|BASINTUTHU BAKING OVEN|
In a significant technical development for the low priced stove market, NDE started marketing a new wood burning Basintuthu Baking Stove.
The design is aimed at the informal food sector. It incorporates the Basintuthu fire grate and adds a novel air control The result is a well proportioned, remarkably fuel-efficient stove. Weighing in at 40 Kg it features a 6mm steel plate top, all welded construction, two pot holes (185mm and 155mm diameter) and a one metre chimney at the back.
The fire grate is a tapered vertical cylinder with primary combustion taking place inside the lower part. A shroud pipe (secondary air tube) passes air up the outside of the hot grate to be heated and injected into the primary combustion smoke. The secondary air reaches 300 degrees C before burning the smoke efficiently for a clean secondary combustion at 750-850 degrees in the upper grate area.
A horizontal sliding damper below the shroud gives a fire intensity range of about 7:1 between open and closed.
Loaded with 250 to 1000 grammes of large weeds, twigs or branches, the oven typically reaches 180 degrees in 20 minutes. With a medium-full firebox at an ambient temperature of 25 deg C. The oven can reach 180 deg C in 10 minutes. To keep it below 200 deg C it is necessary to run on about 5% air at the opening.
The oven (400 x 315 x 200mm) is sized to bake bread (3 loaves) muffins (12 x 2) and patty cakes (up to 36). A steel handle running along each side enables the stove to be moved easily. These also serve as towel racks or to mount an optional hot water tank. The stove also has a removable chimney.
It is a small, inexpensive stove with an oven large enough to bake three loaves of bread at once, or two trays of muffins which will fit inside a 300mm x 400mm space.
The advantages of the stove over other wood burning products are a high fire efficiency, a chimney pipe fitting and a low cost.
Many modern rural households have a coal stove of standard construction. When used to burn wood instead of coal, fuel consumption is typically doubled! An open fire with three stones and a pot sitting on them is much more efficient than a coal stove with a wood fire lit briefly to cook one meal.
The reason for this is that the stove is massive and absorbs a lot of heat before it delivers any through the top to a pot. There is usually no structured secondary combustion and no preheating of the secondary air that does manage to ignite primary combustion products.
The use of a Tsotso burner in a small baking stove offers the high efficiency of a Tsotso Stove (20+%) with the convenience and income saving/generation of a small stove. It uses a small amount of fuel to get going and offers the best efficiency together with a low cost design.
Back/Side View of stove
Fresh muffins baked in the oven
Fresh scones baked in the oven
Inside of oven:
Outside of oven: