Dispersion of multiwalled carbon nanotubes in aluminum powders

Multiwalled carbon nanotubes (MWNTs) were treated with the reflux within the concentrated nitric acid for 0-25 h to purify and disperse the tangled MWNTs. The effect of reflux time on the morphology and the weight loss of MWNTs were investigated. Meanwhile,the dispersion of MWNTs with 0-2.0 wt.% in 2024Al powders using mechanical stirring with an assisting ultrasonic shaker in ethanol was also studied. The results show that the reflux time markedly affects the morphology of MWNTs. The weight loss of MWNTs i...     

连续重整装置压缩机气量调节系统节能改造

上海高桥分公司800kt/a连续重整装置,再接触部分采用美国UOP公司第二代连续重整工艺技术,三台往复式压缩机采用两段式压缩,通过级间回流调节控制系统压力,该调节系统(即旁通调节)无用功耗大,尤其工况耗气量低时,造成能量浪费,且人工调节复杂,系统可操控性较低,只适用于偶尔调节或调节幅度小的场合,无法根据实际工况逐步加、降载荷,不能避免开停机过程中大幅、快速升降压对机组及系统压力的冲击,影响压缩机机组及系统压力控制的稳定。改造中,增压机(K202C)新上一套HydroCOM无级气量调节系统,该系统运用"回流省功"原理,除了能改善压缩机的可操控性,满足复杂多变的工艺需求外,还能节省能源。在装置满负荷运行工况下,压缩机(K202C)运行负荷为50%,系统压力控制稳定,且调节速度快,满足生产要求。2010年10月10日,在压缩机一级负荷率为45%,二级负荷率为50%工况下,经标定,压缩机(K202C)运行电流由原来的250A下降至120A,减少电耗约1300kW.h/h。同时,HydroCOM系统投用后,有效降低了压缩机机组级间冷却器负荷,为装置的系统节能提供了补充。     

笃斯越桔黄酮类化合物提取技术的试验研究

采用对比分析的方法,研究了影响笃斯越桔叶中黄酮类化合物提取率的多种因素,并通过L9(34)正交试验设计优化出热回流法提取笃斯越桔叶中黄酮类化合物的最佳工艺条件:温度为80℃,料液比为1/50,乙醇浓度为80%,时间为25min。     

精馏塔最小回流比的优化

应用操作费用和设备投资费用的数学模型,采用黄金分割法的优化手段,并用C语言进行编程对精馏塔的回流比进行了优化,其结果与文献[8]中得出的结果基本吻合。     

ZnO-Au hybrid nanocrystals via a high temperature reflux route

ZnO-Au hybrid nanocrystals with good dispersibility and uniform size are prepared via a high temperature reflux route. The structure, morphology, interface structure and optical properties were characterized by X-ray diffraction high resolution transmission electron microscope and UV-vis absorption spectrophotometer. The formation of hybrid nanocrystals was believed to arise from the heterogeneous nucleation and epitaxial growth, high temperature and surfactant are proposed as the key factors for producing fine and uniform hybrid nanocrystals.     

一种新型水气蒸馏回流仪

提出了一种新型水气蒸馏回流仪,该仪器具有水气蒸馏、回流提取及分水等多种功能,且便于操作。经试用,效果良好。     

基于HFSS的差分信号回流路径设计与仿真

为满足高速电路中差分信号对信号线的低反射与高传输的设计要求，通过对差分信号线的电磁场分布与耦合情况的理论分析，提出了差分信号回流路径的一种优化方案，并给出了建模仿真的方法。运用三维电磁仿真软件HFSS通过在模型中设置参考平面、过孔相关信息等操作分别对差分信号的回流路径进行设计与仿真，利用S参数及模型电场分布分析差分信号的信号质量。仿真结果表明，本优化方案能够有效降低信号线的反射，提高信号线的传输性能与信号完整性。     

污水厂二级出水的深度处理中试研究

为使沈阳北部污水处理厂二级生化处理出水达到回用水水质,在中试规模(1 m3/h)下采用污泥回流高效絮凝+过滤工艺对其进行了深度处理。试验结果表明,经该工艺处理后,色度、浊度、CODCr、总磷平均去除率分别达到43%、90.6%、65.6%、86.3%,出水色度为19.7度,浊度为0.6 NTU,CODCr为25.3 mg/L,总磷为0.6 mg/L,出水色度、浊度、CODCr、总磷达到《城市污水再生利用工业用水水质》(GB/T 19923—2005)的要求。但系统对氨氮的去除率仅为19.7%,有待进一步提高。     

Study of heterogeneously catalysed reactive distillation using the D+R tray—A novel type of laboratory equipment

Recently, novel equipment for heterogeneously catalysed reactive distillation, the D+R tray, has been introduced by Schmitt et al. (2009). The present work reports results of measurements of the separation capacity of D+R trays. Furthermore, results of reactive distillation experiments on two test systems are presented that show that the D+R tray can be used routinely for laboratory studies of heterogeneously catalysed reactive distillation. As test systems, the esterifications yielding butyl acetate and hexyl acetate were chosen. Reactive distillation using catalytic packings was studied previously in detail ( [Parada, 2008], [Schmitt et al., 2004] and [Schmitt et al., 2005]) with the same test system. The experiments of the present work are carried out so that a direct comparison is possible. For both test systems, the most important process parameters such as feed rate and mass of catalyst were systematically varied. High conversions of the reactants and high purities of the products were achieved. The reproducibility of the results is excellent. The study shows that the D+R tray is a novel laboratory equipment that facilitates fast and flexible investigations of heterogeneously catalysed reactive distillation processes and that it can be used for studying process designs of columns equipped with either catalytic packings or trays.     

水解酸化+生化A/O工艺处理碎煤加压气化废水的试验研究

针对碎煤加压气化所产生的废水具有含酚高、氨氮高、可生化性差等特点,采用水解酸化+生化A/O组合工艺进行处理,考察了停留时间和回流比对处理效果的影响。结果表明:水解酸化池较合适的水力停留时间在22.7 h^35.7 h;生化A/O池的水力停留时间超过100 h时,COD的质量浓度可降到300 mg/L左右;生化A/O池的混合液回流比对总氮的去除率影响较大,且维持3倍左右的回流比时,可获得较好的总氮去除率。