Influencing Factors And Suppression Of Aluminum Powder Explosion

Based on its excellent characteristics,aluminum is widely used in many fields such as smelting,painting,manufacturing and construction,which brings great convenience to people and also brings hidden safety risks.When aluminum is processed,aluminum powder is generated.When the generated aluminum powder is suspended in the air and reaches a certain concentration,it will cause an explosion accident when excited by an ignition source,which will endanger personnel and the environment.Therefore,in order to prevent and control the explosion of aluminum powder,it is necessary to study the rules of aluminum powder explosion and suppress the explosion.This paper uses a 20L spherical explosion test system to test the influence of ignition delay time,aluminum powder concentration and initial ignition energy on the characteristics of aluminum powder explosion.Simultaneously,the inhibitory effect of three different inert media of Ca CO₃、NH₄H₂PO₄、Na HCO₃and their compound flame retardants on the explosion of aluminum powder was also explored.The results show that The maximum explosion pressure and the maximum explosion pressure increase rate of aluminum powder first increase and then decrease as the ignition delay time increases..The optimal ignition delay times for different concentrations of aluminum powder are different.The optimal ignition delay times for aluminum powders with concentrations of 100g/m³,300g/m³and 500g/m³are 50ms,60ms and 70ms.With the increase of aluminum powder concentration,the maximum explosion pressure and the maximum explosion pressure increase rate of aluminum powder show a trend of first increase and then decrease.The maximum explosion net pressure of aluminum powder does not have much relationship with the initial ignition energy,and the maximum explosion pressure of aluminum powder increases linearly with the increase of the initial ignition energy.NH₄H₂PO₄has the best inhibitory effect on aluminum powder explosion,Followed by Ca CO₃,and then Na HCO₃.Composite flame retardants can obviously show synergistic effects,which is better than single flame retardants in suppressing the explosion of aluminum powder.