| Boiling Point No. 05 - September 1983 |
'MODERN STOVES FOR ALL' by Waclaw Micuta is currently being revised and is expected to be published in the near future. m e revision has keen commissioned by the French organisation GRET/GERES. m e principal modifications are the inclusion of a new chapter devoted to 'cooking methods', and extended sections on the preparation of clay materials and stove testing. A new Kenyan Jiko charcoal stove is included, and a chapter on the use of charcoal. In addition, the specifications of the 'Pogbi', 'Polish', and 'Crescent' stoves have been improved in the light of field experience.
During a trip to Kenya earlier this year Mr Micuta, and his colleague Emil Haas, developed 'communal' stoves to meet the needs of schools, dispensaries, hospitals, and similar institutions.
Two versions are described. Both are constructed according to the same principles and techniques, only the dimensions differ. As can be seen from the drawings, they are based on the 'Polish' and 'Crescent' models. m e first is a universal version equipped with a 42 litre pot for all purpose cooking. The second has been modified for 'Ugali' preparation, which requires a sturdy, relatively shallow pot, with a large diameter. m e clay and brickwork involved presents no major difficulties for trained masons. Once all the materials have been prepared, one mason working with 2 helpers should be able to construct a plinth and stove within 2 days.
The firewood economy achieved was considerable. For example, the cooking time for dry beans was reduced from 4-5 hours to 15-30 minutes. This dramatic reduction in cooking time is also due to the fact that the beans were pre-soaked.
In use it is not necessary to put more wood in the stove after the food has boiled. Instead the door should be closed and a bag of hay placed over the covered pot. The stove then acts as a hay box. When any foodstuffs were pre-soaked the consumption of firewood needed to cook a meal of beans and dry corn could be reduced from approximately 50kg to 6kg.
Stove Testing in Kenya
In Cookstove News Vol. 2 No. 3 Stephen Joseph outlined the results of 'Ugali' cooking tests carried out on a range of stoves at Ruthgiti in the Karai District of Kenya. Since then a series of follow-up tests have been carried out by Joseph Ngugi. Joseph Njoroge and Janevah Wanijiku, trainees of Waclaw Micuta (Fondation de Bellerive). The cooking tests were carried out with maize and beans to establish the performance of the stoves for a meal that takes up to 3 hours. A mixture of half each of maize and beans was cooked with water in Pot 1. Unfortunately, uniform quantities of food and water were not used in testing each stove. However, a consideration of the Specific Fuel Consumption ratios allows reasonable deductions to be made on performance.
The cooking test was carried out on the following stoves
- open fire
- Pogbi (2-pot chimney stove)
- a shielded open fire
- two modified Tungku Lowon stoves (I and II in the Table) - 2 pot chimneyless stoves.
It should be noted that only the open fire, the Pogbi and shielded fire were previously tested with 'Ugali'.
The Table below shows the results obtained.
Summary of Conclusions
It can be seen that the new stoves cook faster than the open fire, even when taking into account the differing quantities of food processed. When only Pot 1 is considered, it appears that the modified Tungku Lowon models used significantly less wood than the open fire. If the second pot is considered then both the Pogbi and the chimneyless stoves are far more fuel efficient than the well tended open fire.