Tanzania Environmental Health
Insulating ceramic rocket stoves are fabricated using small curved bricks
Projects with the stoves will be largely independent of outside support. Clay workers who produce the small curved bricks of the stove may be independent, much the same being true of their neighbors who fabricate the stoves. Rural entrepreneurship is a vital outcome, making possible proliferation of the technology.
Ceramics in environmental health is vital!
In the developing world the two most apparent problems with environmental health involve drinking water and clean air around cook stoves. Waterborne illnesses and deaths are due to pathogen contaminated drinking water and respiratory illnesses are caused by smoke and fumes around cook stoves. Both of these environmental health challenges are addressed squarely by sustainable ceramic approaches: insulating ceramic rocket stoves and water filter media and systems of granulated ceramics.
These are thoroughly sustainable approaches and as such are remarkably low cost and easily reproducible; uniquely appropriate, and arguably state-of-the-art as such. Projects with these can be undertaken by rural clay workers, given proper guidance, bringing about rural entrepreneurship in the process.
Tanzania Environmental Health Update
February 21, 2019
In the March, 2019 issue of Ceramic Bulletin, membership magazine of the American Ceramic Society, is the article, Reducing air pollution: Insulating ceramic rocket stoves. Scroll down to page 22 at the PDF link, http://ceramics.org/wp-content/bulletin/2019/pdf/March2019.pdf
Why the rocket stove design? For burning sticks of wood for cooking, but preferably bio-mass, the rocket stove is far and away the most environmentally responsible alternative, sustainable as such. The rocket stove was introduced, through the NGO, Aprovecho. While burning wood is considered by some as damaging to the environment, in fact, the opposite is true, by comparison with the use of charcoal. While charcoal is the preferred fuel because it gives no smoke, its production requires ten times its weight in wood. Thus, the insulating rocket stove will help greatly in preventing deforestation!
Considering the shape of the combustion chamber, and the fact that the the cook pot fits down inside, no smoke is vented. Our improvement of the rocket stove design is in having made it sustainable: low cost with fabrication possible by rural clay workers. Because of this, the insulating rocket stove can be produced almost anywhere.
Side view of an insulating ceramic rocket stove
for small to medium cook pots, 24 to 48 cms. diameter
Note that for small to medium stoves the diameter of the combustion chamber is about the same as the height. The sides of the pot are 1.2 cms. (~0.5 inches) from the inside stove liner. Ideally, the top of the pot is 1.2 cms (~0.5 inches) above the top of the stove, but watch your fingers!
For the upcoming second phase of the Tanzania Environmental Health project, master molds for the special bricks of the stove, will be introduced, and these are shown. (Their shape is roughly trapezoidal.)
Here shown is the inside of the institution-sized rocket stove, built in Kibondo, Tanzania, in December 2016. This accommodates a cookpot of 48 cms. diameter.
Shown here is the stove under construction, the small curved bricks built up within a sheet metal cylinder. Rather than sheet metal, chicken wire is appropriate, and either of these allows the portability of the stove.
Above, at left, is a set of four, of the new master molds. These will replace the rubber faced master mold, shown at the right. These new, concentric master molds, are plastic, having been formed with epoxy putty. These master molds are used in forming, working molds, which resemble the plaster mold shown at right, at the top of the picture, and with these, the special bricks are formed.
Note that for a properly designed rocket stove, the cookpot fits down inside. Because of this, the only real disadvantage is that a given stove is appropriate to only one diameter of cookpot. Importantly, given the new master molds, shown above, it is readily possible to fabricate stoves that will accommodate cookpots, anywhere from 24 to 48 cms. diameter.
As above, at left, one of the new concentric master molds, is turned upside-down, and placed within cottles.
Together such cottles resemble a box, and this is of adjustable dimensions. Into this box is poured gypsum plaster, which upon setting gives a working mold (as shown above).
The working mold is then used to cast such bricks as those shown in the picture at right. These are black because the composition of the clay is fifty percent each, of powders of charcoal and clay.
In this outdoor kiln, curved insulating bricks are shown. For these, the charcoal has burned out, leaving voids. Thus, the bricks are insulating, and the exterior of the stoves are cool to the touch.
At left is a catenary arch kiln, under construction. Front and back walls, plus chimney were yet to be built Construction of this will enable production of granulated ceramic water filter material.
At the right is a wood form, upon which the bricks are built up. Note that pegs are placed under the four corners, prior to placing bricks. These are to be pulled out after brick placement, so as to remove the form.
Checkout the Rocket Stove Videos:
Three YouTube videos follow! These were put together in 2008, during a training in Indonesia. (If the links don’t open, probably due to your particular device, search YouTube by title.)
Building the pottery rocket stove.
https://www.youtube.com/watch?v=LXxmc6rU2-A
Cooking with the pottery rocket stove:
(Note that while these stoves burn bio-mass with no smoke at all, smoke can be seen in this video because of wind, swirling around the stove, pushing the smoke out while blowing into the entrance to the combustion chamber. Best to shield the entrance to the combustion chamber from any wind.)
https://www.youtube.com/watch?v=PdJB0lwwIpI
Construction of the outdoor kiln (for firing the special bricks of the stove):
