基于固液交互作用调控的聚氨酯烟尘捕集润湿作用机理

Wetting Mechanism of Smoke Dust Capture in Polyurethane Combustion Based on Solid-Liquid Interaction Regulation

摘要

冷库火灾过程中因为保温材料燃烧生成大量烟气,导致可见度大幅降低影响消防救援效率．为提升对冷库常用保温材料聚氨酯烟尘颗粒的捕集抑尘效率,本研究首先使用光学显微镜与场发射扫描电镜观测聚氨酯烟尘颗粒的宏观与微观形貌,使用傅里叶变换红外光谱仪测定聚氨酯烟尘颗粒表面官能团构成,然后测定了十八烷基三甲基氯化铵(STAC)、十六烷基三甲基溴化铵(CTAB)、十二烷基硫酸钠(SDS)、椰油酰胺丙基甜菜碱(CAB-35) 4种表面活性剂水溶液的表面张力曲线与zeta 电位值,并通过接触角测量与沉降实验探究了不同溶液对聚氨酯烟尘样品颗粒的捕集润湿性能的影响机制．研究结果表明表面活性剂对样品颗粒的润湿性能主要受固相颗粒表面电性与液相表面张力的影响:表面活性剂电性显著调控初期沉降过程(0～7 s),对于表面带负电的样品颗粒,其在阴离子表面活性剂 SDS 中的沉降速度约为在其他 3 种表面活性剂中的 3.0倍；表面张力显著影响后期沉降过程(＞7 s),溶液表面张力与后期沉降速度呈强负相关(r＝-0.968 3),阳离子表面活性剂 STAC 的后期沉降速度约为阴离子表面活性剂 SDS 的 2.9倍．相关研究结果可为消防除烟药剂设计中表面活性剂选择提供理论依据．

Abstract

During cold storage fires, the combustion of thermal insulation materials generates large quantities of smoke dust, which significantly reduces visibility and hinders fire rescue efficiency. This study comprehensively investigated methods that enhanced the collection efficiency of fire suppressants for combustion smoke dust particles generated from polyurethane insulation materials. The macro/micromorphological characteristics of the polyurethane combustion products were investigated using optical microscopy and field-emission scanning electron microscopy. Furthermore, surface functional groups were analyzed using Fourier transform infrared spectroscopy. Subsequently, the surface tension curves and zeta potential values of four surfactant solutions—stearyltrimethylammonium chloride (STAC), cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and cocamidopropyl betaine (CAB-35)—were experimentally measured. Contact angle measurement and sedimentation experiments were conducted to investigate mechanisms influencing wetting and particle capture performance. The main findings indicate that surfactant performance in terms of particle wettability is governed by the surface charge of solid particles and the surface tension of the liquid. The surfactant electrical properties critically control initial sedimentation (i.e.,0—7 s). For negatively charged particles, sedimentation velocity in an anionic SDS solution is approximately three times higher than that in other surfactant solutions. Surface tension strongly correlates with late-stage sedimentation (i.e.,＞7 s) velocity (r＝-0.968 3). The cationic surfactant STAC exhibits 2.9 times higher sedimentation velocity than SDS. These results provide theoretical foundations for surfactant selection in designing smokeproof agents for firefighting.

关键词

冷库火灾 / 烟尘 / 固液交互作用 / 表面活性剂 / 润湿捕集

Key words

cold storage fire / smoke dust / solid-liquid interaction / surfactant / wetting and particle capture

参考文献

[1] Singh H, Jain A K. Ignition, combustion, toxicity, and fire retardancy of polyurethane foams: A comprehensive review[J]. Journal of Applied Polymer Science, 2009, 111(2):1115-1143.

[2] 唐秀翠. 冷库火灾频发成因分析防范对策研究[C]// 中国消防协会学术工作委员会消防科技论文集(2022). 北京, 中国, 2022:163-165.

[3] Tang Xiucui. . Analysis of the causes of frequent cold storage fires and research on preventive measures[C]// Collection of Fire Science and Technology Papers by Academic Work Committee of China Fire Protection Association(2022). Beijing, China, 2022:163-165(in Chinese).

[4] 王岳. 冷库建筑火灾风险分析及对策研究[C]// 中国消防协会学术工作委员会消防科技论文集(2022). 北京, 中国, 2022:423-425.

[5] Wang Yue. Research on fire risk analysis and countermeasures of cold storage buildings[C]// Collection of Fire Science and Technology Papers by Academic Work Committee of China Fire Protection Association(2022). Beijing, China, 2022:423-425(in Chinese).

[6] Wang P F, Liu R H, Tang M, et al. Experimental study on atomization characteristics and dust suppression efficiency of high—pressure spray in underground coal mine[J]. Journal of China Coal Society, 2015, 40(9):2124-2130.

