加热炉炉管穿孔事故处理及原因分析

以一起直接式原油加热炉炉管穿孔事故为例,介绍了事故处理程序,分析了炉管穿孔的原因是由于漏点腐蚀、坑点腐蚀以及炉管管卡损坏导致的,并提出了类似事故防范对策.     

Evaluation of the emission characteristics of PCDD/Fs from electric arc furnaces

Distribution of PCDD/F (polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran) congeners at two electric arc furnaces (EAFs) in Taiwan is evaluated via intensive stack sampling and analysis. Two kinds of exhaust system in EAFs including stack system and shutter system are selected for measuring dioxin emissions. In addition, dioxin emissions during oxidation and reduction stages at EAF-A were characterized. Results indicate that the PCDD/F concentration of stack gas in EAF-A was 4.39 ng/N m³ while total Toxic Equivalent Quantity (TEQ) concentration was 0.35 ng I-TEQ/N m³. The PCDD/F concentration of stack gas in EAF-B was 2.20 ng/N m³ and the TEQ concentration was 0.14 ng I-TEQ/N m³. 1,2,3,4,6,7,8-H_pCDF, OCDD and OCDF are the major contributors of the dioxin concentrations for two EAFs investigated and the percentage of PCDD/F in particulate phase increases as the chlorination level of the PCDD/F congener increases. The results obtained on gas/particulate partitioning of PCDD/Fs in flue gases prior to the APCD in EAFs indicate that more than 90% exists in particulate phase. In EAF-A, the PCDD/F concentration during oxidation stage is slightly higher than that measured during reduction stage, including the sampling points of CO converter outlet, prior to bag filter and stack. Majority of PCDD/Fs emitted from steel-making processes exists in particulate-phase (about 60–70%) at both EAFs investigated.     

振动加载下转换型密封电磁继电器的性能退化行为研究

目的研究航空用继电器的失效机理。方法通过对电磁继电器进行振动与工作载荷单独施加以及二者综合加载情况下的试验方法及性能退化行为研究,实时监测继电器内部触点间接触电阻等性能参数的变化趋势,并对不同条件下触点表面的微观形貌进行对比分析。结果发现相比较工作载荷单独施加而言,振动应力的加入使得继电器的寿命大幅度降低,并使得触点表面呈现"雪花"一般的形貌。结论振动环境导致了触点之间电弧的变化,以及触点表面接触压力、接触面积和接触超程等,并通过燃弧时间和超程时间的变化趋势对其进行了验证。     

邯钢焦化厂1#～4#焦炉烟尘治理

介绍了邯钢焦化厂1^#～4^#焦炉采用布袋式除尘的烟尘治理方案,装煤和出焦除尘工艺流程及部分改进措施。     

蓄热式加热炉的系统安全分析

采用事故树分析法,分别选取加热炉爆炸事故和煤气中毒事故作为顶上事件,对蓄热式加热炉进行系统安全分析,并从监控系统,作业管理和设备三方面提出了增强其安全性的技术措施。     

高炉渣制备光催化剂及其催化活性的研究

以废弃的冶金高炉渣为原料,采用混酸酸溶-水热合成法制备了光催化剂,并对其进行了SEM、UV-Vis、XRD、比表面积等物性测试分析;通过处理甲基橙模拟废水,探讨了制备过程中渣酸比、混酸配比、渣用量、溶渣时间等条件对高炉渣制光催化剂活性的影响。将所制光催化剂与P25光催化剂进行对比分析,结果表明,高炉渣制光催化剂不仅具有较高的光催化活性,而且制备成本低廉,仅为P25光催化剂的1/10,这对于冶金高炉渣的循环再利用及光催化氧化技术的工业化应用具有重要的实际意义。     

移动通风槽技术在攀钢炼铁高炉矿槽除尘系统的应用

采用移动通风槽技术对攀钢炼铁高炉矿槽除尘系统槽上原有吸尘点进行改造,改造后达到节能减排、降低成本的目的,具有一定的经济效益及环境效益.     

雷击引燃森林可燃物概率的实验研究

利用自主设计的雷击点燃森林可燃物的模拟实验装置,采用大兴安岭地区的松针和白草作为实验材料进行了雷击点燃实验。通过Logistic回归分析得到雷击点燃概率方程,并且通过主成分分析发现可燃物含水率和设备的低压值是决定可燃物是否被点燃的主要因素。通过不同可燃物含水率和电极间距参数条件下的实验证明了Lo-gistic回归方程结果的合理性,并对电极间距改变范围对实验的局限性进行了分析。     

Laboratory investigation of Waelz slag stabilization

Electric Arc Furnace dusts are considered hazardous waste due to their high heavy metals content (zinc, lead, etc.). The Waelz process is one of the most efficient technologies, in terms of capacity and quality, able to recover nearly the 90% of zinc contained in such EAF dusts. Unfortunately, the resulting slag still has eco-compatibility problems, although its mechanical and chemical properties are suitable for civil engineering applications. Stabilization tests, by quartz addition, were performed on EAF dusts in a laboratory furnace. Temperature, treatment time and cooling rate were varied in order to define the best conditions for regulating the formation of a stable microstructure able to hinder the release of substances. Microstructural characterization was carried-out using SEM and XRD analysis. Leaching tests were performed according to EN 12457-2 standards and water analyses were performed using ICP-OES. The best chemical stability was achieved when dust powders were mixed with 20% of silica and water-cooled.     

升流式生物催化电解反应器(UBER)处理硝基苯废水试验研究

升流式生物催化电解反应器(UBER)是一种将生物方法与电化学相结合的新型废水处理技术,使用UBER降解硝基芳香烃类化合物,不但处理周期短、效率高,而且成本低,占地面积小。通过UBER处理含硝基苯模拟废水,对生物催化电解技术的原理进行讨论,并探索最佳反应条件,为该项技术处理实际废水提供理论依据。考察了进水浓度对硝基苯去除率的影响,同时对阴极催化硝基苯定向还原为苯胺进行探讨,最后分别从外加电压、进水乙酸盐质量浓度及进水p H值3个方面,对UBER还原硝基苯的关键影响因素进行最优试验条件分析。结果表明,UBER可以高效处理硝基苯废水,当硝基苯进水质量浓度为200 mg/L时,去除率可以达到97. 2%,但随进水质量浓度进一步提高至220 mg/L,硝基苯的去除效果不佳,去除率仅为79. 13%。当进水硝基苯质量浓度较低时,苯胺生成率较高,平均值达到91%,随硝基苯进水质量浓度提高,引起阴极电势波动,使得还原反应按照多种途径发生,硝基苯不仅被定向还原为苯胺,还被还原成其他副产物,同时,微生物也可以将部分生成的苯胺进一步氧化利用,造成出水苯胺含量偏低。最优条件试验表明,外加电压在0. 3～0. 5 V,硝基苯的去除率均达到93%以上,此时阳极微生物具有良好的电化学活性,当电压降到0. 2 V时,硝基苯去除率仅为36%,表明外加电压过低会严重影响反应器的稳定运行;将乙酸钠质量浓度从1 000 mg/L逐渐减小,质量浓度降低至700 mg/L时,阳极电位依然保持在-440 m V vs. SCE左右,UBER系统运行稳定,当乙酸钠质量浓度进一步降低,阳极微生物电化学活性逐渐受到抑制;UBER中微生物最佳生长p H值为6～7,当p H值超出这一范围,会影响微生物生长代谢,进而影响硝基苯的去除效果。