Small-scale fire performance assessment of intumescent coatings on metal tubes containing ammonium nitrate. A stepping-stone towards their application as a fire safety measure on road transportation tanks?

Ammonium nitrate is used in vast amounts globally, first and foremost as a component of fertilizers and explosive formulations. This usage necessitates its transportation which, as for most hazardous materials, involves certain risks. For oxidizing materials such as ammonium nitrate, the ultimate consequence of road transportation incidents is usually considered to be fire followed by explosion. Even though the probability in general is low, substantial reduction in its risk is a great gain for public safety. Thus, identifying novel and improving current safety measures for risk reduction, is an important aspect in the field of hazardous materials. Herein, a series of experiments are reported, which demonstrate the fire protection performance of two state-of-the-art intumescent passive fire protection materials on small-scale metal test tubes containing ammonium nitrate. Albeit being initial experiments on laboratory-scale, these results provide a promising starting point for further investigations on the potential of these materials for the fire protection of ammonium nitrate when carried in metal tanks. At its best, a prominent protection of ammonium nitrate from heat exposure was observed, as the temperature was kept well below its boiling point for more than 2.5 h. Successively, it resulted in a complete recovery of the sample material. This was in large contrast to the observed results for the unprotected test tubes, which led to complete decomposition of the sample after 11 min.     

对天津港“8·12”特别重大火灾爆炸事故相关法规标准的思考

硝化棉已分别列入危险化学品、易制爆危险化学品和第二批重点监管的危险化学品,硝酸铵也分别列入危险化学品、民用爆炸物品和首批重点监管的危险化学品,二者都是重点监管的对象,但二者相关事故还是时有发生。为了更全面和深刻理解天津港“8·12”特别重大火灾爆炸事故的发生,以危险化学品储存场所外部距离标准要求为切入点,分析了储存场所外部距离变化过程;介绍了初始起火物质硝化棉和导致事故后果严重扩大的硝酸铵2种危险化学品的国内监管分类和相关标准要求,并与事故调查报告中给出的结论进行了对比;针对本起火灾爆炸事故后果特点和非法储存危险物质罪罪行认定条件,剖析了现存的问题。分析结果旨在为政府有关部门及事故调查等工作提供参考。     

熔融硝盐高温分解爆炸事故后果严重度评价

为评价热处理用硝盐槽熔融硝盐高温分解爆炸事故机理和后果严重度，结合某企业铝合金件硝盐固溶热处理工艺进行研究。 利用压缩气体容器爆炸能量计算模型、超压准则和TNT当量法估算热处理用硝盐槽内熔融硝盐高温分解爆炸事故后果，得出35 000 kg熔融硝盐在高温分解转化率为50%时爆炸的TNT当量为1 257.6 kg，爆炸会造成半径53.97 m范围内的人员轻伤，该结果和利用政府推荐的危险指数法得出的外部防护距离为50 m较为接近。 以上分析计算表明:超温爆炸过程中，熔融硝盐在硝盐槽中超温分解快速产生大量气体，在硝盐槽上盖及上部硝盐的阻挡下不能及时排出，致使硝盐槽内气体压力瞬间升高，形成类似于压力容器的空间，发生物理爆炸并引发高温硝盐喷溅。     

城市危险源爆炸灾害应急损失评估研究

采用冲击波伤害-破坏超压准则,首先确定了不同当量TNT炸药爆炸引起的人员伤害区域和建筑物破坏区域;再通过确定危险物爆炸所产生热量值的大小,将各种危险物料转化为相应当量的TNT炸药,可用于评估各种不同危险物料爆炸所造成的损失。同时,结合GIS软件平台,编制了爆炸灾害评估模拟程序。在软件平台中以图形的形式给出了设定条件下人员伤害区域及建筑物破坏区域的范围,根据区域内的人员分布和建筑物造价、财产多少,给出了定量的人员伤亡和经济损失应急评估。     

