不锈钢容器及管道的局部腐蚀

针对在化工行业中局部腐蚀的危险性,本文着重介绍了局部腐蚀中的晶间腐蚀和应力腐蚀发生的条件、机理以及防范的措施。     

非牛顿流体在搅拌槽内的传热

基于搅拌桨旋转扭矩和搅拌槽内所有壁面的平均扭矩近似相等的关系,引入流况系数,提出了计算非牛顿流体表观粘度的剪切速率模型.并对内蛇管、外蛇管和直管以及不同几何尺寸的MIG、透平、三叶后掠式、板式、锚和半椭圆片桨组成的多种搅拌体系,用该模型关联夹套侧和冷却管侧的给热系数,分别得到了统一不同几何尺寸搅拌桨的给热系数关联式.该模型适用于不同冷却构件.不同类型、不同几何尺寸的搅拌桨、过渡域和湍流域以及夹套侧和冷却管侧的非牛顿流体给热系数关联.另外,对多种剪切速率模型进行了比较和讨论.     

钛钢复合板在海水中电偶腐蚀研究

电偶腐蚀电位接近碳钢自腐蚀电位,不随面积比的增大而变化;电偶腐蚀电流密度和腐蚀深度,随阴阳面积比的增加成倍增大。钛钢复合板制设备一旦内层钛局部腐蚀穿孔,钛与碳钢形成大阴极小阳极的电偶对,很大的电偶腐蚀电流密度作用在碳钢上,使碳钢加速腐蚀,造成设备早期失效。     

有挡板和无挡板搅拌容器的对比

本文对有挡板和无挡板搅拌容器在流体动力学领域的一些特有情况,均质分散过程,以及热传递操作中的有效作用进行比较研究,给出了研究结果。     

Galvanic Corrosion Theory for Adherence of Porcelain Enamel Ground Coats to Steel

The galvanic corrosion theory of adherence between ground-coat enamels and steel was investigated as a part of a broad study of the bonding mechanism between ceramics and metals. The theory, which is outlined in this report, is based on the mechanical anchoring of the enamel into the pits formed by the galvanic attack of the enamel on the steel surface. The theory was first examined from the standpoint of the data on adherence obtained in earlier studies at the National Bureau of Standards. In addition, several experiments were performed which demonstrated that galvanic corrosion of the metal base could occur during the short firing times encountered in enamel processing. On the other hand, certain inconsistencies were observed in the data which indicated that the mechanism of galvanic attack followed by mechanical anchoring was not the only important factor affecting the bond strength.     

碳素行业用浸渍罐制造要点

近年来,随着碳素行业的快速发展,对浸渍罐的开门位置及密封要求越来越高。在经过数年的摸索和实践当中,笔者对在用设备的监测和实地测绘,对出现的问题及时现场解决,得出了一些关键性数据和制造要点。我厂制造的浸渍罐已逐渐完善并形成一定的制造工艺标准。望能对同行业及工程技术人员有些许帮助。     

卧式气液搅拌槽中比界面积的测定

本文应用绕射理论,对光透射法测量气液分散体系比界面积进行了分析和讨论,用激光代替一般光源,从而提高了测量装置的稳定性和测量精度.同时,还对卧式气液搅拌槽中的比界面积进行了研究,得到了可用于实际聚合釜设计的关联式,指出增大桨径比是增强气液接触效果的有效途径,加入少量乳化剂可使体系的比界面积较纯水体系提高10—25倍.     

浅谈压力容器的安全可靠性设计

本文就压力容器设计如何做到安全可靠阐述自己论点。首先准确确定工艺条件的设计参数;然后选择合理的受压元件材料;进行合理的结构设计及受压元件的强度计算;通过制造检测手段及加强安全操作与管理,确保压力容器的安全可靠性设计     

Corrosion Resistance of Steels Used in Alcohol and Sugar Industry

Evaporators used in power plants for sugar production are vessels with two boxes of heat exchangers. These heat exchangers made of a low‐corrosion resistance material are frequently replaced during the alcohol production process. In view of the growing production of cane, sugar, and alcohol, and the corrosion of materials used in power plants, it was necessary to find alternative materials for carbon steel applied in the evaporators. A comparative study of the corrosion resistance of stainless steel as well as unalloyed and alloyed carbon‐manganese steels in neutral and acid sugar cane juice electrolytes is presented. The alloyed carbon steels showed the best corrosion behavior in an acid environment compared to a neutral medium. Among the alloyed carbon steels, ASTM T11 and ASTM T22 steels provided the highest corrosion resistance in sugar cane juice.     

