When we warm something on gas stove, lot of energy is wasted from the sides of the pot.

Imagine, there are three dishes being cooked on a gas stove, one requires big flame, one medium and one requires a small flame (for slow cooking).

We can do this using only one flame. Keep first pot at the bottom right on flame, next one on top of it and one for slow cooking being the topmost.

Hot gases escaping from sides of the first pot warm the second pot, thus getting somewhat cooler and then warming the topmost pot.

On sidenote: The hot escaping air is normally thrown out of kitchen. Instead we we should capture it at the top of stove and through a pipe feed it back at gas flame. I think this will save energy.

I suspect this will be more useful at industrial scale cooking.
-- VJW, Dec 19 2010

Triple expansion steam engine http://en.wikipedia...e_expansion_engines
Magically delicious? Hell, it's thermodynamically efficient! [rmutt, Dec 20 2010]

http://www.cotswold...ogleBase-_-94210015 [hippo, Dec 20 2010]

http://www.cotswold...0/group/329/level/3 [hippo, Dec 20 2010]

There are multi-storey steamers which achieve something similar but [+].
-- nineteenthly, Dec 19 2010


We can save further energy if a food is being cooked has a lot of water and is being cooked in an open top container and cook it from top ( rather than from bottom, *through* container) using butane torch, thus giving the heat directly to food. No heat wasted n container.
-- VJW, Dec 19 2010


Unfortunately you may have some problems trying to heat the food equally like that. I remember a science demonstration where a block of ice is placed in a tube of water, and the top of the tube is heated by a bunsen until it starts to boil, and the ice stays solid. Without convection, water is rather insulating.

As to the idea, the pans could have double-layer walls, open at the top and bottom. The gap between them would let the hot gasses through, the outer layer would be insulated.
-- mitxela, Dec 19 2010


good point. ! convection will not happen when warm layer of water at the top will remain at top.

Idea still might work if dish is stirred at regular intervals, as some dishes need to be done anyway.

If a soup is being cooker on large scale, I think a boiler kind of heating mechanism might be worth looking at; This will involve spiralling pipes containing hot gases through soup.
-- VJW, Dec 19 2010


That's exactly what's done in large commercial cookers.
-- 8th of 7, Dec 19 2010


If using electric, then a tea-cosy over the pan would help.
-- saedi, Dec 19 2010


Plus, if you use electricity, you save roughly 100% of cooking gas.
-- MaxwellBuchanan, Dec 19 2010


A point I sadly missed:O(
-- saedi, Dec 19 2010


// Efficient usage of cooking gas //

1. Mix fuel gas with an appropriate volume of air in a closed space so as to produce a stoichiometric mixture (q.v.).

2. Retire to a safe distance.

3. Initiate combustion via a remote control system.

4. Enjoy.
-- 8th of 7, Dec 19 2010


I think 8th meant to type "stoichiometric." HTH.
-- rmutt, Dec 20 2010


SP. fixed.
-- 8th of 7, Dec 20 2010


If you want to see how to use gas efficiently, look at good quality camping stoves and pots (e.g. the Primus EtaPower pots or the JetBoil pots - linked). These have heat exchangers and cleverly designed bases to catch all the heat they can from the gas flame. It's a shame you don't see these in domestic saucepans.
-- hippo, Dec 20 2010


yah I was going to mention that designing the bottom of a cooking pan would increase heat capture, also the specific heat of flue gases aren't as high as one may think, by the time the gases have reached have gone up a few inches they've expanded and lost a lot of their heat to adiabatic cooling.

of courses using an enclosed volume would increase efficiency. they invented that too...

it's called an oven.

also induction based oven's are very efficient and safe, albeit not very common.
-- metarinka, Dec 21 2010


yah I was going to mention that designing the bottom of a cooking pan would increase heat capture, also the specific heat of flue gases aren't as high as one may think, by the time the gases have reached have gone up a few inches they've expanded and lost a lot of their heat to adiabatic cooling.

of courses using an enclosed volume would increase efficiency. they invented that too...

it's called an oven.

also induction based oven's are very efficient and safe, albeit not very common.
-- metarinka, Dec 21 2010


There is a more efficient way to use cooking gas.

Simply place the food in a small, sealed vessel, and fill with cooking gas. Unless you have a high-pressure supply, a modified bicycle pump should be used to raise the pressure to several atmospheres.

Leave food for several hours.

Vent pressure vessel; the surplus gas may be recovered and recycled.

Almost immediately, or sooner, bring a naked flame close to the now gas-saturated and (possibly) fizzing food item.

The remainder of the process is self-evident.
-- MaxwellBuchanan, Dec 22 2010


we are all forgetting to create a closed loop cycle. If one were to capture the waste byproducts of baked food digestion, we could use the methane as a cooking gas. and hence increase the efficiency of cooking baked beans.
-- metarinka, Dec 22 2010



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