大段筒体翻转设计及实施

大段筒体翻转的设计及实施在超大型塔器整体制造、整体运输中不可或缺,其设计及吊耳强度计算是否科学正确,直接关系到大段筒体翻转过程的安全。结合工程实际,介绍超大型塔器大段筒体翻转的设计及实施,为实现超大型塔器在制造厂整体制造整体交付提供技术支撑和安全保障。     

分段塔器现场卧式组对相似三角形法

正在石油化工、煤化工等装置中的塔类设备由于运输条件的限制,大多塔器需分段制造、分段交货,再由施工单位在施工现场将分段到货的塔节组对焊接成整体。分段塔器组对通常采用滚动胎、道木垛并通过塔器中心基准线的水平和垂直面,即沿圆周0°、90°、180°、270°四个部位调整其直线度的方法进行组对,但在部分施工现场由于现场     

超大型塔器主吊耳处塔体局部应力计算方法比较

结合二甲苯塔(吊装质量2638t)吊装实践,依据相关规范及软件,介绍整体吊装超大型立式塔器主吊耳处塔体局部应力计算的多种方法和应用,并结合吊装作业现场塔器主吊耳处局部应力实时监测数据的采集和分析,对理论计算进行对比和验证。     

小直径塔器筒体上组焊人孔的工艺操作

分析了小直径塔器筒体上人孔组焊后筒体变形的原因,提出了保证塔器直线度和筒体圆度的技术措施和操作要求。     

大型塔器厂内分段制造的质量控制要点

一部分大型塔器由于受到一些条件的限制,需要将塔分成几段在厂内制造。而这种分段制造的塔器如果厂内制造时质量控制不严格,极易在现场最终组对时出现部分尺寸超标。本文根据多年的施工经验,探讨了塔器在厂内分段制造时,塔的总长度、塔器椭圆度和直线度以及塔盘支持圈水平度等方面的质量控制要点,从而保证整台塔器的制造质量。     

大型塔器厂内分段制造的质量控制要点

一部分大型塔器由于受到一些条件的限制,需要将塔分成几段在厂内制造。而这种分段制造的塔器如果厂内制造时质量控制不严格,极易在现场最终组对时出现部分尺寸超标。本文根据以往施工经验,探讨了塔器在厂内分段制造时,塔的总长度、塔器椭圆度和直线度以及塔盘支持圈水平度等方面质量控制要点,从而保证整台塔器的制造质量。     

塔器筒体直线度的优化及裙座部分设计

通过对SH/T 3098—2011《石油化工塔器设计规范》与HG 20652—1998《塔器设计技术规定》标准中塔体直线度进行探讨并提出优化,同时,通过NB/T47041—2014《塔式容器》、HG 20652—1998《塔器设计技术规定》、SH/T 3098—2011《石油化工塔器设计规范》中裙座厚度的要求、裙座设计温度和材料、隔气圈设计等问题进行了探讨。     

奥氏体不锈钢塔器的关键制造技术

针对奥氏体不锈钢塔器设备长度较长、筒体壁厚较薄、产品直线度和筒体椭圆度要求较高的特点,介绍了典型的奥氏体不锈钢塔的制造、焊接和压力试验工艺,保证了产品的质量。     

大型塔器塔盘支撑圈安装工装对比优化

以多晶硅塔器制造为例,介绍了大型化工塔器塔盘支撑圈在安装过程中易产生的错位、直线度及平行度超标等问题,分别分析了产生这些问题的原因、对后续内件安装和工艺流程操作的影响。并提出一种新型的塔盘支撑圈安装、定位工装来解决以上问题。新型塔盘支撑圈安装工装根据内件安装高度的需要长度可进行调节,并与另一种环形塔盘支撑圈安装工装进行对比,阐述了两种塔盘支撑圈的优劣性,对比分析其优缺点和使用范围。新型塔盘支撑圈可提高生产效率,满足塔盘支撑圈水平度的要求,从而保证了塔器的制造质量。     

变径塔器运输鞍座设置与壳体应力校核

塔器在整体交货情况下选择鞍座支撑运输。本文对变径塔器在整体运输过程中的受力进行力学分析,针对外部载荷可能对设备壳体造成的失稳或破坏作了详细的讨论,提出了对壳体强度的校核方法和应力失效的解决方案。     

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。     

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.     

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.     

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…     

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。     

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.     

酚醛树脂热降解动力学研究

用热失重非等温法对不同甲醛,苯酚魔鬼洋比的酚树脂进行了热降解动力学研究。结果表明,甲醛,苯酚摩尔比为１．５时,酚醛树旨的热发活化能最高。耐热性最好。     

剪力对梁变形影响的分析

本文用材料力学的分析方法,导出了一个计入剪力时梁的挠曲线的微分方程式。为了估计剪力对梁变形的影响,在集中力作用下梁内剪力用一个单值连续的反三角函数表示。由能量法确定了截面因子数值之后,定量地给出计入剪力时梁变形的分析结果。其结果和弹性力学的结来是一致的。     

热塑性塑料熔体质量流动速度测量不确定度的评定

本文分析了聚丙烯熔体质量流动速率测量过程中不确定度的来源，并对各不确定度分量进行了评估。该测量过程中所产生的测量不确定度主要来源于测量重复性。