高分子材料の燃焼性状に関する研究: 小型UFAを用いた米松の燃焼試験による考察

摘要

本研究では，小型UFAを使用した燃焼試験の結果，以下の知見を得た． 1）燃焼性状 酸素濃度21%～15%の実験条件では，“有炎燃焼”となり，酸素濃度12.5%の実験条件では“燻焼燃焼”なった．全実験条件で，米松からの熱分解ガスの発生終了後に“木炭の無炎燃焼”となった．%Database currently being applied to the fire modeling has been mostly based on the data on free burning. It means that the free burning data may result in under-predict of fire propagation and smoke toxicity. In fact, oxygen and thermal condition within a compartment fire is unsteady. Therefore, growth, flashover, fully-developed and decay period fire data is actually nec­essary depending on which period the fire research investigates. Fire data should be experimentally measured and input into the database to reconstruct the fire scene as many as possible. Time to ignition, mass loss rate, yields of carbon monoxide (CO) and carbon dioxide (CO_2) of Douglas fir for each grain direction depended on the thermal and oxygen condition (Xo2(volume fraction of oxygen) = 21-12.5 vol% and Φ (equivalence ratio) = 0 - 0.3) were investigated using the small scale Universal Flammability Apparatus (UFA) which reproduce thermal and oxygen condition in a compartment. Time to ignition of across the grain is twice as much as the one of along the grain. This is attributed to the difference of thermal conductivity for each grain direction. Mass loss rate of Douglas fir shows char layer above live Douglas fir relative to PMMA controls radiation feedback from flame to the fuel surface. Carbon monoxide yield as a function of oxygen concentration and equivalence ratio is different for across and along the grain as well as time to ignition.