无垫片焊接密封法兰唇焊结构的泄漏原因及改进

甲醇合成塔密封结构为焊环式无垫片焊接密封法兰唇焊结构。在制作、试车过程中,焊唇出现了泄漏。针对这一问题,进行了原因分析并采取了相应的措施,从而保证了唇焊密封结构的可靠性和设备的良好运行。     

高温高压废热锅炉设备法兰密封泄漏原因及对策

针对高温高压废热锅炉首次煮炉出现设备法兰密封泄漏,结合现场检测,从其采用的焊唇式密封和螺栓预紧力两方面分析,发现螺栓预紧力不足和不均匀导致密封面压紧力不够是密封泄漏的主要原因。通过修复密封,按计算螺栓预紧力合理上紧高压螺栓等措施后解决了密封泄漏问题。     

大直径法兰泄漏原因和唇焊结构的应用

分析大直径法兰泄漏原因，分析唇焊结构优点，采用尘兰密封面外唇焊结构可彻底解决泄漏问题；并且对唇焊结构提出相应的要求。     

大直径法兰的泄露原因和唇焊结构的应用

通过对大直径法兰泄漏原因的分析，采用法兰密封面外唇焊结构可彻底解决泄漏问题；并且对唇焊结构提出相应的要求。     

焊接垫片的应用实践

中原大化集团公司合成氨装置中,有１０台设备１３处采用了焊接垫片密封,装置投运１０年来,这些焊接垫片运行情况良好,作为一种新颖的密封形式,在大型氨厂得到了成功的运用。化工部已制订ＨＧ２０５３０－９２钢制管法兰用焊唇密封环可供设计选用。ａ焊环式密封ｂ圆唇...     

E0702的“Ω”环密封损坏原因及修复

E0702的“Ω”环密封损坏泄漏原因进行分析，根据其材质选择相应的焊条和焊补工艺。施焊后运行效果较好，为以后对“Ω”环密封唇面泄漏处理积累了一些经验。     

高压设备用焊接密封元件的有限元分析

为了研究焊接密封元件在高压环境下的密封性能,本文应用ANSYS软件对圆形空腔式、焊环式和卵形空腔式焊接密封元件进行有限元分析,得出如下结论:根据等效应力值和应变值,给出三种焊接密封元件的危险截面,且密封元件的应力与密封元件的焊唇长度及焊环的密封焊位置密切相关;通过对三种焊接密封元件进行应力线性化分析,可知三种密封元件均满足强度要求。     

合成氨装置废锅管束上封头密封结构改造

介绍美荷型合成氨装置第一废热高压锅炉上封头密封结构改造情况，由原设计焊唇式平面密封结构改为榫槽型＋复合齿形垫结构，效果良好。     

化工设备开口焊接密封的设计与焊接施工

石油化工装置中化工设备和换热器的法兰密封或设备开口密封多采用焊接密封结构,以防止在压力、温度变化下法兰螺栓松弛而造成的开口分离和介质泄漏。从焊接密封结构的分类、焊接密封垫片尺寸的确定、焊接密封垫片的制造和施工以及焊接密封垫片的焊后检验等方面阐述了化工设备开口焊接密封的设计方法与施工要求。     

氟化聚合物延长唇形轴用密封圈寿命

把聚四氟乙烯轴承材料应用于密封唇,能有效地提高径向唇形轴用密封圈的寿命,並改善其性能。密封失效常常是由于弹性密封唇口磨损过度造成的。由于磨损增加.唇口在轴丧而上的接触宽度加宽.唇口对轴的过盈减小。当密封失效时.润滑剂的泄漏通常也就逐渐地随时间增     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

我国聚碳酸酯工业发展概况

介绍我国聚碳酸酯生产能力和消费需求,对聚碳酸酯在信息工业中的应用作了简短介绍     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

气化给煤系统故障分析

气化给煤装置自投运以来,出现了气化煤仓堵煤、称重给煤机输送皮带因跑偏而损伤以及清扫装置故障频繁等问题,多次造成气化系统减负荷运行。通过对出现的各种问题进行分析,找到了产生这些问题的原因,并有针对性地采用配煤和改进清扫链等措施,使出现的问题得到了极大的改善。     

船舶柴油机涡轮增压器的清洗

采用喷射清洗剂的方法，清洗涡轮叶片积炭。     

醋酸纤维素取代基分布与性质的关系

分析了以吡啶为溶剂的醋酸纤维素的13C-NMR核磁共振谱,得出了三种不同位置羟基的取代度。结合X—射线和DSC分析,初步说明具有相同取代度但未经水解和经过水解的醋酸纤维素(CA) 性质上的差异是由于三个羟基上的取代度分布不同及消晶程度差异所致。     

Generalization of vdW type of equations of state

1 INTRODUCTIONBecause of importance of equations of state (EOS)in science and industry,hundreds forms of EOS havebeen presented since latter 19th century.It seems impossible to develop a general equation covering vari-ous kinds of EOS.But for cubic EOS,several generalequations have been reported already. Martin presented the first general equation whichis following p=RT/V-α(T)/(υ β)(υ γ) δ(T)/υ(υ β)(υ γ) (1) Kumar et a1.presented an equation called the most general form of a density-cubic or, alterna tively,volume-cubic mathematical equation,the form of which is as follows