A project of Volunteers in Asia . oodstove -Rend= Published by: Eindhoven Institute of Technology Woodburning Stove Group P.O. Box 513 5600 MB Eindhoven The Netherlands Paper copies are $ 12.00. Available from: Eindhoven Institute of Technology Woodburning Stove Group P.O. Box 513 5600 MB Zindhoven The Netherlands Reproduced by permission of Eindhoven Institute of Technology. Reproduction of this microfiche document in any form is subject to the same restrictions as those of the original document. a woodstove compendi bY G. De Lepeleire K. Krishna Prasad P. Verhaart P. Visser prepared for the technical panel on fuel wood and charcoal on the U.N. Conference on new and renewable sources of energy Nairobi Aug. 81 a publication from the wood-burning stove group, the Netherlands. a woodstove compendium bY G. De Lepeleire K. U. Leuven University Belgium K. Krishna Prasad P. Verhaart P. Visser Eindhoven University of Technology, The Netherlands Prepared for the technical panel on fuel wood and charcoal for the U.N. conference on new and renewable sources of energy Nairobi, Aug. 1981. A publication from the wood burning stove group Eindhoven University of Technology Postbus 513 5600 MB Eindhoven The Netherlands Preface To live, man must eat. To be edible, food must be cooked. For more than half the world’s population, living in the rural areas or the cities of the third world, fuelwood and its derivativt, charcoal, are as essential to survival as food itself. The problem of fuelwood is more menacing than is usually realized. Unless adequate measures are taken, the fuelwood supply for some 1000 million people will be so critical by the year 2000 that they are no longer able to cook their food adequately. A further 2000 million or more will then be facing similar critical shortages within one or two decades. As more wood is cut, deserts will spread. We may be heading for a famine worse than any known famine in history. For the large majority of the populations involved, there is no alternative to using wood, charcoal or agricultural waste: in the current international economic order, imported fossil fuels are too expensive, and the infrastructure to ensure their availability is lacking. Increasing the supply of the biomass fuels, and using 3 them more efficiently, will be vital tasks in the coming decades. It is not widely known that in developing countries roughly three times as much fuel per person is used for the cooking process as in the industrialized nations. The main reason is the poor fuel efficiency of the traditional stoves. Many proposals for better stoves have been made, but up to tile present few have shown proven performance or have received widespread acceptance. There is no doubt, however, that much improved fuel use is possible. In the coming decades, many people all over the world will be work’pg on designing, manufacturing and introducing improved cooking stoves. In asking for this compendium to be prepared, our Technical Panel has aimed at creating a tool that would be of use to all these workers, and to all those who have the responsibility for initiating, funding, managing and evaluating projects in this field. For this task, we were fortunate to be able to call on the expertise of a number of scientists closely associated with the Woodstove Group at the Eindhoven University of Technology. It is largely due to their initiative that this compendium has been expanded from a simple survey of existing literature to the present form, which evaluates both the present atate of our scientific understanding and the still considerable gaps in our knowledge. The subject of cooking stoves is entering a period of rapid development. One can expect that, within a few years, the transition from ‘art’ to ‘science* and ‘idea’ to ‘practice’ will have proceeded far enough for some future compendium