storing Dry Ice

[OB2]

may I just add, that the domestic chest freezer, is actually not a home freezer and owned by the theatre and hasnt been turned on in years!!!

[si_cole]

For my 2 penneth worth, there are alternatives such as the Le Maitre dry ice mixer that uses a CO2 cylinder. Produces much the same effect and is a hell of a lot easier.

 

OB2, PM me for details if you need.

[paulears]

depends who you get it from, but many suppliers deliver in storasge containers that are chest freezer size - and 3, sometimes 4 days is not a problem. being a hot summer won't assist, but when you choose your supplier, ask them for advice- they're all happy to give it.

[Ynot]

Update!

 

Having spent the past 30-40 mins googling within government or government recommended websites it seems that alot of American sites suggest using Dry Ice as a means to save stored food in case of an emergency i.e. Power Failure, Hurricanes (using power can be dangerous) etc..

 

This (to me) suggests that there is no real cause for alarm when the freezer decides to start back up again, it also does not specify that you must reduce or discard the Dry Ice as soon as the Freezer is back up and working, in some cases it states that it is a good way of keeping everything frozen until the freezer is back to temperature

** laughs out loud **!!

So - you'd say that in the case of a hurricane or whatever that causes the power to fail, the average Joe American is going to rush out and buy a couple of blocks of CO2 to keep his freezer cold? Hmmm..... I somehow doubt that!! :blink: (And I've been through a hurricane in Florida, by the way!!)

 

I wouldn't dispute that using dry ice CAN be a substitute for a freezer, and if said freezer were not on at the time, it would most certainly do the needful, though I would definitely give some serious thought to letting the machine 'warm up' by removing the CO2 well before switching on again.

 

Come on - you've had the more technical explanation from Bruce - explained very well, by the way - and you've had my comments (and others) which are based on years of experience.

Take my word for it - I have SEEN freezers that have been used (mis-used) by ignorants who've thought it was a good idea to just pop it into a domestic unit.

Make your own decision?

And so people should - based on reasoned arguments. You appear to be on your own here with the opinion that it doesn't harm the freezer! And if in your lone experience you've managed to get away without screwing your mom's freezer, then great - you've been lucky.

 

BUT (and it is a big BUT) there are less experienced people reading this forum who are looking for advice - this is an excellent example - and if you as an individual give bad advice like this which is acted upon and subsequently leaves the OP with a knackered white box in the corner, then that reflects poorly on the reputation of the group, not just you.

 

Please stop trying to justify your unique experience, and bend a little to accept that we do know of what we speak and let it go.

 

Thanks for listening

Tony

[DC FX]

Just for your information I am not trying to justify that using a powered freezer is a good idea, just merely that that is what I have always used and it has never been a problem

 

I thought the reason for a forum like this was to share experiences in the industry which is what I am doing, and if I was wrong or if anyone can tell me of a real technical reason why we shouldn't use a domestic powered fridge ten I am more than happy to accept it.

 

Bruce could be absolutley correct and I would never dispute a man with more technical experience in a certain field but (and forgive me if I'm wrong Bruce) this is just his opinon and isn't actually based on fact - again I could be wrong

 

And so people should - based on reasoned arguments. You appear to be on your own here with the opinion that it doesn't harm the freezer! And if in your lone experience you've managed to get away without screwing your mom's freezer, then great - you've been lucky.

 

I think it would be a very sad and uninteresting industry that we did not all have different opinions on subjects, how are we supposed to progress if we take your word and only your word as gospel, as we all know especially in special effects that just because something doesn't work the first time you don't just give up,some of the best inventions in the special effects industry are created by people who (with respect) go that little bit further and go about a problem in order to find a solution

 

With regards to this link try not to lose your cool because someone has questioned you, we all have our own opinions and I think maybe you should accept that, I'm sure there are also many people that have kept a freezer on in use, I know it is common occurence within the Film Industry

 

Regards

 

P.S. There is a reason why I posted the links on the previous reply, they are suggestions of how to overcome the inconvieniences of Hurricanes etc.. might be worth a look for next time your in one!!

