煤质粉末活性炭自燃和热稳定性分析

针对煤质粉末活性炭最显著的热危险特性——自燃危险性进行试验。采用粉尘层最低着火温度测定系统对煤质粉末活性炭进行自燃试验,测定煤质粉末活性炭的最低着火温度;采用SDT Q600热重分析仪测定煤质粉末活性炭在氮气和空气气氛中以20℃/min的速率升温至700℃时的热解和燃烧特性,通过TG/DTG曲线计算其着火温度,并进行热稳定性评价。粉尘层自燃试验结果表明,煤质粉末活性炭最低着火温度为400℃,具有自燃危险性,易形成阴燃;氮气气氛中热解试验表明,热解过程经历了室温~120.0℃和280.0~700.0℃两次轻缓失重阶段,646.44℃时挥发分热失重速率最大,对应热失重速率峰值为0.082 6%/℃,自燃危险性较低;空气气氛中燃烧试验表明,燃烧过程经历了室温~95.5℃和300.0~600.0℃两次剧烈失重阶段,分别为吸附水分受热蒸发和氧化生成的有机官能团分解脱附导致,565.35℃时挥发分热失重速率最大,对应热失重速率峰值为13.20%/min,粉末较强的氧气吸附效应和较低的导热系数导致其自燃倾向较高,火灾危险性较大。     

湖北省自然保护区建设现状及空缺分析

建立自然保护区是保护生物多样性以及重要自然与文化遗产的主要措施,是保护生态环境和自然资源的基本方式,具有重大的经济、生态、文化、科学以及美学和娱乐价值。根据实地调查和资料汇总,截至2007年12月,湖北省共建立自然保护区58个,总面积108.01万hm2,占湖北省国土面积的5.79%。文章在分析已建自然保护区基础上,研究了自然保护区类型、物种多样性、区域体系布局等方面存在的空缺,提出了调整现有自然保护区(主要方式为合并、升级、扩区)和新建自然保护区(小区、点)的建议,包括合并堵河源和十八里长峡自然保护区、麋鹿自然保护区的扩区,新建三峡库区湿地自然保护区、火烧坪草地生态系统自然保护区等一批自然保护区的规划建议,为湖北省自然保护区管理和规划提供依据。     

池塘悬浮物COD值与灼烧减重燃烧热值的定量关系

为了快速监测水体悬浮有机物的数量,文章采用密封法测定COD,研究了池塘水体悬浮物及固体干物质样品的COD值与燃烧热值及灼烧减重之间的定量关系。结果表明:池塘水体悬浮物及固体干物质样品的COD值与燃烧热值及灼烧减重之间存在显著的相关关系。而且池塘水体悬浮物的COD值与燃烧热值之间的线性回归关系极显著,回归方程为,燃烧热值(J/L)=12.34COD(mg/L)+329.9。给定燃烧热值与有机碳的量以及与有机物量之间的换算系数,就可以推算出池塘悬浮有机物的数量。研究提出了一种池塘水体悬浮有机物的间接定量方法。     

地面爆燃式电打火装置在火炬上的应用

介绍了地面爆燃式电打火装置的结构及安装要点,实践表明该装置点火效率高、故障率低、便于检修,非常适合石油化工行业的火炬打火系统。     

井喷点火后对周边井和集气站的影响研究

以实际工程项目为例,利用计算流体动力学软件（CFD）,以3种不同压力、外界风速和2种出口直径为边界条件,分别对井喷情况下的流场分布进行了18组数值模拟计算,并对模拟结果及其对周边设施的影响进行了分析。数值模拟结果表明,在压力为10MPa,出口直径为62mm,风速为1m／s时,井喷后气流的出口速度超过400m／s,而火焰表面温度超过1500K,喷射火对周边建筑物的伤害范围超过65m,对周边的设备与建筑造成毁坏;超过104m才不会有明显伤害。     

Inhibiting effects by Fe2O3 on combustion and explosion characteristics of ABS resin

