Guest Post by Willis Eschenbach
This one is for fun and also for real. The theme of this post is “There’s never enough time.” I worked in the villages of the developing world off and on for a number of years. A recurring issue is the inefficiency of most stoves. The simplest is the “three stone” variety, made with three stones to put the pot on.
Figure 1. An obviously ancient three-stone fire with a modern cookpot in Tanzania. Photo Source
This is hugely wasteful of fuel, particularly in lands where wood and even branches and twigs are scarce. Among my known defects is that I’m an inventor. Over the years I’ve worked on making and designing a variety of stoves to try to improve stove efficiency. As a result, in one of my peregrinations around the web a few days ago I was intrigued to stumble across the “Kelly Kettle”.
The Kelly Kettle was used in Ireland by the shepherds to brew their cuppa tea. Here’s one at work on a beach somewhere.
Figure 2. Kelly Kettle cooking on a beach. Note the fire coming out the chimney.
The brilliance of the plan is that the water in the kettle surrounds the fire. I looked at that, and my inventor’s soul rose to the fore, and I thought “Man, I could make the radical Dutch Oven using that plan. Here’s what I think it might look like.
Figure 3. What I call the “Magic Cookpot”. Note the split (two part) lids, one of which has been removed, flipped over, and laid on the ground for clarity. Lids will have handles in the final version.
And here’s a cross-section:
Figure 4. Cross-section of Magic Cookpot without the lids.
No good to throw away waste heat, so the Kelly Kettles have a pan-holder that fits in the chimney to allow you to cook another pot of food on top.
Figure 5. Kelly Kettle with cookpot. Source.
Looks good to me, so here’s my version of the same. This would allow you to cook soup or stew and have a frypan on top …
Figure 6. Potholder inserts into chimney of Magic Cookpot.
OK, advantages of this plan:
• Efficiency, efficiency, efficiency. Even without cooking anything on the top, this will heat water with less fuel than any design I’ve ever seen.
• Cost. Because the stove and the cookpot are one, you don’t need to buy both.
• Portability. It can be moved easily.
• Adaptability. It can use a variety of fuels, including a propane burner.
• Speed. It will heat water fast.
As I mentioned, the theme of this post is the theme of life—there’s never enough time.
In a perfect world, I’d take this idea and run with it and make a big difference in the amount of wood burned around the planet. I don’t have time, I have a bunch of other projects going on. But I’d hate to see this idea die, it’s a really good one that could make a big difference. So I figure I’ll cast the idea free on the web, make a gift of it to the world of stoves, and see what becomes of it out in the greater marketplace of ideas.
How could this rough plan be improved? It needs a damper to control the draft, and some kind of flap to control the air intake. You could probably increase the heat transfer (fire to liquid) by putting some spiral fins up the chimney. This would increase the surface area and transfer extra heat to the cookpot.
In any case, there it is, and I encourage anyone with the time and energy to become the champion of the idea. You’ll make a name for yourself and have women blessing you all around the planet. All it needs are a couple of sharp Brazilian or Indian or Chinese (or European or American) college students who’d like to make a difference in the world.
w.
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Good thinking Willis – although there are some fairly good designs out there already – e.g. the Sierra Stove which doesn’t use the Kelly Kettle principle but instead uses a battery powered fan to blast warm air onto the fire and burn the fuel much more efficiently – http://www.digitalmarketingusa.com/ZipStove.html
I think there’s another similar product on the market also.
Excellent…I’ve seen parabolic mirror solar cookers here in australia.
Tools are what we need, better tools…I fear part of the green religion is technophobic.
…while decoupling all that waste cash from the bottlomless money pit of CAGW and applying a fifth of it to providing clean water to put in the pot….
Willis
We have had a similar working one like that in NZ for many decades (thermette), predates the great depression if Im not mistaken.
http://www.jackmtn.com/simplog/gear/thermette-vs-kelly-kettle-challenge/
Im also not sure about trying to control the fire with dampers etc, they never last and also they starve the fire of air creating smoke which is both wasteful fuel and not so flash for health. Best way is simplest way and for my money I would be controlling heat by fuel addition. But its good to see if there are any other ideas that might work and be robust.
Very clever idea. I hope someone can develop it.
These have been on sale in the UK for decades.
Would not a better idea be to actually supply these impoverished peoples with a cheap form of energy at the push of a switch. It is called Electricity and it has done more to help peoples development than anything else.
Oh! I forgot that would mean using coal, that cheap plentiful power source, which would mean an increase in anthropomorphic produced CO2!
The history of the thermette
http://www.thermette.com/thermette_history.htm
My father always said that during the second world war the Germans could work out where the Kiwis had been by the tell-tale circular fire burns their thermettes left behind.
The whole concept, takes me back to my childhood in Australia, and the old chip heater that we had in the bathroom, it was basically a tall light metal cylinder with an internal copper tank on the upper inside. There was a cast iron door and frame for introducing small woodchips, paper, and internal cast grate that stopped the coals from dropping down into the ash tray.
Basic operation was to get a fire going and run cold water into one end of the internal copper tank and the other end was a spout outlet to run the hot water into the bathtub, when the bath was a suitable temperature the children all got put through the bath.
Woe betide you if you set too hot a kindling or chip fire and got the internal circular tank too hot and steam developed, sometimes bursting the copper seams and the sore backside for doing it taught you not to repeat the exercise!!
Those were less complicated days – good luck with your idea, it sounds good. When they put us back into the dark ages, maybe we will all need such a cooking pot if we are allowed (a) to be trusted to operate it (b) to fuel it (c) to own or possess it (d) rent it from the ruler, with suitable carbon indulgences.
