尿素合成塔安全使用管理的研究与分析

根据尿素合成塔的实际使用和维护情况,系统地介绍尿素合成塔不同状况下的腐蚀特点,并针对不同工况下如何减缓尿素合成塔腐蚀问题,提出相应的预防措施和注意事项.     

我厂尿素合成塔的防腐小结

根据尿素合成塔的实际使用和维护情况,系统地介绍尿素合成塔不同状况下的腐蚀特点,并针对不同工况下如何减缓尿素合成塔腐蚀问题,提出相应的预防措施和注意事项。     

尿素合成塔的安全使用探讨

介绍尿素合成塔使用的基本情况,探讨尿素合成塔生产和停车过程中的保护问题.该文就不同状况下如何采取措施,以保护合成塔、减缓腐蚀问题进行了技术探讨.     

尿素合成系统设备的腐蚀与防护

讨论了尿素合成系统设备的腐蚀机理、腐蚀现象和防护措施。尿素合成反应是在尿素合成塔中高温、高压下进行的,尿液和甲铵液对设备有强烈的腐蚀性。尿素合成塔的腐蚀情况,因不同的部位和操作条件,所产生的腐蚀现象与结果也不同。从材质的选择、材质的处理、采用合理的检漏设计和生产中的操作与控制进行防护。     

尿素合成塔的腐蚀特点与防腐蚀分析

介绍氨汽提尿素生产工艺中尿素合成塔的腐蚀特点、影响腐蚀的因素和不同状况下的腐蚀原因分析,并提出相应的防护措施和注意事项。     

关于尿素合成塔衬里腐蚀原因分析及处理方法

尿素生产工艺中,尿素合成塔作为关键设备,其腐蚀的典型区域发生在耐腐蚀衬里部位,本文针对尿素合成塔工艺,对尿素合成塔衬里腐蚀的机理进行初步分析,提出合成塔衬里腐蚀的修复措施和处理办法,供相关人士参考。     

尿素合成塔的腐蚀及局部修理

针对尿素合成塔衬里腐蚀和泄漏的现象,分析衬里焊缝腐蚀的原因,提出装置定期检修或合成塔发生泄漏时应进行全面腐蚀检查,介绍合成塔衬里及碳钢壳体腐蚀的局部修理方法及保证尿素合成塔正常运行的安全措施.     

镍含量分析小结

尿素成品及合成塔出口熔融物中镍含量的测定，是尿素生产装置高压系统平均腐蚀程度的依据。尿素合成塔衬里与塔板及一些设备管件的材质均为不锈钢，在高温、高压下的尿素一甲铵介质作用下，每时每刻都有镍不断溶解下来，尿素成品、尿素合成塔出口熔融物中含镍就是这种腐蚀作用的客观反应，所以测定尿素合成塔中镍的含量在生产中是重要的控制分析项目。     

关于改进型CO_2汽提法尿素装置尿素合成塔的腐蚀与控制

尿素合成塔是改进型CO2汽提法尿素装置的4大重要高压设备之一。介绍了34万t/a尿素合成塔的基本结构;阐述了尿素合成塔的腐蚀机理;从温度、氨碳比、水碳比、甲铵液浓度、氧含量等方面等论述了尿素合成塔产生腐蚀的影响因素;提出了正常运行、开车、停车、封塔停车以及低负荷运行期间减缓尿素合成塔腐蚀的控制方法。     

尿素合成塔的腐蚀与防护

讨论了尿素合成塔衬里的腐蚀形式、腐蚀机理 ,并介绍了尿素合成塔的检测检修方法及防护措施     

Hydrogenation of heavy liquids from a direct coal liquefaction residue for improved oil yield

For hydrogenation of heavy liquids in direct coal liquefaction residue (DCLR) within the direct coal liquefaction (DCL) process, heavy liquids in a DCLR derived from a bench-scale Shenhua DCL process using Shenhua coal are evaluated under two conditions. One simulates the coal liquefaction conditions of the Shenhua plant in the presence of a Fe-based Shenhua catalyst; the other one simulates the online hydrotreating conditions in the presence of a NiMo/Al₂O₃ catalyst. The results show that the heavy liquids of DCLR can be hydrogenated under these two conditions yielding less heavy products; hydrogenating the heavy liquids under the online hydrotreating conditions is more effective than that under the coal liquefaction conditions; the preasphaltene fraction is a main problem that yields non-soluble materials under these hydrogenation conditions. The results suggest that hydrogenation of toluene soluble and tetrahydrofuran soluble fractions of the DCLR under the coal liquefaction and online hydrotreating conditions is feasible, but their conversion to lighter products are inapparent under the coal liquefaction conditions, and elimination of the formation of tetrahydrofuran insoluble fraction in the online hydrotreator should be considered.     

