The effect of boiling point on fuels with carbon dioxide hydrate

This study aims to experimentally elucidate the fire extinction mechanism by the carbon dioxide hydrate in detail. The effect of the boiling point of fuel on the fire extinction by the carbon dioxide hydrate is focused. The extinction of the laminar flame formed over a fuel pool in 27.2mm diameter and 15mm depth fuel container by the carbon dioxide hydrate is observed. Temperature variations in the fuel and the air region above the fuel surface are measured by K type thermocouples to discuss the cooling effect. Methanol, Ethanol, 1-Propanol, 1-Hexanol are used because the boiling point are 64.7°C, 78.4°C, 97.4°C, 157°C respectively. Ice and dry-ice are used as the extinguishing agent to compare with carbon dioxide hydrate. Endothermic quantity per unit mass of dry ice is almost the same in fire extinction each fuels because the cool effect of dry ice is only the heat of sublimation. On the other hand that of carbon dioxide hydrate and ice is increased in the order of the boiling point. These results indicate the evaporation of water dissociated from hydrate and ice is more active in the order of fuel boiling point. These results suggest that the evaporation of water plays an important role for fire extinction by the carbon dioxide hydrate.