烧结机尾及整粒除尘系统除尘器“电改袋”

叙述某烧结厂3套烧结机尾及整粒除尘系统的电除尘器改造为长袋低压脉冲除尘器的设计及工程实例。介绍原电除尘器存在的缺陷、“电改袋”具体措施、主要设备选型以及除尘系统运行数据测试结果等方面的问题。除尘系统可靠运行已2年,各项技术指标始终保持优良状态。     

重庆地区大气干降尘化学组分及其在中和降雨酸度中的作用

用直径50cm 的聚乙烯漏斗,在冬夏两季分别截获了白天和夜间的干降尘。结果表明,干降尘中主要阳离子是钙,虽然它吸附二氧化硫,但不酸。计算表明城区干降尘能中和降水中11.8％的酸,四面山中和6.2％。     

Suppression effects of powder suppressants on the explosions of oxyhydrogen gas

Suppression tests of oxyhydrogen gas explosions were performed in an explosion tube with five types of dry powder used as the suppressants. The experimental results showed that the powder with large dust cloud density and small radius has better suppression effect, which agrees well with previous correlative results. Moreover, our results also showed that particles with chemical activity and light material density, their suppression effect are more prominent than that of the inert particles with heavy density. To discover the detailed suppression process of dust powder, governing equations were developed based on the homogeneous reactive two-phase flow. The TVD scheme and the Lax–Wendroff–Rubin scheme were adopted to solve the reactive gas phase and particle phase, respectively. The time splitting technique was employed to handle the stiffness of the coupled equations. Our calculated results showed that the dust cloud has the suppression effect on the explosion of oxyhydrogen gas, and with the increase of dust cloud density or the decrease of particle diameter, its suppression effect become more evident, which is in good agreement with our experimental results, in addition, the numerical results showed that with the same particle diameter, the suppression performance is enhanced with the reduction in particle material density.     

分流制泵站旱流放江对受纳河道水质的影响

为了探明分流制泵站旱流放江对受纳河道的影响,以上海市中心城区典型分流制系统Z泵站为例,研究了旱流放江对受纳河道水质的影响。结果显示:（1）受泵站放江的影响,河道COD、硫化物以及氨氮的增幅分别为0.23%～37.68%、7.4%～76.19%、10.60%～76.15%;（2）旱流放江污染物对河道水质的影响有显著差异,其中COD与氨氮浓度的下降主要源于水体的稀释扩散作用;而H₂S、FeS等硫化物浓度的降低则更多的受到氧化还原反应的影响;（3）Z泵站旱流放江对Z河水质的显著影响范围为泵站排放口上下游40 m范围内,对黄浦江水质的影响则总体不大。     

载体结构对Co/MgO-Al2O3催化剂催化C2H6/CO2反应性能的影响

采用共沉淀-浸渍法制备了不同载体结构的Co/Al₂O₃、Co/MgO_（25）-Al₂O_3（75） （Co/M₁A₃-Spinel）、Co/MgO_（75）-Al₂O_3（25） （Co/M₃A₁-Solid）和Co/MgO催化剂,用于CO₂氧化乙烷脱氢（ODEC）和乙烷干重整（DRE）反应.XRD、Raman、H₂-TPR、XPS表征结果表明,载体结构显著影响催化剂上Co物种的落位、结构和还原性能.Co³⁺和Co²⁺在C₂H₆/CO₂反应气氛中可相互转化,促进C₂H₆和CO₂活化;尖晶石结构中的Co物种比固溶体中的Co物种可还原性强,在高温ODEC反应条件下,催化剂表面的Co物种会被还原成Co⁰,协同Co³⁺/Co²⁺导致C—C键和/或CC键断裂,使得反应路径向DRE转变.MgO基固溶体结构中Co物种与载体相互作用更强,在高温ODEC反应中避免了被大量还原为低价态的Co⁰,ODEC反应可稳定进行.     

岷江干旱河谷甜樱桃发展优势及栽培技术研究

岷江上游干旱河谷特有的生态环境条件适宜发展优质特色水果.甜樱桃作为该区域新兴特色水果之一,近5年来发展面积已超过了400hm2.甜樱桃的引种和规模化栽培表明,岷江上游干旱河谷区发展优质、高产甜樱桃具有独特的优势.总结了岷江干旱河谷栽培甜樱桃的成熟技术和管理措施,探讨了发展甜樱桃的巨大潜力,同时对存在的问题进行了分析,以期为汶川地震灾害农业产业的恢复重建和结构调整提出新的思路.     

Contribution of atmospheric nitrogen deposition to diffuse pollution in a typical hilly red soil catchment in southern China

Atmospheric nitrogen （hi） deposition is currently high and meanwhile diffuse N pollution is also serious in China. The correlation between N deposition and riverine N export and the contribution of N deposition to riverine N export were investigated in a typical hilly red soil catchment in southern China over a two-year period. N deposition was as high as 26.1 to 55.8 kg N/（ha-yr） across different land uses in the studied catchment, while the riverine N exports ranged from 7.2 to 9.6 kg N/（ha-yr） in the forest sub-catchment and 27.4 to 30.3 kg N/（ha.yr） in the agricultural sub-catchment. The correlations between both wet N deposition and riverine N export and precipitation were highly positive, and so were the correlations between NH-N or NO2-N wet deposition and riverine NH4-N or NO3-N exports except for NH-N in the agricultural sub-catchment, indicating that N deposition contributed to riverine N export. The monthly export coefficients of atmospheric deposited N from land to river in the forest sub-catchment （with a mean of 14%） presented a significant positive correlation With precipitation, while the monthly contributions of atmospheric deposition to riverine N export （with a mean of 18.7% in the agricultural sub-catchment and a mean of 21.0% in the whole catchment） were significantly and negatively correlated with precipitation. The relatively high contribution of N deposition to diffuse N pollution in the catchment suggests that efforts should be done to control anthropogenic reactive N emissions to the atmosphere in hilly red soil regions in southern China.     

对美国一起高温氢腐蚀重大事故的反思

介绍了美国TESORO公司阿那科特斯炼厂催化重整装置石脑油预加氢单元换热器高温氢腐蚀所致火灾爆炸事故的概况、经过、事故原因及调查分析过程。就高温氢腐蚀,结合国内炼化行业生产实际进行了分析反思,并提出安全生产建议。     

Size and elemental composition of dry-deposited particles during a severe dust storm at a coastal site of Eastern China

Dry-deposited particles were collected during the passage of an extremely strong dust storm in March, 2010 at a coastal site in Qingdao(36.15°N, 120.49°E), a city located in Eastern China. The size, morphology, and elemental composition of the particles were quantified with a scanning electron microscope equipped with an energy dispersive X-ray instrument(SEM–EDX). The particles appeared in various shapes, and their size mainly varied from 0.4to 10 μm, with the mean diameters of 0.5, 1.5, and 1.0 μm before, during, and after the dust storm, respectively. The critical size of the mineral particles settling on the surface in the current case was about 0.3–0.4 μm before the dust storm and about 0.5–0.7 μm during the dust storm. Particles that appeared in high concentration but were smaller than the critical size deposited onto the surface at a small number flux. The elements Al, Si and Mg were frequently detected in all samples, indicating the dominance of mineral particles. The frequency of Al in particles collected before the dust storm was significantly lower than for those collected during and after the dust storm. The frequencies of Cl and Fe did not show obvious changes, while those of S, K and Ca decreased after the dust arrival. These results indicate that the dust particles deposited onto the surface were less influenced by anthropogenic pollutants in terms of particle number.