曝气生物滤池中含苦味酸废水的COD降解动力学特性

An empirical model for COD removal in a biological aerated filter (BAF) in the presence of 2,4,6-trinitrophenol (TNP) was developed, which related effluent COD to influent COD or hydraulic loading rate along the bed height. The overall reaction rate for substrate biodegradation could be described as pseudo first order. The experimental data of COD removal against reactor height were used to calculate the parameters in the empirical model. The COD concentration at different reactor height was expressed as a function of influent COD concentration and hydraulic loading rate, and , respectively, under the experimental condi-tion. The models may be used to predict the COD removal profiles along the reactor height at different hydraulic loading rates and influent COD concentration for design, selection and sizing of BAF.     

ZL50活性炭吸附脱除二氧化硫的吸附动力学模型(英文)

A semi-empirical adsorption kinetic model was proposed with the time compensation method to describe the chemisorption of SO2 in flue gas by carbon adsorbents for flue gas purification. The change in adsorption capacity and adsorption rate with time at different water vapor concentrations and different SO2 concentrations was studied. The model was in good agreement with experimental data. The surface reaction was probably the rate controlling step in the early stage for SO2 adsorption by ZL50 activated carbon. The parameters m and n in the nth order adsorption kinetic model were related to the magnitude of the time compensation and adsorption driving force, respectively. The change of parameter n with water vapor concentrations and sulfur dioxide concentrations was studied and some physical implications were given. The sum of square errors was less than 1.0 and the average absolute percentage deviations ranged from 0.5 to 3.2. The kinetic model was compared with other models in the literature.     

用各向异性代数应力模型数值模拟搅拌槽中的三维全流场

In accordance to the anisotropic feature of turbulent flow, an anisotropic algebraic stress model is adopted to predict the turbulent flow field and turbulent characteristics generated by a Rushton disc turbine with the improved inner-outer iterative procedure. The predicted turbulent flow is compared with experimental data and the simulation by the standard κ-ε turbulence model. The anisotropic algebraic stress model is found to give better prediction than the standard κ-ε turbulence model. The predicted turbulent flow field is in accordance to experimental data and the trend of the turbulence intensity can be effectively reflected in the simulation. The distribution of turbulent shear rate in the stirred tanks was simulated with the established numerical procedure.     

臭氧氧化阳离子红染料的动力学研究

The ozonation of Cationic Red X-GRL in a semi-batch reactor was studied with variation of the gas flow rate, initial Cationic Red X-GRL concentration, temperature, and pH value. By the evaluation of the liquid mass transfer coefficient, the interfacial area, and the stoichiometric ratio between ozone and Cationic Red X-GRL, the rate constants and the kinetic regime of the reaction between ozone and Cationic Red X-GRL were investigated by applying the experimental data to a model based on the film mass transfer theory. The results obtained support a second order overall reaction, first order with respect to both ozone and dye, and the rate constants were correlated by a modified Arrhenius Equation of temperature and pH value with activation energy of 18.06kJ·mol-1. Hatta number of the reaction was found to be between 0.026 and 0.041, it indicates that the reaction occurs in the liquid bulk, corresponding to the slow kinetic regime.     

Investigation of the liquid recycle in the reactor cascade of an industrial scale ebullated bed hydrocracking unit

One of the commercial means to convert heavy oil residue is hydrocracking in an ebullated bed. The ebullated bed reactor includes a complex gas–liquid–solid backmixed system which attracts the attention of many scientists and research groups. This work is aimed at the calculation of the internal recycle flow rate and understanding its effect on other parameters of the ebullated bed. Measured data were collected from an industrial scale residual hydrocracking unit consisting of a cascade of three ebullated bed reactors. A simplified block model of the ebullated bed reactors was created in Aspen Plus and fed with measured data. For reaction yield calculation, a lumped kinetic model was used. The model was verified by comparing experimental and calculated distillation curves as well as the calculated and measured reactor inlet temperature. Influence of the feed rate on the recycle ratio(recycle to feed flow rate) was estimated. A relation between the recycle flow rate, pump pressure difference and catalyst inventory has been identified. The recycle ratio also affects the temperature gradient along the reactor cascade. Influence of the recycle ratio on the temperature gradient decreased with the cascade member order.     

