This Idea was inspired by thinking about another Idea and its first two annotations (link).

We start with an appropriate metal cooking pot, and add food. Then we close the pot with a good lid (but we are not attempting to seal it against pressure build-up), and then surround the pot with a lot of insulation. Let's assume the "block" of insulation is designed to accommodate the pot in its interior.

Now we put the pot on a special "heater", such that it can induction-heat the pot across the thickness of the insulation. It is possible that the heater may need to be shaped like a parabolic dish, so that its electromagnetic energy can be focused on the pot.

As mentioned in the subtitle, if we can add energy to the pot faster than heat can escape through the insulation, then the pot and its contents MUST get hotter. This would allow us to use a low-energy heat source, such as is described in the first link.
-- Vernon, Jun 07 2015

Inspiration Mechanical_20induction_20cooker
As mentioned in the main text. [Vernon, Jun 07 2015]

About insulation http://www.todaysho...insulation-r-value/
As mentioned in the main text. [Vernon, Jun 07 2015]

Breville - Slow Cook or Pressure Cook http://www.breville...st-slow-cooker.html
[xaviergisz, Jun 09 2015]

Jetboil insulated hiking cooking pot/system http://www.jetboil.com/
Insulated pot (coupled with heat exchanger and collapsible setup) [Custardguts, Jun 15 2015]

Well insulated and uses waste heat.. Peltier_20Crock_20Pot
[bs0u0155, Jun 15 2015]

Sort of a slow cooker. You might be able to power this one with a windmill.
-- bungston, Jun 07 2015


I was surprised to see that slow cookers generally use 100-200W - perhaps a better insulated one would use less.

On the other hand, if you're venting the cooker then you're losing quite a lot of energy as steam (even below boiling point).

You might overcome the steam-loss issue by overlaying your food with an edible oil; below 100°C that would eliminate most evaporation and therefore most heat loss. PCRs are still sometimes done with an overlay of mineral oil to prevent evaporation.
-- MaxwellBuchanan, Jun 07 2015


I have never seen slow-cooker-baked-bread for sale in a shop.
-- pocmloc, Jun 08 2015


[MaxwellBuchanan], thanks for pointing that out. It obviously means that we need more than just one type of insulation, surrounding the pot. The innermost layer of insulation should be highly water-absorbant, to keep steam (and its heat) from getting very far away from the pot. Towels, perhaps?
-- Vernon, Jun 08 2015


Better yet, just make the whole thing a pressure cooker with a pressure relief valve. The actual pressure would be quite low (assuming that you're not cooking above 100°C), and there would be zero losses from steam or hot air escaping.
-- MaxwellBuchanan, Jun 08 2015


Just keep the steam in, a bit of pressure is fine, Shirley?
-- bs0u0155, Jun 08 2015


/overlaying your food with an edible oil/ Purely by accident, it turns out all my slow cooking uses exactly this technique! The moisture retaining part was an accident. I knew very well what was in the bacon and ham hocks.
-- bungston, Jun 08 2015


Perhaps use a heat exchanger to let the steam escape while not losing all of its heat.
-- notexactly, Jun 14 2015


This is very similar to the ultra-high efficiency solar cooker designs, except those use a double or triple pane glass lid to let the energy in.
-- MechE, Jun 15 2015


I have the presusre cooker in [xav]'s link - and the cooking pot is relatively well insulated within the body of the machine. For a pressure cooker it doesn't vent much steam at all, so I must presume it's relatively efficient.

See linked hiking cooker, which is insulated. This is obviously done for reasons of thermal efficiency, and are pretty good gear. Very low gas usage. Also note the heat exchanging pot bottom. Couple of other brands are coming out with competing products now, which is nice.

As to the idea, sure, why not. Although I think a more humanitarian use of the concept would be for fuel-poor people in third world countries to be able to cook more with the same volume of fuel.
-- Custardguts, Jun 15 2015



random, halfbakery