EFFECTS OF SECONDARY AIR INLETS OF DIFFERENT HOLE PATTERNS ON WOOD BURNING COOKSTOVE PERFORMANCE

Abstract

Billions of households worldwide cook using biomass fires and suffer from the toxic smoke emitted into their homes. Laboratory studies of wood-burning cookstoves demonstrate that secondary air injection can greatly reduce the emission of harmful air pollution, but these experimental advancements are not easily translated into practical cookstove designs that can be widely adopted. This study was conducted at Haramaya University on four designed and constructed sleeves of different secondary air inlets hole patterns (two circular, one spiral shape and one of vertical). In the study five wood burning cookstoves were used, four with secondary air inlet inner sleeves and one without inner sleeve (control). Comparisons were made in terms of onset of cooking and effective cooking times. The findings indicate no benefit of secondary air inlet in terms of onset of cooking. However, there is a glimpse that secondary air inlet at a proper location (but not too close to the rim or the bottom of the pot) can positively impact effective cooking time. In the current study the proper distance was 3 cm from the rim. More studies are required to pinpoint the exact location by trying distance such as 0.5 cm up to 3 cm. additional tests could also be done by varying the diameters of the secondary inlet holes.