PV型旋风分离器减阻杆减阻性能的试验研究

在PV型旋风分离器内加装减阻杆,可以大幅度降低旋风分离器的总压降.对比实验结果表明,加装减阻杆的根数不同,压降的降低幅度也不同,最大降低幅度达50%以上.结果表明加装一根减阻杆,可使旋风分离器总压降最大降低37.53%.     

静电旋风分离器流场的实验研究

介绍了静电旋风分离器内的速度场和压力场的测试结果 ,并对此进行了详细的分析 ,指出了安装电晕极不仅能降低常规旋风分离器的阻力 ,而且有利于提高常规旋风分离器的效率 ,即电晕极对静电旋风分离器起到了减阻增效的作用。     

基于CFD技术的旋风分离器减阻性能研究

利用雷诺应力模型对旋风分离器气相流场进行数值模拟研究，在此基础上对安装在旋风分离器排气芯管下口的双进口螺旋减阻装置进行了研究，并通过与直径为205mm的Stairmand旋风分离器和直径为150mm的Bohnet型旋风分离器的试验数据进行比较，结果表明，减阻装置可以使排气管下口切向速度降低，内外漩涡交接面半径明显外移，合理改变旋风分离器内部压力分布，能有效降低旋风分离器的压力损失35％以上。研究结果还表明，旋风分离器数值模拟结果和试验数据吻合较好，应用计算流体动力学（CFD）来研究旋风分离器性能方便且可行。     

方形旋风分离器数值模拟研究

针对圆形旋风分离器空间利用率不高,安装后密封性能低等问题,提出一种柱锥式方形旋风分离器,并通过数值模拟对其流动特性、分离性能的影响机理进行研究。采用雷诺应力模型(RSM)和随机轨道模型(DPM),重点分析了该结构方形旋风分离器不同流量下流场压力分布和速度分布,及颗粒入射位置对颗粒运动轨迹的影响。结果表明:该结构旋风分离器流场特征与圆形旋风分离器近似,存在对分离性能有较大影响的二次流。在分离效果损失不大的情况下,在空间利用和安装排布上有明显优势。     

基于CFD的旋风分离器的结构优化设计

应用计算流体力学软件FLUENT对旋风分离器进行三维气固两相流场的数值模拟。根据不同结构参数(排气管直径、排气管插入深度以及锥体和筒体的相对尺寸)的旋风分离器内部流场模拟结果,分析了不同参数对分离效率和压降的影响,得到旋风分离器的最优结构参数,并对最优结构参数的旋风分离器动、静压力和三维速度进行数值模拟和分析。     

喷油压缩机用旋风式油气分离器筒体尺寸设计方法

针对喷油压缩机系统用旋风式油气分离器筒体尺寸(直径和高度)设计基本依赖实际经验,缺乏理论依据的问题,提出了一种结合数值模拟的理论设计方法。通过理论计算可以得出设计分离器筒体直径的方法——依据切向速度关系曲线,通过选取合适的筒体直径而使外旋涡的平均切向速度大于临界切向速度。考虑到直筒形与筒锥形旋风分离器存在差异,借助数值模拟方法对理论计算的切向速度和有效分离高度进行了修正。建立了旋风式油气分离器的三维非稳态数值模型,其中气相流场采用RSM湍流模型,油滴运动轨迹采用离散相模型。计算了适用于额定工况下容积流量为6 m3/min、排气压力为0.8MPa(a)的空压机系统油气旋风分离器筒体尺寸,并计算分析了容积流量改变时(50%～100%)对分离器筒体尺寸的影响。最后经过数值模拟验证,结果表明所设计的分离器可对粒径为5μm以上的油滴完全分离。本方法适用于喷油压缩机系统中旋风式油气分离器的设计工作,也可以为其他场合应用旋风分离器作为设计指导。     

石油化工重油催化裂化装置旋风分离器安装分析

文中以某石化千万吨炼油项目350×10~4t/a重油催化裂化装置的旋风分离器安装为例详细阐述旋风分离器的安装过程。     

再生器旋风分离器系统开裂原因分析

对某石化公司炼油厂催化裂化装置中再生器内发生开裂的一、二级串联的旋风分离器系统进行了受力分析,并在有限元分析的基础上指出,导致一、二级旋风分离器串联处开裂的原因是一、二级旋风分离器吊挂结构承载不平衡,致使开裂处的应力超过了旋风分离器材料(1Cr18Ni9Ti)的持久强度而发生高温持久破坏。     

