Experimental investigation of novel dry liquids with aqueous potassium Solution@Nano-SiO₂ for the suppression of liquid fuel fires: Preparation, application, and stability

Taking advantage of solid and liquid fire extinguishants in one material is desirable, especially for the selection of liquid phase components aimed at specific fire disaster situations. In this investigation, the feasibility of novel dry liquids with core-shell structure as fire extinguishants in liquid fuel fires was conducted. The microencapsulated functional materials were formed by the high-speed shearing method, which were then characterized for their liquid content, micromorphology, particle size, and fluidity. The surface tension of inner liquids and hydrophobicity of outer shell were the critical factors for the preparation and the addition of Gellangum enhanced the structural strength, and the formed gel-type particles reduced the rate of water loss by at least 50%. The fire extinguishing efficiency of gel-type dry liquids was obtained by the consumption and times of fire suppression compared to the dry powder and water mist, both in small and medium scale tests. The obtained results indicated that the performance of gel-type dry water is comparable to that of ultrafine dry powder in small-scale cyclohexane fire based on a total flooding ejection with a dosage of 44.3% lower than that of water mist as the consumption of ultrafine dry powder, gel-type dry water and water mist was 48.7g, 47.6g, and 85.4g, respectively. The efficiency of gel-type dry water in gasoline fire was increased from 13.4 to 27.7% with the increase in pressure from 0.5 to 1.0 MPa and fire power from 0.05 to 0.25 MW compared to the water mist with the dosages of gel-type dry water and water mist were 35.2g and 40.6g in small scale, meanwhile 262.7g and 363.3g in medium scale. The performance in diesel is 12.7% higher than that of gasoline fire under the same experimental conditions. The unique properties of gel-type dry liquids are due to their suspension characteristics and limited evaporation, and the mechanism of extinguishing is the result of comprehensive synergetic effects of cooling, dilution, homogeneous chemical, and heterogeneous inhibition.