Building the ultimate dryer

[Erik_V]

I'd like to build a custom dryer for taking high moisture content food scraps, using as little energy as possible. I realize that this is a subject that many have tackled, and with concrete efficiency limits. A nudge to any resources devoted specifically to this, or any corrections you could make to my understanding of the relevant systems, materials, equations, or other ideas would be hugely helpful.

My understanding is that the 'best' system will strike a balance between continuously supplying dry air ad removing moisture saturated air while efficiently maintaining the interior temperature. Moisture removal via condensation, ventilation, heating all consume energy. Efficiency can be maintained by using well insulated materials and minimizing interior volume, but only to an extent. If somebody could tell me the equations governing each of these aspects, so that I can optimize them and plug in renewable technologies where possible, it would help out enormously. There are a couple of other interesting caviates that could generate some ideas:

1. A solar thermal system is being considered for heating coils and exchanging energy with fluids such as glycol.
2. This will be located up North (NJ), and it would be possible to incorporate passive air condensation during winter if the heat loss does not make this a lousy idea.
3. I've heard of enthalpy recapture and other techniques for drying things efficiently while preserving energy, are their any other tools you might recommend plugging in?

Relevant details:
1. Moisture Content in - 40 -60 percent
2. Moisture content out - 10 - 20 percent
3. Surrounding air can be assumed to be 70 degrees, outside of the dryer.

I greatly apprecite the help, as I am an environmental engineer and not a HVAC specialist.

 

[MintJulep]

Batch or continuous?

How much?

 

[Erik_V]

Batch is more likely, in terms of tonnage, 6-12 would be ideal (of incoming mass).

 

[MintJulep]

(.4-.2)*6 = 1.2
(.6-.1)*12 = 6

Huge difference in capacity for a single machine.

If you are using free energy (i.e. solar), why worry about using as little energy as possible?

 

[berkshire]

Erik-V ,
Look to the feed milling and processed foods industry , Particularly Grain dryers, and pellet dryers . They have been solving this problem for the last 100 years.
Suggested companies; California Pellet mill Co, GSI, Brock,

https://www.potatopro.com/product-types/industrial-drying-equipment

B.E.


You are judged not by what you know, but by what you can do.