锅炉给水预热器管箱法兰泄漏原因分析

就甲醇装置锅炉给水预热器管箱法兰泄漏的原因进行了分析，提出了相应的改进措施，为类似设备法兰泄漏问题的处理，提供了一定的借鉴和帮助作用。     

硝酸尾气预热器泄漏问题的分析及处理

分析了硝酸尾气预热器管端胀口泄漏的原因，提出在吸收二塔出口处加设气液分离器的处理方案，此方案实施后，尾气预热器多年的泄漏问题得到解决，经济效益也很明显。     

HFC-134a预热器失效分析

针对HFC-134a预热器泄漏事故分析问题,采用失效分析理论和方法,对其进行全面的检测和解剖分析,获得了预热器壳体材料的化学成分、力学性能、金相组织以及腐蚀机理等多项失效分析指标。综合分析结果表明,该预热器失效的主要原因是局部过热、组织劣化、强度下降、介质腐蚀、壁厚减薄和鼓包开裂。     

变换预热器法兰泄漏原因分析及检修措施

介绍合成氨装置变换工段预热器因腐蚀对筒体挖补补焊后多次发生法兰密封面泄漏的问题,对泄漏原因进行分析,并根据现场条件采取相应的检修措施,最终达到设备消缺恢复原功能的目的。     

高压氨预热器换型研究

高压氨预热器是高压法三聚氰胺生产工艺中的关键设备之一,该换热器自装置开车以来频繁出现列管泄漏,通过对泄漏原因进行逐一分析,发现换热器在选型上存在一些问题,在充分分析和论证的基础上,决定对换热器进行换型改造,从换热器的结构形式和选材上都做了改进,新型换热器投用后效果较好。     

甲醛回收塔进料预热器泄漏原因探析

介绍了甲醛回收塔的基本情况和存在问题,对进料预热器的泄漏腐蚀原因进行了说明和探析,给出了解决办法及对策建议.     

水溶液全循环法尿素装置高压甲铵预热器泄漏分析

分析尿素装置高压甲铵预热器多次发生列管泄漏的原因，从调节氯碳比、调节水碳比、控制高压甲铵预热器操作温度、控制中压吸收塔液位及其顶部温度、调整高压甲铵泵负昔等方面提出避免腐蚀、泄漏的措施，确保安全稳定运行。     

E5D西封头泄漏原因分析及对策

分析IDR尿素装置氨预热器E5系统封头在开车送氨时易发生泄漏的原因,以及探讨如何改变操作方法,从而防止封头泄漏的思路和技改方向。     

尿素生产高压氨预热器列管及封头泄漏的解决

介绍了三聚氰胺尾气联产尿素装置的高压氨预热器列管及封头发生泄漏的情况,分析了泄漏产生的危害及原因,提出了防止类似事故发生的方法.     

壳牌煤气化制氢变换装置开车运行分析

对壳牌煤气化制氢变换装置在实际开车运行过程中出现的几个突出问题进行了简要的分析,提出了对变换原料气H2S含量控制、防止变换煤气预热器堵塞、减缓系统腐蚀、避免和减少变换装置开车导气过程合成气频繁泄漏等问题的解决方法或建议措施。     

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。     

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…     

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。     

聚酰亚胺的合成法

本文评述了缩聚型聚酰亚胺的主要合成方法和近年来国际上在合成中所做的探索。