THEORETICAL INVESTIGATION ON BY-ONLY-CURRENT ELECTROMAGNETIC SEPARATION OF INCLUSION FROM MOLTEN METALS

The electromagnetic field under applied AC and DC current in round and rectangular pipe was systematically investigated, then a concept of "equivalent current density" was proposed for evaluating the inhomogeneous electromagnetic pinch force, and the mono-component removal efficiency and the overall removal efficiency of inclusion were formulated. It is founded that flat pipe is superior to round pipe for the electromagnetic removal of inclusion, and DC current can get a higher removal efficiency than A C current due to absence of skin phenomenon. Under usual condition, a removal efficiency of 52% for 10μm inclusion or more than 92% for 20μm inclusion can be achieved by imposing a current density of 3×106A/m2 in a flat pipe.     

关于复杂黄铜的等效方法及其它

在复杂黄铜等效变换的多元变化过程中，存在着第三种当量系数Ｉ。它是确保合金转化为二元形式所必不可少的导向给定值，是一个定位常数。找出了Ｋ＋Ｊ＝０的误解的产生原因，论证了Ｋ＋Ｊ＝１所在达的过程的实质。指出用二元相图理解等效变换这一三元变化过程的认识误区。     

等效梁法及其在柔性铰链机构中的应用

文章讨论了等效梁法的基本原理，然后以双平行四杆柔性铰链机构为例分析其位移性能；采用该方法进行有限元建模，一个柔性铰链由4个梁单元组成，因而，整个柔性铰链机构的单元数很少。分析结果表明：等效梁法仿真效率高，且有很高的精度。这一点对于仿真分析复杂的柔性铰链机构非常重要。     

Hydrodynamics and liquid phase axial mixing in orifice pipe reactor

Two phase flow in a horizontal pipe, with orifice plates placed at regular intervals as obstructions, was studied for the effect of phase velocities on flow patterns, fractional phase hold-ups, pressure drop and liquid phase axial dispersion. Radioactive technetium-99m (as an aqueous solution of sodium pertechnatate) was used as tracer. A pulse injection technique with two point measurements was employed. Three different orifice diameters were used (8 mm, 16 mm, and 20 mm) in a pipe diameter of 32 mm. The orifice spacing was 500 mm in all cases. Superficial gas (air) velocity was varied over a range from 0.02 m/s to 1.0 m/s and superficial liquid (water) velocity from 0.03 m/s to 0.85 m/s. Different flow patterns under different flow conditions were identified and a generalised flow map is presented. Variations in hold-ups and pressure drop with flow patterns have been explained. Rational correlations have been developed for fractional phase hold-ups and pressure drop. A preliminary comparison of two phase gas-liquid flow in a horizontal pipe with orifice obstructions (to be called orifice pipe reactor), as a gas-liquid contacting device, is made with a conventional bubble column reactor. Recommendations have been made for future work.     

斜板沉降器的设计

简要叙述了流离倾斜斜板的层膜上的单个液滴的基本聚结原理。着重介绍重力沉降器的设计方法，并指出在设计过程中可能出现的错误。     

炭粒床高效工业除尘装置的设计与开发

The new dust removal technical route using the carbon-granular bed filter,packed of carbon particles with appropriate grade derive from an online-process vibration sieve,to replace the traditional baggy filter had been developed successfully for capturing the micro-carbon dusts produced from pulverization of petroleum coke,and the green close loop of carbon materials is thus completed in the combined pulverizing and classifying system and pulverized carbon dust removal process.The high dust removal efficiency greater than 99%,low outlet dust concentration less than 100 mg.m-3,low pressure drop through dust filtration chamber less than 980 Pa,simple and easy design,and flexible and stable operation were achieved also with the carbon-granular bed filter in both bench and industrial scale operations.     

中国是世界拱坝大国也是世界拱坝强国——在《特高拱坝建设总结及安全运行管理研究》会议上的发言

中国拱坝数量占全世界的40%,数量最多;世界最高的三座拱坝都在中国,因此中国是世界拱坝大国。中国解决了岩溶地区拱坝防渗、狭窄河谷拱坝大流量泄洪等技术难题,发展了碾压混凝土拱坝筑坝技术。中国学者首创大坝混凝土标号分区技术,首创混凝土坝温度应力理论体系,解决了大坝裂缝这一世界性难题;建立了拱坝优化理论、混凝土坝仿真分析方法、混凝土坝有限元等效应力方法、混凝土坝数值监控方法等,在拱坝设计和科研上取得了全世界最多的重要成果,因此中国既是世界拱坝大国,又是世界拱坝强国。     

突扩突跌掺气设施后泄槽底板脉动压力试验研究

有压洞出口后的突扩突跌掺气减蚀设施在水利工程中经常使用。由于水流受边界条件和掺气的影响,其流态和脉动压力往往与普通水槽的情况有很大的不同。通过水工模型试验,对突扩突跌掺气设施后泄槽底板上的脉动压力进行研究,揭示了掺气设施后泄槽底板上不同流动区域的脉动压力特性。从脉动压力的时域过程、均方根值、偏态系数、峰态系数和主频率等多方面得出冲击区、反射区和稳定区脉动压力的特性是不相同的结论。同一流量时,沿流程底板的时均压力都大于脉动压力的均方根值,在冲击区、反射区和稳定区,脉动压力的均方根值分别是同位置时均压力值的约0.5倍、0.6倍和0.7倍。研究成果可为更好地利用突扩突跌掺气设施提供有益的理论和试验依据。     

基于层面参数等效的碾压混凝土坝渗流场与应力场耦合分析

受施工、龄期、环境及服役期大坝承受的反复静动荷载等多因素影响,坝体和层面出现不同程度的劣化损伤,碾压层本体及层面物理参数呈渐变特性。针对碾压层内力学参数渐变的特性,提出了相应物理参数的等效算法,且给出了耦合性态参数间的数学转换关系,分析坝体应力场与渗流场相互影响机理,据此建立了考虑层内参数渐变的碾压混凝土坝渗流场与应力场耦合分析模型,并编制了相应的有限元分析程序。工程实例分析表明,耦合作用致使大坝的渗流场发生改变,坝体的应力较未耦合时普遍偏大,坝踵处的应力集中显著;渗流场与应力场耦合作用激励下的不利因素可为大坝的设计、施工及安全运行提供参考。     

一种用于洗气塔的新型塔顿——淋降式穿流角钢塔板

淋降式穿流角钢塔板由于结构简单、防堵效果好、压降低，已在国内40余座塔中得到成功应用。本文主要介绍了该塔板的基本结构、压降估算、塔内排列新方案以及应用实例。