[OB2]

For my 2 penneth worth, there are alternatives such as the Le Maitre dry ice mixer that uses a CO2 cylinder. Produces much the same effect and is a hell of a lot easier.

 

Thanks for that, however I dont think I would be able to use something like that mainly for space reasons, it is my theatre company's youth theatre and I would be sat behind a set with it! (also a couple of kids having to walk around it (obv with me on gaurd!!!))

[Ynot]

Just for your information I am not trying to justify that using a powered freezer is a good idea, just merely that that is what I have always used and it has never been a problem

Sorry, but you ARE, or have done -

"The best way of storing Dry Ice is in a domestic chest freezer"

You only now seem to be trying to justify your original bold statement as opinion.

I thought the reason for a forum like this was to share experiences in the industry which is what I am doing, and if I was wrong or if anyone can tell me of a real technical reason why we shouldn't use a domestic powered fridge ten I am more than happy to accept it.

And so they should be!

But as I said above, weshould all be careful what advice we give because there may be a variety of consequences. Some minor, some potentially expensive (like this one) others potentially fatal (eg recommending the use of very poor safety practices).

 

Bruce could be absolutley correct and I would never dispute a man with more technical experience in a certain field but (and forgive me if I'm wrong Bruce) this is just his opinon and isn't actually based on fact - again I could be wrong

Actually, Bruce started his post with the words "it has been over 20 years since I studied thermodynamics" which suggests that whilst the detail MAY be fuzzy, the principle stands - I would take Bruce's comments with a great deal of respect for past training.

I think it would be a very sad and uninteresting industry that we did not all have different opinions on subjects, how are we supposed to progress if we take your word and only your word as gospel

Indeed it would be sad, and I for one am happy to discuss issues, examine alternatives and if the occasion demands, I will change my viewpoint - it does happen, honest!!

But if you read the thread back, you'll see that there are at least four of us who have all agreed with my point. Others, I'm sure, would add their weight if needed.

...try not to lose your cool because someone has questioned you, we all have our own opinions and I think maybe you should accept that, I'm sure there are also many people that have kept a freezer on in use, I know it is common occurence within the Film Industry

Interesting statement... I can only say that I suspect that the film industry may well source proper CO2 refrigeration plant rather than rely on domestic appliances. Do you have examples of household type freezers being used by film companies?

And don't worry - it will take FAR more than this sort of discussion for me to lose my cool! (Something you probably do not want to experience!!! :blink: )

P.S. There is a reason why I posted the links on the previous reply, they are suggestions of how to overcome the inconvieniences of Hurricanes etc.. might be worth a look for next time your in one!!

LOLOLOLOL! I can assure you that when the hurricane approached, the last thing on my mind was worrying about whether I could get hold of some dry ice to cool a freezer! :** laughs out loud **: ;)

[Stig]

We have used dry ice a number of times and our supplier will supply a big insulated plastic container specifically for storing dry ice for free. It has all the relevant COSHH and warning labels all over it and if full will keep dry ice for a good 4 days or more. PM if you want details.

 

Cheers

 

Stig

 

PS it is neither white nor a freezer chest or otherwise

[bruce]

[

Bruce could be absolutley correct and I would never dispute a man with more technical experience in a certain field but (and forgive me if I'm wrong Bruce) this is just his opinon and isn't actually based on fact - again I could be wrong

Actually, Bruce started his post with the words "it has been over 20 years since I studied thermodynamics" which suggests that whilst the detail MAY be fuzzy, the principle stands - I would take Bruce's comments with a great deal of respect for past training.

 

It's been a while since I studied Thermodynamics (although I do have a 1st class honours degree in Physics) , and I don't think I've ever really thought about it much since I graduated 20 years ago.

 

As I said, it's just conjecture. But I could easily convince myself that cooling the fridge to that level would cause the gaseous refrigerant to condense within the "inside" heat exchanger, on the low pressure side of the compressor where it would normally be a gas. I could also probably convince myself that this would stop the compressor compressing (it expects a gas input, not liquid), and that the lack of fluid flowing in it could cause the compressor to overheat.