危险化学品仓储事故演化规律及消防力量需求研究

危险化学品仓储火灾事故复杂,处置难度大,易引发事故多米诺效应,对人民的生命和财产造成严重威胁。本文分析了危化品仓储火灾爆炸事故的演化规律和事故风险,结合事故案例剖析危化品仓储火灾爆炸事故后果及对周边区域的影响。针对危险化学品仓储火灾爆炸事故,建立危化品仓储火灾扑救泡沫需求评价二级指标体系,采用模糊层次分析法建立了泡沫灭火剂用量评价数学模型,并根据救援力量类别需求、各种应急救援装备与作战人员需求建立危化品火灾消防力量需求预测模型,准确预测危化品仓储事故消防力量需求。     

危化品事故应急救援能力提升方法研究——基于天津港“8·12”瑞海公司危险品仓库特别重大火灾爆炸事故教训

为提升危化品事故应急救援能力，保障消防救援队员救援时安全，基于2015年天津港“8·12”瑞海公司危险品仓库特别重大火灾爆炸事故教训，从应急管理生命周期的角度构建危化品应急管理体系，研究危化品事故应急救援能力提升方法。结果表明:事故发生及特大伤亡与预防和应急准备工作不足有密切关系。构建基于应急管理生命周期的危化品企业、有关监管部门、技术服务机构、消防队联动应急管理体系是提升危化品应急救援能力的重要方法。危化品企业、有关监管部门、技术服务机构、消防队应做好危化品事故预防与应急准备工作，通过充足的预防和准备工作促使有效应急响应。事故发生后，危化品企业做好早期处置利于消防队采取针对性应急救援方案。对于复杂性危化品事故，及时成立抢险救援指挥部，科学应急响应，可保障消防救援的安全有效。     

天然气储气罐破坏效应分析

针对城市天然气储气罐的不断兴建与发展趋势的大型化,对于已建和待建储罐区对周围环境的潜在安全性问题,指出运用破坏伤害范围评价法可直观地预测破坏效应。通过对储罐爆炸释放能量的估算,采用模拟比法结合TNT爆炸试验数据计算出距离储气罐不同距离处爆破冲击波超压值,运用超压准则模拟预测出不同规格、储压下储罐爆破破坏伤害严重程度及危及半径范围;采用世界银行推荐的危害关系式,结合伤害破坏等级分析天然气爆炸破坏效应并与爆破效应比较。5000m3储气罐、储压1.20MPa下,储罐爆破和天然气爆炸危及距离分别可达144.0m和247.7m。依据预测结果,可将罐区周围划分不同区域,为实际工程中罐区选址、建设、安全距离确定及安全预案制定提供参考。     

无机酸对硝酸铵热稳定性影响的研究

为了研究硫酸、盐酸两种无机酸对含能材料硝酸铵热稳定性的影响,使用绝热加速量热仪ARC和微量量热仪C80,对纯硝酸铵及硝酸铵和硫酸、盐酸的混合物进行了热分析实验并研究各种样品在恒温以及升温条件下的吸、放热特性。根据化学反应动力学和热力学理论,确定了硝酸铵及其与无机酸的混合物发生放热分解反应的反应动力学参数和热力学参数。基于Semenov热爆炸模型,计算并比较了各样品标准包装的自加速分解反应温度。     

有机过氧化物生产火灾爆炸危险性分析

针对有机过氧化物自分解温度较低、反应过程易引发火灾爆炸等危险特性,采用危险与可操作分析(HAZOP)方法和事故树(FTA)分析对过氧化物生产过程中存在的火灾爆炸危险性进行分析.结果表明,有机过氧化物生产过程中低温的保证是关键,应对制冷系统进行故障类型及影响分析(FMEA),从而确保制冷系统安全可靠.     

石油库储罐区池火灾事故后果模拟探讨

石油库储罐区火灾、爆炸事故危害巨大.通过对某石油库储罐区池火灾事故后果进行预测评价,对石油库储罐区池火灾事故后果模拟方法进行了讨论和对比,为石油库安全管理、安全评价和应急救援预案编制提供有益的探索.     

