Research on Suppressing Premixed Fuel-air Explosion by Ultra-fine Cold Aerosol

AbstractThe problem of prevention and suppression of gas-and air explosions is extremely important because such explosions represent serious threat to firemen life. It is significant that ultra-fine cold aerosol with typical characteristics of compressibility, flow ability and good dispersion attributed, can suppress the deflagration and detonation of leaking of flammable oil gases. In this paper, some series of the explosion suppression experiments were carried out in the laboratory 20-liter apparatus with three gas routes and two igniters of chemical and high-voltage pulse which provide a reliable, multiple-point ignition source. The main series were about the suppressing the developed explosion process of oil gas premixed air and ultra-fine cold aerosol, or 1301 fire extinguishing agent. The results are shown that in case of suppressing the developed explosion, the increase of the concentration of ultra-fine powder and 1301 both causes the decrease of the maximum explosion pressure and maximum rate of pressure rise of oil gases. Moreover, 1301 fire extinguishing agent has distinctly threshold nature and the induced time of oil explosion is delayed. Furthermore, it is shown that the explosion suppression effect is associated to inherent property and concentration of suppressing agent and ignition condition. And the rank of suppressing capability of ultra-fine aerosol or gas suppressing agent for oil gas atmosphere was proposed, and the maximum suppressed explosion pressure may be used as the criterion to estimate explosion-suppression efficiency of oil gas. This research helps optimize explosion suppression condition of oil gas, and have important reference values for further application on explosion suppression technology in large oil rank farm and other danger sites