Abstract: Taking flour as the research object,using 20 L ball and Hartmann tube explosion test system,the effects of calcium carbonate, ammonia dihydrogen phosphate, silica, and compound of calcium carbonate and ammonia dihydrogen phosphate on the maximum explosion pressure, pressure rise rate and flame propagation rate of flour were tested respectively.The inhibition effect and mechanism of 4 kinds of inert powders were compared and analyzed. The results showed that in addition to physical heat absorption,ammonium biphosphate also inhibits dust combustion and explosion by chemical decomposition,and its explosion suppression effect is better than that of silicon dioxide and calcium carbonate. There is additional reaction between calcium carbonate and ammonia dihydrogen phosphate which can inhibit combustion and explosion,and the composite of this two has higher inerting efficiency than the single inerting powder.

Key words: flour explosion, calcium carbonate, ammonium biphosphate, silica, compound, explosion suppression performance