[Stoves] Designs

[Dean Still]

Dear Vincent,

Drying is usually pretty inefficient. So it is easy to improve by following
these principles:

Keep sun off of food (decreases quality)
Keep bugs off of food
Keep temperatures usually below 130F (Can be higher in beginning when there
is more moisture in the food)
Increase velocity of dry air touching food. (Touching food, not passing
somewhere close.)
Remove moist air as quickly as it is made.
Use a very effective heat exchanger into drying chamber, preheat incoming
air.

In our big 1,000lb dryer at Aprovecho we used about 12 lbs of wood/hr. A
tall chimney pulled moist air out of the drying chamber. A small fan
increased uniform drying pushing pre-dried air through the shelves but it
also worked without the fan. Tomatoes took 14 hours.

Best,

Dean