Anyone ever try making dry ice?

[lestblight]

Ive seen some videos on making dry ice from fire extinguishers.. a bucket and a sock.

Not conventional.. but it seems to work. I need to get access to dry ice... but really dont have the time to go and pick it up when i need it.. Since it last a few days.

Anyone know of a more cost friendly way to do this? Perhaps i can get the liquid co2 at a welding supply store? Anyone try this ?

Also. needed to make it into a semi fine powder or small pellet.. Can i do this with a blender i dont use anymore? food processor?

Thanks!!!

[Coogles]

In a lab that I worked at we used a device like the one shown here...

http://www.amazon.com/ThermoSafe-Dry-Machines-Block-Maker/dp/B001CLO0M0

Essentially just a box with two side panels that allow gas to escape. It's hooked up to a CO2 tank that you turn on full blast, as the CO2 changes state from liquid to gas it gets cold enough to freeze some of the gas in to dry ice snow which is caught by the box and forms in to a block. When the block of dry ice is fully formed a pressure relief valve pops to let you know you're done. All you need is a supply of CO2 tanks and you're good to go, each tank is good for 2 or 3 three pound blocks. I don't know if they make these any more, but you may be able to find a used one on ebay or here is another possibility that isn't too expensive but which I don't have experience with...

hhttps://www.vwrsp.com/catalog/product/index.cgi?catalog_number=35751-178&inE=1&highlight=35751-178

Edit to add..

After a little searching, this is exactly what we were using...

http://www.medicalrefrigeration.com/p...

[lestblight]

Thanks for your input.

Like i said.. i am just worried about losing my yield after it sits for a while. How long do you thinkg a 20 pound block would last me?

It is pricey to make it your own.. so it is defnitely not practical./. but that is something i would invest in, iin the future.

I defnitely get a kick out of learning from it and seeing how i can apply it in other ways.

Thanks again.

[Coogles]

At my current workplace we use dry ice chests like this one...

https://www.vwrsp.com/catalog/product...

They could probably keep a 20 lb block of dry ice for up to two weeks. A cheaper alternative would be to line a good quality beer cooler with sheets of stryofoam leaving enough space to put a sheet on top of the dry ice block and still close the cooler lid. Depending on how good the insulation is you should be able to keep the block for at least a week, maybe longer. Just be sure to NOT make it air tight.

[wattacetti]

Well, let's see: a fire extinguisher would expend a lot of its pressurized CO2 while you attempt to fill a sock, and given that the gas will displace the oxygen, chances are good that you'll pass out from lack thereof especially if you attempt this indoors.

There is no such thing as liquid CO2 unless you were say a bit further down in the atmosphere of Jupiter, at which point (if it were currently possible) you'd be crushed by the gravitation.

Powder and pellets are made very simply with a block of dry ice, a towel and a mallet.

Given that you're all ready to try all the convoluted methods why not save yourself the bother (and risk of death) and just go and buy a cube of the stuff from a regular source? Oh, and roll down the car windows if you do.

[lestblight]

I understand the concerns.. But i am trying to avoid going to the dry ice source by me.

I need this for a small business and dont have the time to pick it up day of. I also dont need Big quantities so i cannot have them bring it to me when i need it.

From what i understand DRY Ice shelf life is 2 days or so?

If i buy 20 pound on FRIDAY...whats my yield by Sunday ?

I have called a welding shop.. and they can provide me with a liquid c02 siphon for around 230$(20 pounds) and 30 for the gas.

Not sure if this will be more costy .. since i am not sure of the yield of a 20 pound tank.

If the dry ice can last me more then 2-3 days. i wuld be happy.

But i am also unfamiliar with how much dry ice is needed. If i was to keep a 50 gallon cooloer of wet ice from melting... how much dry ice would i need and how often would i need to add more?

thank you for the info.

[cowboyardee]

How much dry ice do you need and what do you need it for?

No offense, but I'm thinking that unless you need a huge amount on a regular basis or you just find the idea of making it yourself interesting (or maybe you have a grudge against your local dry ice supplier), you're just not thinking laterally enough. Buying dry ice is cheap; making it is expensive, and potentially dangerous if you don't know exactly what you're doing. With the money you could save by buying dry ice rather than making it, you could easily pay someone to pick it up for you. Craigslist is a fantastic thing.