Kiln temp issue

[AmaxB]

I agree with AmaxB. I have been using his container method now for about 6 weeks with great results. No mold. Before I used his method I was always fighting mold in the high humidity chamber. Now I just check my containers every few days and mist if needed. I run at 121 degrees and have good air circulation. All my containers are under 5 lbs.

Yesterday I was wondering how you were getting on with your kiln Rickey60 so I am glad to hear it's worked out for you. It is good to hear small amounts work could be good information for others.
The PID we have... I retired mine and wired up my eurotherm to replace it. The thing went wacky, one day I checked it and my temp was up to 140F glad I caught it early it was scorching my tobacco.

Fisherman tobacco will mold in the best of conditions if wet, moist is what you want.

For control in my book a good PID with on / off (not pulse) is the way to go for steady temp. If I set mine to 120F my ambient air stays at 120F, no up, or down, just 120F on the money.

 

[DrBob]

Dr. Bob,
I see what you're saying. That's an interesting issue.

The sensor of a water heater thermostat is engineered to be directly attached to the exterior of a metal tank of heated water, so that the entire surface area of the tank serves as its liquid-heated heat sink. In a kiln, the tiny sensor is exposed only to a small surface of much lower density air.

If the thermal conductivity of the heat sink and that of the exposed sensor were the same, I believe that you would be correct: increased mass would slow the temp registration during changes in ambient temp. On the other hand, if the heat sink were made of material with significantly greater thermal conductivity than that of the sensor, then I would imagine that the exposed surface area of the heat sink would come into play. My brain is too crusty to do the math. Air flow (by fan or even by convection) past the heat sink would determine the time required to bring the heat sink into equilibrium with the ambient temp. With that thermal flow, I would expect the mass of air in contact with the high surface area of the heat sink to transfer more energy to the much smaller heat sensor than the relatively tiny mass of air that would otherwise be in contact with the sensor alone.

You may indeed be correct, but that's my notion of it. I suppose it would be easy enough to test, if a kiln contained two heat sensors--one with a heat sink and one without. But I'm too lazy to fuss with it.

Bob

EDIT: In my wooden, baby kiln, a hole in the wood allows the sensor of the thermostat to be exposed to the air inside the kiln, with no heat sink. In my Cozy Can, a similar thermostat is attached directly to the exterior of the metal can, which serves as a heat sink. The tobacco that comes out of the two can not be distinguished.

you must be a better typer than me. I can't talk too fast with a computer.

 

[Dean]

Still having issues I think the thermo I have is faulty. Temps hit 160f with baccy in it today about 12 hours at that temp. I assume the leaf is fragged now and won't ferment any more. It was running hot but not that hot.

i can use another thermo I have here that will run 118-120f accurately, will that do. It won't run over 120.

i have been trying to contact the supplier of the faulty one, maybe he will answer the phone on Monday.

cheers guys.

 

[Jitterbugdude]

120 max is fine. That is the max temp I kiln my tobacco.

 

[Dean]

Sorry for all the splatters and splats but it seems I have been running with a thermo that is was faulty...

if I can run lower I will use the one I have that is an ultra accurate.



this also puts flue curing of the cost out of my reach but maybe I can fluke it with the right summy day etc.

 

[Chicken]

lot of good point made,

proper air circulation, and ventage is very important.

but then more heat will dissapate, a high r/h issue,

getting the right r/h and temp to coincide with each other, is allmost impossible, without , a fine tuned very expensive instrument to control all the varibles,

...if my bacca goes into a higher case, than desired, then ill cook it a longer,,,, bit if it dries out on me very bad, then ill put the humidity part of the kiln on overdrive,

thats what cures bacca. going in and out of case,