Construction Steps for an Institutional Stove
For a 40 cm Pot
This design is for outdoor cooking for an institution with a large number of people. A flue pipe could be added for indoor use, which was done by the Hines Uganda Ministry with great success (see calculations for changes). It is assumed that the technician is a mason and has constructed the family stove. The design is very robust and any pot having a diameter of 36 to 44 cm should work satisfactory.
Step 1. Base
Construct the base of the stove that is 66 cm wide (front) and 56 cm deep. The height of the base is a function of the overall height of the stove. For an overall height of 80 cm, the height of the base would be 36 cm. The base can be constructed of adobe (A), regular brick (RB), or cinder block (CB). Depending on the condition of the soil, it may be desirable to have an 8 cm concrete base.
Step 2. Combustion Chamber
The construction of the combustion chamber is the same as for the family stove except for the width. The rear brick is 19.3 cm, which makes a bigger combustion chamber, as shown in Figure 2 below. The overall width of the second level is 34.5 cm; therefore, the first level must also be 34.5 cm, which it is. Figure 3 and Figure 4 are the same as Figure 4 and 5, respectively, in the instructions for the family stove.
|Figure 1||Figure 2|
|Figure 3||Figure 4|
Step 3. Regular Brick Addition
Regular bricks (shaded ones) of same dimensions as the fire or insulative bricks are placed as shown in Figure 5 with the front one having its 11.5 cm dimension against the combustion chamber and the other three having their 7.6 cm dimension against the combustion chamber. All four piers are 3.5 cm above the top of the combustion chamber. The pot will rest on the top of these bricks and the pot skirt will be embedded in them as per the pot skirt step. Cut the four regular bricks in a curve with a depth of cut of 3.5 cm as shown in Figure 6. The front brick should only have material removed from the edges and not the center of the curve. The diameter of the pot skirt is 3.5 cm larger than the diameter of the pot, which should be 40 cm +/- 4 cm. Thus, there is a gap all around of 1.75 cm between the pot and the pot skirt. Fill the volume from the base to the top of the combustion chamber with A, RB, and/ or CB that is mortared. Thus, the dimensions should be about 55 cm in the front and about 42 cm from front to back.
|Figure 5||Figure 6|
Step 4. Pot Skirt
Install the pot skirt as shown in Figure 7, which will be about 140 cm long. The height of the pot skirt will be 1 cm more than the height of the pot and the top of the pot will be 2.5 cm above the pot skirt, because 3.5 cm of the pot skirt is embedded in the four piers. The pot skirt will be off center a few centimeters; however, this should have a minimal effect on the efficiency.
Step 5. Completed Stove
Fill the volume behind the pot skirt with mortared in pieces of A, RB, and/or CB and finish the top and outside with stucco. See Figure 8 for the finished stove without the shelf. Allow the mortar to dry at least one day and preferably two, then follow the user guide.
If a grate is used across the top of the pot skirt, then a large frying pan could be used; however, it will probably be inefficient.
|Figure 7||Figure 8|