大口径高温高压管道下沉分析

以某电厂的主蒸汽管道为例,对其支吊架进行冷、热态检验,发现炉侧连续恒力吊架冷态时指针卡死下极限位置,热态时实际垂直热位移值较小,与设计严重不符。根据现场情况和应力计算结果综合分析,发现管道壁厚存在严重误差导致管道下沉。针对以上情况,首次提出了支吊架配置改造方案需要考虑的4个方面,给解决此类问题提供帮助。     

碳钢管路在某型艇舱底水中的腐蚀原因分析

目的调查20号碳钢在海水和舱内污水中的腐蚀原因。方法采用全浸腐蚀试验、电偶腐蚀测试、电化学测试和腐蚀形貌分析等方法对某型艇碳钢海水管路的腐蚀原因进行研究。结果获得了20号碳钢在海水和舱内污水中的腐蚀速率、腐蚀电位、极化曲线、阻抗图谱、腐蚀形貌等数据。结论舱底碳钢管的腐蚀主要是由于管内海水的腐蚀、焊接对管材的热影响和舱内污水的腐蚀作用引起的,其中管内海水的腐蚀作用是主要因素。     

Temperature profile across the combustion zone propagating through an iron particle cloud

Knowledge of the mechanism of combustion zone propagation during dust explosion is of great importance to prevent damage caused by accidental dust explosions. In this study, the temperature profile across the combustion zone propagating through an iron particle cloud is measured experimentally by a thermocouple to elucidate the propagation mechanism. The measured temperature starts to increase slowly at a position about 5 mm ahead of the leading edge of the combustion zone, increases quickly at a position about 3 mm ahead of the leading edge, reaches a maximum value near the end of the combustion zone, and then decreases. As the iron particle concentration increases, the maximum temperature increases at lower concentration, takes a maximum value, and then decreases at higher concentration. The relation between the propagation velocity of the combustion zone and the maximum temperature is also examined. It is found that the propagation velocity has a linear relationship with the maximum temperature. This result suggests that the conductive heat transfer is dominant in the propagation process of the combustion zone through an iron particle cloud.     

Exploitation of iron ore tailing for the development of ceramic tiles

India ranks as the sixth largest producer of iron ore in the world. The current practice of washing iron ore in India generates as high as 18 million tonnes of tailings per year. These tailings are stored in massive ponds and pose environmental hazards. Safe disposal or utilisation of these materials thus remains a challenging task for the iron ore industry in India. The present paper describes a new development in managing these tailings by converting them into value added products such as ceramic floor and wall tiles for building application. These tiles have high strength and hardness compared to conventional tiles and conform to most of the EN standards. Energy economy and lower production costs are some other benefits.     

Remediation of DDT-Contaminated Water and Soil by Using Pretreated Iron Byproducts from the Automotive Industry

The objective of this study was to quantify the effectiveness of different pretreated iron byproducts from the automotive industry to degrade DDT [(1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane] in aqueous solutions and soil slurry. Iron byproducts from automotive manufacturing were pretreated by three different methods (heating, solvent and 0.5N HCl acid washing) prior to experimentation. All pretreated irons were used at 5% (wt v^{? 1}) to treat 0.014 mM (5 mgL^{? 1}) of DDT in aqueous solution. Among the pretreated irons, acid pretreated iron results in the fastest destruction rates, with a pseudo first-order degradation rate of 0.364 d^{? 1}. By lowering the pH of the DDT aqueous solution from 9 to 3, destruction kinetic rates increase more than 20%. In addition, when DDT-contaminated soil slurry (3.54 mg kg^{? 1}) was incubated with 5% (wt v^{? 1}) acid-pretreated iron, more than 90% destruction of DDT was observed within 8 weeks. Moreover, DDT destruction kinetics were enhanced when Fe(II), Fe(III) or Al(III) sulfate salts were added to the soil slurry, with the following order of destruction kinetics: Al(III) sulfate > Fe(III) sulfate > Fe(II) sulfate. These results provide proof-of concept that inexpensive iron byproducts of the automotive industry can be used to remediate DDT-contaminated water and soil.     

