[Stoves] Belonio burner top on TLUD stoves was Re: radiant heat capture, total heat measurement

[Marc Pare]

# I appeal to Marc not to hide his light under a bushel. These discussion
also need numbers and methods so the reality of things becomes widespread.

Write-up is coming :)
Putting in some effort so that it's a useful resource for folks in the
future.

Marc Paré
B.S. Mechanical Engineering
Georgia Institute of Technology | Université de Technologie de Compiègne

my cv, etc. | http://notwandering.com


On Sat, Mar 17, 2012 at 1:55 PM, Crispin Pemberton-Pigott <
crispinpigott at gmail.com> wrote:

> Dear Alexis and Paul****
>
> ** **
>
> Thanks so much for the very open discussion and open design of the
> burners. Alexis, when we met in Thailand you mentioned that you have
> switched to a premixed flame and if you recall we did talk a bit about the
> top end of the version of the stove you demonstrated.****
>
> ** **
>
> Is it correct that you are now using a premixed flame? I have been in
> extensive conversation with Paul O about the burner for some time and it
> seems at present to be a blend of premixing with secondary air and as Paul
> says, some tertiary air for the final burnout.****
>
> ** **
>
> The difference in performance that Paul mentioned and which got some much
> discussion going about heat transfer from the hot dome could have at least
> three quite different origins and there is a lot of merit in tracking down
> the difference. The first might be that the structure under the pot on
> Paul’s present configuration is much more closed than the one I saw in
> Thailand. That could account for all the difference in the boiling time. A
> second possibility is the reduction in excess air either through the burner
> where flames are present or between the flames and the final departure of
> the pot and stove structure, by which I mean the outer ring. Until the hot
> gases leave the pot and vent into the room, the air present in that gas
> stream is technically part of the combustor. If there is a lot of cold air
> entering the region under the pot, then it is counted as excess air in the
> heat exchanger.****
>
> ** **
>
> Paul, thanks for putting the pictures of the development work you are
> doing. It is helpful for those who would like to work on stoves with
> minimal equipment to see how things work and what has been tried. It saves
> a lot of reinventing.****
>
> ** **
>
> With regard to the heat transfer from a radiant dome, Marc has been doing
> some calculations which I hope he will post here when he is confident in
> the method. That should settle the question as to whether or not a large
> increase in performance can be obtained by changing hot, relatively non-IR
> radiant gas into IR emitted from a wide gauze surface.****
>
> ** **
>
> It is well worth remembering that because a flame is pale blue in the
> visible range, that does not tell us what it is emitting in the IR which is
> invisible to human eyes. Looking through a translucent flame is not really
> a measure of emissions of heat. If you point an IR gun at a flame it will
> register a high temperature, even if it is as inaccurate as an unshielded
> thermocouple.****
>
> ** **
>
> I agree with the others that the discussion about heat transfer has been a
> good exploration of the subject. I appeal to Marc not to hide his light
> under a bushel. These discussion also need numbers and methods so the
> reality of things becomes widespread.****
>
> ** **
>
> Regards****
>
> Crispin****
>
> ** **
>
> ** **
>
> *++++++*****
>
> ** **
>
> Alexis,
>
> Here is the drawing of your burner:
> http://dl.dropbox.com/u/22013094/150%20Gasifier/Drawings/005.pdf
> Here is the drawing of the burner housing:
> http://dl.dropbox.com/u/22013094/150%20Gasifier/Drawings/006.pdf
> The housing is not easy to make without large pressing equipment.
>
> The housing is placed over the burner.
> The two parts are welded together at the four points where they touch.
> http://dl.dropbox.com/u/22013094/150%20Gasifier/Boiling/IMG_1024a.JPG
>
> 446 stainless, as the drawings suggest, is too expensive.
> Making both parts in cast iron could be considered.
> But cast iron normally involves a considerable thickness.
>
> I foresee a third part that fits above the burner housing.
> This part is embedded within the counter-top.
> This third part restrains the flow of excess air, and it shields the
> flames from wind.
>
> Thanks.
> Paul****
>
> On Sat, Mar 17, 2012 at 9:16 AM, alexis belonio <atbelonio at yahoo.com>
> wrote:****
>
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