Insulative Clay

Gustavo Peña, November 2011

Tom varios amigos me han escrito que no reciben el documento aqui te lo mando, si lo van a poner en la web por favor agregar los siguientes comentarios

  1. Està fabricada con làmina de 3 milìmetros en la parte exterior y la càmara interna es de tubo acero al carbòn de 5 milìmetros
  2. tengo varios modelos en pruebas con gente que la usa todos los dias y los resultados hasta el momento son los siguientes
  3. A- en nuetro medio un negocio comun es la venta de tortillas, una de las usuarias ha logrado producir 800 tortillas con 10 libras de leña.
  4. B- la primera estufa con 2 quemadores tiene ya 8 meses de prueba y las condiciones de la càmara son exelentes no se ve deterioro alguno, esto nos da un parametro de vida de mas o menos 4 años de uso diario.
  5. C-los usuarios que estan haciendo las pruebas estan muy contentos por el desempeño y el ahorro, pues antes gastaban $7.50 usd en gas licuado (LPG) y con este modelo ahorran $5.00 por dia con un ahorro total de $1,800.00 usd por año
  6. D- los resultados finales con relacion al peso de la leña en comparacion de estufa tradicional estaran listos en 2 semanas.

Aqui van las fotos y los dibujos de la càmara, en el power point puedes ver los modelos que estoy produciendo, la Ecocina es la lider en ventas, al final del power point veras una estuva de metal con protector amarillo para evitar quemaduras la he nombrado HOPE y espero presentarla a una universidad de Africa en unas semanas.
la estufa HOPE esta equipada con la nueva càmara de combustion
cualquier pregunto por favor estoy a la orden

Cecil Cook with Technoshare, November, 2011


Baseline Study of the Socio‐economic Patterns of Charcoal, Wood and Stove use in greater Lusaka, Zambia

Some highlights:

  • Previous stove improvement projects have failed to properly appreciate the central role played by one and two person tinsmith enterprises that produce and sell ordinary mbaulas at very low prices. The tinsmiths of Lusaka constitute a well distributed network of producers and sellers of ordinary mbaulas fabricated from scrap sheet metal who conveniently service all the major markets and townships of the city.
  • In addition to underestimating the multiple competitive advantages of a well distributed network of tinsmiths who fabricate and directly sell a charcoal stove that everybody knows how to operate, previous stove improvement projects failed to appreciate just how poor the bottom 2/3rds of the Lusaka economy really is and how little money low income families are able to save from their daily and weekly income for the purchase of a replacement mbaula when the old one finally breaks down. It is the initial retail price of an improved stove, not how much money it will save a household during the course of a month, that determines whether they are willing and able to spend two, three, four or more times the K4 000 to K6 000 for a 20cm ordinary mbaula. The ordinary mbaula is the industry standard. Every household without access to firewood, no matter how poor, has to pay out at least K4 000 once or twice a year to purchase a replacement mbaula.

Cecil did a good job of discovering the buying patterns in households of at least 3 different income levels, and uncovered that the ordinary (less effecient) Mduala stove has great traction among ordinary lower income members of Lusaka Zambia because the stoves work as expected, and they are inexpensively produced by local stove manufacturers.

He has also shared with us some of the highlights of the report in the attached pdfs.

Save Money, Save Energy, Eat Well!

Since the introduction of our line of Cookswell Energy Efficient Charcoal Ovens in 1992, thousands of ovens have been sold regionally and countrywide, to all manner of people for all manner of uses.

Fuel, Stoves and Water for Haiti
January 27, 2009

There are several projects to supply fuel, stoves and potable water to Haiti. Some have been been ongoing since before the quake and some. The organizations we know of are:

CHF International, Helps (Water Purifier)
To donate a $35 water purifying system, go to https://secure.helpsintl.org/store/haiti.php

Legacy Foundation (Fuel Briquettes)

Miombo, Project Haiti www.prohaiti.org
Peko Pe TLUD pellet fueled stoves to be distributed by Project Haiti. Pellets from Georgia.