多管气升式环流反应器的液体循环

A multi-tube air-lift loop reactor (MT-ALR) is presented in this paper. Based on the energy conservation, a mathematical model describing the liquid circulation flow rate was developed, which was determined by gas velocity, the cross areas of riser and downcomer, gas hold-up and the local frictional loss coefficient. The experimental data indicate that either increase of gas flow rate or reduction of the downcomer diameter contributes to higher liquid circulation rate. The correlation between total and the local frictional loss coefficients was also established.Effects of gas flowrate in two risers and diameter of downcomer on the liquid circulation rate were examined. The value of total frictional loss coefficient was measured as a function of the cross area of downcomer and independent of the gas flow rate. The calculated results of liquid circulation rates agreed well with the experimental data with an average relative error of 9.6%.     

Model for seawater fouling and effects of temperature,flow velocity and surface free energy on seawater fouling☆

A kinetic model was proposed to predict the seawater fouling process in the seawater heat exchangers.The new model adopted an expression combining depositional and removal behaviors for seawater fouling based on the Kern–Seaton model.The present model parameters include the integrated kinetic rate of deposition(k d)and the integrated kinetic rate of removal(k r),which have clear physical signi ficance.A seawater-fouling monitoring device was established to validate the model.The experimental data were well fitted to the model,and the parameters were obtained in different conditions.SEM and EDX analyses were performed after the experiments,and the results show that the main components of seawater fouling are magnesium hydroxide and aluminum hydroxide.The effects of surface temperature,flow velocity and surface free energy were assessed by the model and the experimental data.The results indicate that the seawater fouling becomes aggravated as the surface temperature increased in a certain range,and the seawater fouling resistance reduced as the flow velocity of seawater increased.Furthermore,the effect of the surface free energy of metals was analyzed,showing that the lower surface free energy mitigates the seawater fouling accumulation.     

地塞米松磷酸钠的粒度相关生长速率模型

The size-dependent growth of dexamethasone sodium phosphate was studied in a MSMPR crystallizer. The Bransom, CR, ASL, MJ2 and MJ3 size-dependent growth rate models were discussed in details. Using experimental steady state population density data of dexamethasone sodium phosphate, the parameters of five size-dependent growth rate models were determined by the non-linear least - squares method. By comparison of experimental population density data and linear growth rate data with those calculated from five size-dependent growth rate models, it was found that the MJ3 model was the best one for predicting the growth of dexarnethasone sodium phosphate.     

气相有机化合物在改性TiO2/AC复合光催化剂上的光催化降解动力学（英文）

This study is focused on the kinetic characteristics of photocatalytic degradation of gaseous organic compounds on modified titanium dioxide/activated carbon composite photocatalyst(MTA).The MTA,which co-doping with iron(Fe) and nitrogen(N),was synthesized by a sol-gel method,and its photocatalytic performance was investigated under different reaction conditions.The experimental data obtained were tested by the zero,first and second order kinetic model,and the factors affecting the kinetic model were analyzed.It was clearly demonstrated that the experimental data of toluene and acetone on MTA fit quite well with second order kinetic model equation,but the experimental data of formaldehyde fits well with zero order kinetic model equation.     

A Modified Peng-Robinson Equation State for Prediction of Gas Adsorption Isotherm

This research proposes a modified two-dimensional Peng-Robinson equation model to predict adsorp-tion isotherm in adsorbate-adsorbent systems. The parameters of the proposed model are calculated by using the op-timization of experimental data for the different single gas adsorption systems at various temperatures. The experi-mental adsorption equilibrium data of adsorbate-adsorbent systems was compared with the calculated results in our proposed model and the two-dimensional Hill-deBoer equation model. The proposed model as indicated in the re-sults shows a better prediction of the experimental results compared with two others.     

