Build of a cooking stove with white oven and water-heater

[rava]

I'd like to share some pictures and drawings of the kitchen batch rocket stove that I'm building at the moment.
To inspire others but also any remarks or suggestion are very welcome.

Here is a (zipped) version 16 Sketch up file: kitchen stove drawing

And here's some pictures of the modified industrial gas water heater. I've build a new exhaust and intake manifold to increase the pipe diameters (160mm).  
The smallest internal passage in the last stage is about 210cm2. It will pass the heat on to a 1500 litre warm-water-buffer.



 
The core is almost finished. It has an 15,5 cm octagonal riser out of high alumina-oxide bricks




The door is also ready but have no picture at hand right now.

Was planning to increase the diameter in the top row of the riser to 20 cm (as in the sketch up drawing). To help spreading the heat a bit more underneath the metal cook top surface. These are two rather big plates of about 55*50 cm. made out of 8mm mild steel, with 10mm steel plate welded underneath.

I'm still a bit unsure about the white oven position and the path of the gasses around it.

I'm wondering if the bell construction underneath the plates will not heat them up to equally all over. Well I mean some area with bit milder cooking temperatures is off-course also wanted.  

Ah, and I plan to make a bypass in the top right of the cooking bell.

I had had started this project already two years ago when we were building the kitchen. Chose the make a deepened section in the floor to accommodate the recommended riser height. By now I would have skipped that and go for a shorter riser design as I see now here appearing. Loading this thing is going to be a bit uncomfortable. Well it will be a unusual stove set up with hopefully very good performance.

Any thoughts are welcome..

[pigbuttons]

Wow! I'm really impressed with your skills. That is a very professional looking build, the welding, the masonry, all look excellent. I kind of like the sunken floor idea. It looks like you'll be able to sit with your feet in the loading area and get a quick warm up on cold mornings.

1500 litres is a huge amount of water to warm up. I guess it will depend on your usage as to how effective the stove will be at heating that much up. Will the holding tank be well insulated or will it be used as thermal mass to warm the living space?

At any rate, you will have a beautiful and hopefully effective rocket stove. I'm not that much into the exact size ratios but yours looks to be very consistent with the batch box standard so I would expect good results.

[satamax]

I like the idea But i wonder if the oven will heat!

[rava]

Thanks for the responses!
I love to work precise and give detail to what I'm building.

As for the oven, any ideas how to optimise heat transfer? I'm designing the thing right now.
I would imagine that the top will receive sufficient heat but the bottom area might not.
I made the height of box pretty low with big top and bottom surfaces. there will fit two big restaurant trays inside.

Lowering the the exhaust further down? somehow forcing more hot gasses underneath the thing?
Naja, with 200 Celsius I would already be happy. Later on a separate baking oven is planned.

The buffer tank will be insulated and sit directly next door in a separate room together with the exchanger and all the piping and pumps.
The water will be used for showering, kitchen use, washing-machines. And for lightly heating a cob-bench and some wall surfaces in the room. In total some 80 meters op piping superficially buried in mud.  
For all these users the stove will have to run pretty much trough out the day I guess. We are 10 to sometimes 30 people living together and there is lots of cooking happening. 


 

[drooster]

Very nice floor-channel.
Are those storage-heater bricks for the sides of the firebox? (just look like them from the shape)

[rava]

I don't really know. Bought them here local as a refractory brick made in Brasil. They're quite heavy.

[Orange]

there are gasses flowing under the oven and the metal is a good heat conductor so I guess it will heat up evenly. And the whole thing is massive so it will take time to absorb the heat. Any concerns about the water condensation around the tank?

[rava]

Water condensation around the tank? I don't see any problem there. If you mean the buffer tank. Its insulated and I would not go higher then 90 Celsius there. 
Good to hear you see the oven plausible.. 

[Orange]

try looking at the similar projects.. here's a great one: donkey32.proboards.com/thread/2272/hydronic-heating-bbr-project

[rava]

thanks for the link, interesting
understand your remark now.
But I'm having a different approach. Not a tank in a bell but a exchanger with a much smaller water content.
The water will only start to circulate to my big buffer tank when that thing has warmed up. And it will be fed via a charge valve at 60 C.
It gives more complicated hydraulics but it eliminates any condensation problems.