Trees, Water, People TWP
Ananda Marga Universal Relief Team AMURT http://www.amurthaiti.org/ and
Recho Rocket stove made from mud formed in a bucket, the Haiti Rocket Stove
Stovetec Rocket Stoves in a metal bucket.

World Stove, International Lifeline Fund
Biucci, Everything Nice TLUD stoves fabricated in Haiti. Pellet fuel from Florida (Green Circle). Grass pellets to be made in Haiti.

VIDEO: How to build a Rocket Stove (includes making insulative refractory bricks)
Jeremy Roth, Aprovecho Research Center, June 12, 2007

A new video from Aprovecho showing step-by-step instructions for building a small, single-pot rocket stove made from sheet metal and insulative refractory bricks. Instructions for making refractory bricks are also included in the video.

The video is available for viewing and download from Aprovecho's website www.Aprovecho.org

See http://www.aprovecho.org/web-content/media/rocket/rocket.htm

Dean Still, June, 2005

download the Insulated Rocket Stove for Charcoal pdf
Preliminary Fuel Use and Emissions Test Results:

    Wood Stove
Benchmark
Charcoal
Rocket
(Without
Skirt)
Ghana
Charcoal
Stove
WFP Wood
Rocket
(with Skirt)
Time to Boil min - 22 29 22
Fuel to Cook g 850 604 675 733
Energy to Cook kJ 15,000 23,983 26,089 12,579
CO to Cook g 20 12 74 15
PM to Cook mg 1500 81 85 1289

Dean Still and Brad van Appel, Aprovecho Research Center, January 1, 2002

The Effect of Material Choice on the Combustion Chamber of a Rocket Cooking Stove: Adobe, Common Brick, Vernacular Insulative Ceramic, and Guatemalan Floor Tile (Baldosa)

The Search for Vernacular Refractory Materials

Multiple tests of the Lorena stove beginning in 1983 at the Aprovecho Research Center have shown that placing thermal mass near the fire has a negative effect on the responsiveness and fuel efficiency of a cooking stove. In 1996, Leoni Mvungi built a Rocket stove from earth, sand, and clay that was a replica of a low mass Rocket consisting of metal chimney parts. His version weighed hundreds of pounds even though the Rocket internal chimney was only eleven inches high. Tests of a low mass sheet metal version scored around 30% fuel efficiency. But the best result achieved by the Mvungi stove was around 15%.

Building Rocket stoves from sand and clay showed little promise of improving on the three stone fire which was scoring around 18% in repeated boiling tests performed by Jim Kness and Dean Still (1994). Unfortunately, metal stove parts also have a major drawback in that the high heat in the combustion chamber quickly destroys thin metal. Consultants were in agreement that a good stove should last for years without requiring maintenance. Replacing metal parts as they wear out was not considered a viable solution.

A women's co-operative in Honduras (Nueva Esperansa) makes ceramic stove parts that have a reputation for working well in stoves. Aprovecho consultants Mike Hatfield and Peter Scott contracted with this group to produce combustion chambers for the Dona Justa plancha stoves that they helped to design. This material seemed to work well and, in fact, the Rocket elbow made by Nueva Esperansa has been successful in Honduras and Nicaragua. It is difficult, however, to deliver the fragile combustion chambers without breaking them. Also they are relatively expensive, costing about eight dollars each.

Don O'Neal (HELPS International) and Dr. Larry Winiarski have shown that cast iron combustion chambers, which do last, also have problems. Tests showed that the very conductive cast iron made the fire hard to start. In fact, a group of indigenous Guatemalan women stove testers living in Santa Avelina were unhappy with the expensive cast iron combustion chamber and asked for it to be replaced. They wanted a more responsive stove that started quickly, and quickly cooked food in the morning. Don and Larry eventually found an alternative material: an inexpensive Guatemalan ceramic floor tile (called a baldosa in Spanish) which seemed to function well when cut up to make the walls of the Rocket combustion chamber. The baldosa was about an inch thick so the combustion chamber only weighed eighteen and a half pounds. Like all Rocket combustion chambers it is surrounded by insulation, either wood ash or pumice rock.

