填料密封腐蚀磨损的牺牲阳极保护研究(Ⅱ)--牺牲阳极保护系统参数的设计

填料密封腐蚀磨损是填料密封装置失效的主要原因。牺牲阳极保护法可以有效地从抑制腐蚀的角度来减弱腐蚀磨损。在前期研究的基础上，对填料密封腐蚀磨损的牺牲阳极保护系统的参数进行了设计。     

填料密封腐蚀磨损的牺牲阳极保护研究(Ⅲ)——牺牲阳极保护系统的结构设计

填料密封腐蚀磨损是填料密封装置失效的主要原因。牺牲阳极保护法可以有效地从抑制腐蚀的角度来减弱腐蚀磨损。在前期研究的基础上。对填料密封腐蚀磨损的牺牲阳极保护系统的结构进行了设计。     

填料密封腐蚀磨损的牺牲阳极保护研究(Ⅰ)

在自行设计的实验装置上对填料密封装置中常用轴材料的阴极保护参数进行了实验研究 ,得到了静态最小阴极保护电流密度 ,并分析了环境条件对阴极保护参数的影响 ,为后续的牺牲阳极结构设计提供了必要的理论依据     

集气站分离器牺牲阳极保护应用分析

集气站分离器内腐蚀严重,牺牲阳极保护可以进行有效防腐保护,延长分离器使用寿命,是一种有效的保护措施。     

火驱生产井牺牲阳极防腐实验研究

火烧油层技术由于工艺复杂,现场实验时会遇到严重的腐蚀问题。改性牺牲阳极不但有一般阴极保护的特点,而且改性物质使阳极的反应物在管、杆表面形成保护膜,有效提高防腐效果。模拟火烧油层生产井的生产环境,采用自然腐蚀,考察普通和改性两种牺牲阳极保护的防腐技术效果。结果表明,改性牺牲阳极保护法起到了有效的缓腐作用,在温度较低的27℃时,普通牺牲阳极、改性牺牲阳极保护下的缓蚀率分别为6.04%和96.87%;而温度升高到110℃后,改性牺牲阳极的缓蚀率下降,但仍比普通阳极防腐效果好。     

火驱生产井牺牲阳极防腐实验研究

火烧油层技术由于工艺复杂,现场实验时会遇到严重的腐蚀问题。改性牺牲阳极不但有一般阴极保护的特点,而且改性物质使阳极的反应物在管、杆表面形成保护膜,有效提高防腐效果。模拟火烧油层生产井的生产环境,采用自然腐蚀,考察普通和改性两种牺牲阳极保护的防腐技术效果。结果表明,改性牺牲阳极保护法起到了有效的缓腐作用,在温度较低的27℃时,普通牺牲阳极、改性牺牲阳极保护下的缓蚀率分别为6.04%和96.87%;而温度升高到110℃后,改性牺牲阳极的缓蚀率下降,但仍比普通阳极防腐效果好。     

涂层-牺牲阳极联合保护在水工金属结构防腐中的应用

水下或地下金属结构的腐蚀属电化学反应。其防腐措施通常有：涂漆、喷锌和外加阴极电流,这几种方法都存在不同的缺点,文中提出将涂漆和牺牲阳极同时用于水工金属的防腐。实践证明：联合保护法经济、防腐效果好。     

牺牲阳极法在换热器防腐蚀中的应用

利用 Zn作为牺牲阳极 ,可解决管壳式换热器的电化学腐蚀问题。     

渤西陆地终端工程登陆油气长输管线的牺牲阳极保护

阴极保护电位的确定要根据具体腐蚀环境,优质防腐涂层的管线牺牲阳极可与管道同沟敷设,阳极单支等距布局比多支成组布局更能使管道电位分布均匀,充分利用单支阳极的输出电流,减少阳极间电场干扰的影响,达到理想的保护效果。     

管道内牺牲阳极补口装置的研究应用

随着大庆油田高矿化度水驱区块的开发,管道内腐蚀问题显现,特别是管道焊接热影响区域的内腐蚀较突出,本文简要介绍管道内铝合金(材料A12)牺牲阳极补口装置的工作原理,整体结构,并测试补口牺牲阳极装置运行的数据,并进行参数验证,应用后改善了管道内补口处防腐环境,限时控制了该区域管道的内腐蚀。     

EIS testing of new aluminium sacrificial anodes

Aluminium alloys In/Hg free, suitable as sacrificial anodes for cathodic protection, have been developed. Short-term electrochemical tests were performed on these new alloys to obtain their electrochemical efficiency and to reveal any tendencies to passivation. Samples were galvanostatically held at different current densities, which changed every 24 h according to DNV RP 401. Electrochemical impedance spectroscopy (EIS), polarization curves and electrode potential against time measurements were employed to study the main features of the processes taking place at the alloy–solution interface.     