 

A fairly poor analogy might be sticking a block of ice (or something colder) around the oil filter in your car. The oil in that area could become really viscous - so much so that potentially the oil might not circulate, and the engine could sieze...

[dbuckley]

Those of you who know anything about refrigeration (and it doesnt look like many blue roomers fit into that category) will know that in the wall of the freezer there is a series of tubes through which the refrigerent flows, to basically cool the thing down. That series of tubes is called an evaporator, what happens is that liquid refrigerent flows into the evaporator, and it boils, becoming gasseous, absorbing heat in the process. That gas then passes into a (usually) reciprocating pump that raises the pressure of the gas, which then passes to the condensor, the tubes on the back, where the gas gives off its heat, and condenses back to liquid.

 

Now anyone who knows anything about anything knows what happens when you try and compress a liquid. It doesn't. So if liquid refrigerent gets into the pump then the pump will meet its maker very quickly. Thus it is absolutely critical to the survival of the pump that the refrigerent does actually boil in the evaporator.

 

If you store dry ice in said freezer, the temperature will equilibrate around -78.5C. Will the refrigerent boil at that temperature? The answer is "it depends", both on the choice of refrigerent, and the pressure it finds itself under at the time. For example, R22 has a boiling point of -40.8C at 1 bar. So given that the low side pressure is normally above 1 bar, you can guess that the R22 is going to stay liquid.

 

So, if you want a repair bill, go ahead, and put dry ice in a working freezer. otherwise, dont put dry ice in a working freezer.

 

The history of refrigeration is actually the history of chemistry and thermodynamics, the trick is to find gasses that have the right properties, particularly boiling point at a range of pressures that it is cheaply and easily possible to contain, and preferably not too toxic. Add the fact that most of the really good refrigerents are CFCs and thus ozone layer killers and are thus now highly restricted, the choices get even harder.

[bruce]

David is spot on - it's the "liquid into the compressor" which will do the serious damage, more than (but as well as) the lack of lubrication/cooling.

[Storm_machine]

Since we are ignoring the question - budget for 5kg per night and a spare bag (10kg) and then try to decipher the above to store it, dead freezer bulked out with expanded polystyrene for my money, and after the effect remove the unused dry ice from the peasouper and stick it back in the freezer, you will lose a couple of kilos a day so the last bag I suggested is a sacrificial one.

 

Colin

[Ynot]

after the effect remove the unused dry ice from the peasouper and stick it back in the freezer

Sorry to be a pedant, but it's probably best not to put part-used CO2 back in for use the next night if it's already been in the souper.

The reason here is that when the ice is dropped into the hot water, thewater will start to freeze, forming a layer of ordinary ice around the exterior of the block. This then creates a barrier between the CO2 and the water meaning the CO2 can't evaporate quickly enough to produce decent fog. Taking the block from water to storage and leaving overnight means when you put that old block back in, the barrier is still there.

 

This is why it's a good idea when using blocks of dry ice to break it up (safely, using a hessian sack, and quality insulating gloves eg) before putting it in the basket. That way, what's unused and has NOT been dipped in the water can then be re-stored for further shows.

Of course, you can get CO2 granules/pellets as well instead of blocks.

 

TD

[OB2]

one more question - the dry ice when melts bcomes gas, so dead freezer has a lid on not letting the gas relaease - build up of pressure and then discuss.......

[DC FX]

one more question - the dry ice when melts bcomes gas, so dead freezer has a lid on not letting the gas relaease - build up of pressure and then discuss.......

 

Yes you must make sure the area is well ventilated, you must also make sure that you don't store anything on top of the lid to prevent the gas escaping if it ever got that high, it is als a good idea to make sure the lid is well secure when open and your getting the product out - fear of the lid coming back down on your head and knocking you out with you still inside a CO2 flled compartment

 

Regards