Guess what I’m designing....

[William Fretwell]

How does wood behave at -76C? Trees still stand, branches do fall. I have gone for a walk at -52C but failed to kick the fence, more interested in stopping my eyeballs from freezing.
Local large company makes dry ice so I’m going to find out. Need a large chest container at reasonable cost, perhaps more than several. Possible government sponsored.
To be continued.....

[David Publicover]

Good luck with the design. I’m hoping you are very busy building them over the next few months!

[Lee Schierer]

I know that some living trees will pop quite loudly when temperatures get really cold.

[Jamie Buxton]

Storage or distribution for Pfizer's Covid vaccine?

[Bruce King]

We make our own vaccines down south. Don’t need no high flutin dry ice or nuttin.

[Gary Ragatz]

Is the wood going to be in direct contact with the dry ice? I'd be thinking about a wooden chest, lined with a layer of EPS foam and a metal liner inside the foam to contain the dry ice. That way, the dry ice should have minimal effect on the wood. Snug, but not too tight fit on the top to allow CO2 to escape as some of the ice melts.

[Bill Carey]

Storage or distribution for Pfizer's Covid vaccine?

If the knuckleheads in DC are just now realizing they need something to transport the vaccine in, we're all FUBAR. No, I think William's on to something else. Canada, huh? How about core samples from glaciers? Left over pizza? I know - a case of fresh frozen walleye from Lac Seul sent right to my front door.

[William Fretwell]

Yes Jamie,
Storage and transport is a nightmare, stable at -70C for 15 days then 4 days at fridge temp. A logistical nightmare. Multi dose vials save some space and are very likely.
Chatting with head of dry ice production and distribution for Ontario this morning. They just bought new equipment and have spare capacity. No need to work 24/7 now, they get a day off!
Will take my prototype to the factory for testing. Commercial boxes are up to $18,000 each!
The liner need not be waterproof, just protect the foam but containing the dry ice in the box needs thought.

[Stan Calow]

On NBC news just now, they described the Pfizer vaccine as needing to be shipped at -94℉ and showed testing of shipping and loading going on.

[Bill Carey]

Yes Jamie,
Storage and transport is a nightmare, stable at -70C for 15 days then 4 days at fridge temp. A logistical nightmare. Multi dose vials save some space and are very likely.
Chatting with head of dry ice production and distribution for Ontario this morning. They just bought new equipment and have spare capacity. No need to work 24/7 now, they get a day off!
Will take my prototype to the factory for testing. Commercial boxes are up to $18,000 each!
The liner need not be waterproof, just protect the foam but containing the dry ice in the box needs thought.

Mea culpa Wiliam. Hope it works out for you. Pretty cool project and I'm curious to see what you come up with. I guess this means no walleye huh?

[William Fretwell]

Yes I doubt Pfizer is thinking of anything else at the moment. When I spoke to them they found the answers to my questions as I waited, real people, doing nothing but this, exceptional!
The level of expectation by those that can see they will be involved in some role is impressive.
The trial of 40,000 patients spread across various countries will have given them some small experience.
This years flu shot handling was bad at so many levels, will anyone listen? Of course not; yes, I’m very well qualified to comment.
Anyway back to the design...

[Steven Cooper2]

Wood is usually pretty tough at least to 77K, I use it to do nothing important in liquid nitrogen regularly. G-10 and similar composites are generally more predictable, but for only dry ice temperatures, it may not matter as much.

Glue will perform poorly.

Styrofoam works very well but seams are difficult. I have used the pink stuff and it does OK, but it can crack. If you don't have to hold any liquid, you should have no problems here. I built some stuff that was tested in an apparently liquid tight 10'x20'x2' pink styrofoam box held together probably with aluminum tape.

Cardboard actually does really well. NASA has some cheap cardboard and foam dewar examples for testing. Probably because is it isotropic. I would imagine masonite and MDF perform similarly.

For superfluid helium testing we often use rohacell closed cell foam for random non-structural parts and it holds up very well. Do not underestimate how awesome styrofoam type products are as insulators. Still way worse than vacuum flask type things, but still amazing.

Good luck!

[Lee Schierer]

Since dry ice usually comes in block forms, why not bore holes in the blocks to hold the vials as a carrier and refrigerant simultaneously. Then place the blocks in the styrofoam shipping containers that they ship fish from Alaska to the lower 48 via FedEx second day air. I received 50 pounds of fish I caught in Alaska this way and most of the dry ice block was still there. It lasted an additional 3 days after I opened the box while still in the box.

mason-bee-house3.jpg

[William Fretwell]

Thanks Stephen, most interesting. I won’t be drilling holes in blocks of dry ice Lee. It comes as snow, pellets as thick as my little finger, blocks and slices the size of a large chocolate bar (used by the airline industry). The blocks weigh 50lbs apparently, the stuff is quite dense. It can be cut with a bandsaw. I’m only interested in working with what is commercially available.
The boxes of vials are light but bulky for the content. The container volume needs to be quite large, two layers of foam board at least with a zigzag corner joint and filler. The outer wood structure need only support the foam box and door, it could be an ‘open design’. The inside structure to hold dry ice top and bottom and allow easy quick and frequent opening without loosing too much cold.

[Lee Schierer]

The inside structure to hold dry ice top and bottom and allow easy quick and frequent opening without loosing too much cold.

In that case you want the lid on top as cold air sinks.