Experimental Simulation of the Reactor Section of Fluid Cokers: Comparison of FCC and Fluid Coke Particles

The hydrodynamics of fluid cokers were studied in a pressurized fully cylindrical cold model of diameter 483 mm, geometrically and dynamically scaled down by a factor of ～20 from commercial units. Differential pressure fluctuations, voidage distributions, solids momentum flux distributions and steady state gas mixing behaviour in the reactor section are compared for the same operating conditions with two kinds of particles, FCC and fluid coke. The voidage distributions and core‐annular flow structures in the reactor section were similar enough that either FCC or fluid coke particles can be used for cold modelling of fluid cokers.     

Étude expérimentale du mélange réactif au sein d'un réacteur torique ondulé (RTO)

Reactive mixing in a wavy torus reactor (WTR) has been examined experimentally. Its performances are compared to these of two other reactors: a plane torus reactor (PTR) and a baffled stirred tank reactor (BSTR). hydrodynamics of mixing has been studied using a plug flow model with axial dispersion for the WTR and PTR. The effect of axial dispersion on the kinetic of a chemical reaction was then analysed for the WTR, PTR and BSTR. Mixing times were slightly longer for the WTR due to a weaker axial dispersion. We also noticed an improvement of the convertion rate for low dissipated power.     

Energy Efficiency of Two‐Phase Mixing in a Modified Bubble Column

Energy efficiency for gas liquid mixing in a modified downflow bubble column reactor has been analyzed in this paper. Efficiencies of the different parts of the bubble column have been assessed on the basis of energy dissipation. Prediction of the energy dissipation coefficient as well as energy utilization efficiency due to gas‐liquid mixing as a function of different physical, geometric and dynamic variables of the system has been done by correlation method. The distribution of energy utilization in the different zones of the column has also been analyzed. Experiments were carried out with air‐water and air‐aqueous solutions of carboxy methyl cellulose with different concentrations.     

强化单螺杆挤出机内层流混合的方法

综述了单螺杆挤出机内聚合物熔体层流混合机理的研究进展，对提高混合的措施进行了分析总结，指出了进一步强化混合效果的方法。     

考虑边界反射的河流离岸排放污染混合区计算方法

在等强度点源离岸排放条件下,从简化二维移流扩散方程的解析解出发,探讨了考虑两岸反射作用的中宽河流污染混合区的计算方法。给出了污染混合区边界形状曲线与量纲一方程的形式;采用迭代计算和试算比较法,给出了靠岸与离岸两种类型混合区各几何特征参数(坐标)、面积及面积系数与相对离岸距离的关系曲线,提出了以相对离岸距离a'作为判据的排放类型分区条件。给出了河流岸边、离岸与中心排放的分类判别准则:(1)当0≤a'≤a'1时,简化为岸边(近岸)排放类型;(2)当a'1a'a'2时,称为离岸排放类型;(3)当a'2≤a'≤0.5时,简化为中心排放类型,并给出了岸边排放类型与离岸排放类型的临界相对离岸距离a'1和中心排放类型与离岸排放类型的临界相对离岸距离a'2的表达式。通过回归分析,给出了中宽河流离岸排放类型混合区主要特征参数的实用计算公式,可作为中宽河流污染混合区范围计算和排污口位置优化设计的依据。     

NON-CUBIC EQUATION OF STATE FOR PHASE EQUILIBRIUM CALCULATIONS

A new non-cubic equation of state is proposed for calculation of the thermodynamic properties ofnonpolar and polar fluids and their mixtures,including,saturated vapor pressure,saturated liquid volume,saturated vapor volume,heats of vaporization and vapor-liquid equilibria.The new equation is derived from thegeneralized van der Waals partition function in which the repulsive terms are expressed with the Carnahan andStarling equation for hard spheres,and the attractive terms are made up of the dispersive energy and theChemical association energy. The rules of dependence of parameters α and σ and on temperature are considered broadly so that the newequation yields good agreement with experimental saturated properties of 20 nonpolar and 27 polar fluids in therange of reduced temperatures of 0.5 to 1.0 The new equation with parameters group-contributed generally givessatisfactory predictions on saturated properties. Correlations of vapor-liquid equilibrium data for alcohol-containing systems by using van d     

采用高性能搅拌设施生产适应市场的水泥

在欧洲和世界其它地区，CEMⅠ水泥(渡特兰水泥)日益为CEMⅡ水泥(有几个主要组份的渡特兰水泥)和CEMⅢ水泥(高炉矿渣水泥)所替代。为了满足生产具有特定粒径分布的高质量水泥的要求，现广为采用的不同水泥组分的混合粉磨工艺已经被单独粉磨然后再在高性能均化设施中进行均化的工艺所代替。依据情况不同，可以采用连续或间歇式搅拌机。文章描述了不同工艺技术．并介绍了最近的几个实例：     

Mixing in Wave Processes Propagating in Gas Mixtures (Review)

A review is made of uptodate investigations in the field of physicomathematical modeling of mixing of solid particles with highvelocity gas flows arising under the action on shock waves, compression waves, and expansion waves on unstable dust deposits on the boundaries of channels or plates and in cavities, as well as on free clouds of particles. In particular, experiments in shock tubes with particles initially located in cavities and on surfaces are described. The experimental data presented in the form of distributions of particle concentrations at various points of space above the unstable layer, pressure distributions on the lower wall of the shock tube, etc., are used for verification of proposed mathematical models in regimes of single particles, interacting continua, and turbulent diffusion. An analysis of experimental and numerical data shows that the models considered sometimes allow adequate identification of the wave structure of motion of the mixture and the field of parameters inside and outside the layer.     

碰撞式混合器的设计和使用

从反应注射成型过程对混合器的结构设计、操作条件等的要求出发，对碰撞式混合器的设计和使用应注意的问题进行了分析探讨，并提出了相应的解决办法和处理措施。     

含白炭黑胎面胶的混炼

以白炭黑作填充剂的轮胎具有滚动阻力低等优点。但是白炭黑在橡胶中不易分散。介绍了为提高含白炭黑的胎面胶的混炼质量，加速白炭黑在轮胎中的推广应用而采取的原材料、混炼工艺和混炼设备。