Abstract:

Foam extinguishing agent is one of the commonly used fire fighting methods, but conventional foam extinguishing agent has a short half-life, liquid separation and rapid accumulation, which affect the fire extinguishing efficiency. Based on fire chemistry and active agent technology, a ternary system of hydrocarbon surfactant SDS, silicone surfactant LS-99 and low carbon alcohol was proposed and the compounding ratio of hydrocarbon/silicone/low carbon alcohol was systematically investigated. The critical micelle concentration of LS-99 was found to be 0.0083% by extensive testing of surface tension, foaming height and foam stabilization coefficient. LS-99 and SDS binary systems have good synergistic effects in terms of reducing surface tension, increasing foam height and foam stabilization coefficient. Based on this foundation, a hydrocarbon/silicone/low carbon alcohol foam extinguishing agent has been designed by introducing an appropriate concentration of isobutanol, which retards foam precipitation and polyhydration. At 0.1% mass concentration of LS-99, SDS and isobutanol, the test results show that the SDS/LS-99/alcohol ternary foam has a foaming multiplier of 52.5 times, a 25% drainage time of 210 s and a stability coefficient of 0.958 at 300 s, with a half-life far exceeding that of conventional foams. Fire suppression experiments on coal spontaneous combustion show that the activation energy of all reaction stages of coal spontaneous combustion under the action of SDS/LS-99/alcohol ternary foam increases compared to the air atmosphere, and the difficulty of the reaction increases; the maximum mass loss rate decreases and the intensity of the reaction decreases. The heat absorption in the initial heat absorption phase is 78.3 J/g, which is greater than the heat absorption of the coal sample in the air atmosphere, with an increase in heat absorption of up to 2.16 times. The heat release in the exothermic phase was 1765.4 J/g, a reduction of 15.15% compared to the exothermic air atmosphere, which indicates that the SDS/LS-99/alcohol ternary foam has a good extinguishing effect on spontaneous coal combustion.

Key words: ternary foam systems, surfactant, low carbon alcohol, 25% drainage time, foam stabilization coefficient, maximum mass loss rate, heat absorption and discharge

摘要：

泡沫灭火剂是常用的火灾扑救方法之一，但常规泡沫灭火剂存在半衰期短，析液、聚并迅速而影响灭火效能的问题，基于火灾化学和活性剂技术，提出碳氢表面活性剂SDS、有机硅表面活性剂LS-99和低碳醇的三元系泡沫体系，并系统探究碳氢/有机硅/低碳醇的复配配比。通过表面张力、发泡高度、稳泡系数的大量测试，发现LS-99的临界胶束浓度为0.0083%。LS-99和SDS二元系在降低表面张力、提升发泡高度和稳泡系数方面具有良好的协同增效作用。在此基础上引入适量浓度的能够延缓泡沫析液、聚并的异丁醇，设计出了性能优良的碳氢/有机硅/低碳醇泡沫灭火剂。LS-99、SDS和异丁醇的质量分数为0.1%时，测试结果表明SDS/LS-99/醇三元系泡沫的发泡倍数可达52.5倍，25%析液时间可达210 s，300 s时的稳泡系数高达0.958，半衰期远超常规泡沫。煤自燃的灭火抑制实验表明，SDS/LS-99/醇三元系泡沫作用下，煤自燃各反应阶段的活化能相较于空气氛围均增大，反应难度增强；最大失重速率下降，反应剧烈程度减弱。初期吸热阶段的吸热量为78.3 J/g，大于空气氛围下煤氧复合的吸热量，吸热增幅高达2.16倍。放热阶段的放热量为1765.4 J/g，相较于空气氛围放热降幅达到15.15%，表明SDS/LS-99/醇三元系泡沫对煤自燃具有良好的灭火效果。

关键词: 三元系泡沫, 表面活性剂, 低碳醇, 25%析液时间, 稳泡系数, 最大失重速率, 吸放热量