The rocket-lorena stove is a two-pot rest stove and has an efficient conversion chamber which requires very little fuel. It has a firewood chamber and a chimney which further improves efficient burning. It can be made from locally available materials and so is affordable.
It is a great improvement over the normal three stone stove, that is common in villages, because of the vastly reduced fuel consumption, it simplicity to use and the short time it takes to cook food. The chimney mechanism reduces smoke and associated problems and it is firmly attached to the ground meaning there is less risk of injury occuring from spillages or accidents.
Its disadvantages are that it is less portable than the three stone stove and occupies a larger space. The rocket-lorena normally takes a number of hours and several people working to finish. That said once built, it is long lasting and durable (at least 10 years).
Material for firewood shelf - thin metallic steel or fired clay slab
Water - as appropriate for wetness of soil
It is best to build during the dry season as the stove once build takes several weeks to dry and be ready for use. In the dry seasion this happens much quicker. The stove is best build as a community effort by getting a group to work together to gather and build the stove from the raw materials.
Preparing Materials
Mix one wheelbarrow of anthill soil with one wheelbarrow of sawdust - add water gradually and knead the mixture as water is added * The mix is ready when it has a firm mortar like consistancy
Mix two wheelbarrows of soil with one wheelbarrow of sand/silt
Add water gradually and knead the mixture as water is added - the mix is ready when it has a firm mortar like consistancy
The reason that these two different mixtures are used is that the soil/sawdust mixture holds heat well and can hence improve the efficiency of the stove. The soil/sand mixture is less efficient and is hence used for the main structure of the stove
Construction
The stove is the process of being built
A plan of the stove is shown below for guidance (to follow). The exact dimensions depend on the size of pots that the villager has available. It is best to use what is available. This stove holds two pots, one needs to be smaller than the other.
Foundations
As the stove will be locate in a hut over a long period it is best to position the stove in a corner and on a reasonably flat setting.
First mark the area for the stove.
Pour water on the foundation area.
Add a layer of soil/sand mixture and then lay 1 layer of bricks.
The bricks should be separated by approx 1cm, in between the bricks, fill with soil/sand mixture like building normal wall.
Position the firewood chamber
The firewood chamber need to be set now. This will be below the position of the first pot (see diagram). Measure this position, it will be approximately 15cm + half the diameter of the first (largest) pot.
Get two bricks and wrap each in plastic bags. Fix the first in position to form what will be the firewood chamber and the second to form what will be the conversion chamber.
Building the main stove
Build up the structure to the appropriate height using bricks and the mixtures as mortar.
Wherever heat is likely to be transferred use the soil/sawdust mixture rather than the soil/sand mixture. (e.g all around the firewood/conversion chamber bricks).
Put the pots to be used in place and complete the stove, building around them.
You will need to hollow though between the pots and then through to the chimney.
Build the chimney, it needs to be 1-2m high. This pull the heat through the combustion chamber to the second pot.
Final Touches
The firewood/combustion chamber can now be completed by removing the bricks to leave a hole for these chambers
Fix the firewood shelf in position
The stove needs to be left to dry for several weeks. If used prematurely it will crack and will not last so long
After several weeks the stove will dry. The materials will naturally crack to some extent, any cracks can be filled in making more of the soil/sand mixture and filling.
Diagrams
Dimensions of the stoveCross section of the stove all measurements in cm
(big respect to google sketchup for making drawing 3d models free and simple)
Uses
Completed stove
This above stove is used in several locations in Uganda. It is the standard design used by the appropriate technology centre (ATC) in Mbale, East Uganda, and passed through to the rural villages within the region.