The baldosa tile has done well in test stoves. It seems to be durable, lasting a year so far, and the group of testers from Santa Avelina reported that their stoves are much improved. The ceramic material made the stove much quicker to heat up. The women approved the improved stove for general dissemination to neighbors and other villages. The HELPS molded griddle stove now uses a preformed ceramic combustion chamber made by a local baldosa manufacturer. Unfortunately, all baldosa are not equally resistant to heat and it's important to test tiles before using them in stoves.

Appreciating that ceramic seemed a promising material for Rocket combustion chambers, Ken Goyer, an Aprovecho Board Member and consultant, spent a year, 2000-2001, testing ceramic mixes. His research resulted in a vernacular insulative ceramic material (VIC) that is refractory, insulative and can be home made. Six bricks made from this material combine to make a complete Rocket combustion chamber. Making the chamber from separate bricks has resulted in a greatly reduced tendency to crack. The bricks have held up so far in durability tests and they seem to create a very active fire.

The purpose of this paper is to describe the results of experiments involving same sized brick combustion chambers made from adobe, the insulative ceramic mix and common ceramic brick material. All bricks shared the same dimensions. Six bricks (11 ½" high by 2 ½" thick) made up a hexagonal cylinder surrounding a four inch in diameter chimney. Sticks of wood entered the bottom of the chimney through a hole sawn in the bricks. A combustion chamber made to similar dimensions was constructed using baldosa tile bought in Guatemala. Vermiculite filled in around the baldosa creating a combustion chamber with approximately the same dimensions as the brick stoves.

Protocols for Standard Stove Tests Using PICO Software

The First Sixbricks Rocket Stove in Darfur
Ken Goyer, AID Africa, Dan Wolf, International Lifeline Fund,September 4, 2006

Yesterday we had our first demonstration of the SixBricks Rocket stove in North Darfur. We had successfully fired about 1,000 of our special lightweight bricks using a local brickmaker, and now we have now started to show off the stove. Our first demonstration was a huge success. While the demonstration was intended to show the stove to a few nonprofit organizations, about 100 women came and took over the cooking action.The local staple food, aceda, was made in the largest round bottomed pot and then meat and sauces were cooked in other pots. The surprise was that after cooking this large and rather complicated meal, two thirds of it was handed over the fence and spirited away into a hut where some men were gathered. So the women were left with very little to taste. None the less they were very happy with the performance of the stove.

The political situation here remains touchy and for various reasons we will not travel to Kebkabia. Instead, we will stay here and work in El Fasher for now. Next, we hope to start a demonstration stove project in a camp which is actually a part of El Fasher. This way, access is easier, and it is safer, and still there are 32,000 people there, desperate for fuel with no trees in sight. Traveling even to the closest outside camp requires permits and permission and some worry about personal security or at least the theft of your vehicle by various rebel groups.

I have attached two photos to this email. The first one is of the stove and the second one is looking the other way at the crowd. Dan Wolf, founder and director of the International Lifeline Fund, and the benefactor of this project, has decided to rename the stove the "Miracle" Stove. I told him that it should be called the "Science" Stove, but that name just doesn't have quite the same ring.

Thanks to everybody who has made the invention and development and dissemination of this stove possible. The fruits of our labor are about to ripen.

Best regards, Ken Goyer

The Sprocket Rocket (pdf) (Uganda)
Ken Goyer June 4, 2006

Ken Goyer describes the "sprocket rocket" charcoal stove and its use in Uganda.

This is a bicycle sprocket. I was visiting a camp near Lira and this woman came along holding this sprocket. She said that she was planning to make a Sprocket Rocket and that she had paid 1000 shillings (about 54 cents) for it.

File attachments: 

Manual clay ring forming machine for making the combustion chamber of a small single-pot Rocket Stove.
New Dawn Engineering
Crispin Pemberton-Pigott June 2 2006

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