Suppression of polyethylene dust explosion by sodium bicarbonate

Sodium bicarbonate (NaHCO3) was used to suppress the explosion of polyethylene (PE) dust. The maximum explosion pressure, flame propagation behaviour, and the minimum ignition temperature of PE dust mixed with NaHCO3 powder were measured, aiming to evaluate the suppression effect of NaHCO3 on PE dust explosion. The results showed that NaHCO3 powder can effectively suppress PE dust explosions and the suppression effect increases gradually as the inert ratio increases. PE dust explosions can be suppressed by NaHCO3 through physical and chemical mechanisms. From the physical aspect, the thermal decomposition of NaHCO3 particles can effectively absorb heat from the flame front of PE dust. From the chemical aspect, the Na-containing species generated can effectively react with and scavenge the radicals in the PE flame, especially the O radical. Both the rate of chain reaction and the rate of heat release are then decreased, leading to an effective suppression effect.