[7] Mehaddi R, Collin A, Boulet P, et al. Use of a water mist for smoke confinement and radiation shielding in case of fire during tunnel construction[J]. International Journal of Thermal Sciences, 2020, 148:106156.

[8] Wang X N, Yuan S J, Jiang B Y. Experimental investigation of the wetting ability of surfactants to coals dust based on physical chemistry characteristics of the different coal samples[J]. Advanced Powder Technology, 2019, 30(8):1696-1708.

[9] Wang X N, Yuan S J, Jiang B Y. Wetting process and adsorption mechanism of surfactant solutions on coal dust surface[J]. Journal of Chemistry, 2019, 2019:9085310.

[10] Li S G, Zhao B, Lin H F, et al. Review and prospects of surfactant—enhanced spray dust suppression: Mechanisms and effectiveness[J]. Process Safety and Environmental Protection, 2021, 154:410-424.

[11] 王凯, 杨孟娇, 徐敏. 煤矿井下湿式喷雾除尘技术研究前沿与展望[J]. 煤炭技术, 2023, 42(11):183-186.

[12] Wang Kai, Yang Mengjiao, Xu Min. Research frontier and prospect of wet spray dust removal technology underground coal mine[J]. Coal Technology, 2023, 42(11):183-186(in Chinese).

[13] 王利军, 张友兰, 刘志华, 等. 炭黑在水性体系中的分散及分散剂结构的影响[J]. 天津大学学报, 1999, 32(5):616-620.

[14] Wang Lijun, Zhang Youlan, Liu Zhihua. et al. Dispersion of carbon black in waterborne system and the effect of dispersant structure[J]. Journal of Tianjin University, 1999, 32(5):616-620(in Chinese).

[15] 赵少静, 程发, 陈宇, 等. Gemini 表面活性剂的合成及性能[J]. 天津大学学报, 2012, 45(1):81-86.

[16] Zhao Shaojing, Cheng Fa, Chen Yu, et al. Synthesis and properties of Gemini surfactants[J]. Journal of Tianjin University, 2012, 45(1):81-86(in Chinese).

[17] 顾海林, 陈斌康, 郭佳琪, 等. 含表面活性剂溶液的雾化特性及对细颗粒物的强化去除效果[J]. 化工进展, 2024, 43(2):865-871.

[18] Gu Hailin, Chen Binkang, Guo Jiaqi, et al. Atomization characteristics of surfactant—containing solutions and enhanced removal of fine particulate matter[J]. Chemical Industry and Engineering Progress, 2024, 43(2):865-871(in Chinese).

[19] Chang P, Zhao Z D, Xu G, et al. Evaluation of the coal dust suppression efficiency of different surfactants: A factorial experiment[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2020, 595:124686.

[20] Zhou Q, Qin B T, Li H Z, et al. Changes of physical properties of coal dust with crush degrees and their effects on dust control ability of the surfactant solution spray[J]. Environmental Science and Pollution Research, 2022, 29(22):33785-33795.

[21] 易双霞, 袁梅, 何季民, 等. 表面活性剂对无烟煤润湿性的影响实验研究[J]. 煤矿安全, 2024, 55(10):38-45.

[22] Yi Shuangxia, Yuan Mei, He Jimin, et al. Experimental study on the effect of surfactant on wettability of anthracite[J]. Safety in Coal Mines, 2024, 55(10):38-45(in Chinese).

[23] Ji B, Jiang B Y, Yuan L, et al. Experimental and molecular dynamics simulation study on the influence of SDS and JFC composite ratios on bituminous coal wettability[J]. Process Safety and Environmental Protection, 2023, 174:473-484.

[24] 张坤尹, 严敏, 李树刚, 等. 煤体表面粗糙度对非阳离子表面活性剂润湿性影响的实验研究[J]. 煤矿安全, 2021, 52(11):8-15.

[25] Zhang Kunyin, Yan Min, Li Shugang, et al. Experimental study on the influence of coal surface roughness on wettability of non—cationic surfactants[J]. Safety in Coal Mines, 2021, 52(11):8-15(in Chinese).

[26] 王晓婷, 袁红, 李梅. 不同表面活性剂对煤的润湿性的影响研究[J]. 煤矿安全, 2024, 55(12):97-105.

[27] Wang Xiaoting, Yuan Hong, Li Mei. Study on the influence of different surfactants on the wettability of coal[J]. Safety in Coal Mines, 2024, 55(12):97-105(in Chinese).

[28] Jin H, Zhang Y S, Chen K, et al. Preparation and characterization of a composite dust suppressant for coal mines[J]. Polymers, 2020, 12(12):2942.

[29] Chang P, Xu G, Chen Y P, et al. Experimental evaluation of the surfactant adsorptions performance on coal particles with different properties[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2022, 648:129408.

基金资助

国家自然科学基金资助项目(21978204)