Flame inhibition by calcium compounds: Effects of calcium compounds on downward flame spread over solid cellulosic fuel
Flame inhibition by calcium compounds: Effects of calcium compounds on downward flame spread over solid cellulosic fuel
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DOI：
10.1016/j.firesaf.2019.102865
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发表时间：
2019-10-01
影响因子：
3.1
通讯作者：
Ohtani, Hideo
中科院分区：
文献类型：
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作者：
Koshiba, Yusuke;Haga, Takuya;Ohtani, Hideo
由于磷矿的枯竭风险和成本的上升，对无磷灭火剂的需求不断增长。本文旨在开发一种不使用磷酸盐的新型灭火剂，并报道了钙化合物的阻燃性能：乙酰丙酮钙(Ca（acac)(2)）、乙酸钙(Ca（OAc)(2)）、氢氧化钙(Ca（OH)(2)）、碳酸钙（CaCO3）、硝酸钙(Ca（NO3)(2)）和氧化钙（CaO）。通过测量每一种钙化合物吸附在纤维素燃料上的向下火焰蔓延速率来评估它们的抑火能力。抑制实验表明，Ca(acac)(2)、Ca(OAc)(2)、Ca(OH)(2)和CaCO3对火焰有灭火作用。Ca(OAc)(2)和Ca(acac)(2)的效果分别约为1.6和1.4倍于磷酸二氢铵。为了阐明钙化合物对纤维素热解和炭燃烧的影响，通过热重测量的动力学分析确定了纤维素热解的活化能(E)、指前因子(A)和炭产率(Y)。动力学分析使我们得出结论，没有钙化合物阻碍纤维素热解或炭燃烧。化合物的键能与最小消光浓度呈正相关，表明容易释放原子钙的化合物能有效抑制火焰。
Owing to depletion risks and the rising cost of phosphate rock, phosphorus-free fire-extinguishing agents are in growing demand. This paper aims to develop a new fire suppressant that does not use phosphates and reports the flame-inhibition properties of calcium compounds: calcium acetylacetonate (Ca(acac)(2)), calcium acetate (Ca(OAc)(2)), calcium hydroxide (Ca(OH)(2)), calcium carbonate (CaCO3), calcium nitrate (Ca(NO3)(2)), and calcium oxide (CaO). Their flame-inhibition capabilities were evaluated by measuring the downward flame-spread rates over cellulosic fuels on which each calcium compound was adsorbed. Suppression experiments demonstrated that Ca(acac)(2), Ca(OAc)(2), Ca(OH)(2), and CaCO3 extinguished flames. Ca(OAc)(2) and Ca(acac)(2) were more effective by factors of approximately 1.6 and 1.4, respectively, than ammonium dihydrogen phosphate. To elucidate the influences of the calcium compounds on the pyrolysis of cellulose and char combustion, the activation energy (E) and pre-exponential factor (A) associated with the pyrolysis of cellulose and the char yield (Y) were determined by kinetic analyses involving thermogravimetric measurements. The kinetic analysis permitted us to conclude that none of the calcium compounds hindered cellulose pyrolysis or char combustion. A positive correlation between the bond energy of the compound and minimum extinction concentrations was found, thus suggesting that compounds that easily release atomic calcium effectively inhibit flames.