Study On Preparation Of New Environment Protection Foam Extinguish Agent

Foam fire extinguishing technology is one of the most effective ways to deal with liquid fires.However,traditional foam fire extinguishing agent is gradually phased out because its core component,perfluorooctane sulfonic acid(PFOS),is difficult to degrade and will cause serious harm to the environment.At present,the research of its replacement is mainly focused on the development of fluorine-free foam extinguishing agent or foam containing short chain fluorocarbon surfactant.But the foam performance and spreading performance of the former are generally poor,and the development of the latter is not mature,and the product performance needs to be improved.Based on the above background,this paper studies the composition of foam fire extinguishing agent with short chain fluorocarbon surfactants and without fluorocarbon surfactants.Firstly,the surface tension,foaming capacity,foam stability and other performance parameters of different types of hydrocarbon surfactants were tested.On this basis,the properties of these hydrocarbon surfactants were further discussed.Finally,the foaming components of fluorine-free foam extinguishing agent and short-chain fluorocarbon foam extinguishing agent were determined based on this.Secondly,the effects of different types of foam stabilizer on foaming volume,surface activity and fire resistance of fire extinguishing agent were discussed,and the types and optimal concentrations of foam stabilizer in the formula were determined.Thirdly,the paper also compares the effects of several different types of flame retardants on the performance of foam extinguishing agent and the mechanism of action,and determines the best additive and the amount of additive.Finally,the complete formulations of fluorine-free foam extinguishing agent and short-chain fluorocarbon surfactant foam extinguishing agent were designed respectively,and their properties were compared with those of commercially available foam extinguishing agent products.The main research conclusions of this paper are as follows:(1)There is obvious synergistic effect between different types of surfactants.Short-chain fluorocarbon-hydrocarbon surfactant complex system LG-95P/APG-0810 /CAB-35 /SMF-1157 and organosilica-hydrocarbon surfactant complex system LG-95P/APG-0810/CAB-35 / BY-348 have better comprehensive performance.However,PCG-12/ TSPE/LG-95 P has strong foam stability,and the lowest surface tension can reach 16.2m N/m.(2)Among the viscosifying foam stabilizing agents,xanthan gum has the best foam stabilizing effect,but the excessive concentration of xanthan gum will affect the foaming amount.The results show that when the concentration of Xanthan gum is 0.03%,the burning resistance of the foam solution is the strongest.LAO-30,CMMEA and other non-viscosifying foam stabilizing agents containing nitrogen can obviously improve the burning resistance of foam solution,and have little effect on foaming volume,but the surface tension will increase when the concentration is too high.(3)The decomposition residual weight rate and decomposition heat absorption capacity of four nitrogenous flame retardants,urea,ammonium chloride,ammonium polyphosphate and ammonium dihydrogen phosphate,were analyzed and compared.The results showed that the optimal addition concentration of them was 0.2%,and the order of combustion inhibition capacity was urea > ammonium chloride > ammonium polyphosphate > ammonium dihydrogen phosphate.Especially when the temperature reached 400℃,the decomposition residual weight rate of urea was 4.1%,and the maximum heat absorption rate was3.94 m W/mg,which was much better than other nitrogenous flame retardants.(4)Ferrocene as an additive of foam fire extinguishing agent has a strong effect on flue gas suppression.The results show that the optimal extinguishing concentration is 100 ppm,and ferrocene dissolved in organic solvent can be stable in the form of microemulsion in the short-chain fluorocarbon foam extinguishing agent and fluorine-free foam extinguishing agent solution.(5)The short-chain fluorocarbon foam extinguishing agent,silicone foam extinguishing agent and pure hydrocarbon foam extinguishing agent developed in this paper have good spreading properties,and their spreading quantities on kerosene are 30μL,10μL and 30μL respectively,and the foam stability is strong.The fire extinguishing comparative test shows that the fire extinguishing efficiency of the short-chain fluorocarbon foam extinguishing agent developed in this paper is better than that of the commercially available water film foam extinguishing agent(AFFF),while the fire extinguishing performance of the organosilicone foam extinguishing agent and the pure hydrocarbon foam extinguishing agent is slightly worse than that of the commercially available water film foam extinguishing agent(AFFF).