【摘要】 针对新一代超细高效粉体灭火剂的要求,构建了一套小型固定式粉体灭火装置,对3种粉体的灭火性能进行对比研究,通过扫描电子显微镜(SEM)观察粉体颗粒的粒径分布和表面形态,研究了粒径等因素影响粉体灭火性能的规律,指出了改性前后粉体灭火时间不同的原因。实验结果表明,与普通干粉相比,经改性细化的粉体的灭火时间缩短了1/2,灭火性能显著提高。更多还原

【Abstract】 The present article is concerned about the authors’ experimental research on the method to improve the property of the fire suppression agents. As is known, one of the most useful fire suppression agents, the traditional dry powder has been applied in portable fire extinguishers for years. When the production of Class I ozone depleting substances (ODS), such as Halon 1301, began to stop after adoption of the Montreal Protocol, dry powder is considered as a suitable alternative due to its environmental compatibility, fast fire extinguishing power and lower cost. According to the demands of the new clean and effective fire suppression agents, the present authors have built a laboratory-scale immovable fire suppression system, in which three kinds of typical powder are used, that is, the normal ammonium phosphate dry powder, sodium bicarbonate dry powder and superfine surface treatment sodium bicarbonate powder. Our investigation has been focusing on the relationship between the powder surface structure and the fire suppression effectiveness. The fire extinguishing time was recorded when powder types, particle sizes and working pressures were changed. The particle size of the powder and microcosmic structure of powder surface were observed through the electronic microscope scanning. And then the fire suppression mechanism of powder was also studied. Our research results show that there is a significant impact on the fire suppression effectiveness when the particle size is lower than 10 μm. Besides, the working pressure also proves to have influences on the fire suppression effectiveness. It was found that when the working pressure increased, the extinguishing time of the normal ammonium phosphate chemical and sodium bicarbonate powder would gradually decrease. Under the same experimental condition, kerosene fires prove to be easier to be extinguished when superfine and surface treatment sodium bicarbonate powder is used. By analyzing the results of the research, it can be concluded that the pressure, the particle size of the powder and microcosmic structure of powder surface plays chief role in determining the capability of the powder in fire extinguishing. It is also found by the authors that the fire extinguishing time of superfine powder is just half of the ordinary dry powder.更多还原