Influence of physical properties of ammonium nitrate on the detonation behaviour of ANFO

In order to obtain a better understanding of the non-ideal detonation behaviour of ammonium nitrate based explosives, detonation velocities of ANFO (ammonium nitrate and fuel oil) prepared with different kinds of ammonium nitrate (AN) were measured in steel tubes. In this series of test six kinds of AN were used and the influence of the pore diameter, the pore volume and the particle diameter of the AN particle on the detonation velocity of ANFO was investigated.

It was found that the pore diameter and the pore volume had a strong influence on the detonation velocities of ANFO. In the case of ANFO samples which were prepared with AN that had the same pore diameter and the pore volume, when tested the highest detonation velocity (3.85 km/s) was observed when the smallest particle diameter (<0.85 mm) was used. This value corresponded to 75% of the ideal detonation velocity, which was theoretically predicted by the CHEETAH code with the JCZ3-EOS.

The 12 months aging showed the change of the detonation velocities of ANFO and the reaction of ANFO was influenced both by the physical and the chemical properties of AN particles and oil during the storage period.     

An integrated quantitative hazard analysis method for natural gas jet release from underground gas storage caverns in salt rock. I: Models and validation

It is very important and necessary to perform quantitative hazard analysis for possible accidental leakage from an underground gas storage cavern in salt rock. An integrated quantitative hazard analysis method for natural gas jet release from salt caverns is presented in this paper, which was constituted by a revised model for gas leakage rate calculation, a consequence analysis and a model of probability assessment for harm. The presented method was validated by comparing the analytical results with the data collected from the real accidents (including the leakage, jet fire, fireball and vapor cloud explosion). It is indicated that the proposed method was more accurate than the TNT equivalence method for vapor cloud explosion and gave more reasonable results when applied to the consequence analysis for the thermal radiation from jet fire and fireball.     

Ammonium nitrate thermal decomposition with additives

Runaway reactions present a potentially serious threat to the chemical process industry and the community; such reactions occur time and time again often with devastating consequences. The main objective of this research is to study the root causes associated with ammonium nitrate (AN) explosions during storage. The research focuses on AN fertilizers and studies the effects of different types of fertilizer compatible additives on AN thermal decomposition. Reactive Systems Screening Tool (RSST) has been used for reactivity evaluation and to better understand the mechanisms that result in explosion hazards. The results obtained from this tool have been reported in terms of parameters such as “onset” temperature, rate of temperature and pressure rise and maximum temperature. The runaway behavior of AN has been studied as a solid and solution in water. The effect of additives such as sodium sulfate (Na₂SO₄) and potassium chloride (KCl) has also been studied. Multiple tests have been conducted to determine the characteristics of AN decomposition accurately. The results show that the presence of sodium sulfate can increase the “onset” temperature of AN decomposition thus acting as AN thermal decomposition inhibitor, while potassium chloride tends to decrease the “onset” temperature thus acting as AN thermal decomposition promoter.     

提高铵梯炸药生产安全性的技术途径

本采用粗制TNT代替军工TNT应用于工业炸药中,不仅可减少环境的污染,而且可提高生产安全性。实验证明由粗制TNT制成的炸药,其性能可满足使用要求。     

Quantification of inherent safety aspects of the Dow indices

The Dow fire and explosion index (F&EI) and chemical exposure index (CEI) have been successfully implemented in a Visual Basic environment as a tool for the inherent safety assessment of chemical processes. Subprograms were developed to quantify the inherent safety aspects of the Dow indices. These aspects are presented graphically with the indices on the vertical axis and an inherent safety indicator on the horizontal axis. Dow indices of the MIC storage unit involved in the Bhopal disaster were evaluated to quantify the effects of process temperature, pressure and inventory of hazardous materials on the index values.

