I am looking for a more defined "heuristic" curve based upon the internal temperature. I am sure that your engineers probably have tables for such things. I also know that different foods freeze at different rates, that is why I am asking for a heuristic answer.
The ideal vacuum pressure and drying temperature is maintained for each material—preserves freshness and potency
Our electricity was very high when we had it in AK because our electric company charged a lot, but in Texas, it’s very cheap to run. I don’t mind that I can’t freeze dry some things, as most of the things that you can’t freeze dry, you can purchase commercially or they shelf stable as is. For instance, I don’t freeze dry butter, but I do buy powdered butter. Oh, here’s one more potential con:
I would prefer those fittings to have internal O rings and knurled thread on ports (similar to R134a vacuum gauge sets) that do not require high torque compression fittings. Finger tight and you are good to go. You spot a leak, change the O ring and you're back in business.
Now that you understand the conditions, you can better understand what happened when we finally turned off our FDer after an extended use in these conditions.
Odds are the problem is the vacuum hose or its end connections, the drain valve, or the door gasket. Based upon my experience I'd double check the fittings while installed on the FDer.
14 Posted December 16, 2015 On 7/31/2015 at 11:12 PM, TonyC said: Here is my first pass on a Vapor Trap... it is an old whole house water filter that I modified. It failed to reduce the moisture in the oil... I'm in the process of modifying it to catch and suspend the moisture in the container long enough for desiccant beads to absorb the water. The air flow comes into the inlet, down the central pipe to the bottom of the screen and filters up through the beads and out the top. I know this was like forever ago, but I thought I would respond anyway. I haven't been on much in a while, I only run my freeze dryer in the winter. So I think you'll find it's a lot harder to remove water vapor from a vacuum than just using desiccant, as the vacuum will just pull the water out of the desiccant.
This includes setting as many as five different shelf temperatures, thus allowing the material to dry in phases, at different temperatures. For instance, you might have the material begin drying at 10ºF and increase the temperature in phases until the ultimate final dry temperature is 70ºF.
The evaporator coils that touch the surface of the stainless steel vacuum chamber reach about -42 F. With food in the chamber and because the location of the thermister is on the middle shelf of the four shelves, the temperature it records is going to range from -25 to -30 F in the 9 hour default freeze time. This temperature is very adequate for freeze drying the food.
We had a sponsored post come over on my other sites that asked the question, “Should you buy a freeze dryer?
Posted January 21, 2016 (edited) On 12/1/2015 at 0:16 PM, Jenipher said: Tony, if you see this, Buy Freeze Dryer online Canada I went ahead and purchased the catch can. Do you think it's okay to just purchase a reducer to go from the size of the exhaust to the size of the hose that came with the can? Hopefully I said that in a way that makes sense! As well, does it matter which port is used as "in" and which as "out"? Thanks so much, Jen Hi Jen, Sorry to be gone so long. I did exactly as you proposed. I purchased a brass reducer and pushed the blue hose over it.
Another best practice is to set up a station. This will take space. Having a freeze dryer, freezer, prep table, and processing area all together has been a good decision. It can all be done in a large kitchen, but the machines are noisy and a freeze-drying project can take up a lot of space.
If you don’t have the time or money, or if you believe the food crisis will hit hard very soon, then it makes more sense to buy freeze-dried food instead.
Freeze dried Skittles are a favorite in my family. They end up with a crunchy texture. Other candies have a crunchy exterior and an airy interior.