🚀 go-pugleaf

mann@orion.cmc.uab.edu (RANDY P. MANN) writes:

>What is a good way to transport liquid nitrogen (inexpensively) ,
>about 20 miles.  It has to be taken from our laboratory to a 
>High School classroom.  Remember it is very hot and humid in 
>Alabama this time of year. 

>Our goal is to do this without having to buy an expensive dewar flask.

How much LN are you talking about here?  Are you going to walk or drive
the 20 miles?  I've kept a quart of LN in a regular (metal) coffee thermos
for a week with no significant loss.  If you need to transport a gallon
or more, I'd buy a plastic insulated water jug like the type you use for
picnics or on construction sites.  The plastic probably won't crack.
Basically, any covered container will work well enough if you have only
a 30 minute drive or so.  There would be moderate evaporation loss with
an uncovered container in that length of time (10% to 50% of a gallon is
my rough guess) and you wouldn't want to use an uncovered container anyway
because of the safety hazard (frost burns).  There would be very little
evaporation loss with a loosely covered container in thirty minutes (<10%).
And remember, LN is about the same price as milk, so buy more than you 
think you'll need.  It's cheap and fun to play with.

-- 

"Warm...warmer...disco." - Pulp Fiction