奥氏体不锈钢压力容器晶间腐蚀原因及预防

晶间腐蚀是奥氏体不锈钢制压力容器产生失效的主要原因之一,严重影响了容器的安全运行。本文阐述了奥氏体不锈钢产生晶间腐蚀的基本机理,并提出了四种预防不锈钢制压力容器产生晶间腐蚀的措施。     

重防腐涂料在化肥行业的应用

阐述了厚浆型玻璃鳞片涂料的防护机理,并结合化肥厂设备腐蚀应用实例介绍了两种新型防腐涂料。     

LNG接收站不锈钢防腐保护浅析

结合江苏LNG(液化天然气)项目的实际情况,综合分析了不锈钢不锈与锈的原因,结合国内国外标准,阐述对于LNG接收站,不锈钢涂漆的必要性,并提出了不锈钢涂漆需要注意的事项,为同类型工程项目的工作提供了参考。     

碳钢/钛合金复合材料在3%NaCl溶液中的电偶腐蚀研究

采用失重方法和电化学方法,研究碳钢/钛合金复合材料在3%NaC l溶液中的电偶腐蚀行为。结果表明,在碳钢/钛合金电偶腐蚀过程中,碳钢为阳极,钛合金为阴极,随着阴/阳面积比的增大,电偶电流增大,碳钢腐蚀速率变大,而电偶电位基本不变。     

非牛顿流体和牛顿流体在搅拌槽内的传热研究

本文根据边界层理论,通过搅拌槽壁面扭矩与搅拌桨旋转扭矩近似相等的关系,提出非牛顿流体在搅拌槽传热阻力层的实际表观粘度的计算方法.使佐野雄二的给热系数关联式也能适用于不同桨型的非牛顿流体的给热系数计算,从而获得了同时适用于牛顿流体和非牛顿流体在装有各种桨型的搅拌槽壁侧给热系数的统一关联式:     

石油化工钢储罐与其基础的关系

本文介绍钢储罐基础种类、钢储罐内物料性质与其合理的基础形式以及钢储罐基础的抗震措施等，供设计人员参考。     

Application of Central Composite Rotatable Design for Mixing Time Analysis in Mechanically Agitated Vessels

Central composite rotatable design (CCRD) was applied for analyzing and optimizing the effects of impeller rotational speed, gas flow rate, probe location, and tracer injection point on the gas‐liquid two‐phase mixing time in an agitated vessel with a dual six‐blade Rushton turbine. Knowledge of the effects of independent factors on the mixing time is necessary in order to optimize the mixing process. The mathematical relationship between mixing time and four significant independent variables can be approximated by a nonlinear polynomial model. The obtained results demonstrate that CCRD could efficiently be applied for modeling mixing time. It requires fewer experimental runs and provides sufficient information as compared to a factorial design.     

舰船用长效防腐涂料甲苯释放规律研究

为预防和控制舰艇舱室等密闭环境中甲苯的污染,以舰艇常用的一种非金属材料--长效防腐涂料作为实验样品,密封于实验箱中,在不同的温度条件下脱气,应用气相色谱法在90天的时间内对释放的甲苯浓度进行分析,并做曲线拟合与回归,总结出甲苯浓度随时间和温度变化的规律.     

A Digital Imaging Technique for the Analysis of Local Inhomogeneities from Agitated Vessels

A novel, cheap and simple technique for the analysis of the mixing properties from a stirred vessel is introduced. The technique is based on a digital imaging technique and the analysis can be undertaken based on the properties of the image. Using this technique, it is easy to analyze mixing inhomogeneities. Test measurements with non‐Newtonian viscous, aqueous xanthan solutions and fluids as well as liquid‐particle suspensions showed that the developed method is a quick and quantitative tool for the analysis of local mixing inhomogeneities, mixing times and particle suspension speeds.