Research On Safety Of Production Special Equipments For Expanded Ammonium Nitrate Explosive

Exponded ammonium nitrate explosive is one kind of powdered explosives without TNT. It has many adervantages such as:non-toxic, non-polluting, low cost, physical properties and explosion excellent performance. In the nationwide nearly 100 production lines are running now.Today the production of expanded AN explosive mainly use the PengHun-LianJian process which makes three processes:AN's exponded, mixture of various components and cooling of Explosives just in one production workshop. It is helpful for the automatic and continuous way production, but the risk of production is increased too.In order to improve the safety of the expanded ammonium nitrate explosive, it's production process were analyzed on systematicness, from the safety of production, risky factors of the production process were researched:define the dangerous specially equipment units, classify the risky attribute of hazardous material, identify the risky of process units, security problems of expanded ammonium nitrate explosive production equipment were studied on systematicness, it was helpful for finding the safety management system method for the production equipment.The structure of grinding and mixing machine was studied from the security perspective. Then production limit experiment was done on it. Plugging material conditions and the detonation velocity of explosive were observed via adjusting operation parameters:feeding speed,scraper angle,grinding and mixing machine speed. The safety of the grinding and mixing machine was analyzed and discussed. This results showed that the feeding speed shouldn't exceed 5.5 t/h, the highest speed of the grinding and mixing machine was 22.8 r/min, the range of scraper angle was 16～24°; when the speed of the grinding and mixing machine was 22.8 r/min, the feeding speed was 4 t/h, the scraper angle was 24°, the system was running very safe and the detonation velocity of explosive was much higher than before.A circulation pulverizing system was designed with the CAM crusher which was used specially for expanded ammonium nitrate explosive as its center. The safety of the CAM crusher crushing expanded ammonium nitrate was analyzed and discussed. This results showed that the maximum speed of the CAM crusher was about 2950 r/min, the feeding temperature should be less than 105℃, the highest feeding speed was 39 Kg/min; when the speed of the CAM crusher was 2950 r/min, the feeding speed was 39 Kg/min, the feeding temperature was 105℃and the gap between hammer and shell was 15 mm, the system was running very safe and the fineness was much higher than before.The trajectory of material layer and acceleration of expanded an particles were studied by the analyses for the stress of expanded an particles and the movement rules of material layer. The results showed that quality larger particles have greater acceleration, the trajectory of material layer approximates a solenoid, uniform linear motion in the shaft upward and circular motion in the radial upward. The study may provide a good reference for the safety research and design for the CAM crusher. The theoretical basis was provided for the relationship between fineness with equipment normal temperature and operation parameters after expanded AN was crushed.