frozen gas bottle and regulator

[ralphstralph]

sooo ive been away on holiday for some time now and got home and the missis has taken my kegs out of my keg fridge and has been using it a ha freezer hahaha.... but she forgot to take out the co2 tank and regulator ...... will this have done any damage to it ?


cheers guys

 

[DJ_L3ThAL]

Shouldn't have... thaw it out slowly, in the fridge or an esky, ensure the cylinder valve is closed.... but yeah should not have done any lasting damage. Worst case i can think of is the regulator seat or diaphragm may have become brittle and not seal or control anymore.

 

[ralphstralph]

thanks mate ill try the slow thaw..... worst case a new regulator isnt to bad i guess

cheers

 

[Grott]

Frozen Co2 is dry ice and I believe to achieve that the freezer would need to be at around -60 degrees. I don't think any damage will have occurred.
Cheers

 

[DJ_L3ThAL]

-90 is the temperature of dry ice at atmospheric pressure.... but even refrigerating it down to that temperature does not create dry ice, because the cylinder is under pressure. If it became dry ice in an enclosed container you'd be in trouble as dry ice has a lower density than the liquid therefore it takes up more space and would pop the bursting disc or rupture the cylinder.

Changing the temp down to our freezer temps will not affect the CO2 as it is held in liquid/gas equilibrium under pressure. One other main risk would be if your freezer is a deep freeze and got the cylinder down to -20C or colder, if it's a carbon steel cylinder the metal could become brittle and if you knock it it could fail under embrittlement (explode with fragments flying everywhere). So best not to touch it while you thaw it out just turn freezer off and let everything thaw out. Sorry I didn't think of that in my first post.

 

[ralphstralph]

cheers guys ..... man ive missed this site .. super fast and great replies .... thanks guys :chug:

 

[AJS2154]

cheers guys ..... man ive missed this site .. super fast and great replies .... thanks guys :chug:

sooo ive been away on holiday for some time now and got home and the missis has taken my kegs out of my keg fridge and has been using it a ha freezer hahaha.... but she forgot to take out the co2 tank and regulator ...... will this have done any damage to it ?


cheers guys

Whilst I would agree with you ralphstraph, this is a wonderful site that has many good folks giving freely of their time and knowledge, it appears the advice given in this case has failed to address the root cause of the issue.......it seems that whilst you were away on holiday her indoors has in fact had unauthorised use of the keg fridge. I write unauthorised beacuse I would assume you would never give addvanced permission for such actions.

I absence of addressing the real issue, could I suggest before you disappear for some well deserved personal leave in the future, the issue of unauthorised use of all beer making equipment be addressed. That should in future negate the frozen gas bottle problem, or any other related misadventures. I know I sound harsh here mate....but it is the way to go.

Just trying to help! Anthony

 

[ralphstralph]

hahaha yup thats just it aj :kooi:

 

[dannymars]

don't they freeze CO2 bottles in order to fill them?

 

[DJ_L3ThAL]

No, the freezing is from the slight depressurisation from a high pressure into a lower pressure cylinder being filled. Known as the Joule-Thomson effect https://en.m.wikipedia.org/wiki/Joule%E2%80%93Thomson_effect

 

[MHB]

-90 is the temperature of dry ice at atmospheric pressure.... but even refrigerating it down to that temperature does not create dry ice, because the cylinder is under pressure. If it became dry ice in an enclosed container you'd be in trouble as dry ice has a lower density than the liquid therefore it takes up more space and would pop the bursting disc or rupture the cylinder.

Changing the temp down to our freezer temps will not affect the CO2 as it is held in liquid/gas equilibrium under pressure. One other main risk would be if your freezer is a deep freeze and got the cylinder down to -20C or colder, if it's a carbon steel cylinder the metal could become brittle and if you knock it it could fail under embrittlement (explode with fragments flying everywhere). So best not to touch it while you thaw it out just turn freezer off and let everything thaw out. Sorry I didn't think of that in my first post.

I'm afraid I have to question most of this, the sublimation temperature of CO2 is ~78.5oC and the liquid form at high pressure (over 5 bar) its a bit more complicated than just solid/liquid/gas you need to take pressure into account to, good to have a look at the phase diagram.

I doubt any domestic freezer is ever going to get cold enough to freeze a bottle of CO2 solid. The other point about embrittlement would be important if CO2 bottles were made out of mild steel, they aren't (well the disposable single use ones might be), to get approval in Australia as a CO2 pressure vessel they would have to be able to withstand repeated filling and emptying and the cooling that occurs when the bottle is vented (i.e. -78.5oC) which is very stressful for the bottle so they are made of a spring type of steel, designed for the job, or Aluminium that will actually get stronger as it gets cooler (to well under the temperatures we are talking about).

Unless your freezer is getting down to below -78.5oC I wouldn't be worried.
Mark

 

[DJ_L3ThAL]

I'm afraid I have to question most of this, the sublimation temperature of CO2 is ~78.5oC and the liquid form at high pressure (over 5 bar) its a bit more complicated than just solid/liquid/gas you need to take pressure into account to, good to have a look at the phase diagram.

phasediagramco2.png
I doubt any domestic freezer is ever going to get cold enough to freeze a bottle of CO2 solid. The other point about embrittlement would be important if CO2 bottles were made out of mild steel, they aren't (well the disposable single use ones might be), to get approval in Australia as a CO2 pressure vessel they would have to be able to withstand repeated filling and emptying and the cooling that occurs when the bottle is vented (i.e. -78.5oC) which is very stressful for the bottle so they are made of a spring type of steel, designed for the job, or Aluminium that will actually get stronger as it gets cooler (to well under the temperatures we are talking about).

Unless your freezer is getting down to below -78.5oC I wouldn't be worried.
Mark

What is it that you question? We have dry ice making equipment through work and dry ice is -90C because not all of the expanding liquid becomes dry ice, it's an inefficient process and depending on the pressures could be as much as 50% dry ice, 50% gas. The gas is quite warm in comparison hence the temperature/mass balance of the equation. Dry ice circa -90C and Gas circa -15C.

In any case I don't think I was wrong in stating that dropping the temperature alone (at the temps in question - domestic freezer temps) of a CO2 cylinder would be able to create dry ice, as shown on your phase chart, cylinder pressure would be around 50bar (51atm) so you'd need to take it to -60C or colder to get the phase change to occur.

So again, unsure of what you were questioning in my response?

In terms of cylinder construction, carbon steel is quite common. CO2 cylinders are compliant with AS2030 if constructed with carbon steel. So think you've assumed wrong there. They won't experience the full sublimation temp or dry ice temp you have mentioned in normal use, as they deliver gas, so the condensation on the outer wall would be nowhere near carbon steel embrittlement temps. Using the cylinder on it's side or upside down may, but that is not "normal use" of a cylinder. However, putting a cylinder in a deep freeze just might get the cylinder to carbon steel embrittlement temps, I wouldn't want to be the one to check or try this.

Either way, the OP wanted to know the risks associated with what has occurred and I detailed what is possible.

 

[AJS2154]

Wow.....this is no longer fun. I have to go now. Bye.

 

[DJ_L3ThAL]