新型反应釜釜内物料流动模型的研究

着重研究新型反应釜釜内颗粒的轴向流动模型,采用颗粒受力矢量分析确定单颗粒分别在螺旋叶片和重力作用下的轴向运动轨迹,从而求得为保证实现颗粒轴向流动的螺旋叶片结构,为螺旋叶片的合理设计选择提供可靠的理论依据.     

无泄漏磁力釜

由上海化工研究院化学工程及装备研究所研制的无泄漏磁力釜,革除了转轴的动密封,改为静密封,使物料在全密封状态下进行搅拌操作;密封与润滑不再需要注入介质,从而保证了釜内物料的纯度;节约能耗,取消了密封用压紧填料,可减少搅拌功率20％左右;比传统搅拌速度提高2～6倍,缩短了搅拌时间,强化反应过程,提高设备生产能力;运转平稳,振动小、噪声     

热喷涂修复液压釜

介绍了受损液压釜采用热喷涂技术修复的工艺方法及具体应用实例。     

改进型的四氟乙烯衬里精馏釜

硅单晶在半导体材料中占有极其重要的位置,而多晶硅的质量又是单品硅质量的基础,多晶硅质量的好坏又取决于化学提纯。精馏塔乃是化学提纯方法必不可少的物质条件之一。要获得高纯度的三氯氢硅,必须选择材料优质和高效的精馏塔。当前,聚四氟乙烯     

φ1400×6000机械釜

Φ1400×6000机械釜用于金川贵金属车间,从铜镍合金中提取贵金属。铜镍合金通过盐酸浸出和控制电位氯化等工艺过程,使贵贱金属分离,再经精炼分别提取铂、钯、铑、铱、锇、钌、金等贵金属。该机械釜是四轴卧式垂直轴传动的压力容器。釜上设有四套搅拌装置,采用LC型立式两级齿轮减速机传动,各由17kW的防爆电机单独驱动搅拌桨旋转。轴封是单端面外装式四氟波纹管机械密封。本釜自1980年10月投产以来,运转正常,满足了工艺要求,保证了生产的顺利进行。一、技术性能 1.几何容积:     

高温脱硅釜的设计与使用

高温脱硅釜是钒铬还原渣制备氧化铬的重要生产设备,是一种搪瓷反应釜。详细介绍了高温脱硅釜的设计过程,并提出了在安装、使用过程中一些注意事项。     

浅议加压浸出釜液位的过程控制

简要说明了加压酸浸工艺中，加压浸出釜过程控制的关键——液位控制的实现方法、存在的问题以及解决的方案。     

基于扫描电镜的蒸压釜腐蚀失效分析

本文以一台蒸压釜定期检验过程中发现的腐蚀缺陷为例,对其筒体内壁点状腐蚀凹坑的产生原因进行分析。通过宏观检验确定了腐蚀类型,采用金相组织、扫描电镜、X射线衍射分析以及原材料化学成分分析等,发现造成该台容器点腐蚀的原因是碱腐蚀和氧腐蚀。将该台蒸压釜安全状况等级评定为4级,监控6个月使用,在使用过程中进行壁厚监测,如壁厚腐蚀超过容器腐蚀裕量,须立即停止使用。     

机械搅拌压力釜加热方式的探讨

湿法冶炼工业中,机械搅拌压力釜的加热方式及热载体多种多样。本文主要介绍蒸汽夹套、导热油半圆管夹套和远红外电加热方式的结构形式、性能特点。     

锆钢复合板制备水解釜技术探讨

探讨了选用锆钢复合板制备水解釜的技术问题。通过采用一系列措施,成功解决了锆材在250℃的15%硫酸介质中的耐腐蚀问题,使设备的安全性和可靠性得到保障。实践证明,水解釜选用锆钢复合板是完全可行的。     

Flow in Helical Annular Pipe

In this paper, the axial and the secondary flow in a helical annular pipe are examined by a perturbation method in a curvilinear coordinate system, and the second-order perturbation solution is obtained completely. The secondary flow, the axial velocity, and the flux ratio are studied in detail. When the torsion is zero, the secondary flow behaves as four vortexes, and they are symmetrical up and down. When it is not zero, the symmetry is destroyed, and the intensity and number of the secondary flow vortexes are affected by the Dean number and the radius ratio of the inner∕outer circle wall of the annular cross section. The maximum of the axial velocity appears near the inner bend when the Dean number is small, and it is moved toward the outer bend as the Dean number increases.     

