弹性支吊架在调节管端推力中的应用

叙述在管道应力分析中调节管端推力的几种方法，通过实例分析及计算结果表明，弹性支吊架对调节管端推力和控制端点“热失载”影响是可行的。     

大载荷下空间桁架结构主承力用碳/环氧推力管的重量优化设计

航天发动机推力支架空间桁架结构通常采用金属材料。碳／环氧复合材料用于这种空间桁架结构的主承力推力管可以显著减轻推力支架的重量。为了节约昂贵的实验费用，通常先对支架结构和重量进行优化设计。本文以橡胶芯模辅助RTM工艺制备的碳／环氧管件为模型建立了某种结构优化后的推力支架空间桁架结构的有限元模型，采用大型有限元分析软件ANSYS7．0对推力管的外径、壁厚和重量进行了优化设计，得出推力管最佳参数为外径7．8cm，壁厚2．23mm，总重11．58kg。     

湿磨干烧掺部分无烟煤的煅烧技术探讨(二)

（续2002年第3期）2 燃烧器 我厂选用 SWIRLAX三通道喷煤管（见图1）,喷煤管中心是用于气体和液体燃料的通道。其中径向和轴向风这两股气流在通过锥形空气喷嘴前混合后喷出,有利于保证煤粉（尤其是低挥发分燃烧煤）燃烧完全,且通过轴向风和径向风的灵活调整,可有效控制火焰的长短。 燃低挥发分燃煤选用SWIRLAX喷煤管时,推力大小决定于单位时间内喷煤管的风速（推力=一次风相对动量％×风速m/s）。风速越高推力越大,火焰就越短。短火焰可以形成高温区,这将有     

管道应力分析中减少管端推力的若干措施

从应力分析与推力计算出发，欲减少管端推力，可采取增加或调节管系柔性，即布管原则及方法，恰当使用补偿器；对管道进行冷紧，合理选配支吊架等措施和办法。     

管架结构条件探讨

介绍管道专业提管架结构条件的步骤：先确定包括管架走向、管架宽度、层数、各层标高及管架柱距等管架形式和基本参数,然后再计算管道垂直荷载及水平推力。     

基于柔性模辅助RTM技术的整体推力结构的分析与设计

本文介绍了柔性模辅助RTM(FMARTM)技术的基本原理。基于FMARTM成型技术,设计了一种整体复合材料推力结构。该结构解决了支架式推力结构的复合材料推力管与法兰边连接的难题,同时也克服了锥形壳式推力结构通风散热性能差和不便于管路设计连接的缺点。利用有限元方法对该结构的铺层方式进行了优化,采用优化铺层方式的整体推力结构的垂直压缩率和偏心率都小于1%,表明推力结构的设计是可靠的。     

石油化工外管架设计要点简析

介绍了管架荷载的分类,对石油化工行业管架设计过程中的荷载推力进行了计算和分析,并结合实际工程经验的做法,提出了系统管架设计中应注意的事项,旨在对相关的工程设计提供参考。     

几种调节管系柔性的适用办法

笔者根据工作体会，提出了配管技术中几种调节管系柔性的适用方法和管原则；论述了在管系应力分析中增加补偿器所起的作用，以及如何合理配置支吊架调节管端推力和力矩的作用等。     

减小管廊固定点推力的方法探讨

本文介绍了几种在外管设计中常见的减小管廊固定点推力的方法,并结合工程实例分析,验证其有效性。     

浅谈石油化工装置外管架结构条件

介绍管道专业提管架结构条件的步骤:先确定包括外管道与外管架的布置、管架宽度、层数、各层标高、滑动支架间距、导向支架间距及固定支架间距等形式和基本参数,再确定操作平台及检修通道的设置,最后计算管道垂直荷载及水平推力。     

结构刚度对管道受力的分析论证

在工程项目中,会遇到两设备管口直连的管道长度较短,按照常规应力计算后,其管口荷载通常较大,严重超出设备管口的许用荷载,而且通过模型计算发现,推力和管道长度无关,然而在实际的运行过程中,短距离管道直连设计却能够安全有效运行,同时,根据实践经验,管道长度越长,推力必然会越大.鉴于此,本文将从支架或钢结构的刚度出发,对由温度...     

A sliding plate normal thrust rheometer for molten plastics

A sliding plate rheometer has been developed to measure the normal thrust of a molten plastic in large amplitude oscillatory shear. The normal thrust of a molten plastic in large amplitude oscillatory shear is a significant nonlinear effect that has previously been unobtainable. Normal thrust measurements may now be used to help understand and characterize nonlinear viscoelastic behavior inherent in most molten plastics. The new rhemoeter incorporates a piezoelectric pressure transducer in a very stiff plate that minimizes compliance. Normal thrust measurements with cone and plate rheometers are made by measuring the total force on the plate (or cone) and are subject to error due to edge effects. The new rheometer measures the local pressure in the sample and is therefore unaffected by sample size or edge effects. Normal thrust measurements in large amplitude oscillatory shear are reported for both molten Phillips TR480 high density polyethylene pipe resin which contains 2% by weight of carbon black filler and IUPAC LDPE X. Crosstalk due to shear stress on the active face of the pressure transducer causes signal error which for oscillatory shear is filtered out using a discrete Fourier transform.     

