[Stoves] SPAM Dung Rocket Stove - Failed Test

Fri Jan 6 11:02:14 CST 2023

Dear Kevin

There are a few stoves designed to burn dung, depending on the presentation. In general, dung requires very good control of the primary air supply because it devolatilizes easily.

I was involved in an Engineer's Without Borders project to burn yak dung above 14,000 ft in Tibet in a Vesto stove (which was used indoors, amazingly) and that worked well (no smoke).

There is an open source design for a cooking and heating stove available in the Library/Stoves/Kyrgyzstan at www.newdawnengineering.com - look for model KG2.0 and the larger KG2.5, the latter being far more developed with cast iron top decks and chimney connection. It can burn for 4 to 5 hours unattended, which is rare for a dung burner.

There is a design available (licensed) for a Kay Dung burning stove shaped to the traditional expectations for southern Tibet. The rights to this are divided between China and not-China. It uses yak dung as it occurs naturally - which is a large pellet. No processing is expected.

All dung is high ash and requires relatively large grate gaps. And a grate of course.

In Central Asia cooking and heating with dung is very common among the rural and the poor. It is better and pressed into round dinner plate sized cookies about 60mm think in the centre and 25 at the edge. These are slapped on a South facing wall to dry. Homes may accumulate several tons under shelter - 5 or more. It should be very dry when burned.

It is broken into 4 pie-slice-shaped parts before burning.

The required conditions (in my experience) are:

Low and controllable primary air.
More than usual secondary air, preheated if possible.
A separate section where the gases and smoke are burned away from the pyrolysis zone. One way to do this is the flame tube used in the KG2.5.  It is so effective at this tertiary combustion that cooking can be done on top of the heat exchanger above the exit of the flame tube.
The concept of "end lighting" is very useful. The fire is lighted at the entrance of the flame tube and fuel packed towards the air source. The fire will evolve towards the air source. New smoke is burned in the hot zone before entering the flame tube where most of the remaining CO will burn.
There will be lot of fly ash because there is so much, and it is so light. This means access to "inner chambers" must be provided.

To burn dung in a vertical chamber (only, for one pot cooking) all the above applies so it needs staged combustion and enough room to finish the flames before striking the pot. The minimum height needed is about 425mm, to 450.

I burned not particularly dry dung in Ethiopia in a Vesto and it made no smoke or smell at all. I have some photos of that. The flame is greenish because of minerals. Very unexpected. And pretty.

With reference to the KG2.5, there are sets of old drawings cached there. The heat exchanger was shortened by 80mm for the final version because the efficiency was too high. The chimney temperature was too low as a result.  This will result in condensation in the chimney so if you go that route, it is something to watch for.

You can top light dung if it can breathe well enough, and do not try to pass all the second air through the fuel. It will smoke a lot. The fuel is not "smoky", stoves that cannot burn it, are. The smoke is unburned fuel.

Best wished
Crispin

From: tmiles at trmiles.com
Sent: January 6, 2023 9:05 AM
To: stoves at lists.bioenergylists.org
Reply-to: stoves at lists.bioenergylists.org
Subject: Re: [Stoves] ***SPAM*** Dung Rocket Stove - Failed Test

SNV put a lot of effort into the development of dung stoves for high altitudes several years ago.

Leaching nutrients and minerals from dung prior to drying and burning makes a lot of sense. The principle has been used at the farm and industrial scale. Key nutrients are about 90% water soluble. The challenge is often finding enough water.

Tom

From: Stoves <stoves-bounces at lists.bioenergylists.org> On Behalf Of K McLean
Sent: Friday, January 6, 2023 6:05 AM
To: Discussion of biomass cooking stoves <stoves at lists.bioenergylists.org>
Subject: Re: [Stoves] ***SPAM*** Dung Rocket Stove - Failed Test

Richard,

Can you please explain further?  I don't understand.  Do you have photos or videos?

