Study on the relationship between the particle size distribution and the effectiveness of the K-powder fire extinguishing agent

The relationship between the particle size distribution and the extinguishing effectiveness of the new K-powder fire extinguishing agent has been studied experimentally, to explore the reason of the great extinguishing efficiency exhibited by the new K-powder fire extinguishing agent on Class B fire (liquid fuel fire). The results of the experiment showed that the extinguishing effectiveness increased along with the decrease of the particle size distribution. In addition, a sharp discontinuity appeared around the limiting size, about 40 μm. The powder with the particle size below 40 μm exhibited highly effective extinguishing with the minimum effective extinguishing concentration C_xr = 23 g·m⁻³, while the powder with the particle size above 40 μm exhibited little fire extinguishing efficiency. Compared with other fire extinguishing agents produced by different substances, the new K-powder fire extinguishing has the bigger limiting size. That means, in the same particle size distribution, the new K-powder fire extinguishing agent contains more highly effective powder than others contain, and is more effective.