to be able to present what at this moment is still lacking: explicit guidelines for stove design, and explicit recommendations of proven designs. This compendium has been prepared for the Technical Panel on Fuelwood and Charcoal, one of the eight Technical Panels of the United Nations Conference on New and Renewable Sources of 4 Energy (UNERG), to be held in Nairobi in August 1981. The preparation, publishing and dissemination of this compendium was made possible by the financial support of the Netherlands government, to whom we express our thanks. We are also grateful for the constant support given to this publication by the Forestry Department of F.A.O.,which supplied the technical secretariat for our panel. Eindhoven, June 1981 Eric T. Ferguson Member of the Technical Panel on Fuelwood and Charcoal. Fifteen stove designs, together with relevant data were contributed by Mr.Stephen Joseph of ITDG, London. Sound practical advice from her experience as a field worker was given by Ms. Margo Bulk. Mr. Joan A. Boer contributed many useful suggestions from his experience as a Netherlands Volunteer. The authors think back with pleasure on the hours spent in fruitful discussion with these persons. We owe a special debt of gratitude to Mr. J.D.L. Harrison of the Energy Technology Support Unit at AERE Harwell for critically reviewing an earlier draft of the work. Our thanks go to Mr. J.J. Arts of the library of the Department of Architecture THE for doing the Bibliography, to Ms. Noor van Gerwen and Ms. Els van der Steen for the large amount of typing they did for this compendium and to Ms. Christine C. Schermey and Mr. Peter D. de Graaf for transforming sketches into decent drawings of stoves. A word of tha.nks too, to the printer of this compendium, Mr. Th. M, van Stiphout who kept assuring us that it would be finished on 7 time and did this so convincingly that we found the peace of mind to get the manuscript ready. In the same breath we must mention the enthousiastic help of the computer wizards of the Mechanical Engineering Department, Messrs. Jos Banens, Erhan Dukul and Lambert van Beukering who made it possible to transfer the contents of this compendium by telephone line to the printer’s word processor. The authors want to express their thanks to the Forestry Department of FAO and in particular to Mr. M.C. de Montalembert, who as Technical Secretary to the Panel made the arrangements to have this compendium prepared and actively stimulated our task by his constant interest. The infectuous enthusiasm for wood stoves, the neat balance required between our engineering daydreaming and the stark field realism, and the occasional harassment to finish the work on time - these and many patient hours of his time were supplied with an abundant measure of goodwill by Dr. E.T. Ferguson. A mere thanks is not compensation enough for his contributions to the work. Three of us (KKP and the two PV’s) look back with affection on the alacrity with which Guido De Lepeleire produced the many sketches that adorn this book, very much like a magician pulling rabbits out of a hat. Special mention must be made of our wives and colleagues for tolerating with cheer and forbearance our preoccupation with this work, much to their disadvantage. This work has taken a long time to come to fruition. Many friends and wellwishers have helped us in keeping our noses to the grindwheel with cries of ‘when will it be ready?‘. Our thanks for their enthusiasm. Eindhoven, 30 june 1981. 8 Errata We regret that many errors have crept into the text. These errata sheets provide corrections to only those that are likely to cause confusion. The authors. line/no page no 7 12 20 15 20 20 23 18 24 4, 5 38 49 53 54 56 96 133 159 209 255 20 8 22 23 8, 9 Ms. Noor van Gerwen analyzing nag attenton (VITA 1980 and Appro- vecho Institute 1980) possible for example GATE (1980) overleaf in the sketch below Shelton and Shapiro 1978 dimension 3720 3 24 29 21 This pot van have Simon, Soli 1976 Garberson An examination of figure 4.5. 