锅炉给水泵机组故障诊断及处理

运用油样分析和振动频谱分析相结合的方法,对锅炉给水泵机组轴承振动、温度的异常变化全面分析,准确诊断出减速机高速轴及低速轴止推轴承部位均发生不规则摩擦故障,通过针对性维修验证了故障诊断结果,并对故障进行了原因分析和处理。     

5EH-6BD汽轮机轴振动故障分析与处理

针对合成气压缩机的驱动汽轮机5EH-6BD轴振动异常的现象,对引起汽轮机轴振动故障的可能原因(负荷变化、转速波动、轴振动监测仪表故障、轴系对中不良、油膜振荡等)进行分析与排查,并结合汽轮机的安装和运行历史记录,最终推断此次汽轮机轴振动异常的原因是转子不平衡,经拆检证实了该推断,为及时、准确处理故障提供了理论指导。     

余热电站汽轮发电机组轴振大的处理

巴基斯坦某余热电站汽轮发电机组从额定转速到带负荷运行过程中,3号和4号轴承的轴振存在不同特征。其中3号轴承轴振逐渐增大,数小时后能够在振幅较高范围内趋于稳定运行,而4号轴承的轴振则一直偏大。经过检查轴承结构参数,比较类似机组稳定运行的轴承,分别找出了机组轴振异常的原因。振动故障主要是由质量不平衡、轴承的热稳定性较差造成,进行逐项消除缺陷等改进后,振幅得到减小。     

空冷汽轮机机组振动大的原因分析

印度某余热电站空冷汽轮机机组在运行中,随着负荷的上升,出现个别轴承轴振增大的现象。根据轴振动特征,比较同类型机组配套的排汽管道结构的设计差异,经分析,找出机组轴振异常的原因,提出解决同类型机组轴振增大的方法。     

二氧化碳压缩机增速箱异常跳车原因分析及对策

在开车过程中，甲醇装置二氧化碳压缩机增速箱低速轴驱动端轴承振动异常，造成机组连锁跳车。从轴承系统装配数据、静电腐蚀、润滑油及频谱图谱等方面进行了分析排查，确认为轴瓦间隙变大，造成轴承系统稳定性变差，启机过程中转子失稳发生油膜涡动，最终导致跳车。     

中压锅炉给水泵透平J542振动大原因分析与处理

中压锅炉给水泵透平调速系统定位器故障,引起透平转速波动大,从而导致透平轴承振动大。通过分析中压锅炉给水泵透平转速波动大的原因,提出处理措施,从而彻底解决透平轴承振动大的问题。     

管道应力对离心式压缩机轴振动的影响

武汉石化80万t/a乙烯项目线性低密度聚乙烯装置,离心式循环气压缩机首次单机试运行,试运行期间出现轴承振动过大的现象。在其后的现场检查和技术分析确定为压缩机入口管线存在应力,经过对管线进行改造后,消除了轴振动异常的问题,设备运行平稳。     

篦冷机破碎机窜轴原因浅析

篦冷机破碎机窜轴的原因主要表现为轴承未紧固好、轴承座振动大、轴承失效或轴磨损等,也有检修方法的原因,并介绍了窜轴的处理措施。     

重整装置预加氢循环气压缩机运行异常波动原因分析及处理措施

循环氢压缩机在炼油装置中起着至关重要的作用。任何可能引起压缩机非计划停车的异常波动,都应该引起足够的重视。该文阐述了压缩机工艺参数异常波动的现象,通过对轴振动的频谱分析,结合重整预加氢装置工艺的特色,对日常运行时压缩机突发的异常状况进行了分析,并提出了相应的处理措施。     

增速机轴承振动高的原因分析与处理办法

从2013年开车至2017年7月美克化工二期空压机组增速机驱动端靠近汽轮侧低速轴轴承在过临界转速的过程中振动一直比较高远远超出连锁值,同时持续时间比较长导致机组无法正常启动。针对增速机驱动端低速轴轴承在机组过临界转速的过程中振动高,并且持续时间比较长的问题。通过在低速轴测振处安装IMO远程在线监测诊断分析系统和停机检修测量轴承分析。发现轴承安装方向和轴颈测振处划痕是导致增速机驱动端轴承在机组过临界转速的过程中振动高的主要原因,之后对轴承进行的调整,完全解决了振动高的问题。     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.     

环氧树脂羟基值测定方法的研究

利用乙酸酐、吡啶和浓硫酸混合的乙酰化试剂测定环氧树脂中羟基值含量的方法具有操作简便、滴定终点明显和分析结果误差小等优点。     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

几种针状焦性能对比

针状焦分石油系和煤系两大类,这主要取决于针状焦的原料来源。在同一系列中由于原料不同和工艺条件不同 ,针状焦的各自性能也不相同。针状焦是生产超高功率石墨电极和高功率石墨电极的主要原料 ,针状焦的性能对石墨电极的质量有至关重要的影响。所以对针状焦性能以及其对石墨电极质量影响的研究十分必要的。以下是常用的几种进口针状焦和国产针状焦的性能对比。１原料性能分析对比原料试样包括４种针状焦 ,其中两种为进口针状焦：三菱针状焦和新日化针状焦;另两种为国产针状焦：鞍山针状焦和锦州针状焦。其中除锦州针状焦是石油系针状焦外…     

用两个形状指数表征粉煤灰颗粒形貌的研究

引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。