Experimental Research On Ammonium Phosphate Dry Powder To Repress Gas Explosion

Gas explosion is one of the serious natural disasters in coal mines, which brought a lot of casualties and property losses. Now most state-owned coal mines are gas mines, which have 44 percent in the total of the national mine including gas outburst mines and high concentration gas mines .Gas explosion has a large proportion at serious accident in coal mines. The inhibitory blasting technology using powder can prevent or inhibits gas explosion hazard .In practice how to use powder materials and choosing proper powder materials better, it has the extremely vital significance for gas explosion calamity prevention and control.This article discussed the development and application situation about the technical of all kinds of powder suppression from the the suppression mechanism and theory of the powder. Using 20L nearly spherical stainless steel explosion experiment system to test the powder, and choose two kinds of ammonium phosphate powder (which is the main composition of ABC dry powder) which have different proportion and different particular size. The article investigated the functions and parameters about the dry powder suppressing the gas explosion, and analyzed the relationship about the powder concentration, methane concentration, ignition delay timeand the explosive characteristic parameters through quantitative and qualitative analysis, brought the suppression of ultra-fine powder explosive rule.The experimental results show that: two kinds of powder produce certain inhibitory effect, little difference from the two powder blasting suppression. Two kinds of powder made methane explosion limits narrowed, the influence of the powder for the upper explosive limit is stronger to lower explosive limit,the powder B make the explosion limit narrowed much more than the powder A. The powder A achieved the best inhibitory effect when its powder density is 50mg/L and 100mg/L, the powder B achieved the best inhibitory effect when its powder density is 100mg/L.When the methane concentrations are less than 9.5%,the inhibitory effect of the powder A is better than the powder B; when the methane concentrations are more than 9.5%,the inhibitory effect of the powder B is better than the powder A. The inhibitory effect has close relationship with the methane concentrations, the inhibitory effects are different when the methane concentrations are different. With extension of the ignition delay time, the inhibitory effect become more and more unconspicuous; with the change of the ignition delay time, the inhibitory effect of the two powder show the same rule.The experiments data and conclusions provide the theoretical basis about ammonium phosphate powder used in explosive suppression, and which show the importance of powdery super refining at the same time. The research conclusion has certain directive significance about powder using inhibition of gas explosion.