高温气体过滤除尘脉冲反吹再生过程的研究进展

叙述近年来高温气体过滤除尘技术的实验和理论研究进展,指出脉冲反吹再生过程是高温气体过滤除尘过程持续操作的关键。操作参数以及结构设计(包括喷嘴直径、喷嘴与文氏嘴之间的距离、喷嘴出口速度以及文氏嘴结构等)对除尘工艺过程和再生效果具有很大影响。分析了脉冲反吹过程中所涉及的传递现象数值模拟,以期更为深入地了解反吹再生过程的气流流动与能量传递规律,以指导和优化过滤装置的操作参数和结构设计。     

连续重整烧结金属过滤器的过滤和反吹

在连续催化重整过程中,贵金属催化剂因磨损会产生粉尘。收集粉尘既保护下游设备,又具有经济效益。烧结金属过滤器具有可靠、高效的过滤性能,已在连续重整催化剂除尘领域得到了广泛的应用。针对烧结金属过滤器在线再生不彻底,以及反吹气对工艺系统扰动较大的问题,研究了一定过滤压降增量下,反吹压力及脉冲宽度对过滤器再生效果及系统的影响,确定了烧结金属过滤器在线反吹的适宜操作条件。这对烧结金属过滤器在连续重整工艺中的应用具有一定的指导作用。     

刚性高分子微孔过滤在脱碳液过滤改造中的应用

以刚性高分子微孔管作为过滤介质的精密过滤 ,具有过滤效率高、可反吹再生、操作简单、耐腐蚀、使用寿命长等特点。它从微孔过滤介质、过滤机结构、精密过滤计算方法等方面改革了传统的精密过滤作业。采用该技术改造合成氨净化系统的脱碳液过滤 ,取得了良好的使用效果和经济效益。     

反吹型过滤除尘系统及其在MTO装置中的应用

文章介绍了反吹型过滤除尘系统在MTO装置中的应用情况,并从设计角度讨论了选用时应注意的问题。该系统除尘效率高,排出气体含尘量不大于30mg/m3,满足国家环保法规的排放要求,同时还可回收大量催化剂,效益可观。这种除尘系统可进一步取代再生烟气四旋,具有推广前景。     

烧结金属除尘技术的研究进展

介绍一种高性能的过滤材料——烧结金属过滤材料及其特性。探讨了该过滤材料在除尘技术中的应用及其发展状况 ,对于烧结金属过滤式除尘的设计优化进行了初步研究 ,最后对该除尘技术的前景做了展望     

烧结金属过滤式除尘技术研究

以烧结金属微孔材料为研究对象,分析了过滤层介质不均匀的影响。不均匀的滤层设计能减小压降,提高反吹清洗的效率;使用Fluent6.1的多孔介质单元模型模拟过滤元件内的二维流动,探讨过滤层为V形褶皱几何结构中一些参数变化对过滤的影响,最后对过滤的设计优化进行了探讨,研究结果对烧结金属过滤器的理论和设计有参考价值。     

碳化硅陶瓷膜管高温除尘实验研究

采用自制碳化硅陶瓷膜管对某电厂烟气进行了高温过滤性能和再生效果的实验研究。主要考察了三种陶瓷膜管的处理气量对过滤效率、阻力损失的影响以及反吹再生效果。结果表明,随着含尘烟气量的增加,过滤效率逐渐降低,同时压降损失逐渐增大;复合膜的过滤性能优于单一膜或支撑体,反吹再生效果最佳。     

高温气体除尘技术及其研究进展

介绍了几种常用且有效的高温气体除尘技术及其研究进展,包括:陶瓷过滤除尘技术、颗粒层过滤除尘技术、金属微孔过滤除尘技术、旋风除尘技术、静电除尘技术,其中,颗粒层过滤除尘技术是最有发展前途的可用于IGCC和PFBC-CC(增压流化床联合循环)的高温除尘技术之一,指出高温除尘技术需要解决的问题是高温下延长滤材寿命、优化滤材再生技术、提高过滤效率。分析表明,高温除尘技术具有广阔的工业应用前景。     

