Packing Density of Binary Mixtures of Wet Spheres

An experimental study of the packing of binary mixtures of coarse spheres with the addition of water has been conducted. The results indicate a similarity between dry and wet packings, either in the relationship between the packing density and the moisture content or in the relationship between the packing density and the particle-size distribution. The Westman equation is used to describe the wet packing after necessary modification. The approach is verified by the good agreement between the calculated and measured packing densities.     

Improved Equation of the Continuous Particle Size Distribution for Dense Packing

The Furnas model describes the discrete particle size distribution for densest packing. Using a model that considers a continuous particle size distribution for the densest packing to be a mixture of infinite Furnas discrete particle size groups, an equation for the cumulative particle size distribution providing the densest packing was derived. Monosize particles with different shapes have a different packing pore fraction. One parameter in the equation is the pore fraction of packed monosize particles; the particle size distribution for achieving densest packing is a function of this pore fraction. A reduced form of this equation is also presented as a working equation. The equation derived here is compared to the modified Andreasen equation for dense packing. An equation and the correlated graph for calculating theoretically the geometric mean particle size and an equation for calculating the specific surface area of the particle size distribution of the improved equation are also derived.     

粗骨料颗粒堆积简化计算模型的研究

提出了一种粗骨料颗粒堆积简化计算模型。此模型将粗骨料颗粒特征化为椭圆形颗粒,利用定量体视学原理采集粗骨料颗粒的形状特征参数,建立了骨料颗粒的堆积法则,设计了可以快速计算其堆积密度的计算方法,得到了粗骨料实际堆积密度PR与虚拟堆积密度PV的修正公式PR=0.896PV＋8.697。经验证,修正后的虚拟堆积密度与实际堆积密度的平均相对误差仅为0.32%,准确度较高。可利用此模型计算出的骨料堆积空隙率,进行混凝土配合比设计。     

有机粉末真密度的测定

为了更快、更准确的测定有机粉末的真密度,本文详细介绍了利用比重瓶超声沉降法测定有机粉末的密度,并且讨论了影响测定结果的因素。对用比重瓶测定粉末密度的过程进行了详细的阐述,给出了密度的计算公式。最后,通过对直接浸润、压片、超声三种方法测定有机粉末真密度的结果进行比较,表明比重瓶超声法测得的结果更加精确。     

散堆填料塔填料层分段高度的随机计算

依据随机函数ＲＮＤ（Ｉ）在程序运行过程中产生的一系列随机数,模拟散堆填料塔中液体在填料层中的流动情况,并推算出填料层适宜的分段高度。     

塔填料的研究现状及发展趋势

介绍了散堆填料的发展过程，分析了通过改变散堆填料的几何结构以改变填料性能的方法；并对规整填料的发展、现状作了综述性的介绍，阐述了提高规整填料传质效率的途径；简单分析了今后填料塔的发展方向。     

散装填料的发展趋势

介绍了散装填料的种类、主要生产厂商、填料的表面处理方法和散装填料的应用范围,分析了散装填料未来的发展趋势,并指出散装填料与其它类型的塔填料相比,在今后的一段时期仍将占有重要地位。     

高效规整填料性能和应用

介绍国外各种高效规整填料和天津博隆公司的专利产品——Ｃｈｉｎａｐａｋ规整填料的性能和应用。     

泥状填料应用于泵密封

以新型泥状填料为研究对象,通过对密封原理的分析及新老泵类轴端密封材料性能的比较,从而得出两代密封材料的优缺点.本文还对泥状填料的应用范围进行分析.     

Effect of Interparticle Potentials and Sedimentation on Particle Packing Density of Bimodal Particle Distributions During Pressure Filtration

Effect of interparticle forces, bimodal particle size distribution, and slurry viscosity on particle packing in alumina bodies consolidated by pressure filtration is presented. The requirements for packing colloidal particles to their highest density are strong repulsive interparticle forces and optimum particle size distribution. Even though these conditions are met, the high packing density in consolidated bodies may be adversely affected by particle segregation resulting from sedimentation. Therefore, the slurry during consolidation must have a sufficiently high viscosity to prevent sedimentation.     