Heat-transfer phenomena in water-cooled zinc-fuming furnace jackets

In the zinc slag-fuming process, zinc is removed from lead blast furnace slag by reduction with a coal-air mixture injected into the slag through submerged tuyeres. The furnace is constructed of water-cooled jackets which freeze a slag layer and contain the bath. This greatly reduces vessel wear caused by the violently agitated and corrosive bath. The jackets, however, fail due to the formation of cracks which grow from the slag face through the working face of the jacket to the water channel. In this study, in-plant measurements and mathematical modeling of heat transfer in the jackets have been combined to elucidate the mechanism of failure. The working face of a water jacket was instrumented with thermocouples and installed in a fuming furnace at the Trail smelter of Cominco Ltd., Trail, BC. Measurements revealed the presence of large thermal transients or temperature “spikes” in the panel in the region immediately above the tuyeres. These were generally observed during charging and tapping of the furnace and are likely associated with disturbances on the surface of the bath or gas injection effects when the liquid level is low. Temperatures at the midthickness were seen to rise by as much as 180 °C above the steady-state level. Under these conditions, low-cycle fatigue may lead to crack formation and propagation. A mathematical modeling analysis of the transient freezing phenomena indicates that the temperature spikes are associated with sudden slag falloff and direct contact of molten slag on the jacket. In order to reduce slag falloff, an increased number of anchoring fins should be used in critical areas.     

Bond Strength of Lap-Spliced Bars in Concrete Confined with Composite Jackets

The effectiveness of fiber-reinforced polymer (FRP) and textile-reinforced mortar (TRM) jackets was investigated experimentally and analytically in this study to confine old-type reinforced concrete (RC) columns with limited capacity because of bond failure at lap-splice regions. The local bond strength between lap-spliced bars and concrete was measured experimentally along the lap-splice region of six full-scale RC columns subjected to cyclic uniaxial flexure under constant axial load. The bond strength of the two column specimens tested without retrofitting was found to be in good agreement with the predictions given by two existing bond models. These models were modified to account for the contribution of composite material jacketing to the bond resistance between lap-spliced bars and concrete. The effectiveness of FRP and TRM jackets against splitting at lap splices was quantified as a function of jacket properties and geometry as well as in terms of the jacket effective strain, which was found to depend on the ratio of lap-splice length to bar diameter. Consequently, simple equations for calculating the bond strength of lap splices in members confined with composite materials (FRP or TRM) are proposed.     

Turbulence Characteristics in Gradual Channel Transition

A field study was conducted to determine the effects of a channel transition on turbulence characteristics. Detailed three-dimensional (3D) flow measurements were collected at a cross section that is located downstream of a gradual channel expansion. These measurements were obtained via an acoustic doppler velocimeter and include the 3D velocity field, the mean local velocities, the turbulent intensities, the frictional characteristics of the flow, the secondary velocity along the transverse plane, and the instantaneous shear stress components in the streamwise and transverse directions. Analysis of the 3D flow data indicates that the turbulent flow on the outer bank of the channel is anisotropic. Such anisotropy of turbulence, which is attributed to the gradual expansion in the channel and bed roughness, yields the development of a secondary flow of Prandtl’s second kind as reported in 1952. In particular, it was found that turbulent intensities in the vertical and transverse directions on the outer bank section are different in magnitude creating turbulence anisotropy in the cross-sectional plane and secondary flows of the second kind. Turbulent intensities increase toward the free surface indicating the transfer of a higher-momentum flux from the channel bed to the free surface, which contradicts common wisdom. Results for the normalized stress components in the streamwise and transverse direction show similar behavior to the intensities. Moreover, the nonlinear distribution of stresses is indicative of the oscillatory nature of the flow induced by the secondary flows of Prandtl’s second kind. A similar behavior was found for flows in straight rectangular channels over different roughness. Finally, a comparison between the secondary current velocity with the mainstream velocity indicates that secondary flow of Prandtl’s second kind is present within the right half of the measured cross section.     