高分子精密过滤在化工领域中的应用

高分子微孔过滤技术既可适用于高效精密滤饼过滤,也可用作高效精密澄清过滤,它从微孔过滤介质、微孔过滤机结构、精密过滤计算方法等方面改革了传统的精密过滤作业。它具有过滤效率高、可反吹再生、耐腐蚀、操作简单、使用寿命长等特点,在许多化工装置中已获得应用,并取得了显著的经济效益。     

TiAl金属间化合物分离膜在TiCl_4工业分离中的应用

TiAl金属间化合物分离膜具有高过滤精度和长期稳定的过滤通量。使用TiAl金属间化合物分离膜的固液分离可以大大提高TiCl_4生产工业中的生产效率。反吹和反冲洗技术相结合,确保了长期密封和过滤过程,大大降低了劳动强度,避免了污染。本文对滤饼层中固体颗粒的清洗和再生进行了研究,结果表明,反向过滤可以显着提高TiAl膜的渗透通量,并且采用化学清洗效果最好。     

几种多孔金属材料的性能对比

测试了金属烧结纤维毡、五层不锈钢复合网的过滤性能,并通过与金属烧结粉末过滤材料对比,分析了其过滤性能与过滤精度的关系,结果表明,金属烧结纤维毡的过滤性能最好,烧结五层复合网、金属烧结粉末次之。再结合它们的一些其它性能,依次给出了它们不同的应用领域。     

金属烧结滤网在聚丙烯生产中的创新应用

通过将多层金属烧结网和金属烧结毡在聚丙烯生产上进行应用,来提升聚丙烯的产能。多层金属烧结网在挤出机组上的改良使挤出机组原更换滤网的时间由1～2天延长为7天更换,并通过对挤出机组过滤部件的改造,使挤出机组的过滤效率提升了1.6倍;金属烧结毡在聚丙烯原料的回收除尘应用使聚丙烯除尘滤筒维护时间由半年延长为2年。     

Evaluation of metallic filter media for sub-micrometer soot particle removal at elevated temperature

Soot particle removal performance of two types of metallic filter media, sintered metal powder and sintered metal fiber, is experimentally evaluated as potential improvements to conventional ceramic filtration media for gasoline direct injection (GDI) engine PM after-treatment application. Soot collection efficiency and flow resistance of several grades of metallic media are measured at temperatures of 25, 350, and 650°C and a range of representative filtration velocities for sub-micrometer soot particles generated from a propane flame. Theoretical collection efficiency based on single fiber efficiency theory shows good agreement with experimental data for nearly spherical KCl particles at 350°C. Improved collection efficiency is observed for soot particles in the interception-dominated size range above ～100 nm due to enhanced interception length. Soot collection is slightly enhanced at higher temperature, which is consistent with model predictions. Sintered metal fiber media are found capable of removing ～75% of soot particles by mass with an incremental flow resistance of less than 1.5 kPa under 10 cm/s and 350°C, which is promising for gasoline particulate filter (GPF) application. The media level figure of merit (FOM) is used to quantify the soot collection efficiency versus flow resistance tradeoff of all media tested. It is found that due to their more open structure (higher porosity) sintered metal fiber media have FOMs nearly one order of magnitude higher than those of sintered metal powder media, and by analogy those of conventional wall flow ceramic media. This suggests that sintered metal fiber media represents an attractive alternative to ceramic media for designing GPFs; however, further research into creating comparable surface area to the honeycomb structures used for wall flow filters is needed to extract the full potential of metal fiber media.

Copyright © 2017 American Association for Aerosol Research     

Permeability of sintered microfibrous composites for heterogeneous catalysis and other chemical processing opportunities

Microstructured materials have potential for enhanced mass and heat transfer compared to typical catalyst particulates used in industrial processes. The pressure drop through catalyst-containing materials is a very important reactor design consideration. A model equation to predict porous media permeability (PMP) over the entire range of possible bed voidages is extended to predict properties of sintered metal meshes. A correlation of data for sintered meshes of nickel fibers is presented in the form of a Kozeny constant form drag plot. Comparison of predictions by the PMP equation with data taken on a sintered composite fiber/particle mesh is presented. Use of the PMP equation as a design tool for optimization of media for adsorbents, catalysts, and filters is discussed.     