257 2 257 5 257 23 259 20 263 6 265 6 266 4 Q, = F12A1 CT1 4-T24) Q r = T F,2A,(T,4-~24) is the Stefan- T is the Stefan- is a property of X is a property of for for different for different Z is max 266 268 12 I I The table below (Krishna Prasad, 1981) (8 < a ~16) = 18.900 kJ/kg. text - should read as ~-- Ms. Noor van Gemert analyzes not attention (VITA/ITDC 1980 and k0tt et al 1980) possible. For example Acott et al (1980) previous page in the sketch on page 55 Shelton and Shapiro 1976 372 This pot can have Simon and Solis 1976 Garberson (1979) An examination of figure 4.2. Z max (see figure 4.5) is Table 4.1 (Krishna Prasad, 1981 b) (8 c: Li c 20) = 18.700 k.J/kg. page no 270 270 273 299 309 309 316 318 318 319 321 327 327 354 Table 6.1 1 ine/no 9 10 17 3 23, 24 26 9 13 20 9 9 14 26 Table 6, 357 358 Mass Time Volume text The figure has I m.so8-’ (see figure 4.6) the following table r L than e few friction factor f V’ is the density f is the pressure heat input from table 4. square root of 2 12 x 1o-3 % = 29,5 = 406 cm2 of 5) k M G -2 ton (short) 9,072 x 10 Velocity ftlmin I 5,08 x clay cu. inch 1,639 x IO+ gallon (Brit.) 4,546 x gallon (U.S.) 3,785 x Sp. masd lb(cu. in. I Sp. Volume cu,ft./lb. 6,243 x IO’ I .___ should read A:, -.- Figure 4.8 has I m.s -1 (see figure 4.11) table 4.3 T than a few friction factor h V’ P is the density f l is the pressure heat input from table 4.3. square root of 1 12 x IO3 $ = 2g,5 = 406 cm2 of 6) k ?-I G lo3 lo6 IO9 ton (short) 9,072 x IO2 day -5 cu. inch 1,639 x IO gallon (Brit.) 4,546 x 10-j gallon (U.S.) 3,785 x 10v3 f tlmin 5,08 x lO-3 Ib/cu. in. cu. ft./lb. 6,243 x IO-’ Table 6.2 360 360 365 365 366 366 366 366 368 Heating value Specific heat Mass flow Heat flux Heat conduc- tivity 9 7 '5 '1 16 17 '9 22 7 I 4 10, 13, 16 I text r...., - _i- Btu/lb. 2,324 x Cal/g 4,186 x Btu/lb. F 4,186 x IO kcal/kg C 4,186 x '0 kglmin 1,667 x lb/min 7,56 x '0 Btu (m.sq.ft) Btu. in/(sq.ft.h.F) 1,441 x kcal/(m.h.) K = $ F = + 255,37 Ahuja, S.B.C. Home Information Series Sahel Iran zone Anon (1978) Preliminairy Anon (1979) (a) Aton, C., Brown, M. and MC Gowan, T. Corlett Eckert and Drake Emmons Evans, J. K&mer, K.K.H. should read as Btu/lb. 2,324 x IO' Cal/g 4,186 x IO3 Btu/(lb.F) 4,186 x IO3 kcal/(kg C) 4,186 x 10' kg/min 1,667 x lo-' lb/min 7,56 x 'O-3 Btu/(h.sq.ft.) Btu. in/(sq.ft.h.F.) 1,441 x 10-l kcal/(m.h. 'C) K= 7 F + 255,37 9 Ahuja, S.B.D. Home Science series Sahelian zone Shelton, J.W.,Black, T., Chaffee, M. and Schwartz, M. (1978) preliminary Saubolle, B.R. (1979) Aton, C.L., Brown, M.L. and MC Gowan, T.F. Corlett, R.C. Eckert, E.R.G. and Drake, R.M. Emmons, H.W. Evans, I. K%mner, K.K.H. ('980) ._ --- .., -..._ ,_( page no 376 9 377 7 378 I 378 ‘6 378 ‘7 line/no text Saubolle, B. Silva, D. da, Vandele, L. Williams "Condenset.... 1 f :bculd read as Saubolle, B.R. Silva, D. de, Vandaele, L. Williams, F. "Condensed.... Additi&s to the bibliography: Eckholm, E.P. (l9/$. "Losing ground: Envir?unental stress and world food prospects. W.W. Norton & co., New York. --- 7_ - 'I Bussmann, P.J.T. ('98') Personal correspondence, University of Technoiogy, .T Eindhoven. VITA/ITDG ('980) Wood conserving cookstoves. pp. Ill. VITA (Volunteers in Technical Assistance), Mt. Rainier, Maryland. tent 1 Introduction 2 A common sense stove guide 2.1 The use of heat in preparing food 2.1 O 1 Introduction 2.1.2 Boiling 2.1.3 Frying 2.1.4 Grilling 2.1.5 Baking 2.2 Understanding woodfires and stoves 2.3 Choosing a stove 3 Design descriptions 3.1 Overall classification of stoves 3.2 Design data sheets Tools and Skills Lifetime Safety Space Heating Cleaning and Maintenance Efficiencies 3.3 Conversion of data sheets