Study of sacrificial anode cathodic protection of buried tanks: Numerical modelling

A finite element numerical model was set up to calculate the secondary distribution of potential and current density at the surface of a buried tank. The steel gas tank of interest was protected by both coating and two sacrificial anodes (magnesium alloy or zinc). The dispersion of actual soil properties was taken into account by use of three typical soils. The comparison of two dimensional and three-dimensional models shows that the 2D model is obviously both convenient and time saving. The numerical model allows the calculation of the cathodic protection current and of the local potential in every point of the tank. The model intends to compare the relative influence of coating quality, electric conductivity of soil and position, size and type of the sacrificial anodes (magnesium or zinc). Soil conductivity and coating porosity appear as the two most influential parameters. This model justifies the interest of the tank experimental potential and current measurements.List of symbols     

The operation of long-life anodes in amalgam cells

In recent years, long-life anodes have become a well established type of DSA^(R) anodes for the production of chlorine in mercury cells. They offer considerable benefits compared to ‘normal’ or conventional metal anodes, i.e. reduced costs for repair, transportation and installation as well as a lower consumption of energy. The reason for the decline in damage incidents is probably the slightly increased electrical resistance of the coating. The reasons for the extended service life of the anodes are the decrease in the generation of oxygen and the improved protection of the titanium substrate against penetrating brine and oxygen diffusion.     

Development of MnO<Subscript>2</Subscript>-incorporated high performance aluminum alloy matrix sacrificial anodes

Manganese dioxide, a potential catalyst in many electrochemical reactions, was explored as an effective activator in Al + 5% Zn alloy sacrificial anodes. The catalytic influence of MnO₂ on the anodes was micro-structurally and electrochemically characterized using different electrochemical techniques. The process of incorporation of MnO₂ not only improved the grain size but also the galvanic performance of the anodes significantly. A galvanic performance as high as 80% was achieved by incorporating an optimum quantity (0.5%) of MnO₂ in the anode matrix. High and steady active open circuit potential, very low polarization and substantial reduction in self corrosion were achieved during galvanic exposure tests. Effective activation of the anodes by MnO₂ was also revealed by the results of electrochemical impedance analysis. The tolerance to biofouling on the anode surface was studied by quantifying the number of micro-organisms on the anode surface after immersing in natural sea water containing the micro-organisms.     

A mathematical model for the internal cathodic protection of cylindrical structures by wire anodes

The applicability of a two-dimensional mathematical model of the impressed current cathodic protection (CP) system of the interior wall of a cylindrical structure was investigated. The modelled system was an axisymmetric cylindrical column filled with electrolyte with a wire anode running along its entire length and displaced from the column axis. Model inputs included anode and cathode dimensions, the anode-to-cathode distance, the electrolyte conductivity and limiting current density of oxygen reduction. A semi-analytical solution to the Laplace equation was used to compute the distribution of electrical potential. From these results, the nonuniform current density distribution was obtained to a first approximation by entering the computed values of the position-dependent cathode polarization potential into the nonlinear experimentally obtained polarization expression. The experimental electrical potential distribution compared well with that predicted by the model. Results showed the possibility of overprotection occurring in the system. The mathematical analysis was also extended to the case of a system with two wire anodes.     

牺牲阳极保护装置在卫城油田的研制与应用

目前应用于油井防腐方面的技术很多 ,但都有一些不足之处 ,针对缓蚀剂在日常应用中 ,存在着加药方式单一 ,高油气比井入井效果不好的状况 ,研制出了牺牲阳极保护装置 ,是目前油井加缓蚀剂的有益补充。