玻纤滤材过滤阻力的预测

过滤阻力和过滤效率是玻纤空气滤材的关键参数。实际应用中,为了优化滤材阻力和效率之间的矛盾,通常会选择多种尺寸的纤维搭配使用。对这种滤材的过滤阻力进行预测,对于高性能滤材的研制具有重要意义,而目前对玻纤滤材过滤阻力的理论计算大部分还局限于单种纤维的理想情况。本文将针对由多种玻纤原料制备的滤材,根据不同玻纤的比表面积,利用Kozeny-Carman方程计算由此制备的滤材过滤阻力。这种方法计算的过滤阻力理论值与实际测量值非常接近,相关系数R2=0.996 9,可为过滤材料的优化设计提供一定的依据。     

疏油改性对玻纤聚结元件气液过滤性能的影响

气液聚结元件在压缩气体净化等工业领域应用广泛，目前聚结元件的性能难以满足行业不断增长的需求，但是提高聚结元件过滤效率的同时，阻力也会随之升高，不利于其综合性能的优化。为研制低阻高效的聚结元件，利用不同浓度氟硅氧烷丙烯酸酯溶液对聚结滤材进行疏油改性，分析了表面能不同的滤材在气液过滤过程中压降、过滤效率以及二次夹带现象的变化，并对改性在聚结滤芯上的应用效果进行研究。结果表明，改性滤材在过滤效率提高10%的同时，稳态压降可降低约30%。滤材表面性质变化导致的跳跃压降减小是稳态压降降低的主要原因；滤材内液体分布对扩散、惯性分离作用的增强以及二次夹带的减少是效率提高的主要原因。对于表面能不同的疏油滤材，稳态压降和效率均随表面能的减小而升高。聚结滤芯经过改性后品质因子最大可提高92%。     

高效空气过滤用PTFE膜材料的结构和性能

聚四氟乙烯（PTFE）膜高效空气过滤材料以其过滤效率高、初始阻力小和无硼释放等优点,在电子工业洁净室中得到了广泛的应用,然而目前尚缺乏PTFE膜与传统滤材结构及性能的系统对比研究。本文选取了两种商业应用的PTFE膜高效滤材,采用扫描电子显微镜、孔径分析仪、自动滤材测试仪等多种表征手段对材料的微观结构和过滤性能与超细玻璃纤维（简称玻纤）滤材进行了较为全面的对比研究,结果表明,PTFE膜本质上也是一种纤维类滤材,其纤维平均直径为60～85nm,远低于玻纤滤材的668.8nm;高效PTFE膜的过滤效率与玻纤滤材相当,且其初始阻力不及玻纤滤材的50%,但PTFE膜滤材的容尘性能不及玻纤滤材,更适合应用于有再生或预过滤装置的场所。     

静电纺丝复合滤材制备及性能研究

研究了纺丝液浓度对聚丙烯腈(PAN)静电纺丝纤维直径,以及对PAN静电纺丝纳米纤维膜复合滤材过滤性能的影响。测试结果表明,纺丝液浓度增加,静电纺丝纤维直径变粗,孔径增大,其中质量分数为16%的纺丝液具有良好的纺丝性能,静电纺丝所得的纳米纤维直径均匀,复合后滤材在颗粒直径0.3μm,过滤风速5.3 cm/s的测试条件下,过滤效率达到99.98%,阻力为138 Pa,达到H13级别,具有高效低阻特性。     

孔径梯度分布对亲油型滤材气液过滤性能的影响

在天然气净化、大型旋转机械曲轴箱通风和压缩空气过滤等领域,气液聚结过滤器具有广泛的应用。利用滤材过滤性能实验装置,分析了气液过滤过程中不同孔径梯度分布的亲油型滤材的压降、穿透率和饱和度变化,比较了其过滤性能、内部液体分布特性以及对液滴二次夹带现象的影响。结果表明：在气液过滤过程“通道压降”阶段,孔径递增滤材压降和0.8 μm以上液滴穿透率的变化曲线具有明显的分层特征。不同孔径梯度分布滤材的稳态过滤性能存在明显差异,主要原因是滤材内部存在液体运移通道的传递现象。通过与孔径递减和孔径均匀分布滤材的稳态过滤性能对比,发现孔径递增滤材在保证较低压降的同时具有最高的品质因子,有利于减少液滴二次夹带现象的发生,且对0.8 μm以上不同粒径液滴均具有最高的过滤效率,即孔径递增滤材在气液聚结过滤器设计中更具优势。     

