Can you use a dewer for dry ice slurry.

S

skillgannon

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Apr 27, 2009
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I just got my dewer. It will fit 16l. I don't have time right now to get any LN and was wondering if I could use it to hold my dry ice longer. If say I crushed up 25lbs and poured it 1 gallon of denatured alcohol would it hold it for a week? I have a hard time finding dry ice on the weekend when I have time to work.
 
Since nobody has commented on your question I'll comment. Not that I have any knowledge, but I'd suspect the dewar will come close to holding the dry ice/alcohol slurry for close to a week. BUT - what's the cost of 25 lb of dry ice and a gallon or so of alcohol? I know you said the LN was not convenient at this time.

If you do try it, let us know how long it lasts.
 
I had written a reply early this morning, but deleted it because I never tried.

I think the insulating ability of the dewar will hold the slurry for a while, but don't know how long before the dry ice will sublimate. Also, if you crush 25# of DI it will take a lot more than a gallon of alcohol to make a slurry. When I use around 10# to a gallon it is very mushy. Most of the time I use 5# in 3/4 gallon of alcohol.
 
I got off before the welding shop closed today. I bought 25lbs of dry ice and a fresh gallon of denatured alcohol. I tossed the alcohol in the freezer a few minutes ago and will pour it on top once it is cold. I will let you guys know how long it last. I'm going to have to pour it in a cooler anyway because my rush list includes a couple of chef knives that are to large for the neck. I'm hoping it will last through the weekend.

Next month work will be slower I hope and I can track down a place for LN.
 
If youwant it to keep longer, just fill the dewar with dry icie, don't add alchol until you're ready to use it
 
Putting alcohol in freezer for a few hrs before mixing sounds like a good idea. I'd not thought of that before, nor have I heard it mentioned. I guess it's one of those things nobody mentions because it just seems so logical why would it need mentioning? Dummy me {g}
 
I talked about this a little while ago. About putting dry ice in a dewar. It works ok and got me through a few weekends of interrupted heat treating. I would just put the dry ice in the dewar and leave the alcohol in the freezer. In my dewar 10lbs would hold for about 4 days befor it was gone.it alowed me to get through a few large batches of stainless blades over a few days. But in the end I spent more money then if I would have just filled the dewar with LN.
 
Well I checked it yesterday and the dry ice was gone. I filled it Thursday evening and chilled 3 blades. I couldn't see much ice left Friday but it was still bubbling and you could hear it shrink. Maybe 50lbs would hold better. I think you lose a lot bringing down the alcohol.

But hey I got the blades hardened that I needed. Its not the best way but works in a pinch. Now I have to get the alcohol out. Hopefully I can get it filled with LN soon.
 
Hmmm, that's only 4 days (less?) - I really expected it to last longer. If you used 25 lb of Dry Ice that's pretty expensive for 3 blades. I have to pay around $1.50/lb ($1.80?) around here. The alcohol is still good, just pour it back in container.
 
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