|Boiling Point No. 20 - December 1989 (ITDG - ITDG, 1989, 40 p.)|
The Anagi II ('excellent' in Sinhalese) is a ceramic stove from Sri Lanka. It has been designed to burn mainly rubber wood but can burn other woods and coconut husks equally well. There are 2 pot positions and only one fire box and the emissions and excess heat escape around the second pot. A connecting tunnel between the firebox and the 2nd pot hole distributes about 1/3 of the heat output to the second pot hole, sufficient to maintain gentle boiling.
Most retail hardware shops in Sri Lanka now stock the Anagi II stove which is distributed from the producers' tile factories by wholesalers. The stove can be used as sold but its life can be extended from 6 months to 4-5 years by covering it with a layer of clay or cement about 5cm thick. The stoves retail at about US$ 2 and in normal use pay for themselves in 2- 3 months if fuelwood is purchased.
The purchasers have been mainly middle-income households who appreciate its practical convenience as well as its saving of about 1/3 of the cooking time and 1/3 of the fuel consumption.
History and Experience
The Anagi II has evolved out of a long-standing partnership of
Sarvodaya, the Ceylon Electricity Board and ITDG. In 1984, a rural stove
programme was started and to date with the aid of some subsidies has produced
over 200,000 stoves of a simpler design in 2 pieces. In 1987, an urban stove
programme was initiated involving a more sustainable system of larger-scale
production and distribution. The stove was re-designed to the present day
configuration in 1988-9 and sales reached levels of 60,000 per annum on a wholly
commercial basis. This programme will now be extended to rural areas so that
subsidies can be withdrawn.
The Anagi II stove is made by potters and skilled assemblers. Three cylinders are thrown on a potters wheel and slip-jointed together after a short drying period - normally one day. Features such as pot rests and strengtheners are pressed in plaster moulds so as to ensure accuracy and uniformity. Special drying boards are used to minimise distortion during drying. When dry the stoves are fired in down draft kilns along with other ceramic products such as tiles and sewer pipes. Identifying the most crack-resistant clays has been a problem for the project. The results of destructive testing of stoves with different mixes show that over-firing is the main cause but under-firing must also be avoided.
Use of the Stove
The fuel is fed in at the side of the large pot hole and both cooking positions are immediately in front of the cook. The smaller pot hole is used for simmering and small pots and kettles can be rested on the 3 rest supports inside the large pot hole when the fire reaches its char burning phase.