Ultrafine Particles Fire Extinguishing Agent Concentration Measurement Methods Of Research

Fire extinguishing efficiency was one of the most important performance criterions to evaluate super fine powder extinguishing agent(SFPEA). It was also one of basic engineering application data of SFPEA. Based on Principle of Lambert-beer, this paper chose the optic method to measure the extinguishing efficiency of SFPEA and devised relevant measure device. The system was composed of three parts including symmetrical flow field generator, sampling device and laser measurement device. The particles were filtrated by sponge and filter paper and weighed by electronic balance. The sampling gas was cut off by electromagnetic valve. This paper preliminary studied the ammonium phosphate type and sodium carbonate type SFPEA by the system. The results showed that the laser absorption coefficients of different type SFPEA which had closer particle size were similar. The laser absorption coefficient was affected by particle diameter but was independent of the agent type. For SFPEA of same type, the average particle size was smaller, the extinguishing concentration was lower and the extinguishing efficiency was higher. The ammonium phosphate type SFPEA and the sodium carbonate type SFPEA had similar extinguishing efficiency when their particle sizes were near in class B fire.