| Water mist with additives has both physical and chemical fire-extinguishing effects,considered as the most potential substitute for halon fire-extinguishing agents because of its advantages of good resistance to repeated burning,high fire-fighting level,small pollution,low toxicity and low cost,and now has become a hot spot in the field of fire science research.However,in recent years,the effectiveness of fire-extinguishing with water-containing additive for alcohol pool fire has rarely been systematically studied.In order to explore the feasibility of additive water mist on extinguishing alcohol pool fire in practical application,first the fire was suppressed with pure water mist through a self-designed full-size water mist fire-extinguishing system in this paper.And then based on literature research and experimental objectives,choose KNO3,CH3COOK,K2CO3,KCl,K2C2O4,KHCO3,K2SO4,seven kinds of potassium as additives to carry out fire-extinguishing experiments systematically.The experimental results show that the pure water mist is hard to extinguish the flame under the low pressure due to the mutual solubility of alcohol and water,the alcohol itself contains oxygen and has a low ignition point;Different potassium additives under the same conditions on the effectiveness of pure water mist suppression alcohol fire there are differences,but,the overall performance is enhanced fire-extinguishing efficiency.The rank order of fire extinguishing efficacy of different potassium salt additives is K2C2O4>K2CO3>KNO3>CH3COOK≈KCl>KHCO3>K2SO4>pure water.In addition,when K2SO4 mass concentration is not more than 1%,its fire-extinguishing performance is weaker than pure water.According to the cost of additives,fire-extinguishing stability and other factors,selecting three kinds of typical potassium additives KNO3,CH3COOK and KCl to investigate the effect of potassium additives on the extinguishing efficiency of water mist under different pressure and different concentrations.The experimental results show that the fire-extinguishing efficiency of water mist with potassium additives increases with the increase of concentration of additives and working pressure,and appropriately increasing the working pressure phase is more conducive to the fire-extinguishing efficiency of water mist;The chemical inhibition effect of different potassium additives changes with the system pressure and concentration changes;Under the working pressure of 1.0MPa,the potassium additives solution at any concentration cannot get effective fire-extinguishing effect,and the fire-extinguishing efficiency of water mist increases with the increase of working pressure under the same condition of the mass fraction of additives.Chemical additives to play a role in the suppression of the fire need to build on the role of water spray on the physical fire-extinguishing.In addition,in order to explore the existence of different potassium additives synergistic with the role of fire-extinguishing,the fire-fighting experiments was carried out with the potassium additives in pairs.The results show that the fire-extinguishing time of K2C2O4+K2SO4,K2CO3+CH3COOK,K2CO3+KCl,KNO3+K2SO4,CH3COOK+K2SO4is less than the fire-extinguishing time of the single additive,and the percentage decrease of relative pure water fire-extinguishing time is obviously improved,indicating that the chemical inhibition of the additives is enhanced after compounding,and there is a synergistic fire-extinguishing effect among the above-mentioned potassium additives combinations.Under the same conditions,the fire-extinguishing experiment was carried out by changing the mass ratio of synergistic potassium additives,and find that the synergistic fire-extinguishing effect has the best proportioning quality relationship.In the best quality relationship,the combination of K2C2O4 and K2SO4 has the minimum fire-extinguishing time,while the synergistic fire-extinguishing effect of CH3COOK+K2SO4 is the best. |