孔径梯度分布对亲油型滤材气液过滤性能的影响

在天然气净化、大型旋转机械曲轴箱通风和压缩空气过滤等领域,气液聚结过滤器具有广泛的应用。利用滤材过滤性能实验装置,分析了气液过滤过程中不同孔径梯度分布的亲油型滤材的压降、穿透率和饱和度变化,比较了其过滤性能、内部液体分布特性以及对液滴二次夹带现象的影响。结果表明:在气液过滤过程"通道压降"阶段,孔径递增滤材压降和0.8μm以上液滴穿透率的变化曲线具有明显的分层特征。不同孔径梯度分布滤材的稳态过滤性能存在明显差异,主要原因是滤材内部存在液体运移通道的传递现象。通过与孔径递减和孔径均匀分布滤材的稳态过滤性能对比,发现孔径递增滤材在保证较低压降的同时具有最高的品质因子,有利于减少液滴二次夹带现象的发生,且对0.8μm以上不同粒径液滴均具有最高的过滤效率,即孔径递增滤材在气液聚结过滤器设计中更具优势。     

分离用非织造滤材过滤性能及测试研究

针对3种气固分离用非织造滤材的透气、孔径及其分布、过滤效率、容尘量、计重效率以及再生性能等相关过滤性能开展测试研究,比对了滤材的渗透、孔径、截留和再生情况,为非织造滤材的产品质量控制、选择及应用等提供的依据。     

液固分离技术的进展

本文简述了液固分离技术近年来的进展。特别涉及加压电过滤设备、毛细吸附作用下的真空过滤机、动态过滤技术、新型卧式螺旋卸料沉降离心机、滤材等方面技术的国内外进展情况。     

精密单丝滤布透水速率与截留精度的研究

为进一步了解液固分离用织造滤布的过滤性能,以液固分离用新型过滤介质精密单丝滤布为研究对象,对滤布结构、开孔大小、丝径、孔隙率等因素对透水速率的影响进行了理论分析与讨论;并采用国际标准规定的鼓泡孔径、透水速率和截留精度的测试方法,对几种精密单丝滤布的孔径大小、透水速率、截留精度、透水阻力、孔隙度、分离效率进行了实验测定;同时介绍了不同孔隙度及截留精度的测定方法和结果,并对截留精度经验计算进行了实验验证,对正确选择与科学使用过滤介质单丝滤布提供有益的参考。     

关于多孔材料过滤精度的探讨

从多孔材料过滤精度的定义出发,探讨了过滤精度的评定方法和过滤精度与冒泡孔径间的关系,指出了过滤精度与冒泡孔径间具有一定的数值换算关系及换算注意事项,同时也指出了在过滤器设计使用和滤材选用时要考虑过滤精度评定时的试验条件、要结合工况条件对滤材标定过滤精度值进行修正。     

硅藻土-木桨纤维为助滤剂强化过滤过程的研究(英文)

In this paper, a study to enhance the filtration for solid/liquid materials difficult to be filtered, such as highly viscous, highly compactible or gel like materials, is presented. Filter aids diatomaceous earth and wood pulp cellulose are used to enhance the filtration by improving filter cake structure and properties in the filtration of a biological health product and a highly viscous chemical fiber polymer melt product. The property of solid/liquid systems, filtration at different flow rates, specific cake resistance, cake wetness, filtration rate, filtrate turbidity for filter aid selection and evaluation, and operation optimization are investigated. The results are successfully applied to industrial process, and can be used as a reference for similar filtration applications.     

