硅酸铝纤维制备高温气体除尘材料的性能

采用真空抽滤并加热处理的方法制备硅酸铝纤维高温气体除尘材料,并通过扫描电子显微镜(SEM)、金相显微镜和压汞仪分别对材料的显微结构、纤维分散性、孔径大小和分布进行了分析.结果表明,在800℃并保温1h加热处理后,材料的抗折强度达到3.14MPa,过滤阻力为79.75Pa/m/min,孔直径在10～80μm的孔占总体积的70.23％,气孔率达到72.99％.硅酸铝纤维多孔陶瓷材料具有较高的抗折强度,孔隙率和较低的过滤阻力,可用于高温条件下粉尘颗粒的过滤.     

我国用于袋式除尘器的过滤材料

针对我国大气污染物的排放特点,袋式除尘是比较合适、运行稳定可靠的一项烟气除尘技术。介绍了过滤材料的分类,袋式除尘过滤材料的结构以及应用于高温腐蚀性烟气过滤中过滤材料的几种纤维性能,重点介绍了高性能聚四氟乙烯纤维在过滤材料中的应用。     

碳化硅多孔陶瓷制备与应用

主要以SiC多孔陶瓷材料为例，综述了多孔陶瓷的4种常用制备方法，即添加造孔剂法，发泡法，有机泡沫浸渍法和溶胶-凝胶法的工艺特点和制品特性，并且列举了制备SiC多孔陶瓷材料的6种特殊方法，包括含硅树脂热解法、固相反应烧结法、气相反应渗入法、流延成型法、固态烧结法和浸渍热解法。文中还给出了多孔陶瓷的性能与表征，介绍了SiC多孔陶瓷材料在过滤材料、催化剂载体、热工材料、吸声材料和复合材料骨架材料方面应用情况，为SiC多孔陶瓷材料的研究和应用开发提供指导意义。     

高温除尘过滤材料的研究

在现代工业生产过程中,涉及含尘气体在高温下直接净化除尘和应用的领域十分广泛,包括能源工业、石化和化工工业、冶金工业、玻璃工业以及环保领域等。高温工业气体含有大量的物理热、化学潜热及可利用的物质,如固体催化剂,它的合理利用有十分巨大的经济价值。高温气体除尘技术的核心是高性能过滤材料。文章介绍了当前高温气体除尘用过滤材料的特点以及过滤材料国内外研究现状和发展趋势。     

高温烟气过滤陶瓷的研究及应用现状

随着经济的快速发展,我国工业排放的高温烟气粉体日趋增多,高温烟气粉尘的排放不仅污染环境,而且造成大量的热能浪费。高温烟气除尘再利用是一项有效利用气体热能的技术,其中过滤关键部分为高温烟气过滤陶瓷材料。本文主要对国内外多种高温过滤陶瓷的研究及应用现状展开对比,阐述各种高温烟气过滤材质的优缺点。并指出现阶段高温过滤陶瓷研究及应用所面临的问题,以期为后续研究提供参考。     

金属纤维毡在高温除尘方面的应用

滤料是高温除尘技术的关键部分,本文着重介绍了不同过滤温度下选用金属纤维毡滤料的类别以及耐高温原理,并对金属纤维毡在高温除尘过程中的过滤机理和性能特点做了详细介绍,提出金属纤维毡将会成为高温除尘滤料的优先首选材料之一。     

煤气化装置飞灰过滤器用滤芯研究进展及应用

煤粉加压气化是目前第二代煤气化技术发展的主流方向,高温除尘设备是该技术装置中的核心设备。煤气化合成气高温除尘用过滤材料及技术是各国研究热点之一,综述了国内外高温除尘用过滤材料的研究进展及现状,特别介绍了国内开发的金属滤材的耐腐蚀特性及工业化应用进展。     

高温烟气陶瓷过滤材料研究进展

高温烟气过滤技术在工业领域应用广泛,而陶瓷过滤技术是目前高温烟气过滤最有效的手段。本文详细介绍了传统多孔陶瓷过滤材料、陶瓷纤维过滤材料和陶瓷复合微滤膜在高温烟气过滤方面的国内外研究现状及其过滤机制和发展趋势。     

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。     

高温除尘系统在工业窑炉中的应用探究

采用无机多元材料过滤元件制造的高温除尘工艺装备对450~500℃高温含尘烟气的过滤进行了中试试验,概述了其PID工艺流程、主要设备参数及工艺指标。连续1年多的中试运行结果表明,该高温除尘工艺装备过滤风速高、运行阻力低,经净化后的高温气体中粉尘接近零排放,可满足SCR脱硝前端除尘要求,同时能提高余热锅炉传热效率。     

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。     

Use of Disthene-Sillimanite in the Production of Porous Permeable Ceramics

It is proposed to use porous ceramics made of a disthene-sillimanite concentrate as a filtering material in aggressive media; the effect of the plastic component (bentonite) on the properties of ceramics is analyzed; the results of studying the phase formation processes at 1250°C with different isothermal exposures are specified. It is established that disthene becomes mullitized at this temperature and the sillimanite structure becomes perfected.     