夹套容器的结构设计及对比

本文主要介绍了普通整体夹套容器与蜂窝夹套容器的结构形式，并通过工程实例对这两种夹套容器在强度、刚度、传热性能及制造方面进行了对比。通过比较，蜂窝夹套具有明显节省材料、换热性能好、降低成本的优点。具有重要的工程推广意义。     

Acoustic Emission Monitoring of Hybrid FRP-Concrete Columns

Fiber-reinforced plastic tubes can be used as permanent formwork and external reinforcement for concrete columns. Failure of such columns is often accompanied by audible noise from cracking of concrete and shifting and settling of aggregates, snapping of the inner layers of the jacket, and ultimately fiber fracture. Since the state of the concrete core is not readily visible from the outside, nondestructive evaluation tools such as acoustic emission (AE) can help assess its structural integrity. The objective of this research was to investigate the applicability of AE technique to hybrid columns, and to correlate the AE parameters to the state of stress in concrete. The AE signature of hybrid columns was studied on over 40 specimens with different lengths, cross sections, jacket types, and jacket thicknesses. The study showed that (1) rate of change of cumulative AE counts with respect to the applied load correlates well with the degree of damage sustained by the concrete core; (2) longer specimens, thicker jackets, and unbonded tubes display higher AE activities; and (3) the Kaiser effect is not present in hybrid columns.     

气瓶内部淬火过程的流动换热特性

 大直径厚壁气瓶内部淬火时的流动换热过程极其复杂,受到多种因素的影响,而研究气瓶内部压强和温度的变化规律对改善流动换热效果、提高产品组织性能具有重要的理论指导意义。以914 mm厚壁气瓶和瓶内流体为研究对象,建立了二维等效流 固耦合模型;采用多喷嘴系统对气瓶内外进行喷水淬火,研究了气瓶总长、喷水流速及淬火时间对瓶内压强及内壁温度的影响,通过间歇淬火试验验证了数学模型的正确性。结果发现,气瓶长度对瓶内压强和瓶壁温度的影响显著,喷水流速次之,当喷水流速大于8 m/s后,水量对瓶壁的冷却效果大大降低;气瓶内壁长度方向的温度梯度分别随气瓶总长的增加和淬火时间的延长而减小,但基本不受喷水量的影响。     

板坯连铸内外复合冷却流场和温度场耦合数值模拟

 针对1 240 mm×200 mm板坯连铸提出了一种钢水内外复合冷却技术，即在结晶器内设置内冷却器 U形管，起到提高传热效率改善铸坯内部组织之目的。运用流体力学分析软件，就内外复合冷却结晶器内钢水在流场温度场耦合作用下的凝固状况进行数值模拟，发现内冷却器可以使钢水的流动状态均匀和加快连铸坯的凝固速度。     

Ultimate Condition of Fiber Reinforced Polymer-Confined Concrete

One important application of fiber reinforced polymer (FRP) composites is as a confining material for concrete in the retrofit of existing concrete columns by the provision of FRP jackets. Such jackets are commonly formed in a wet layup process, with the fibers being only or predominantly in the hoop direction. It has been well established in recent studies that the rupture strains/strengths of FRP measured in tests on such FRP-confined concrete cylinders fall substantially below those from flat coupon tensile tests, but the causes are unclear. This paper presents the results of a study that is aimed at clarifying these causes. To this end, the paper reports and compares the ultimate tensile strains of two types of FRP (carbon FRP and glass FRP) obtained from three types of tests—flat coupon tensile tests, ring splitting tests, and FRP-confined concrete cylinder tests. Based on comparisons of these test results, it can be concluded that the FRP hoop rupture strains in FRP-confined concrete cylinders are reduced below the ultimate tensile strains from flat coupon tests by at least three factors—(1) the curvature of the FRP jacket; (2) the deformation localization of the cracked concrete; and (3) the existence of an overlapping zone. While the first factor that reduces the in situ strain capacity of FRP on confined concrete is material dependent, the last two factors that result in a nonuniform strain distribution in the jacket are independent of the FRP material properties. The third effect reduces the average hoop rupture but does not affect the distribution of the confining pressure, as the FRP jacket is thicker in the overlapping zone.     

热轧带钢层流冷却温度控制模型的应用分析

 工业大学金属材料与加工重点实验室, 安徽 马鞍山 243002) 摘要：在带钢热轧后的冷却过程中，热轧带钢卷取温度的数学模型是至关重要的。介绍了某热轧带钢厂的卷取温度控制数学模型，针对传统的热轧带钢层流冷却卷曲温度控制中数学模型的固有缺陷，分别采用了差分方程和有限元数值模拟的方法，建立带钢厚度方向上的温度场。对测得的数据进行了分析，结果表明：在考虑带钢与介质的热交换的同时再考虑带钢内部的热传导大大提高模型的预报精度，为定量地描述计算值与实测值之间的偏差提供了依据。