Controlling Fiber Morphology and Scaffold Design for Treatment of Dry Age-Related Macular Degeneration

Polystyrene (PS), poly(ethylene terephthalate) (PET), and polyurethane (PU) were electrospun in various solvents, to ascertain the ideal conditions for reproducible scaffold production, in order to develop a synthetic Bruch's membrane. Effects of different environmental factors under laboratory conditions and controlled conditions, with and without 1% NaCl, were investigated. For PS, environmental conditions were more important than NaCl addition in fiber diameter reduction; however, NaCl addition showed reduced fiber size variation. For PET, reduction in fiber diameter on addition of NaCl compared to controlled environmental conditions was observed. Fiber size variation for PET was unaffected by NaCl addition or controlled conditions.     

双喷嘴喷射成形柱状坯生长过程模拟

建立了双喷嘴喷射成形柱状坯形成过程数学模型,利用此模型,对下拉速度、喷射夹角和初始偏心距3个工艺条件下沉积柱状坯的生长过程进行了数值模拟,模拟结果表明,各条件对柱状坯形成过程都有影响,只有合理的工艺条件才可得到较合理的柱状沉积坯.通过理论分析,提出了得到稳定增长理想柱状坯的条件,对优化工艺有一定指导意义.     

高温条件实验应力分析及应变测量

讲述了高温条件下实验应力分析、高温应变测量发展及高温条件下的应变测量方法,介绍了几种高温应变测量系统。     

Bifurcation Analysis on Pt and Ir for the Reduction of NO by CO

Due to the importance of the NO‐CO reaction in current catalytic converters, reduction of NO by CO on Pt group catalysts is important to study. Various reaction mechanisms have been proposed for the NO‐CO reaction on Pt(100), which shows bifurcations, kinetic oscillations and multiple steady states under ultra high vacuum (UHV) conditions due to complex surface dynamics. Some experiments on supported Pt group catalysts reported in literature show oscillations and bistability under atmospheric conditions as well. Industrially relevant conditions require the modelling and detailed analysis of the system at atmospheric pressure. We have proposed a reaction mechanism for the NO‐CO system on Pt group catalysts and coupled it with an isothermal PSR model to obtain solutions at atmospheric conditions with the continuation software CONTENT 1.5, at different operating conditions. Simulation results suggest that Pt(111) shows bifurcations at certain operating conditions while Ir(111) shows stable solutions at all the operating conditions studied here.     

一步法柠檬酸钠生产中钙盐条件的优化研究

研究了在使用不同钙盐条件下和柠檬酸的发酵液与钙盐中和反应生产柠檬酸钙的工艺条件,提出了采用不同钙盐条件下,柠檬酸与钙盐的比例关系,以及相应的pH值与柠檬酸根的残留量,为一步法生产柠檬酸钠在中和工序提供了良好的工艺条件,减少了后工序的生产难度,提高了中和工序的收率和最终的产品质量。     

尾管悬挂和回接固井异常工况分析及对策

尾管悬挂、回接固井在固井施工中出现的异常工况将直接影响固井后续施工作业质量和延长施工周期。因此如何避免尾管悬挂和回接固井在施工中异常复杂工况的产生,保证固井施工正常有序的完成,是尾管固完井施工成败的关键之一。对尾管悬挂、回接固井在施工过程中出现的几种异常工况进行了分析和研讨,找出产生异常工况的原因,从而提出合理有效的预防措施,避免固井施工中出现的异常工况。     

氯氢处理工序控制的难点和相应措施

结合氯氢处理工艺的特点，分析正常生产、异常状态下、事故状态下和变更后的生产过程控制中存在的主要难点，并提出相应的解决办法。     

基于不同复合工况条件下轮胎轮辋配合安全问题的研究

本文依托ABAQUS非线性有限元软件,建立了12.00-20 18PR特种越野轮胎的稳态滚动模型,鉴于轮胎实际行驶状态的复杂性,为针对轮胎轮辋配合安全获取合理的仿真设置工况,故通过考虑牵引制动、侧偏和侧倾多工况的不同组合,得到接触区域关于接触压力、摩擦应力分布等关键评价因素的变化趋势,获得对轮胎轮辋配合安全具有实际研究意义的工况。确定了可靠的仿真环境,将有效指导轮胎有关接触安全问题的深入研究。     

Coal liquefaction model: microscopic examination of solids from metal halide catalysed coal hydrogenation experiments

Coal undergoes changes during the hydrogenation process which depend on the balance between carbonization and hydrogenation reactions, which in turn depend on various experimental conditions, i.e. hydrogen availability, heating rate etc. If carbonization conditions prevail, semicoke is formed, whereas liquid hydrocarbons are formed under hydrogenation conditions. This model is applicable to hydrogenation reactions carried out under a wide range of experimental conditions.