On Fri, Jan 6, 2023, 9:00 AM Richard Stanley <rstanley at mind.net<mailto:rstanley at mind.net>> wrote:
Not true paul or only partially true! In rural kenya our partners francis and mary kavita showed hor one sieves out the aromatics and dissolved solids by sloshing the patties of dung in water— then has a good liquid feetiliser as well as a spongy lignin which makes a great fuel whether briquetted or not.  Same
 I discovered that the same process applies to peat in Ireland.
Its good by stink and smoke; hello to clean burn and liquid fertiliser.
Richard Stanley
www.legacyfound.org<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.legacyfound.org%2F&data=05%7C01%7C%7Ccbfba483403e4da9441008daefffd026%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638086179322481080%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=Ankmll%2Ft3BreF6HdYc2bD%2Fs5v15Dfv0eXNEJUjYCVVc%3D&reserved=0>

Sent from my iPhone

On Jan 6, 2023, at 4:28 AM, peetersfrans at telenet.be<mailto:peetersfrans at telenet.be> wrote:

Dear KEVIN

I think we discsed 30 y ago about frensh frees …..but Canada was to cold for patatos down 1,5 $ !
I remember you wash  salt out of dunge  and looked for analytics for the ash danger .
As for dung cooking/baking ,it is done in Anatolia TURKEY.   No trees ,to see. villages of mud and corn looks haver, no mais .
The fireplace is chimney  fumehood  integrated about 3 meter high and always a pasat wind avaiable .
To replace it you need a suction stove , fan , jet  or and partial wood/dung using in the 3th world only…

Regards
F.

Van: Stoves <stoves-bounces at lists.bioenergylists.org<mailto:stoves-bounces at lists.bioenergylists.org>> Namens Ronal Larson
Verzonden: vrijdag 6 januari 2023 5:54
Aan: Kevin McLean <kevin at sun24.org<mailto:kevin at sun24.org>>; Paul Olivier <paul.olivier at esrla.com<mailto:paul.olivier at esrla.com>>; stoves at lists.bioenergylists.org<mailto:stoves at lists.bioenergylists.org>
Onderwerp: Re: [Stoves] ***SPAM*** Dung Rocket Stove - Failed Test

Kevin,  Paul and stoves list

                1.  What is the reason for this test of a rocket - instead of a TLUD or other char-making design?

                2.  I agree with Paul, but I can conceive of cost, time spent,  and CDR advantages of charring dung, at lest with certain family situations.   But I can’t see those advantages with combusting dung.

Ron

On Jan 5, 2023, at 9:57 AM, Paul Olivier <paul.olivier at esrla.com<mailto:paul.olivier at esrla.com>> wrote:

Dung is not a good fuel.
It is much better to ferment it and use it as a feed.

On Thu, Jan 5, 2023 at 10:12 PM Kevin McLean <kevin at sun24.org<mailto:kevin at sun24.org>> wrote:
List,

Today we tested a dung rocket stove.  I'm a little surprised that the test was a failure.  Can anyone suggest changes?  And can anyone in India help us with our testing of dung as fuel?

This is very similar to a sawdust cookstove.  We made cylinders of dung with vertical holes in the center and let them dry for a month.  We did not mix anything into the dung.  We used 5 liter paint cans to form the cylinders.

<Dung rocket stove - wet.jpeg>
<Dung cylinder - Failed test.jpeg>

We tested with and without a metal can over the dung cylinder.  We raised the cylinder and lit a wood fire under it.  The fire was never strong and there was a lot of smoke.  Here is a video<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdrive.google.com%2Ffile%2Fd%2F1xCrABfFFOVlvtGn925VW8FT9lXl660Zk%2Fview%3Fusp%3Dshare_link&data=05%7C01%7C%7Ccbfba483403e4da9441008daefffd026%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638086179322481080%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=DZK%2FvW9DfJFm28hZlea7S5q67k1cSxOHqKrQI7GFbZI%3D&reserved=0> of the test with a metal can over the dung cylinder.

We seem to be having early success with upright dung sticks in a metal band and top lighting piles of dung patties.  But these need to be tested by people more familiar with using dung as fuel.

<Dung sticks in a metal band.jpeg>
<TDB of pile of dung patties.jpeg>

We could use some help from someone in an area where dung is used for cooking.  None of my colleagues live in such an area.

