The deflagration suppression effect of ammonium salt-modified dry water on methane-air mixtures: An experimental investigation

To evaluate the efficacy of ammonium salt-modified dry water in suppressing the deflagration of methane, in this study, four kinds of ammonium salts were chosen to modify the properties of dry water powders. The physical features of the modified dry water were tested and analyzed. Their suppression characteristics on methane ex-plosion were experimentally explored, and the corresponding deflagration parameters were obtained. Results show that the Pmax and the (dP/dt)max first diminish and then increase with increasing amounts of modified dry water. The effect of ammonium dihydrogen phosphate-modified dry water (MAP-DW) on the explosion pressure is superior to that of other kinds. The delay effect of MAP-DW and ammonium polyphosphate-modified dry water (APP-DW) on explosion time is better for methane at equivalence ratios of 0.8 and 1.2. Moreover, the explosion suppression mechanism of the modified dry waters was proposed. The findings of this work are helpful for optimizing gaseous deflagration suppressants.