, these effects are very weak and I see no practical application.

 

Making an aerosol of mercury seems very difficult to me, but if divided into VERY small droplets this could be possible. This, however, is not magnetic. And also, I see no connection with the property of making a cold gas.

[swansont]

Some gases are slightly magnetic. E.g. when you have a flame' date=' and a very strong magnet, then you can see that the flame is slightly attracted by the magnet. IIRC, oxygen also is very slightly magnetic. If you have a thin stream of liquid oxygen, then it is attracted by a magnet. But, these effects are very weak and I see no practical application.

[/quote']

 

I suspect that's because in a flame you have a plasma and moving charges are affected by magnetic fields, and not because the gases themselves are magnetic.