I just acquired a nitrogen generator and want to build a freeze dryer from a 6 rack pizza oven

So I just bought 2 large nitrogen membrane generators and I also recently purchased a restaurant 6 rack revolving pizza oven that I am thinking of repurposing into a large freeze dryer. I am in the beginning stages of thinking up this idea so who knows where it will lead. I have been considering building a freeze dryer for some time and was not considering going this big, but you know:) I am looking for any feedback and ideas to try to help me think-tank this idea. I am in Michigan and we are a legal and medical state with a huge hemp industry up and coming so I am thinking that this will be a great machine to use to help freeze dry large amounts of hemp also which seems to be a problem in the industry. I am having an issue uploading the pictures of the generators but they are membrane generators.


I’m not super familiar with freeze dryers but I believe they all require vacuum right? Which would probably cause your pizza oven to implode.


I’m not certain I see the connection between these two objects.

much like @thesk8nmidget, I’m also rather dubious on the whole “Pizza oven meets the vacuum of space and lives” concept.

If there is nothing else useful you can think of doing with the oven, then sealing it up and trying to collapse it with a vacuum pump seems like it might be good for a laugh.

I suspect that getting it sealed is going to be harder than collapsing it once sealed, but I haven’t actually torn any pizza ovens apart, so I’m only guessing on construction details. the drive-shaft on the rotating rack seems like the first issue you’ll run into.

I have torn apart a smallish convention oven that was surprisingly heavily built, and might have stood up to this sort of abuse, but large volume vac chambers are generally purpose built.

have you noted the shape of the harvest right chamber? cylinders are harder to collapse…


So the pizza oven would be built on the inside of a 1000 gallon fertilizer tank that would be turned onto it’s side. I would not even worry about the seal as much as I would this whole venture being worth the time. I’m looking to build a large freeze dryer for the drying of 100 lbs +-at a time. I’m considering just building shelves inside the tank also, but thought maybe the rotation of the oven racks would be better for several reasons. However the oven may just cause more issues than it helps. I’m still in the thought process of this, but getting closer to Dday.

The fertilizer tank is very similar to this only without the manhole on the side and the tank I have does not have any sort of lid or cover. I’d have to design and build a lid with a hinge or something.

This is the type of oven I have that is disassembled now. I was thinking of using simply the racks and revolver setup inside the fertilizer tank.

if the object is to pull vac on a fertilizer tank, I suspect the pizza oven is a red herring. I see no reason rotating racks would help the drying process. they might make loading and unloading easier.

not sure about vac on a container that large. 15PSI adds up fast.


from a mechanical standpoint I suspect you’d be better off starting with a large autoclave.

they are build for pressure, have large doors & racks, and you can probably run coolant in the jacket. finding one cheap might be a trick. you don’t need it to work, which might help.

1 Like

Does he have to have a vacuum for this to work the way he wants? I do see the benefit and need for vacuum, but I think he’s hoping his nitrogen generator is also a liquid condenser, too. If it is, then I’m speaking out of line and just confirming. He only stated that he has a membrane and generator. Though, if he does have a liquid generator; I think he is wanting the rack to rotate with the ln2 drenching his plant material as he rotates it into position.

With that in mind. I think one would have better luck with more biomass, if you filled the entire vessel with biomass instead of a 4-6 trays. Then, see how fast you can rapidly freeze the contents.

That’s if I’m understanding everything correctly.

that’s “freeze”

“dryer” requires vac.

and if you just start sucking, shit freezes anyway…

1 Like

Very true. Think he’d be able to get it done without having to apply vacuum to that chamber? Possible large nitrogen vapor sweep following. Assuming that doesn’t blow your biomass all over the f00king place.

Yea, probably the only way would be to apply vac somehow. Or, if he makes some form of tumble cryo sift, he can get all of the heads off, collect those. And put in an appropriate freeze dryer.

For this build I’m looking to simply freeze dry in lieu of the drying/curing process. I’m additionally looking at building a smaller 55 gallon tumbler that can be sprayed with co2/ln2 to perform a cryogenic trimming. That build will be similar to a few models already out such as the Original Resinator or Toms Tumbler. The nitrogen generators I have are both membrane generators that produce liquid nitrogen and have onboard storage.