双级分离式旋风分离器数值模拟及试验研究

运用FLUENT软件对3种采用不同二次分离元件直径尺寸的双级分离式旋风分离器模型进行了数值计算,研究分析了其内部流场特性和以旋流切向速度为代表的主要参数的变化规律,在考虑压差阻力和分离效率权重的基础上,得出二次分离元件的最佳直径尺寸,并与模化试验结果进行对比,确定了最优性能的双级分离式旋风分离器结构方案,为优化其结构参数并提高其性能提供理论指导和参考。     

不同结构参数下旋风分离器气相流场的数值研究

采用商用CFD软件FLUENT对直切式旋风分离器内气相流场进行了数值研究,计算值和五孔球探针的测量值吻合较好.在此基础上,研究了结构参数对气相流场的影响.结果表明,减小入口面积比KA、排气管直径比dr和排尘口直径比dc,均可使旋风分离器内的切向速度增大;但同时压降增大.CFD数值模拟方法可以很好地预测旋风分离器结构尺寸变化对内部流场的影响.     

Formation of a flange from a flat blank with a hole

A model of axisymmetric formation of a flange from a flat blank with a hole by expanding by a hard punch with a fixed flat flange is given, taking into consideration contact friction, change of wall thickness, strengthening of material, and the tool bending radius. Elastic, elastic-plastic and hard-plastic process stages are studied.     

装载机新型工作装置设计理论的研究

推出了一种装载机工作装置的新型机构 ,克服了传统工作装置由于设计误差而产生的“干涉”现象 ,实现了无铲斗平移引导油缸工作装置 ,使其结构大为简化 ,设计极为简单。此外 ,还分析研究了这种新机构的设计计算方法。为今后进一步改进现有装载机工作装置提供参考     

Estimation of a Bottom Echo-Signal Level Reflected from a Plane Surface of a Cylindrical Article Using a Normal Probe Operating in a Pulsed Mode

The influence of the pulsed operating mode on a bottom echo-signal level reflected from a plane surface of a cylindrical article is studied during variations in the article's radius. It is shown that the pulsed character of a signal smoothens this function significantly as compared to that in the previously computed continuous mode. Numerical estimates of the bottom echo signal have been made for the ultrasonic inspection of wheel-pair axles of railway vehicles.     

某制冷压缩机爆炸事故的分析

广州市某冷库一台冷凝器压缩机在试压检漏时发生整体爆炸.经现场调查和对爆炸碎片、残骸的研究,分析了爆炸的过程,判断事故原因为试压工艺问题和操作不当,并给出了改进措施.     

Buckling of a thin spherical shell inside a spherical cavity of a contracting massive body

The problem of buckling of a thin elastic spherical shell inside a spherical cavity of uniformly contracting massive body is considered. This problem arises, for example, when designing pressure vessels made of composite materials with a thin metal cap layer. It is assumed that at the beginning of the compression the shell fits tightly against the wall of the cavity (to the rigid frame). An algorithm for searching the equilibrium state of the shell in the supercritical state is described. As a result of solving the problem, among other things, critical values of compressive strain and shell configuration in the supercritical state were obtained.     

Operation of a tight joint under a torque

A tight joint subjected to a torque is considered, in the case of pliability of the joint components and tangential pliability of the contact layer. On that basis, the torque distribution over the joint length may be determined more precisely, and fretting wear may be predicted.     

The use of a segmented cathode of a drift tube for designing a track detector with a high rate capability

Detector rate capability is one of the main parameters for designing a new detector for high energy physics due to the permanent rise of the beam luminosity of modern accelerators. One of the widely used detectors for particle track reconstruction is a straw-detector based on drift tubes. The rate capability of such detectors is limited by the parameters of readout electronics. The traditional method of increasing detector rate capability consists in increasing their granularity (the number of “elementary” detectors = readout channels) by reducing the straw diameter and/or by dividing the straw anode wire into two parts (for decreasing the rate per readout channel). A new method of designing straw detectors with a high rate capability is presented and tested. The method is based on dividing the straw cathode into parts and the independent readout of each part.     

The Formation of a Packet of Radicals with a Short Rise Time of Their Concentration in a Gas over a Solid Surface

The formation technique of a modulated flow of radicals in ground electronic and oscillatory states with the rise time of the radical concentration in the gas over a solid body t = 10 ms is offered.