Experimental Study Of Foam Performance And Fire Extinguishment Of Hydrocarbon/Silicone Foam Regulated By Low Carbon Alcohol

Foam fire extinguishing agent is one of the commonly used agents to effectively fight B type fire and some A type fire.However,the existing foam fire extinguishing agent has some problems,such as short half-life,rapid liquid evolution and coalescence,environmental damage and bioaccumulation effect.In recent years,many scholars have carried out some new foam fire extinguishing agent research work,but there is no foam fire extinguishing agent with environmental friendliness and efficient fire extinguishing ability.Based on the theory of fire chemistry and surfactant technology,this paper carried out the design and experimental research on the ternary system foam compounding scheme of various hydrocarbon,silicone surfactant and low carbon alcohol,in order to obtain the ternary system foam with liquid evolution,slow polymerization,long half-life and high fire extinguishing efficiency.A comparison of the parameters of the mono-,di-and ternary active agent systems shows that the hydrocarbon/silicone surfactants have a good synergistic effect in terms of reducing surface tension,increasing foaming height and foam stabilization factor.The introduction of low-carbon alcohols did not affect the tension and foaming height of the binary system,but had a significant effect on the foaming multiplier and the time to precipitation.The foaming multiplier of the ternary system increases linearly with the addition of isobutyl alcohol,and the foaming time of 25% is prolonged,with the increase of the addition amount.Comparative experiments were carried out on hydrocarbon/silicone and hydrocarbon/silicone/low carbon alcohol systems to extinguish oil fires,and a method was established to evaluate the fire extinguishing effect based on the 25% precipitation time,average precipitation speed,maximum cooling rate and extinguishing time.The results show that the introduction of isobutyl alcohol makes the ternary system foam extinguishing agent better than the conventional foam extinguishing agent in extinguishing oil pool fires.A comparative experiment of LS-99/SDS/ isobutyl alcohol ternary foam containing different gases was carried out to prevent and control coal spontaneous combustion,which showed that LS-99/SDS/ isobutyl alcohol ternary foam with a mass concentration of 0.1% could achieve a foaming multiple of 52.5 times and a half-life much longer than that of conventional foam.An experimental evaluation method of air foam and nitrogen foam for the prevention and control of coal spontaneous combustion based on the parameters of characteristic temperature,thermal weight loss rate,activation energy and exothermic heat was established,and the results showed that nitrogen foam was more effective than air foam in suppressing coal spontaneous combustion fire.Based on the quantitative analysis of foam parameters and the qualitative analysis of the Plateau channel,it was found that the introduction of isobutyl alcohol at the right concentration can effectively reduce intermolecular repulsion and increase the molecular adsorption of the liquid film,which can form a dense structure in the bulk phase of the ternary foam,acting as a barrier to disrupt and prolong,or even block,the foam precipitation path,thus greatly enhancing the stability of the foam.The study points to the superior fire extinguishing performance of ternary foams compared to conventional foams in physical aspects such as capping oxygen barrier,liquid film closure,liquid holding cooling and thermal radiation barrier effects,and elucidates the chemical inhibition mechanism by which low carbon alcohols modulate the interruption of hydrocarbon/silicone foams,destroy OH-radicals in combustion chain reactions and reduce reactivity.