储罐负压排泥技术

油田每年都有大量的储罐需要进行清罐排泥作业,通过对几种常用排泥方法的比较,认为负压排泥装置具有安装简单,操作方便,排泥效率高,排泥费用低等特点,文章详细介绍了储罐负压排泥装置的结构、原理以及安装与操作方法,并提出负压排泥装置使用的注意事项。     

Study of different types of monomer emulsion feedings to semibatch emulsion polymerization reactors

Semibatch emulsion polymerization processes with a monomer emulsion feed are of great importance in both academia and industry. Monomer emulsion feeds can be applied to semibatch reactors using either a stream of an emulsified monomer or two streams of a neat monomer feed and an aqueous solution of an emulsifier. The effect of the feeding policy on the rate of polymerization and on the secondary particle formation was studied for a seeded semibatch emulsion polymerization of styrene. When a single-stream monomer emulsion feed is applied to a semibatch process, the monomer-swollen micelles formed in the feed might become the locus of initiation upon entering the reaction vessel. Under the conditions of this study, the application of monomer emulsion feed in either one stream or two streams did not result in secondary particle formation. The incoming monomer-swollen micelles were disintegrated to supply emulsifier molecules for the stability of growing particles, before they can capture radicals and become polymer particles. The rate of polymerization was found to be independent of the way that the monomer emulsion feed is added. In the absence of nitrogen, the rate of polymerization decreased more appreciably for the monomer emulsion feed, due to the oxygen dissolved in the emulsified monomer. The number of particles, however, was not affected by the purging policy. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2472–2477, 2001     

平整机带钢清洁系统的优化改进

针对湿平整生产中平整液残留缺陷问题,提出了一种高速轧制湿平整模式平整机带钢清洁装置。该装置主要包括吹扫梁系统、封堵系统,以及相对应的通风排雾系统。通过对平整机机架内部出口区域设备重新分区封堵,对工作辊和支撑辊辊颈设计挡水板,可有效阻隔入口平整液的窜流、二次飞溅和凝结滴落;在出口防颤辊,轧制线辊,测张辊等处前后布置多道吹扫梁,吹扫梁的压力梯度设定,使机架内不同区域形成压力差,气体向一个方向流动,避免了各吹扫梁空气的衍射干扰,并结合排雾系统的主动抽吸,形成顺畅的气流通道,减少了湿平整液的二次飞溅,大大提高了带钢的清洁效果,提高了机组产量,经济效益明显。     

天然气净化系统吹扫和压力试验工艺

系统的吹扫和压力试验是对设备、管件、管材及施工质量考核的一个重要环节,长庆气田第三天然气净化厂是西气东输天然气净化的重要组成部分,天然气处理能力300万m3/d。文章分析了天然气净化厂脱硫脱水装置区和集配气总站的特点,针对施工难点编制了切实可行的吹扫和压力试验方案,详细介绍了脱硫脱水装置系统和集配气总站系统的吹扫和压力试验工艺流程,并提出了施工中的注意事项。     

球罐热处理计算机监控系统

针对目前球罐整体热处理自动化程度不高的现状,采用安全性强、成本较低的内部燃烧工艺,应用德国欧科燃烧器、S7-200可编程序控制器、隔离变速模块、研华ADAM模块及研华工控机构成系统硬件体系,由组态王程序、Visual Basic程序及PLC程序构成系统软件体系,研发了一套球罐整体热处理计算机控制系统。该系统控制精度高、实用功能强、可靠性好,在国内外的多项热处理工程中,收到了很好的使用效果。     

Water removal characteristics of proton exchange membrane fuel cells using a dry gas purging method

Water removal from proton exchange membrane fuel cells (PEMFC) is of great importance to improve start-up ability and mitigate cell degradation when the fuel cell operates at subfreezing temperatures. In this study, we report water removal characteristics under various shut down conditions including a dry gas-purging step. In order to estimate the dehydration level of the electrolyte membrane, the high frequency resistance of the fuel cell stack was observed. Also, a novel method for measuring the amount of residual water in the fuel cell was developed to determine the amount of water removal. The method used the phase change of liquid water and was successfully applied to examine the water removal characteristics. Based on these works, the effects of several parameters such as purging time, flow rate of purging gas, operation current, and stack temperature on the amount of residual water were investigated.     

中韩石化武汉乙烯蒸汽管道吹扫分析

介绍我厂蒸汽管网概况,并对蒸汽吹扫原理和参数测算进行分析,制定吹扫方案。介绍我厂蒸汽管线吹扫的流程和吹扫中的问题和原因分析及解决措施。通过总结分析,加深对蒸汽吹扫理论和实际操作方法的认识,对于同类蒸汽管线吹扫具有参考意义。     

公用工程天然气管路设计要点

介绍了天然气的烃类组成和化学性质;论述了天然气管路设计必须遵循的原则;从燃料供应母管的设计及其相关设施的配置等方面,论述了天然气燃料供应系统的设计要点;针对管道压力控制、天然气放空方式、管路惰气吹扫中存在的设计误区,提出了相关解决办法。     

氢燃料电池氢气管道吹扫系统冷启动策略研究

针对现有车载燃料电池管道在吹扫过程中氢气侧管道由于低温结冰易受阻,从而导致冷启动困难的问题,提出氢气管道两级吹扫方案,以实现对燃料电池堆氢管中剩余水、蒸汽含量的独立控制,降低冷启动时的加热能耗,避免冷启动失效。通过三维仿真对4种不同工况下阴极中段在不同时间的温度、阴极中段在不同时间的冰体积分数、电池纵向截面表面不同时间的温度进行分析,结果表明该方案可实现在-20 ℃温度下20 s内的平稳冷启动,既解决了低温冷启动困难问题,又保证了冷启动后的电堆输出性能。     

浅析油库清罐作业中事故的成因及预防

分析了在油库清罐作业中存在着时机选择不当,作业人员安全意识不强,缺乏消防安全知识,违章作业和违章指挥等危险因素,提出清罐作业前一定要对施工队伍进行岗前培训,考核合格后方能上岗,在清罐作业中应加强对清罐作业的安全管理,有效控制爆炸性混合物,控制并消除点火源,妥善处理清罐污物等措施,以保证清罐作业的安全进行。