Batch cookstove with a small riser

[Deleted]

Hi everyone,

I'm in love with cookstoves and the new experiments by Peter and Dcish inspired me to try new things concerning a batch core with a very small riser. Also heaters by Matthewwalker, Adiel and Shilo are very inspiring.

Specs :
- The cookstove is a 165 mm sidewinder. The chimney flue is 150 mm. 4 meters high. The two last meters will be insulated.
- Output power with two fires a day : 2500W.
- Cookstove ISA is 2.5 m2. The bench and 2 meters of uninsulated chimney add 3.8 m2. Total ISA is then 6.4 m2 which is the recommended ISA for a simple bell and this core.
- Material cost (delivered) is approximately 1100€. If it works the final cost for a client would be around 3000€.

The experiments will be :
- a 5B long, round, insulated riser with a small bell right on top of it and a floor channel. The bell is 6 times the CSA. There is 230 mm between the top of the riser and the plancha.
- a 5B long, square riser (only chamfered at the two back corners on a 3B length) with the same configuration (Peter's idea)
- a 5B long, insulated, square riser (only chamfered at the two back corners on a 3B length) with the same configuration
- a 5B long, square riser measuring 2Bx2B with the same configuration
- the three configurations with a floor channel without vertical part

The questions :
- how will the combustion be ?
- how much ISA will be needed ? I think (and hope) there will be less ISA needed, but that's only a guess.

Testo measures will be done as soon as the metal work is done. I finally managed to make a heater at my home.. I will have the time to make proper testo measure. It was always very complicated with clients' heaters. It's a big step for me !

Sketchup plan : uzume-asso.org/assets/docs/experiences/cuisiniere_donkey/batch165_sidewinder_cuisiniere_221117.skp

Pictures of the heater and sketchup drawings :









Regards,

[Dan (Upstate NY, USA)]

Nice, I look forward to seeing the final results.

[Jura]

I can not wait to see the measurements!
Do you happen to posses the more expensive TESTO with NOx measuring capability?

This project is exactly that would suite my needs in a small 25 m² poorly insulated building at my allotment garden.
I would love to have the bench 4 m long. (bent 2x2 m)

OK..enough theory ... going to get my hands into moulding an vaulted ceiling.

[Deleted]

Hi Jura,

Thanks for the message. Unfortunately I don't have a NOx cell on my testo !

Regards,

[matthewwalker]

Looks like a great little cook stove! My guess on the Testo results: I imagine it will cook and heat beautifully, but probably leave a bit of CO unburned due to the lack of Time in the three T's equation, and heavy brick. Likely hard to keep a decent flat line CO under 500ppm, and likely fairly unstable overall with CO spikes, but will still burn better than most of our early rockets. I believe the insulated risers will outperform the bricks by a big difference, and that the shapes will have a small effect. That's my guess! Thanks for sharing with us, good stuff.

[peterberg]

Nov 21, 2017 21:54:22 GMT -8 @yasintoda said:

- the three configurations with a floor channel without vertical part.

I think I missed this statement earlier. That's the stage I started to develop the floor channel in the fall of 2015. That flat channel is very simple but it didn't cut the cake at the time. That is, in my situation, my heater and chimney combination.
I'm curious how it turns out for you, since you are doing part of what I did again. Should yield comparable results but I won't sell the hide of the bear before it's shot.(Dutch expression)

[Deleted]

Thanks matthewwalker , the bets are open ! Mais ne vendons pas la peau de l'ours avant de l'avoir tué. (french expression)

[Deleted]

Hi peterberg did you ever tried risers with a larger diameter ? (I'm sure you did!) For example here I'll try a 165 mm batch firebox and a 240 mm riser.
What were the results like ?
I wonder if it may be a possibility to shorten the risers.

Thanks,

[satamax]

I have, on the range retrofit.

box sized for a 10cm, a smidge short. Riser is 12. And 63cm long iirc. Top gap around 10cm. And it still overloads.

[peterberg]

Nov 25, 2017 21:59:13 GMT -8 @yasintoda said:

Hi peterberg did you ever tried risers with a larger diameter ? (I'm sure you did!)

Hate to disappoint you, but I didn't. The only one that I am aware of is Matt's conversion of an 8" J-tube to a 6" batch rocket while the riser stayed in place.

[docbb]

Nov 25, 2017 21:59:13 GMT -8 @yasintoda said:

Hi peterberg did you ever tried risers with a larger diameter ? (I'm sure you did!) For example here I'll try a 165 mm batch firebox and a 240 mm riser.
What were the results like ?
I wonder if it may be a possibility to shorten the risers.

Thanks,

May be have a look there

[Orange]

hey yasintoda, can't wait for the results. Matt's tiny cookstove can burn efficienty and power the similar ISA. I think uninsulated chimney counts as 1/2 of surface.

to have a fair comparison you can use 2 or 3cm thick firebricks (instead of 6cm), then you have a space for insulation around them.

[pyrophile]

docbb : Can you explain a bit, please, what it is about because I don't undesrtand anything!
Thank You!

Benoit

[docbb]

Nov 27, 2017 6:59:44 GMT -8 pyrophile said:

docbb : Can you explain a bit, please, what it is about because I don't undesrtand anything!
Thank You!

Benoit

Hi Benoît, it is about the construction of a rocket cookstove withe the minimal riser height and a boiler attached on the other side of the wall, hus follow the thread on the other forum , it is in Dutch but chrome should translate it almost harmlessly.

[pyrophile]

Thanks! I forgot google translation! I thought it was about bigger diameters!


What about rounding rhe edges everywhere (also in the horizontal part) of the Yasin's design and keeping the same diameter everywhere(150mm) ? The oven would be sacrified but could be somewhere else (needing more room unfortunately).

Benoit