厚壁管变形横波周向超声检测工艺及缺陷定位系统开发

在理论研究的基础上，利用试块对厚壁管变型横波与折射横波检测灵敏度进行了比较，证实了变型横波在厚壁管件中的检测灵敏度高于折射横波；设计开发计算软件，实现缺陷进行自动定位，大大提高现场检测效率和定位精度。     

常温下铁的硫化产物自燃性

含硫油品储运过程中H2S腐蚀产物是常温下硫铁化合物的主要来源,以H2S与铁粉反应制备的硫铁化合物来模拟设备内H2S的腐蚀产物,利用自然氧化的方法测定了硫化反应产物的一次氧化升温和二次氧化升温,考察了铁粉含水量对硫化反应及硫化反应产物自燃性的影响,采用XRD和SEM手段对硫化反应产物进行了表征。结果表明:H2S与铁粉的硫化反应产物为FeS,呈微小颗粒状,覆盖在铁粉表面;硫化反应产物具有自燃性,一次氧化升温最高达到87℃;未被完全氧化的硫化反应产物密封放置一段时间后自燃性明显增加,其二次氧化升温速率最高超过39℃/min;铁粉中含有适量的水可以增加硫化反应速率,提高硫化反应产物的自燃性。     

Hg0 removal from flue gas over different zeolites modified by FeCl3

The elemental mercury removal abilities of three different zeolites(Na A, Na X, HZSM-5)impregnated with iron(Ⅲ) chloride were studied on a lab-scale fixed-bed reactor. X-ray diffraction, nitrogen adsorption porosimetry, Fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy, and temperature programmed desorption(TPD) analyses were used to investigate the physicochemical properties. Results indicated that the pore structure and active chloride species on the surface of the samples are the key factors for physisorption and oxidation of Hg0, respectively. Relatively high surface area and micropore volume are beneficial to efficient mercury adsorption. The active Cl species generated on the surface of the samples were effective oxidants able to convert elemental mercury(Hg0)into oxidized mercury(Hg2+). The crystallization of Na Cl due to the ion exchange effect during the impregnation of Na A and Na X reduced the number of active Cl species on the surface, and restricted the physisorption of Hg0. Therefore, the Hg0 removal efficiencies of the samples were inhibited. The TPD analysis revealed that the species of mercury on the surface of Fe Cl3–HZSM-5 was mainly in the form of mercuric chloride(Hg Cl2), while on Fe Cl3–Na X and Fe Cl3–Na A it was mainly mercuric oxide(Hg O).     

Disruption of iron homeostasis and resultant health effects upon exposure to various environmental pollutants: A critical review

Environmental pollution has become one of the greatest problems in the world, and the concerns about environmental pollutants released by human activities from agriculture and industrial production have been continuously increasing. Although intense efforts have been made to understand the health effects of environmental pollutants, most studies have only focused on direct toxic effects and failed to simultaneously evaluate the long-term adaptive, compensatory and secondary impacts on health. Burgeoning evidence suggests that environmental pollutants may directly or indirectly give rise to disordered element homeostasis, such as for iron. It is crucially important to maintain concerted cellular and systemic iron metabolism. Otherwise, disordered iron metabolism would lead to cytotoxicity and increased risk for various diseases, including cancers. Thus, study on the effects of environmental pollutants upon iron homeostasis is urgently needed. In this review, we recapitulate the available findings on the direct or indirect impacts of environmental pollutants, including persistent organic pollutants (POPs), heavy metals and pesticides, on iron homeostasis and associated adverse health problems. In view of the unanswered questions, more efforts are warranted to investigate the disruptive effects of environmental pollutants on iron homeostasis and consequent toxicities.     

铁柱撑累托石的制备及其对活性艳蓝的降解

以天然粘土矿物累托石为载体、以铁盐作交联剂,利用水溶液插层方法制备了铁/累托石复合物。采用FT-IR和XRD两种表征方法对铁/累托石复合物进行了表征,分析了复合物的结构变化和层间间距变化,并探讨了复合物制备条件以及反应过程中溶液初始浓度、溶液初始pH、复合物投加量和H2O2浓度因素对催化降解活性艳蓝的影响。研究表明:铁聚合物插入到累托石的层间结构中,扩大了累托石的层间距;当Na+/Fe3+比值为0.5,Fe3+/累托石比值为10 mmol/g,p H为3左右,催化剂用量为0.5 g/L时,H2O2浓度为100 mg/L时,活性艳蓝的去除率达到90%以上。实验表明,铁柱撑累托石/UV/Fenton工艺对活性艳蓝具有良好的降解效果。