梯度多孔陶瓷的制备技术

梯度多孔陶瓷具有高过滤精度、大透气系数、反洗效果好等特点,显示出广阔的应用前景。本文介绍了梯度多孔陶瓷的类别、表征手段和制备方法,重点介绍了一种绿色新工艺—冷冻干燥法的工艺及特点,为梯度多孔陶瓷的产业化发展提供参考。     

Ultra-low cost porous mullite ceramics with excellent dielectric properties and low thermal conductivity fabricated from kaolin for radome applications

Near-net-shape mullite ceramics with high porosity were prepared from ultra-low cost natural aluminosilicate mineral kaolin as raw material and polystyrene micro-sphere (PS) as pore-forming agent. Microstructure, flexural strength, thermal conductivity and dielectric properties of the ceramics were systematically researched. Results show that the porous mullite ceramics possess fibrous skeleton structure formed by a large quantity of interlocked mullite whiskers, which results in good mechanical properties and low-to-zero sintering shrinkage. Flexural strength of the porous mullite ceramics can be up to 41.01 ± 1.12 MPa, even if the porosity is as high as 62.44%. The dielectric constant and loss tangent of the porous mullite ceramics at room temperature are lower than 2.61 and 5.9 × 10⁻³, respectively. Besides, dielectric constant is very stable with the rising of temperature, and the dielectric loss can be consistently lower than 10⁻² when the temperature is not higher than 800 °C. In addition, thermal conductivity at room temperature is as low as 0.163 W/m/K when the porosity of mullite ceramics is 80.05%. The infiltration of SiO₂ aerogels (SiO₂ AGs) can further decrease the thermal conductivity to 0.075 W/m/K, while has just little effects on the dielectric properties. Excellent mechanical, thermal and dielectric properties show that the porous mullite ceramics have potential applications in radome fields. The porous mullite ceramics prepared from kaolin not only have low cost, but also can achieve near-net-shape.     

Preparation of novel reticulated prickly porous ceramics with mullite whiskers

Porous materials are widely used in heat exchangers, sewage treatment, electromagnetic shielding, thermal insulation, gas adsorption, photocatalytic due to their high specific surface area. The specific surface area of materials plays a pivotal role in them. It can be enhanced by increasing the porosity of the material, but the cost of this improvement is reducing the strength of the material. In order to improve performance, it is necessary to increase its surface area without reducing the strength of the material. In this work, mullite porous ceramics with mullite whisker on the inside and outside surfaces structures, which known as prickly porous ceramics(PPCs). They were fabricated using polyurethane foam coated with slurries as the pore-forming agents, sintered after secondary impregnation with silica sol and ammonium fluoroaluminate. The the sintering temperature as well as slurry composition of secondary impregnation were tuned to tailor the strength and surface structures of the PPCs. In addition, the potential of PPCs as high-temperature catalyst supports was demonstrated. Overall, the PPCs demonstrated large surface areas and high mechanical strength. This study paved the way for the fabrication of high-performance porous ceramics.     

泡沫陶瓷的研制

泡沫陶瓷是一种新型的功能陶瓷材料。它具有独特的结构和性能，在工业中有着广泛的应用前景。泡沫陶瓷具有密度小、透气性高、耐高温、抗化学腐蚀等特性。本研究对用颗粒强化的氧化铝骨架合成泡沫陶瓷进行了分析。这种材料比其它多孔陶瓷材料具有更好的热化学性质。这种材料可以用有机海绵浸浆获得，然后烧去海绵，留下多孔陶瓷网。这种方法的优点是它包含了过程参数和陶瓷结构，同时合成物的烧结情况及其它条件的影响在文中也有阐述。     

多孔SiC陶瓷/石蜡复合相变材料定型封装及热性能研究

以微米级SiC粉为原料,采用冷冻干燥工艺制备具有连贯层状孔结构的SiC陶瓷。以多孔SiC陶瓷为基体,石蜡为相变芯材,通过真空浸渍法制备多孔SiC陶瓷/石蜡复合相变材料,研究了石蜡在层状多孔SiC陶瓷内的浸渗行为及复合材料的储热性能。结果表明,层片状多孔SiC陶瓷的显微形貌对石蜡的浸渗过程及储热性能有明显影响。当石蜡负载量为21.7%(质量分数)时,复合相变材料熔融温度为59.6 ℃,凝固温度为53.9 ℃,相变潜热为28.4 J/g,室温下的热导率为2.4 W·(m·K)^-1。复合相变材料吸热峰和放热峰强度随着石蜡负载量减少而降低,当温度为200 ℃时,多孔SiC陶瓷/石蜡复合相变材料失重为5%(质量分数),表明材料具有良好的热稳定性。复合相变材料在100 ℃热处理30 min后陶瓷基体未发生形变,经100次热循环后具有稳定的相变潜热和良好的定型能力。     

Preparation and characteristics of highly porous BN-Si3N4 composite ceramics by combustion synthesis

Nitride based ceramics are considered as a kind of promising material for structural and functional integration due to their robust structure, extreme environmental resistance and electromagnetically transparency. It is still challenging to prepare nitride based ceramics with homogeneous and controllable microstructure because of their low self-diffusion coefficient and difficulty in sintering. Here, we developed a gelcasting-SHS process by combining gelcasting forming and self-propagating high temperature synthesis (SHS) for the preparation of porous BN-Si₃N₄ composite ceramics. First, carbon residue problem in the gelcasting -SHS process was studied. Based on the result, porous BN-Si₃N₄ composite ceramics with high porosity (69.42 ~ 86.48%), high strength (21.7 ~ 81.0 MPa) and low dielectric constants (1.42 ~ 2.87) were synthesized. In addition, the thermal shock resistance of porous BN-Si₃N₄ composite ceramics until 1000 ℃ was evaluated.