Experimental study on preparation of a new cleaner water-based powder agent and its extinguishing efficiency and thermodynamic mechanism on a typical fuel fire

A new cleaner micron-sized water-based powder particles (DW) were prepared by physical dispersion method of hydrophobic silica and ultrapure water at different proportions. The effects of chemical composition of metal salts on physical properties of dry water materials such as fluidity and particle size distribution were analyzed. The microscopic morphology of DW particles with different components was observed by optical microscope, and the effects of different filling pressures on their microscopic morphology and fire extinguishing efficiency were analyzed. The thermal decomposition kinetics of different DW were analyzed to get their thermal mechanism to extinguish. The results showed that the size of DW particles is more uniform; the structure edge is clearer, and the structure is more stable when the mass ratio of SiO2 to water is 1:13. The fluidity and filling performance of DW were improved by different metal salinization components at a certain concentration. When the filling pressure is 0.6 MPa, the DW structure can remain stable and the fire extinguishing efficiency is the best. DW material can instantly extinguish the small-size oil pool fire. DW shows the best extinguishing efficiency compared to dry powder and water mist. Combined with the thermal decomposition analysis, the addition of metallic sodium salt would increase the apparent activation energy by more than 10 times; therefore, the fire extinguishing efficiency of sodium carbonate-modified DW shows the most obvious.