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。     

天然气过滤器滤芯工艺计算

文章从工艺设计的角度通过过滤除尘机理,测算了滤料中过滤器的惯性捕捉效率、布朗扩散效率、直接拦截效率以及各种效应的联合效应得出所能达到的过滤总效率,根据压降测算出不锈钢烧结金属纤维毡的过滤精度和使用寿命,保证过滤器的使用提供了理论依据。     

Development of high efficiency particulate absorbing filter materials

We have developed new high efficiency particulate absorbing filter materials by bonding the fiber web with the help of high pressure water jets emerging from micron sized nozzles and subsequently coating the filters with a chemical binder. Two different types of nonwoven filters are produced by varying the water jet pressure during the bonding process. The performance characteristics of the filter materials are evaluated in terms of filtration parameters, such as filtration efficiency, dust holding capacity, and pressure drop. Filtration efficiency depends on the pore characteristics, namely pore size and their distribution in the filters. The developed filter materials have shown promising performance characteristics by capturing higher amount of dust particles with a relatively low pressure drop during use. These filter materials can be used for a wide range of industrial applications, where high filtration efficiency is required at low energy consumption. A fluid flow simulation is carried out by computational fluid dynamics (CFD) to understand flow pattern during the bonding process. The CFD is also used to predict the pressure drop in the nonwoven filter materials during filtration process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

水清洗对空气净化材料过滤性能的影响

用于空气净化的材料一般为一次性使用,但有的应用场所需要对其进行反复水清洗多次使用。通过实验手段,研究常规涤纶纤维层滤料,在荷尘、清洗、烘干、荷尘等多次反复中其过滤效率、阻力、容尘量的变化情况。实验结果表明,清洗对滤料的过滤效率、阻力和容尘量没有明显的影响,滤料可以通过水清洗的方式反复使用。     

Influence of oleophobic modification on gas-liquid filtration performance of glass fiber coalescing elements

Gas-liquid coalescing elements are widely used in industrial fields such as compressed gas purification. Currently, the performance of coalescing elements is difficult to meet the growing needs of the industry. However, while increasing the filtration efficiency of the coalescing element, the resistance will increase simultaneously, which is not conducive to the optimization of the comprehensive performance. To develop low-resistance high-efficiency coalescing elements, the coalescing filter materials are modified by different concentrations of fluorosilicone acrylate solution. The evolution of pressure drop, filtration efficiency and secondary entrainment of the filter materials with different surface energy during the gas-liquid filtration process were analyzed, the modified filter materials were fabricated into coalescing filters for verification. The results showed that, the filtration efficiency of the modified filter materials was increased by approximately 10%, and the steady-state pressure drop was reduced by approximately 30%. The decrease in jump pressure drop caused by changes in the surface properties of the filter materials is the main cause of the decrease in steady-state pressure drop. The increase in filtration efficiency is caused by the enhancement of diffusion and inertial separation, and the reduction of secondary entrainment. For oleophobic filter materials with different surface energy, the pressure drop and filtration efficiency increase with the decrease of surface energy. The quality factor of the coalescing filter element can be increased by up to 92% after modification.     

Dust Collection by a Fiber Bundle Electret Filter in an MVAC System

Electret filters are composed of thin, electrically charged fibers that are often utilized in industrial fields that require high collection efficiency with low flow resistance. A bundle-type electret filter in the Mechanical Ventilation and Air-Conditioning (MVAC) system of a Metro-subway was characterized in this study. The particle penetration and pressure drop parameters were examined under a filtration velocity ranging from 0.5 to 2.5 m/s. Particle penetration increased significantly in the early stages of filtration, but then became steady. The filter quality, which is a useful index of the filtration performance incorporating pressure drop and filtration efficiency, was evaluated for the test filters. The fiber bundle filter demonstrated a higher filter quality than the mechanical filter or the general panel-type electret filter with a small drop in pressure even at a high filtration velocity. In addition, the three dimensional structure and high electrostatic charge of the fiber bundle filter would enable a long retention time and constant level of pressure drop throughout the filtration.