You should have entered this. All over the UK MSM at weekend.
http://www.thecourier.co.uk/Community/College-and-university/article/13727/efficient-biolite-stove-could-make-world-better.html
On a trip to China I was treated to traditional food from the north of the country. They brought out a “stove” very similar to figure 4 in which you cooked your own bits of food in the boiling water. The boiling section was also partitioned so that you could cook in water or sauces at the same time. I guess the question is why this device has been invented in many places around the world but not in Africa (or has it and merely been forgotten)?
Neat idea, Willis. However I fear the “Kurd” has it on the nail head when he talks of decoupling monies from CAGW. I fear little will be done to eradicate poverty & hunger & disease around the world via CAGW, despite the paltry sums required to do so by comparison. The “realists” are negative people, always seeing the “problems” with this or with that, you know the type, “it’s all very well you saying that but I’m a realist!”, whereas the “realistics” are practical positive people, those who see the problems & come up with solutions to those problems! Wish I was as clever as you though! 🙂
I have a kelly kettle and it is quick and easy to use. It’s only draw-back is that if you have a good fire burning in it, when you take the kettle off to pour out some water, the burning twigs or whatever will fall over making it difficult to get the kettle back on the stove.
Terry,
When I was a teenager in the mid seventies (in NZ) we had a Thermette that we took on regular family picnics. It would run on almost anything as long as the fuel was at least semi-dry and would boil about 4 to 5 litres of water in just a few minutes. Very good for coffee, tea, soup etc, and washing the dishes.
The desert soldiers made “Benghazi Burners” that used what ever fuel they had to hand. Thermette developed from that.
KenB says: (May 10, 2011 at 3:10 am)
The whole concept, takes me back to my childhood in Australia, and the old chip heater that we had in the bathroom…
That’s where it took me, too, Ken. Absolutely brilliant; and luxurious. Ours was a “Malley” from memory. Bit of newspaper, some wood chips or kindling leading to fearsome bubbling and spurts that became a glorious hot bath on the coldest night.
DocD says:
May 10, 2011 at 3:24 am
On a trip to China I was treated to traditional food from the north of the country. They brought out a “stove” very similar to figure 4 in which you cooked your own bits of food in the boiling water.
Commonly known as a Steamboat. See for example http://uktv.co.uk/food/item/aid/511539
BTW: If you have a gas water heater you can find the spiral fin design in the center flu. It’s a drop-in piece that slows the exhaust gas. It increases heat transfer, but also reduces the amount of carbon monoxide to near zero.
Here’s a couple of images of the ultralightweight kelly kettles and alcohol stoves I make from beer and energy drink cans for my backpacking expeditions.
http://cache.backpackinglight.com/backpackinglight/user_uploads/1218618150_07167.jpg
Capacity two cups, boils in 3.5 minutes using 12.5g of 95% pure alcohol. Efficiency is 63%. The kettle and stove setup weighs under 3oz.
http://cache.backpackinglight.com/backpackinglight/user_uploads/1219072939_07233.jpg
Capacity 1 cup, boils in 4 minutes is 6g of 95% pure alcohol. Efficiency is around 67%. The kettle and stove setup weighs under 1 1/4oz
I also have a 4 1/2oz wood burning version made from an aluminium drinks bottle.
http://cache.backpackinglight.com/backpackinglight/user_uploads/1200954209_04394.jpg
The double skinned gasifying woodstove it sits on is made from a syrup can and weighs 5oz. I now make titanium woodstoves from 0.005″ material. They weigh under 2oz.
Finally, and not for the faint hearted. Me on a snowy mountain top demonstrating the all weather applicability of the design:
http://cache.backpackinglight.com/backpackinglight/user_uploads/1288706825_32605.jpg
As the stove and the cookpot are one, when you lift the lot to pour sloppy food out you have an uncontained fire.
A tin for making ring shaped cakes like angel food cake would be a basic first step – the bit that makes the hole in the cake being the chimney.
Willis? Excellent idea, one small change, though. Make the firebox/chimney and the cookpot two separate pieces, so that you can lift the main cookpot off of the firebox/chimney. You can still use the chimney top pan holder, and you could use multiple main cookpot sections on a single chimney set. Also, the chimney could be used stand alone as a heat source while not cooking, if needed.
I have years of experience cooking over all manner of heat sources in in all manner of conditions. Hell, used to cook C-rations on the exhaust manifolds of trucks in US Army, so I am always up for something new!
Hope to see these for sale soon.
Possibly this one would also work:
http://www.newdawnengineering.com/website/stove/singlestove/vesto/
I have a Russian Samovar – it uses the same principle – it heats water very quickly and needs little fire. The Samovar has a long and wide history.
I already came across this as a recognized issue in the news 20 years ago and development projects had been initiated to tackle the problem…
The advantage the three stone fire has is that stones are available everywhere for free. That is an advantage that is going to be hard to beat.
In stoves, you need a hot combustion chamber to burn all gases (the more smoke, the less complete combustion). That’s how best rocket stoves work : with well insulated walls and a good compromise between exhaust gas temperature and speed (the limit being that draft force doesn’t extinguish the fire).
So I suspect the “Kelly Kettle” to be of pratical use but not very efficient because of by-design cold walls. If you want to use it for cooking, you need to add water even if you don’t want hot water otherwise the walls’ temperatures rise rapidly way over 100°C and the reservoir won’t last long if it’s made of tin.