金属垫片密封连接的泄漏率计算

金属垫片密封是压力容器和管道中常见的连接型式,其失效极少是因强度不足引起的,泄漏是连接系统失效的主要原因。在金属垫片泄漏模型基础上,考虑垫片接触应力分布不均匀对泄漏通道的影响,推导了变截面泄漏通道的泄漏率计算公式,此公式将泄漏率、垫片接触应力、介质压力和密封表面分形参数联系在一起,因而使以最大允许泄漏率为准则的金属垫片密封连接设计以及紧密性评价成为可能。     

非金属垫片分形泄漏模型理论分析

以分形几何为基础,建立非金属质垫片分形泄漏模型.研究表明,载荷稳定时垫片中压力分布呈幂律变化,垫片泄漏率与压差成正比,且与分形垫片参数、异常扩散系数等有关.     

膨胀石墨缠绕垫片常温密封性能分析

采用ANSYS商用有限元分析软件,对常温条件下受内压的螺栓法兰连接膨胀石墨缠绕垫片进行了应力分析,并根据多孔介质模型的泄漏率方程计算出膨胀石墨缠绕垫片在常温条件下的泄漏率。运用有限元计算模型对不同带宽的膨胀石墨缠绕垫片进行了不同条件下的数值模拟,模拟结果与实验结果较好地吻合。模拟结果给出了常温条件下介质内压、螺栓预拉伸力和填料带宽对螺栓法兰连接膨胀石墨缠绕垫片泄漏率的影响。     

柔性石墨金属波纹复合增强垫片密封性能试验

在全自动垫片综合性能试验台上分别进行了316L和A3钢作为骨架材料的金属波纹复合垫片的泄漏率、压缩回弹性能和应力松弛试验,考察了柔性石墨覆盖层厚度、骨架材质和垫片应力对垫片密封性能和力学性能的影响,分析了不同覆盖层厚度和垫片应力下的金属波纹残余高度。结果表明:覆盖层厚度对垫片的密封性能有重要影响,厚度为0.6 mm时该类垫片的综合性能最佳;金属波纹复合垫片具有良好的承载能力和密封性能,尤其适宜压力波动、温度剧变等场合的密封,预压缩处理更能真实反映出复合垫片优异的回弹性能;此外,与A3钢作为骨架材料的复合垫片相比,316L复合垫片的密封性能和压缩回弹性能随垫片应力的增加逐渐显现,且其抗松弛能力和抗蠕变性能也得到了显著提高。     

Leckageraten von Dichtungen für Flanschverbindungen: Einflußgrößen,Anforderungen, meßtechnische Erfassung und leckageratenbezogene Dichtungskennwerte

Flow theories can help in determining the fundamental interrelationships between the leak rate of gaskets for flange connections and the relevant influencing parameters. The basic rule for the transfer of results obtained for special boundary conditions to other conditions can be derived. In this way the effort involved in gasket testing can be reduced. This paper gives the interrelations between the leak rate of gaskets on the one hand and the internal pressure, the temperature, the medium, and the gasket thickness on the other and discusses them with aid of measured results. The effect of the gasket stress and thickness can be determined only of experimental investigations. Furthermore, the requirements placed on gaskets, the leak rate related gasket characteristics defined in various standards and the measuring techniques for their determination are discussed.     

