IMPROVED BIOMASS COOKSTOVE PROGRAMMES:FUNDAMENTAL CRITERIA FOR SUCCESSMA Rural Development DissertationAugust 1999Jonathan RouseSupervised by Richard BlackThe Centre for the Comparative Study of Culture, Development & the EnvironmentThe University of SussexPage 2SUMMARYThis paper examines the design of improved biomass cookstoves and the content ofprogrammes that facilitate their effective use and dissemination. The primary aim of improvedcookstove programmes is to improve the overall efficiency of the cooking process.Fundamental technical and practical methods of achieving this are discussed and consolidatedin this paper. Conflicts resulting from balancing technical perfection and user needs are alsoexplored. Finally, a number of the author’s ideas are proposed as further improvements to theeffectiveness of stove programmes.This paper is primarily a technical piece of writing. It is intended to have the potential foradaptation to a guide relating to the fundamentals of stove design and programme planning.Front Cover Pictures.The Traditional Three Stone Fire and The Ceramic Jiko Improved Charcoal Stove. (Kammen 1995).Page 3TABLE OF CONTENTS1. INTRODUCTION TO IMPROVED BIOMASS COOKSTOVE PROGRAMMES................................... 91.1 SHIFTS IN EMPHASIS OF OBJECTIVES ................................................................................................................ 91.1.1 Environmental Objectives.......................................................................................................................... 91.1.2 Human Welfare Objectives........................................................................................................................ 91.2 COMBINING OBJECTIVES ................................................................................................................................. 101.2.1 Improving the Efficiency of Combustion............................................................................................... 101.2.2 Minimising Cooking Times..................................................................................................................... 101.3 EXTENSIONIST AGENDAS ................................................................................................................................ 111.4 BENEFICIARY AGENDAS .................................................................................................................................. 111.5 SUMMARY .........................................................................................................................................................152. THE STOVE DESIGN........................................................................................................................................ 162.1 COMBUSTION THEORY .................................................................................................................................... 162.1.1 Measuring Efficiency.............................................................................................................................. 162.2 THREE STONE FIRES ........................................................................................................................................ 172.3 PRINCIPLES OF DESIGN....................................................................................................................................172.3.1 Fuel Efficient Combustion in Improved Cookstoves............................................................................. 182.4 TECHNICAL PERFECTION AND USER NEEDS ................................................................................................... 182.4.1 Flexibility Issues...................................................................................................................................... 192.5 THE FIREBOX ................................................................................................................................................... 212.5.1 Size........................................................................................................................................................... 212.5.2 Insulation................................................................................................................................................. 212.5.3 Shape....................................................................................................................................................... 232.6 POT - STOVE INTERFACE .................................................................................................................................242.6.1 View Factor and Thermal Radiation...................................................................................................... 242.6.2 Shielding and Thermal Convective Transfer.......................................................................................... 252.6.3 Interface Shrinking Rings....................................................................................................................... 262.7 VENTILATION................................................................................................................................................... 262.7.1 Primary Air and The Grate.................................................................................................................... 262.7.2 Secondary Air.......................................................................................................................................... 272.7.3 Variable Ventilation................................................................................................................................ 282.8 CHIMNEYS........................................................................................................................................................ 292.8.1 Dampers.................................................................................................................................................. 293. FUEL-SAVING STOVE OPERATION TECHNIQUES...............................................................................313.1 AIR VENTS ....................................................................................................................................................... 313.2 FUEL USE