[Stoves] Fwd: Simple Modifications to Traditional Wood Cookstoves - Rocks and Clay Grates

[Ronal Larson]

List:   cc Kevin M

	1.   This is to bring you up-to-date on Kevin McLean’s “zero cost” stove work - that I have learned in the last 4 weeks..  This today is on three (mainly one) new concepts (despite keeping the thread name).   It has applicability especially to those working with Rocket stoves - but I am pretty sure he/we can find ways to work also with TLUDs.  

	2.  After Kevin sent me 3 short videos a few days ago,  we agreed there could be great benefit to his and everybody’s stove research to get this early work out for discussion.  So this is to ask everyone to view Kevin’s annotated 2 minute video on an approach I have not previously seen:
	https://drive.google.com/file/d/1EJQEKKkMTQbcKn3kBC1YZ50oqtZPsbym/view <https://drive.google.com/file/d/1EJQEKKkMTQbcKn3kBC1YZ50oqtZPsbym/view>.   
  I am amazed that so much energy gets to the second pot (and he may develop a 3 pot design, that also looks well worth the relatively small added extra cost).  No metals anywhere.
	Anyone seen this before? 

 	3.  I will try to report soon on two other new (to me) very low cost stove improvement areas on which Kevin has also been working - and which I am unaware of any others pursuing: 
		-   adding energy storage using movable hot rocks or bricks (headed to hay baskets maybe?)
		-  making char while cooking (and NOT with TLUDs)
	Can anyone give a lead to these storage and char-making areas?

	4.   The 4th area of our discussions since the message below still seems brand new:	
		- improved air flow with 3-stones - using "rocks and clay grates” to elevate the fuel.

	5.  Since Kevin is adamant on zero costs to users (and minimum costs allowable when payback time is short), these ideas are not amenable to most companies looking at the 3-stone-user market.  Accordingly, Kevin will not be patenting any of this - all 4 areas will be open source.	  

	Anyone working on any of these 4 areas?  Or know of past results from anywhere?

Ron



> Begin forwarded message:
> 
> From: Ronal Larson <rongretlarson at comcast.net>
> Subject: Re: [Stoves] Simple Modifications to Traditional Wood Cookstoves - Rocks and Clay Grates
> Date: March 29, 2019 at 3:01:27 PM MDT
> To: Discussion of biomass cooking stoves <stoves at lists.bioenergylists.org>
> Cc: K McLean <info at sun24.solar>
> 
> List,  cc Kevin
> 
> 	This is to encourage this list to view the two “Sun24” links given below.   Because I was so impressed when I viewed those, I had a nice phone conversation with Kevin yesterday.  A few things I learned:
> 		  Kevin is a retired lawyer.  Retired for only a year, but already in contact with stove-knowledgeable NGOs in many countries.  Through them, he is offering - for free - improvements in 3-stone use of doubled efficiency, and improved emssions.  Working also with some low-cost rocket designs.  Not yet working on TLUDs - but knowledgeable about them, and supportive at the right price.  Has stove modifications measured in multiples of 10k, I think (in only a few past months).
> 
> 	His emphasis on major stove improvements at zero cost (better air delivery), with local NGO support, is something we have been mostly missing in our stove development efforts.  Emphasis zero cost - described at these two sites given below.
> 
> Ron
> 
> 
>> On Mar 28, 2019, at 9:24 AM, K McLean <info at sun24.solar <mailto:info at sun24.solar>> wrote:
>> 
>> Sun24 and its partners operate at the primitive end of the cookstove spectrum.
>> 
>> We have found that both rocks (or broken clay bricks) and a clay grate improve open-fire wood cookstoves' efficiency.  Here are examples of rocks and a clay grate in a three-stone cookstoves:
>> <Rocks in 3-stone.jpg>
>> <Clay disc grate in 3-stone stove.jpg>
>> SNV tested <https://drive.google.com/file/d/183kPF5DrwIR5mdDhE7xC9AaNJLaorGZt/view?usp=sharing> the rocks and clay grate in its open-fire stove.  Here are SNV's results:
>> Rocks vs unmodified open fire
>> +30%    Thermal efficiency
>> -27%     Wood fuel used
>> -53%     CO 
>> -57%     PM 
>> Clay grate vs unmodified open fire
>> +52%    Thermal efficiency
>> -47%     Wood fuel used 
>> -57%     CO 
>> -58%     PM 
>> 
>> Early user feedback suggests that rocks in traditional charcoal cookstoves also improve efficiency.  We are expanding our informal field testing and hope to test in the lab soon.
>> 
>> Since rocks and broken clay bricks are free and ubiquitous, we only need to disseminate the idea, not a product.  We are rapidly disseminating the idea with success in Kenya, Uganda and India by training women group association leaders to train others who then train at the local level.  In Kenya and Uganda we are working with the Catholic and Anglican Churches.  In just a couple months and at low cost, we have trained tens of thousands of women to use this simple modification.  The trainers' feedback is that the users love it.
>> 
>> Here is our occasionally-but-not-frequently-enough updated Cookstoves Overview <https://docs.google.com/document/d/1ZryS7gQ1q3zKLZPM2KcXdtIHbOYQp4PbloPqMvrlZ5Y/edit?usp=sharing>.
>> 
>> These cookstove modifications are a transitional first step but they are important.
>> 
>> All suggestions are welcome and appreciated.
>> 
>> Kevin
>> 
>> Kevin McLean, President
>> Sun24
>> https://sun24.solar <https://sun24.solar/>  Sun24 Cookstoves Overview <https://docs.google.com/document/d/1ZryS7gQ1q3zKLZPM2KcXdtIHbOYQp4PbloPqMvrlZ5Y/edit?usp=sharing>
>> Tampa, Florida, USA
>> +1 (813) 505-3340
>> 
>>                      
>> 
>> 
>> 
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>> 
> 

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