CNTs阵列增强石蜡/硅橡胶复合相变垫片的散热性能研究

电子技术的高速发展对散热技术提出了更高的要求,热界面材料作为散热技术的关键材料之一,面临着提高热导率以及减小传热热阻的挑战。将垂直碳纳米管阵列(VACNTs)和固-液相变材料石蜡(PA)与硅橡胶(SR)复合,研制了一种新型VACNTs/PA/SR复合相变垫片。研究表明,通过磁场校准方法可以使表面改性的镀镍多壁CNTs在SR中实现垂直定向排列,所得VACNTs/SR垫片较CNTs随机排列的垫片具有更高的热导率,并确定VACNTs/SR垫片中CNTs的适宜含量为6%(质量),对应垫片的热导率可达0.71 W/(m·K)。对于固定CNTs含量为6%(质量)但PA含量不同的一系列VACNTs/PA/SR相变垫片,PA的添加量不大于12.5%(质量)时,相变垫片克服了液态PA的泄漏问题;相变垫片在PA发生固-液相变后表现出硬度显著下降,热阻减少可达55.14%,并具备优异的热可靠性。将最佳VACNTs/SR垫片样品及最佳VACNTs/PA/SR相变垫片样品进行散热性能对比发现,与使用VACNTs/SR垫片的情况相比,使用VACNTs/PA/SR相变垫片时的模拟芯片不仅在温度上升阶段的升温速率更小,而且当芯片温度达到平衡后对应的平衡温度也更低,降低了3.5℃,显示出更好的散热性能。VACNTs/PA/SR相变垫片优良的特性和散热性能使其在电子设备散热领域具有良好的应用前景。     

CNTs阵列增强石蜡/硅橡胶复合相变垫片的散热性能研究

电子技术的高速发展对散热技术提出了更高的要求,热界面材料作为散热技术的关键材料之一,面临着提高热导率以及减小传热热阻的挑战。将垂直碳纳米管阵列(VACNTs)和固-液相变材料石蜡(PA)与硅橡胶(SR)复合,研制了一种新型VACNTs/PA/SR复合相变垫片。研究表明,通过磁场校准方法可以使表面改性的镀镍多壁CNTs在SR中实现垂直定向排列,所得VACNTs/SR垫片较CNTs随机排列的垫片具有更高的热导率,并确定VACNTs/SR垫片中CNTs的适宜含量为6%(质量),对应垫片的热导率可达0.71 W/(m·K)。对于固定CNTs含量为6%(质量)但PA含量不同的一系列VACNTs/PA/SR相变垫片,PA的添加量不大于12.5%(质量)时,相变垫片克服了液态PA的泄漏问题;相变垫片在PA发生固-液相变后表现出硬度显著下降,热阻减少可达55.14%,并具备优异的热可靠性。将最佳VACNTs/SR垫片样品及最佳VACNTs/PA/SR相变垫片样品进行散热性能对比发现,与使用VACNTs/SR垫片的情况相比,使用VACNTs/PA/SR相变垫片时的模拟芯片不仅在温度上升阶段的升温速率更小,而且当芯片温度达到平衡后对应的平衡温度也更低,降低了3.5℃,显示出更好的散热性能。VACNTs/PA/SR相变垫片优良的特性和散热性能使其在电子设备散热领域具有良好的应用前景。     

液下气泡检漏方法研究

探讨了液下气泡检漏法的基本原理、泄漏率计算方法以及检漏精度和分辨率。应用该方法对石棉橡胶垫片的泄漏率进行了测定 ,试验结果与采用集漏空腔增压法测得的泄漏率具有较好的可比性。分析了液下气泡法用于工程实际时应注意的问题。     

氦质谱检漏法应用研究

对氦质谱检漏法的检漏精度、分辨率、检漏范围以及检测结果的重复性进行了系统研究 ,阐述了影响检漏精度的可能因素。在真空密封试验台上对石棉橡胶垫片等密封元件的检漏结果表明 ,该检漏方法的检测精度高、重复性好 ,特别适用于微小泄漏率的精确检测 ,是压力容器和密封元件的理想检漏方法。     

高压法兰密封泄漏处理

概述了高压法兰透镜垫密封的结构和运行情况。针对泄漏产生的原因、从振动、装配、工艺操作及管件材质等不同角度介绍了减少泄漏的措施。根据密封元件的损坏情况，提出了检修密封元件、改造透镜垫等消除泄漏的方法。