3-D hydrodynamics generated in a stirred vessel by a multiple-propeller system

The aim of this study is to optimize the position and the number of propellers in a non-standard tall vessel. Laser sheet flow visualization experiments were carried out for selected geometrical arrangements which produced stable flow patterns and good transport between the propellers. Four double-propeller arrangements corresponding to frequent industrial cases and a three-propeller system have been chosen. Comparison of LDA measurements in the r-z plane, dimensionless global parameters N_Qp, Nt_m, N_p, E_p and spatial distribution of local energy dissipation rate ? shows that a three-propeller system is the most efficient.     

压力容器应力应变在线测量系统研究

应用Ｖｉｓｕａｌ Ｂａｓｉｃ软件开发了一套压力容器的应力采集与处理系统，将ＩＢＭ－３８６微机与ＹＪＤ－１７型应变仪联机，用微机来控制测点应变的采集与处理，并将大型结构分析软件ＳＡＰ５嵌入本系统。     

薄壁内压容器静强度的模糊可靠度与安全系数

应用基于模糊数学与常规可靠性理论相结合的模糊可靠性设计方法,讨论钢制薄壁内压容器模糊静强度在不同工况时,有关标准可接受的模糊可靠度范围;对钢制薄壁内压容器静强度的模糊可靠度范围与安全系数的关系进行研究。分析认为容器静强度在满足最小模糊可靠度要求的前提下,可取屈服安全系数ns≥1.55与抗拉安全系数nb≥1.95。     

Gas hold-up, mixing time and gas-liquid volumetric mass transfer coefficient of various multiple-impeller configurations: Rushton turbine, pitched blade and techmix impeller and their combinations

Gas hold-up, mixing intensity of dispersion characterised by exchange flows between adjacent impellers and a volumetric mass transfer coefficient are presented for 18 impeller configurations in triple-impeller vessel of inner diameter . Rushton Turbines, six Pitched Blade impellers pumping down and hydrofoil impellers Techmix 335 (Techmix co., Czech republic) pumping up or down and their combinations were used. aqueous solution was used as a liquid phase, which represents non-coalescent batches. Gas hold-ups and volumetric mass transfer coefficients are presented for individual configurations as functions of specific power dissipated and superficial gas velocity. The regression of the mass transfer coefficients shows large standard deviation (30%). The power number included to the regression to express the impeller configuration effect did not improve the standard deviation significantly (23%). The impeller configurations with low power number (less than unity) provide higher dispersion mixing intensities, while the impeller configurations with high power number provide better mass transfer performance.     

搅拌槽中垂直列管外壁的传热膜系数分布

在一内径为 12 0 0mm容积为 1.5m3 的搅拌槽中 ,使用CBY螺旋桨、 4 5°斜叶桨和六直叶涡轮桨 ,对牛顿流体采用量热法 ,研究了列管外壁的局部传热膜系数的分布情况。实验结果表明 ,对轴向流桨和径向流桨 ,列管外壁的局部传热膜系数有不同的分布 ;列管外壁各点的局部传热膜系数均与ε0 .197成正比。此外 ,文中还研究了桨叶离底距离、桨径等因素对列管外壁局部传热膜系数的影响。     

小型密闭压力容器法中试验条件对分解反应程度的影响

(dp/dt)max是小型密闭压力容器法（MCPVT）中用来表征自反应物质受热分解反应激烈程度的物理量。本文在大量实验的基础上，通过线性回归推导出了X（样品容器容积V、升温速率R及样品质量m）与（dp/dt)max的数学关系式，已知X0时的(dp/dt)max0,就可求得任意X下的（dp/dt)max，与实测值比较，结果表明，利用该关系式计算的结果较为可靠，从而为MCPVT最终成为国际上评价自反应物质受热分解反应激烈程度标准方法奠定了基础。     

F-12纤维表面处理对复合材料壳体纤维强度转化率的影响

对F-12纤维表面进行聚合物涂层改性，通过NOL环复合材料剪切强度测试，研究不同浓度的聚合物表面处理液对复合材料层间剪切强度的影响．结果表明：F-12纤维表面经TDE-85／DDM体系处理后，复合材料层间剪切强度均高于未表面处理的纤维；当刚性涂层液质量分数为5％时，层间剪切强度最高，比未表面处理的纤维高50％左右．φ150mm容器爆破试验结果表明，F-12纤维表面经涂层液处理后，复合材料壳体纤维强度转化率平均提高2．3％，容器特性系数平均提高12．5％．     

Flow regime, hydrodynamics, floc size distribution and sludge properties in activated sludge bubble column, air-lift and aerated stirred reactors

This paper presents a comparative study how reactor configuration, sludge loading and air flowrate affect flow regimes, hydrodynamics, floc size distribution and sludge solids-liquid separation properties. Three reactor configurations were studied in bench scale activated sludge bubble column reactor (BCR), air-lift reactor (ALR) and aerated stirred reactor (ASR). The ASR demonstrated the highest capacity of gas holdup and resistance, and homogeneity in flow regimes and shearing forces, resulting in producing large numbers of small and compact flocs. The fluid dynamics in the ALR created regularly directed recirculation forces to enhance the gas holdup and sludge flocculation. The BCR distributed a high turbulent flow regime and non-homogeneity in gas holdup and mixing, and generated large numbers of larger and looser flocs. The sludge size distributions, compressibility and settleability were significantly influenced by the reactor configurations associated with the flow regimes and hydrodynamics.     

乐果合成釜故障分析及处理

通过增加底轴承来改变搅拌轴的临界转速,解决了乐果合成釜试车过程中震动较大的问题,达到了生产和工艺要求。     

原子荧光光谱法测定搪瓷容器中微量溶出锑的研究

采用氢化物发生-原子荧光光谱法,用L-半胱氨酸预还原锑,对搪瓷容器中微量溶出锑进行了分析,讨论并确定了实验的最佳测定条件.结果表明,锑的检出限为0.235μg/L,回收率为89.0%～104.2%,相对标准偏差为0.8%.该法准确、快速、简便.