The global increase in the use of, and reliance on, plastics has prompted the demand for acrylonitrile-butadiene-styrene (ABS) resin in various fields. With this increased requirement, numerous failures have occurred in the ABS process. Those incidents, resulting from electrostatic discharge, powder accumulation, heat accumulation, construction sparks, and plant fires, have caused dust fire and explosions.In this study, the ABS resin was gleaned from the site and tested for its explosion parameters, including minimum ignition temperature of dust cloud (MIT_C), minimum ignition energy (MIE), and minimum explosion concentration (MEC). To improve loss prevention in the manufacturing process, ferric oxide (Fe₂O₃) as an inert additive was added in the ABS powder. According to the MIE test, Fe₂O₃ has an apparent inhibiting effect on dust explosion for the ABS dust. With the proportion of Fe₂O₃ increased from 25 to 50 mass% in ABS, the MIE increased from 67 to 540 mJ. The explosion tests via 20-L apparatus indicated that Fe₂O₃ mixed with ABS could not increase the MEC significantly. However, the explosion pressure dropped by increasing in the ratio of Fe₂O₃ in ABS. This inerting strategy of ABS was deemed to substantially lessen the probability and severity of fire and explosion.     

Minimum ignition energy of LDPE dust/ethylene hybrid mixture

An experimental device for evaluating the minimum ignition energy (MIE) of LDPE dust/ethylene hybrid mixture was built with the innovative mixing mode. The MIE of the hybrid mixture that contained ethylene below its lower explosive limit (LEL) was studied. The result indicated that adding a small amount of ethylene significantly reduced the MIE of the original dust cloud. All the MIEs with five different particle sizes were found to show similar trends of exponential attenuation with the increase of ethylene concentration; such attenuating effect grew as the dust particle size rose. When ethylene concentration increased and approached to its LEL, the reaction mechanism dominated by combustible dust turned into one dominated by combustible gas. The MIE decreased first and then increased with the dust mass and increased with the dust particle size. A multifactor mathematical correlation model of the MIE with the dust particle size and ethylene concentration was developed.     

For what it's worth: evaluating revealed preferences for green certification

In a case study that examines the outcomes of a flexible information-based policy, we observe how organizations obtain Leadership in Energy and Environmental Design certification. We use a regression discontinuity analysis to identify practices used to upgrade certification tiers. This analysis reveals preferences for green certification strategies and, we argue, intimates the perceived motivations for green certification. We distinguish practices that potentially confer private gains through returns to efficiency and productivity investments, from practices that only provide public benefits. Data show that organizations strategically certify to avoid high-cost resource use, appeal to key stakeholders, and communicate building and organization quality. Builders upgrading to the highest tiers are more likely to deploy practices with private gains. Results suggest a willingness to extend short time horizons associated with energy-efficiency investments in exchange for marketing benefits. Our discussion notes the capacity for certifications to mitigate market barriers associated with the energy-efficiency gap.     

三环唑粉尘爆炸特性研究

利用激光粒度仪对三环唑粉尘的粒径分布进行分析,并用20 L爆炸球测试装置、哈特曼管装置探讨了粉尘质量浓度、点火延迟时间、点火能量、粒径分布对粉尘爆炸的影响并总结了相关规律。实验结果表明:粉尘粒度是影响粉尘最小点火能和爆炸下限的单调因素,粉尘质量浓度是影响粉尘爆炸压力的极值因素,点火延迟时间是影响粉尘最小点火能的极值因素。     

Minimum ignition energy of medicinal powder – Florfenicol and Tilmicosin

This work aims to help improve the electrostatic safety design and explosion prevention of medical facilities. In this study, the minimum ignition energies (MIEs) of Florfenicol, Tilmicosin and mixtures of Florfenicol and Tilmicosin at ratios of 1:1, 1:2, 2:1 and 1:4 were measured in a Hartmann apparatus. The results demonstrated that the MIEs for Florfenicol, Tilmicosin and mixtures of Florfenicol and Tilmicosin at ratios of 1:1, 1:2, 2:1 and 1:4 are 200, 70, 180, 150, 200 and 110 mJ, respectively. Tilmicosin is more sensitive to static electricity, which is more dangerous than the other two powders examined in this paper. Furthermore, the MIEs of the mixtures are proportional to the Florfenicol content. For all powders, the MIE first decreased with the powder mass and later reached its minimum value. In addition, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) were used to investigate the morphological specificity and thermal decomposition of the powders to elucidate the parameters governing the powder explosions further.