[Neuromancer]

Originally Posted by MaadDaawg

Delivery is never free, and the large dewars gas off real quickly.

Delivery is cheap though, relatively...

As far as Large containers gassing off more quickly I would expect that.

If you look at the size of 20L dewar the device is much larger that the capacity dictates. teh 160L I saw at teh welding supply shop, were NOT 5-6 times larger than my 30L, more like 3-4.

I am assuming that the ratio of insulation to LN2 is much higher on the smaller units.

So if 1.5" insulation on a 20L say, with a 24" diameter, then move up to a 160L and still have 1.5" insulation on a 36" diameter... im no physics expert but would assume that the larger surface allow greater heat transfer to occur and thus would require a larger amount of insulation...

Another consideration is the large dewars require pressure to dispense LN2 since you cant just tip it...

Pressure = agitated molecules = heat. Might be better to have 3 50L dewars laying around and fill the 160L. Should hold the LN2 better and 30L was easy to pour (one hand pour with another holding my coffee mug ) , cant see 50L being too difficult especially if you have a spout.

just gotta remember it shoot out straight at first lol (I wore a glove the first couple of times, but got it figured out after that and poured from dewar too coffee cup with no glove)

I only have had the experience of 1 full dewar I cant wait to do it again though