液氯液下泵故障分析及改进

分析了LSY40 -10/7型液氯液下泵气相部分、支撑管、出液接管、推力盘等部件烧毁,泵轴承断裂的原因,并提出了改进措施.     

扬子石化D套空分的空气净化系统配管设计

扬子石化D套空分的空气净化系统,配管空间小,管径大,且不断经历冷热循环变化,管道应力呈周期性变动,不适宜的配管设计易引起管道或设备管口变形甚至损坏。利用CAESARⅡ应力分析软件辅助空气净化系统的配管设计,按照一定的步骤进行调整,得到适宜的配管走向及支架位置的设置。     

管道设计中支架的合理及优化设计

介绍独立式架空管道支架的设计思路、方法;工程实例中刚性活动支架与柔性活动支架的比较表明,采用柔性活动支架可减小所受的水平推力,提高经济效益;条件许可时,也可采用聚四氟乙烯垫板减小管道与活动支架间的滑动摩擦力。     

BCL507压缩机轴位移故障分析与处理措施

根据甲醇装置合成气压缩机低压缸转子轴位移异常现象,列举出引起压缩机轴位移异常的原因：介质流量变化、排气和进气压差变化、轴位移监测仪表故障、联轴器预拉伸量不合适、止推轴承故障、平衡管堵塞和平衡鼓密封过度磨损或者涂层脱落.结合设备安装和运行的历史记录,通过分析排除方法,推断出此次合成气压缩机低压缸转子轴位移异常的原因是平衡鼓密封涂层脱落.经过拆检证实该推断正确,为准确及时处理故障提供参考.     

Stable micro-feeding of fine powders using a capillary with ultrasonic vibration

Stable micro-feeding of fine powder based on the ultrasonic vibration feeding system is studied in this paper. The excitation source was directly contacted with the capillary in the ultrasonic powder-feeding device, which can transmit mechanical energy to the capillary directly. The capillaries with different structures were tested to determine the proper structure for stable feeding. The capillaries are suitable for stable feeding when the cone angle θ was in the range of 30°-60°. The powders in the pipe may exhibit three different types of structures: blocking, plugging and arching. The arching formed near the nozzle of the pipe was necessary for a stable feeding process. Amplitude of the pipe was another factor which influenced the stable feeding. The powder flowing out the capillary may undergo a process of slightly unstable flow, stable flow and super unstable flow as the amplitudes of the pipe gradually increased. The amplitudes of the pipe can be calculated after the amplitudes of the transformer have been measured. The proper amplitudes of pipe nozzle for stable feeding are in the range of 9.6 to 18 μm in the experiments. Some desired patterns were deposited, indicating the ultrasonic vibration feeder system could satisfy the requirement of stable feeding.     

聚乙烯管道系统的连接技术问题(1)

介绍了各种聚乙烯管道系统的连接技术。连接常是管道系统成败的关键,各种连接技术都有其适用的范围。聚乙烯压力管道的连接以熔接为主,但有些场合需要机械密封连接。在聚乙烯的机械密封连接中特别要注意聚乙烯容易蠕变的特性。有些适用于聚氯乙烯管道的连接方法和设计不适用于聚乙烯管道。聚乙烯无压力管道的连接也有多种方法,要根据对于密封的要求选择。介绍了国内外为解决聚乙烯双壁波纹管承口刚度问题采用的种种做法。简介了交联聚乙烯管道和增强聚乙烯管道的特殊连接技术。提出在聚乙烯管道系统的连接方面希望国内外科技界关注的几个重要研究课题。     

Optimization of process parameters for rehabilitation of pipes through adhesive bonding: experimental study

Abstract

In many industries maintenance and repairing of pipes are crucial elements to engineers. The processes may consume a lot of money and time. Conventional methods like welding, riveting etc. may damage the base material or some times the pipe may carry inflammable fluids which can not be possible to repair by conventional methods. In such a case, adhesive bond may provide an alternative solution to the pipe repair or strengthening applications. The present work focuses on the optimization of process parameters which enhances the adhesive bond capacity (Tensile shear load) between carbon fiber reinforced polymer (CFRP) composite patch and SS (SS 304) plates. Epoxy resin and adhesive combination, pre cure temperature and surface preparation was considered as parameters. The surface roughness of pre-bond surfaces was measured using a 3D-microscope. The quality of the adhesive bond was evaluated using non-destructive testing (Digital Radiography) before performing tensile test. The failed surface morphology was studied using FE-SEM images. The optimal parameters were derived form the tensile test data of the adhesive joint. The bond capacity for lateral loadings was also studied using a three point bending test at the derived conditions. These parameters were also applied to rehabilitate the damaged pipe and its ability was evaluated through hydrostatic pressure test. From the results, it was observed that these parameters hold good for pipe rehabilitation also.