Implications of particle size to transient stage of deep bed filtration

This study was aimed at investigating the effect of particle size, mostly in the submicron range, on break-through stage of filtration. Latex beads, with diameters ranging from 0.46- to 2.967-μm were filtered through filter grains of diameters 0.1-, 0.175- and 0.45-mm. Experimental conditions were chosen so as to obtain breakthrough curves. The experimental results showed that the initial efficiency follows the pattern reported by previous experimental and theoretical studies, i.e., lower efficiency for 0.825-μm particles which fall in the range of critical size. However, the particle removal during the transient stage increased with an increase in particle size for the range of sizes studied. This pattern is qualitatively confirmed by the theoretical predictions of Vigneswaran and Chang (1986) model. This study also provides experimental verification of the effect of the ratio of particle size and grain size at different stages of filtration.     

多支化两亲聚合物合成及其原油乳化作用研究

通过自由基胶束共聚法制备了N-苄基-N-n-十六烷基丙烯酰胺/丙烯酰胺/丙烯酸钠三元共聚两亲聚合物-P(AM/BHAM/NaA),并优化了合成方案。该聚合物具有临界聚集浓度(CAC),当该两亲聚合物质量浓度高于700mg/L时,P(AM/BHAM/NaA)在水溶液中形成聚集体,并随着聚合物质量浓度的增加聚集体的流体力学半径增加,表观黏度也随之增加。P(AM/BHAM/NaA)具有良好的原油乳化能力,研究了不同质量浓度的两亲聚合物对原油乳化性能。结果表明,随着两亲聚合物质量浓度的升高,在水溶液中形成聚集体的体积增大,空间网络结构增大,乳化能力升高。     

A New Research Infrastructure for Investigating Flow Hydraulics and Process Equipment at Critical Fluid Properties

An optimized equipment design for natural gas processing and liquefaction plants becomes increasingly difficult with changing process conditions: Particularly low values of surface tension create rising challenges on the design of phase separators and column internals. The TERESA test rig at HZDR was designed to allow the investigation of multiphase thermohydraulics and phase separator performance under critical fluid properties in industrial dimensions. A versatile pipe test section is available in DN200 and equipment internals may be tested in a sectional DN300/DN500 test separator. The applied test fluid shows a high vapor-liquid density difference between 1470 and 940 kg m⁻³, viscosity as low as 0.12 mm²s⁻¹, and surface tension down to 1.3 mN m⁻¹. Volumetric liquid and vapor flow rates may be varied up to 9 and 530 m³h⁻¹ in the test rig, respectively.     

陶瓷材料延性域去除临界条件新研究

本文是在对磨削过程的应力特征、微裂纹形成及扩展和材料去除机理研究的基础上，针对微裂纹扩展的稳定性条件进行研究。研究中，将宏观断裂力学及微观断裂物理相结合，根据位错产生微裂纹机制，对磨削过程的微裂纹的形成采用位错赛积模型来描述。并从能量平衡的角度，讨论位错裂纹的稳定性及临界裂纹尺寸。     

板材轧制问题中的变形与应力

根据全息干涉法对板材轧制成形中的变形进行分析，假设三种典型轧制板的截面形状模型，计算了纵向非均匀应变分布，给出了其所产生的残余应力及其失稳起皱时的临界参数计算公式。与实测结果比较，变形的最大误差为11％。     

Development of the active balancing device for high-speed spindle system using influence coefficients

A high-speed spindle can be very sensitive to rotating mass unbalance which has harmful effect on many types of rotating machinery. Therefore, the balancing procedure is certainly needed to reduce vibration in all high-speed rotating systems. In this study, an active balancing program using influence coefficient method and an active balancing device of an electro-magnetic type with both simple and reliable structures were applied to the developed high-speed spindle system. A gain scheduling control using influence coefficients of the reference model was proved to be effective in balancing the spindle system although its characteristics were changed. The stability of reference influence coefficients was verified by experiments with frequency response functions. The active balancing experiment of the manufactured spindle system using an active balancing program and device was also performed efficiently during the operation. As a result, controlled unbalance responses after balancing work were below the vibration limit at all rotating speed ranges including critical speeds.     

φ50mm穿孔机后台架的改进

运用力学方法建立了穿孔机后台架的力学模型，导出了顶杆挠度曲线方程，给出了顶杆临界压力及顶杆长度之间的关系式，为穿孔机后台架的改进提供了理论依据。     

滑阀污染敏感尺寸的确定

本文根据滑阀运动副发生污染卡紧与污染磨损的污染物尺寸条件,给出了滑阀污染敏感尺寸范围。试验结果很好地证明理论分析的正确性。这对于确定液压系统中滑阀所需要的过滤精度具有重要价值。     

Al_2O_3/SiC_w陶瓷材料中晶须的极限和最佳含量探讨

从Al2O3与SiC晶须热胀失配分析入手，分析了Al2O3／SiCw陶瓷材料中晶须的极限含量，得出了晶须的极限含量为43vol％。研究表明：晶须含量超过极限值时，Al2O3／SiCw强度大幅下降的主要原因有二个，即1．材料的致密度急剧降低，气孔率增大；2．由于热胀失配所产生的残余张应力导致基体材料的开裂。通过实验证明，当晶须含量为20～30vol％时，Al2O3／SiCw陶瓷材料能获得最佳增韧补强效果。     

锅炉用焊接钢管的制造技术

简述了锅炉用焊接钢管的优势,国内外锅炉用焊接钢管的生产发展概况以及我国焊接钢管用于锅炉制造的情况。详细介绍了锅炉用焊接钢管的质量要求、品种和规格,锅炉用焊接钢管的几种生产工艺方法,典型的制管工艺流程和生产关键技术。对锅炉用焊接钢管生产提出了几点建议。