Thanks,
Kevin

Kevin McLean, President
Sun24.org<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fsun24.org%2F&data=05%7C01%7C%7Ccbfba483403e4da9441008daefffd026%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638086179322481080%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=4AmHipPmLovVsn%2B1RJ545%2Fj9f9IX6mxT0UjmFvwaxBQ%3D&reserved=0>
_______________________________________________
Stoves mailing list

to Send a Message to the list, use the email address
stoves at lists.bioenergylists.org<mailto:stoves at lists.bioenergylists.org>

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.bioenergylists.org%2Fmailman%2Flistinfo%2Fstoves_lists.bioenergylists.org&data=05%7C01%7C%7Ccbfba483403e4da9441008daefffd026%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638086179322481080%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=pJBQfahRKXoTxgs1CUHmUG6S8SWuBDdQbqPbVA6nnq8%3D&reserved=0>

for more Biomass Cooking Stoves,  News and Information see our web site:
http://stoves.bioenergylists.org/<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fstoves.bioenergylists.org%2F&data=05%7C01%7C%7Ccbfba483403e4da9441008daefffd026%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638086179322481080%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=TB0%2BTaqZ2m2rXSR6gMZcYc1cHnAzCulhwGyQFZenZnk%3D&reserved=0>

--
Paul A. Olivier PhD
104/43 Phu Dong Thien Vuong
Dalat
Vietnam

Louisiana telephone: 1-337-447-4124 (rings Vietnam)
Mobile: 090-694-1573 (in Vietnam)
Skype address: Xpolivier
http://epwt.vn/en/home/<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fepwt.vn%2Fen%2Fhome%2F&data=05%7C01%7C%7Ccbfba483403e4da9441008daefffd026%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638086179322481080%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=mk1xMX%2BMtIWs3EfYl%2B0fs7i61%2BjBAy%2FOt%2FxK5oUSi8g%3D&reserved=0>
_______________________________________________
Stoves mailing list

to Send a Message to the list, use the email address
stoves at lists.bioenergylists.org<mailto:stoves at lists.bioenergylists.org>

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.bioenergylists.org%2Fmailman%2Flistinfo%2Fstoves_lists.bioenergylists.org&data=05%7C01%7C%7Ccbfba483403e4da9441008daefffd026%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638086179322481080%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=pJBQfahRKXoTxgs1CUHmUG6S8SWuBDdQbqPbVA6nnq8%3D&reserved=0>

for more Biomass Cooking Stoves,  News and Information see our web site:
http://stoves.bioenergylists.org/<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fstoves.bioenergylists.org%2F&data=05%7C01%7C%7Ccbfba483403e4da9441008daefffd026%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638086179322481080%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=TB0%2BTaqZ2m2rXSR6gMZcYc1cHnAzCulhwGyQFZenZnk%3D&reserved=0>

_______________________________________________
Stoves mailing list

to Send a Message to the list, use the email address
stoves at lists.bioenergylists.org<mailto:stoves at lists.bioenergylists.org>

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.bioenergylists.org%2Fmailman%2Flistinfo%2Fstoves_lists.bioenergylists.org&data=05%7C01%7C%7Ccbfba483403e4da9441008daefffd026%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638086179322481080%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=pJBQfahRKXoTxgs1CUHmUG6S8SWuBDdQbqPbVA6nnq8%3D&reserved=0>

for more Biomass Cooking Stoves,  News and Information see our web site:
http://stoves.bioenergylists.org/<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fstoves.bioenergylists.org%2F&data=05%7C01%7C%7Ccbfba483403e4da9441008daefffd026%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638086179322481080%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=TB0%2BTaqZ2m2rXSR6gMZcYc1cHnAzCulhwGyQFZenZnk%3D&reserved=0>
_______________________________________________
Stoves mailing list

to Send a Message to the list, use the email address
stoves at lists.bioenergylists.org<mailto:stoves at lists.bioenergylists.org>

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.bioenergylists.org%2Fmailman%2Flistinfo%2Fstoves_lists.bioenergylists.org&data=05%7C01%7C%7Ccbfba483403e4da9441008daefffd026%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638086179322481080%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=pJBQfahRKXoTxgs1CUHmUG6S8SWuBDdQbqPbVA6nnq8%3D&reserved=0>

for more Biomass Cooking Stoves,  News and Information see our web site:
http://stoves.bioenergylists.org/<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fstoves.bioenergylists.org%2F&data=05%7C01%7C%7Ccbfba483403e4da9441008daefffd026%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638086179322481080%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=TB0%2BTaqZ2m2rXSR6gMZcYc1cHnAzCulhwGyQFZenZnk%3D&reserved=0>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20230106/d4423294/attachment.html>