填料动密封的技术改进

通过分析填料密封的机理和改进原理,从而提出对填料密封采用低压反吸、高压反冲、不同类型填料搭配组合等改进措施.运用结果表明:能延长使用周期4倍以上,泄漏率减少80%以上.     

组合型填料与焦炭填料塔中餐厅污水氧传递研究

本文分别以焦炭和自行开发的新型组合填料为塔内构件,对清水和餐厅污水中的氧传递特征进行了分析和实验研究,纯氧和空气供氧实验结果证实氧传递过程为液膜控制;通过实验测定了清水和餐厅污水在组合型填料和焦碳填料塔中曝气过程溶解氧的变化规律,从实验结果回归得到了上述填料塔内清水与餐厅污水氧转移系数计算关联式,计算值与实测值吻合较好;最后,对相同操作条件下焦炭与组合型填料在清水与餐厅污水中的氧转移系数进行了比较。     

规整填料层压降的计算及与散装填料的比较

根据文献[6]导出的规整填料层压降关联式,由实验数据计算出9种规整填料本文关联式的压降常数,用空气-水物系和非水物系的实验数据进行了验证,并与Billet关联式计算值和实验值进行了比较;对规整填料层与散装填料的泛点和压降进行了比较。结果表明:该关联式与实验数据吻合较好,压降计算误差在±15％;规整填料力学性能优于散装填料。     

大型填料塔的设计及应用

本文介绍了大型填料塔采用新型规整填料、气液分布器及进气初始分布器的现状、设计及应用。     

滴流反应器的周期性填充:实验与模拟

A periodic packing mode of trickle-bed reactor(TBR)for the gas limited reaction was proposed.Hydrogenation of 2-ethylanthraquinone over Pd/Al2O3 in a laboratory-scale TBR was taken as a test reaction for determining whether the periodic packing mode is advantageous.The effects of operating conditions and packing type on TBR performance were experimentally examined to demonstrate the cause-effect relationships.A mathematic model of TBR considering axial dispersion and fractional wetting was developed to quantitatively illuminate the reason of performance enhancement.     

Sintering of Ceramic Particulate Composites: Effect of Matrix Density

Composites consisting of a fine-grained, polycrystalline zinc oxide matrix and <10 vol% coarse, rigid silicon carbide inclusions were prepared by the same mixing procedure and then compacted to produce samples with matrix densities of 0.45 and 0.68 of the theoretical. The samples were sintered under identical temperature profiles in separate experiments that employed either a constant rate of heating of 4°C/min or near isothermal heating at 735°C. The ratio of the densification rate of the composite matrix to the densification rate of the unreinforced zinc oxide was found to be independent of the initial matrix density. This ratio increased significantly with temperature in the constant-heating-rate experiments but was relatively constant in the isothermal experiments. The results indicate that microstructural coarsening may be an important mechanism for explaining the reduced sinterability of polycrystalline matrix composites.     

聚丙烯孔板波纹填料表面改性研究

采用液相化学法对聚丙烯孔板波纹填料进行表面改性,并对改性后的填料作性能测试。结果表明,改性后的聚丙烯填料表面粗糙度增大并引入含氧极性基团,其表面水接触角从８８°降低至４５°,临界表面张力由２８×－３Ｎ／ｍ提高到５５×１０－３Ｎ／ｍ,气相总传质单元数平均增加２４％,传质性能大为改善。     

规整填料塔的壁流量计算

推导了板波纹填料塔的壁流量计算方法 ,并探讨填料层分段高度的选择。     

高效散装填料的新构型——Impac填料性能分析

介绍了Ｉｍｐａｃ散装填料的结构特点和性能，并进行冷模实验。结果表明Ｉｍｐａｃ具有优良的流体力学和传质的综合性能。尤其适用于精密分离过程，热敏物系以及对旧塔的增容和节能改造。