An electrochemical investigation of sintered thick metal hydride electrodes for oxygen-metal hydride semi-fuel cell applications

Based on a conventional pasting method, a sintering process was applied to fabricate thick metal hydride electrodes for oxygen–metal hydride semi-fuel cell. It was found that, after sintering, the activation and the high-rate dischargeability of the electrodes are greatly improved. The sintering parameters were optimized by measuring the electrochemical properties of the metal hydride electrode sintered in the temperature range 650–900 °C for 10–60 min under mixed argon and hydrogen gases. It was found that to make a thick metal hydride electrode, the use of perforated copper foil as a current collector is better than using perforated nickel strip and copper mesh. A new type of structure is designed for the thick metal hydride electrode, that is, by folding the perforated foil that had been prepasted with active materials into a sandwich structure. This fold-type sandwich electrode was further clamped and held together by copper mesh.     

金属丝网过滤技术在液氦纯化中的研究与应用

介绍了金属丝网过滤技术的结构特点及作用机制,重点阐述了压降特性及捕集能力。利用金属丝网的微孔特性,论证了采用该技术进行低温液体纯化的合理性及优越性。并以液氦纯化为例,在总结国内外技术的基础上提出了金属丝网过滤及再生方案,并比较了现有的过滤模型,指出应用于液氦纯化时需要改进随机函数并考虑沉积的不稳定性的影响。     

Study of gradual porous metallic membranes obtained by powder sedimentation

In our preliminary studies the possibility of obtaining sintered porous materials with gradual structure by sedimentation of metallic powder was demonstrated. In this paper we continued our studies on the influencing factors of the sedimentation of metallic powders. Irregular and spherical nickel particles were used having a grain size in the 2–90 μm range measured by the laser scattering particle size analyzer. The particles with irregular shape and larger diameter can sediment faster than the spherical and the smaller diameter particles. The sedimentation rate is also influenced by the sedimentation medium and the quantity of the dispersant agent. Deviations from Stokes law was observed in the case of the irregular particles. The gradual structure is influenced by the sintering regime and the powders characteristics too. The obtained structures were characterized by scanning electron microscopy and mercury porosimetry. The permeability and the filtration fineness were also determined.     

金属纤维烧结毡过滤材料过滤性能与科学应用

随着污染控制技术的发展及过滤理论的深入研究,金属纤维烧结毡作为新型的过滤材料在化工、化纤、冶金、石化、食品加工、机械设备、环保等行业得到广泛的应用。金属纤维烧结毡过滤材料是采用不锈钢纤维(镍纤维),利用纤维杂乱交织烧结碾压,形成具有无数不规则孔隙通道和一定厚度的载体,用此来拦截液流中的污染物。该材料具有无脱落,高过滤精度,高纳污容量,耐高温,耐高压,耐有机溶剂,可折波,可焊接,可反复清洗等特点。     

高温气体过滤技术及装备发展概况

随着洁净煤发电技术的发展及环保要求的提高,高温气固分离技术取得了重要的进展。本文阐述了在高温过滤材料方面,经过了早期的金属多孔材料、均质陶瓷多孔材料、纤维增强陶瓷复合材料、金属合金及金属间化合物多孔材料等四个阶段的探索,逐渐形成了陶瓷粉末、陶瓷纤维、金属粉末、金属纤维和金属丝网等多种高温气体过滤元件,催化与过滤复合元件近年来也逐渐得到工程应用。此外,在高温过滤元件表面粉尘层结构、脉冲反吹循环再生、高温过滤器结构设计及实时运行优化等方面都取得了重要的技术进展。目前,高温气体过滤技术及装备已在煤气化、催化裂化、冶金及垃圾焚烧处理等方面得到了广泛的应用,其适用的温度范围为260~650℃,压力范围从常压到6.0MPa,过滤效率达到了99.9%以上,可有效除净1μm以上的颗粒,净化后气体中的颗粒物含量低于5mg/m³。指出随着国家经济转型和环保排放要求的提高,高温气体过滤技术在产品质量升级、高温余热利用及颗粒物排放控制等领域具有更加广泛的应用前景。