small deep freezer building help

[Possum]

Howdy There...!
I just had to do it again..post another question about "deep Freezing" blades. I certainly appreciate all the great replies about the cool nitorgen stuff. But..? What I am looking for is how to build something that I can use as a "deep freezer" to bring blades down to low temperatures slowly. Something in the line of a mim-freezer run off a compressor. type deal...? Any help apprecaited..!

Later "Possum"

 

[R.W.Clark]

Cheapest way to go would be to get two dewars that both have npt outlets. Run a cryo pump between the two. In small increments transfer the nitro from one to the other. This will slowly start to drop the temp all the way down to deep cryo. Then after a 8 or so hour soak. Switch the pump and draw the nitro back into the storage dewar.

Without a super high level of education on deep cryo eng. the only other way is to drop at least 10 grand on a cryo freezer. But at that price you will unly get down to around sub 90.

Make sure and get a pump made for nitro, other wise you will totally feeze up the pump.