As operating pressure was reduced, the F&EI decreased in accordance with the principles of inherent safety. The change in F&EI due to reduction of inventory was more significant than that resulting from pressure reduction. The results show that the F&EI change, given the same range of the independent variables (quantity of hazardous materials, operating temperature and pressure), is larger when a unit in the process area is evaluated compared to a unit in a storage area (tank farm). Reduction of the inventory of hazardous materials had no direct effect on the CEI for vapor releases, whereas the size of the hole diameter impacted the CEI to a great extent. However, there is a significant change in the CEI as the inventory of materials decreases for liquid releases involving temperatures above their flash and boiling points. Pressure reduction decreases the CEI, whereas temperature reduction leads to an increase in the CEI when these parameters are treated independently.     

油库雷击事故的预防与控制

油库是储存易燃易爆油品的专用场所,雷电是油库安全生产的重大隐患,油库防雷已成为关系到经济建设、社会发展和人民生命财产安全的重大课题。针对目前我国油库雷击事故频繁发生的问题,在对大量事故资料研究的基础上,分析了油库雷击火灾爆炸事故的原因,指出雷电产生的火花引燃油气是导致油库火灾爆炸的主要原因。并重点从安全管理学的角度,运用事故预防与控制的＂3E＂对策,分别从安全技术、安全管理、安全教育三个方面探讨了油库雷击事故的预防与控制措施。     

基于超压值地铁上覆管道爆炸对隧道及人员安全影响研究*

为分析地铁上覆管道爆炸对乘客安全影响,采用基于超压冲击波阀值数值模拟,通过将泄漏气体能量等效为TNT当量,分析不同泄漏模式爆炸冲击波对地铁隧道及人员安全影响。结果表明:爆炸产生的超压冲击波对隧道及人员影响小于限值,不会造成人员伤亡,研究结果可为地下工程下穿油气管线安全影响分析提供理论支撑。     

硝酸及氯离子对高温硝酸铵水溶液热危险性的影响研究

国内外学者对硝酸铵的危险性进行了大量的研究,而对其水溶液的危险性至今开展不多。笔者采用差示扫描量热仪(DSC)及全自动反应量热仪(RC1e)对高温状态下的硝酸铵水溶液的热分解危险性、杂质离子对其稳定性的影响进行了研究。纯硝酸铵和90%硝酸铵水溶液的DSC实验表明,90%硝酸铵溶液和分析纯硝酸铵具有相似的热爆炸危险;90%硝酸铵水溶液在140~180℃之间的RC1e试验表明:硝酸或氯离子单独存在时,对硝酸铵分解都有不同程度的抑制作用,而同时存在时则大大降低体系的热稳定性。该结果对保障硝酸铵在生产、使用过程中的安全具有重要的参考价值。     

安全评价方法在危险废物处置环境风险评价中的应用探讨

对安全评价方法在危险废物处置建设项目环境风险评价中的运用进行初步探索。主要用"工艺过程风险因素分析表"对工艺过程潜在风险性识别;用蒙德法进行源项分析;用池火灾模型、蒸气云爆炸伤害模型对易燃、易爆物质的火灾、爆炸等重大事故后果进行计算,得出人员的伤亡半径和财产损失半径等参数,以便于判断风险的可接受水平。分析结果表明:采用安全评价方法对危险废物处置建设项目进行环境风险评价是适用的、可行的。     

关于硝酸铵爆炸事前评价的探讨

硝酸铵主要用作肥料大量使用 ,或作为制造工业炸药的重要原料 ,是一种强氧化剂 ,同时又是自反应性物质 ,国内外因对其控制或管理不当 ,曾发生多起重大爆炸事故。为防止在生产、贮存、运输以及使用过程中的爆炸事故 ,笔者探讨并提出了硝酸铵爆炸事前评价模式。这种评价方法 ,对控制和预防硝酸铵发生事故 ,有借鉴、推广和现实意义。