Dear Crispin, Indeed, bringing water to a boil quickly is the first requirement of all the cooks in Benin. That is the reason why, in some institutions, they put wood, sometimes a full log from the top of the combustion chamber. In the military camp Guézo, they do it every time, it is part of their routine. They put logs from the bottom, from the top. Often the top log even sticks out, so the pot will lie on both the pot support and the log. Then the fire is started and the top log will slowly fall down in the combustion chamber during cooking.
Putting heavy logs from the top can remove the top bricks at first, then dismantle the brick combustion chamber over time. We found bricks on the ground near the stoves. That's why I thought a sheet metal plate could be welded on top of the first layer of bricks, in order to protect the bricks. Cheers, Xavier -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: jeudi 26 janvier 2012 19:00 To: [email protected] Subject: Stoves Digest, Vol 17, Issue 39 Send Stoves mailing list submissions to [email protected] To subscribe or unsubscribe via the World Wide Web, visit http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists .org or, via email, send a message with subject or body 'help' to [email protected] You can reach the person managing the list at [email protected] When replying, please edit your Subject line so it is more specific than "Re: Contents of Stoves digest..." Today's Topics: 1. Re: Foyers ? bois institutionnels au Cameroun ? (Crispin Pemberton-Pigott) 2. subscribing to gasification list. was Re: Stoves Digest, Vol 17, Issue 35 (Bruno M.) ---------------------------------------------------------------------- Message: 1 Date: Wed, 25 Jan 2012 16:31:13 -0500 From: "Crispin Pemberton-Pigott" <[email protected]> To: "'Discussion of biomass cooking stoves'" <[email protected]> Subject: Re: [Stoves] Foyers ? bois institutionnels au Cameroun ? Message-ID: <[email protected]> Content-Type: text/plain; charset="iso-8859-1" Dear Xavier Many thanks for your overview of your work testing and manufacturing in Benin - a country we hear nearly nothing from at all. It is interesting how important height is to cooks how have to deal with them every day. You told me something interesting about cooks putting wood into the combustion chamber from the top and it would be great to hear more about that, and why they do it. A similar behaviour was noticed by Cecil Cook in Mongolia. It was related to getting a high heat during the ignition stage to start cooking sooner. Regards Crispin ++++++= "Dear Marc, I don't know if you intend to manufacture institutional stoves also. Metal institutional rocket wood stoves are a good solution if you have access to cheap steel sheet and iron. These stoves have the advantage to have a smaller production cost than other institutional stoves (in Benin at least, because metal is cheap, but not necessarily in all countries !) and production can be centralized in a workshop. Then they can be delivered. No need to move a full team and all materials to build the stove on site. These stoves were conceived by Peter Scott, and promoted in GTZ Probec projects, in Malawi in particular. I could produce and sell these stoves in Benin, but during the year of the project, I had to proceed to a few changes. I am willing to share my technical drawings, and all necessary info so you can make one if you want. What you have to know is that, in Benin at least, institutional stoves are a niche market. Make and sell domestic stoves, this is what will work and sell in large quantities (if they are cheap of course). Institutional stoves activity can be profitable, on a smaller scale though. I don't think this activity can suffice to a company. First, do a thorough market study -> spend time in kitchens of institutions, restaurants, hotels - look at the size of pots where food is cooked - look at the cooks gestures and actions, if they stand up, if they sit down, at what height?) - mesure the size of their stoves, the opening of wood feed. Are these stoves practical to use? - is there space for the pots to sit on or around the stove? How is the food served, or transfered from the pot on the fire to the pot which will be used for the service? - do cooks perform several tasks at the same time or are they waiting about the fire? Are they regularly tending the fire? - how long does the fire last? - how many times is the fire set during the day? - how much costed the stoves? - how long before their deterioration? - can they be repaired? -> submit the cooks to a detailed questionnaire - what do they like or not about the stoves they use already? - what kind of stove would they like to have? - what must be according to them the maximum height of a stove? The minimum height? - what must be the maximum duration to boil water (for a given pot size) >From what I saw from cooking practices in kitchens of institutions in Benin, I think the qualities that are researched by cooks in a stove are, by order of importance: 1/ fast cooking 2/ easiness and comfort of use 3/ durability 4/ wood savings 5/ smokes and noxious gas emissions reduction 6/ stove looks I excluded price here, since it is not the cooks who buy the stove in institutions, hotels and restaurants. They only use it, but for domestic stoves, price is among the most important things. 3 questions are crucial in my opinion : - stove resistance and durability. Heat is very high in institutional stoves. It must be taken care of, otherwise stoves will fall to pieces after a few months. - stove size. It is very important for users (see criteria number 2 on the above mentionned list). Size directly determines the stove comfort of use. Most of the time, the user wants a rather small stove. I made a few changes on the original drawings so the size could be reduced. - the stove power. It has to be high, enough so the pot can boil about as quick as with conventional stoves (see criteria 1). Here again, I modified the drawings a bit to give more power to the stove (so unfortunately, it means a bit less fuel savings). Combustion chamber is the central element of the stove. It has to be resistant. After experience, I do not advise using inox steel. It is expensive, and doesn't resist well to an intense and long-lasting fire. An insulative and light ceramic won't also last long in my opinion. Especially if it is thin. Users put the stove to the test, they have a tendency to mistreat it. We tried to cut clay bricks in 2. The process is extremely long, it is costly, and result is mediocre. Half-bricks may break, this is what we encountered. The best solution: use whole red clay bricks, very resistant and fire proof. These bricks are used in bread ovens and incinerators. Their size is often 220 X 100 X 60 mm. They must lie on the side. They can be cut in width with a brick chisel so their size can be adjusted. This will make a massive and heavy stove. But it will last, and will avoid interventions for repair (which is painful, I can assure you that). I can provide you the drawings, which are a modification of Peter Scott original drawings which can be found on www.rocketstove.org. Once again, I could not recommend enough to avoid light, thin and fragile ceramics, and inox steel. Whole and resistant bricks must be put in the stove, and it will last a long time." ------------------------------ Message: 2 Date: Thu, 26 Jan 2012 02:28:34 +0100 From: "Bruno M." <[email protected]> To: Discussion of biomass cooking stoves <[email protected]> Subject: [Stoves] subscribing to gasification list. was Re: Stoves Digest, Vol 17, Issue 35 Message-ID: <[email protected]> Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" howdy Lloyd, i think its the easiest if you go to this site, to subscribe: http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenerg ylists.org Grts Bruno M. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Op 25-1-2012 21:00, Lloyd Helferty schreef: > Tom, > > I see a *new* list for the first time: > *[email protected]* > How do I join this list? > (Do I send "[email protected] " ??) > > Regards, > Lloyd Helferty, Engineering Technologist > Principal, Biochar Consulting (Canada) > www.biochar-consulting.ca > 48 Suncrest Blvd, Thornhill, ON, Canada > 905-707-8754 > ... > =========================================== -------------- next part -------------- An HTML attachment was scrubbed... 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