The Accident Example of Fireworks Manufacturing Factory and Blast Wall Tests

摘要

The annual number of the fireworks accidents is 0～ 3 at manufacturing plants and a-bout 20 among consumers. There are far more accidents among consumers than during manufacture, however, terrible accidents occurred at fireworks factories in Ibaragi prefecture in 1992 and Kagoshima prefecture in 2003. Three employees were killed and 58 residents near the factory were injured in the 1992 accident and 10 employees were killed and 4 persons living near the factory were injured in the 2003 accident. The problems of security in the fireworks industry are discussed here. Ministry of Economy, Trade and Industry of Japan consigned the planning and the execution of the field experiment concerning the safety of the fireworks factory to the Japan Explosives Security Association. Some kind of fireworks compositions might explode very intensely if covered with the flame due to the accident. An intense explosion of the fireworks composition was obtained by strengthening restraint with the container. Some kind of fireworks compositions was exploded and the causing combustion distance and the shape of the crater were measured. The blast pressure was measured also, and the pressure profile was obtained. Further, the explosion phe-nomena were taken with the normal speed camera, the high-speed camera and the infrared camera, and the flame growing process was understood. The standard blast wall and the high performance blast wall developed were prepared. The effectiveness of the blast wall to the blast wave and the causing combustion was examined. Further, the strain of the surface of the blast wall and the reinforced rod was measured and the damage of the blast wave and the cracks on the surface were observed after explosion. An appropriate blast wall for the work room at the firework factory was considered based on acquired data.