预处理、电泳过滤袋的选型和应用

介绍了袋式过滤的工作原理，过滤袋的分类以及预处理、电泳过滤袋的选型，同时对生产过程中出现的密封缺陷进行了分析。     

车身涂装中黑色中涂层颗粒的成因与控制

对车身黑色中涂层的颗粒缺陷进行了分析,确定了颗粒的类型及来源,其中包括纤维、中涂结块、中涂漆渣、电泳颗粒、焊球颗粒、密封胶杂质等,提出了防控措施,如电泳后车身全打磨,采用不掉毛的无纺布擦拭,清理中涂室体顶部的锈蚀产物,吹净用压缩空气管口增设扁嘴,以及定期更换过滤装置。     

电泳铜质颗粒缺陷的治理

采用鱼骨图分析工具找出公司某电泳线铜质颗粒缺陷的原因——电泳导电铜排过度摩擦磨损。通过对磨损碎屑的清理以及对电泳导电铜排进行改造,解决了电泳铜质颗粒缺陷问题,并提出了电泳工艺及设备管理的新关注点,以供电泳工艺管理及涂装设备行业人士参考。     

磷化膜质量对阴极电泳涂装的影响

针对车身电泳涂装后表面出现均匀分布的细小颗粒以及电泳槽液过滤系统过滤出细腻泥状沉淀物的现象,分析了磷化液中沉淀物多对阴极电泳涂装的影响及沉淀物产生的原因,并提出了相应的解决和预防措施.     

一次电泳缩孔缺陷的原因分析与解决

介绍了某汽车涂装生产线生产过程中遇到的一次电泳缩孔现象。为了快速解决问题,通过交叉法设计了缩孔缺陷排查方案,根据实验结果确认了产生缩孔缺陷的工序为电泳。对产生缩孔的根本原因进行分析,并对解决方案进行模拟实验。最终通过提高电泳槽液颜基比和使用除油型过滤袋对电泳槽液进行全过滤解决了该问题。     

汽车涂装电泳颗粒问题研究

通过对电泳漆膜颗粒的分析研究,确定了引起电泳颗粒缺陷的主要原因是焊渣、焊球、金属屑,且颗粒主要分布在车身水平面。生产现场采取焊装吸尘收集铁屑、预清洗增加白车身表面擦拭、调整清洗喷淋等方法,改善了电泳涂装漆膜颗粒问题,单台统计电泳颗粒数下降60%左右,提升了汽车电泳涂装质量,提高了涂装一次合格率,降低了返修成本,提高了生产效率。     

电子纸显示器中电泳颗粒制备的研究进展

分类综述了近年来白色、黑色及彩色电泳颗粒的制备及包覆修饰方法,评价了各种制备或包覆修饰方法应用于电泳颗粒制备中的优劣. 相比机械法,化学法,尤其是高分子包覆法在制备电泳颗粒上具有优势. 此外,还介绍了国内在制备白色、黑色和彩色电泳颗粒方面的部分最新进展,为各色电泳颗粒的制备提供了新思路. 最后,概括了电泳型电子纸显示器中电泳颗粒的现状及制备技术中存在的问题和发展方向.     

消除汽车车身中涂层颗粒缺陷的若干方法

总结了工作人员、升降台升降速率、输送管路、中涂烘干炉、中涂漆内高沸点溶剂、电泳涂层研磨工具、台车等因素对中涂层颗粒缺陷的影响。明确了导致颗粒缺陷的主要原因是烘干炉出现焊缝缝隙以及台车被污染。给出了相应的解决措施,有效地降低了颗粒缺陷的发生。     

工程机械驾驶室涂装颗粒分析与控制

电泳涂装质量分涂层内在特性指标和外观质量。外观质量直接体现涂装线的管理水平,而涂层表面颗粒的多少是涂膜质量的重要评价因素,也体现了整条线的综合水平。本文结合三一车身有限公司电泳涂装线实际情况,对驾驶室产品进行了颗粒缺陷采样分析,重点分析涂装颗粒的产生原因和采取的相应措施,缺陷发生率下降75％,改善效果显著。     

浅谈电泳二次流痕缺陷的控制

阴极电泳已广泛应用于汽车涂装,电泳二次流痕(俗称电泳水)是阴极电泳过程中的常见缺陷。结合车身调整、电泳滴水挡板设计、电泳吹气3种措施改善电泳二次流痕缺陷的实际案例,介绍控制电泳二次流痕缺陷的方法。     

Simulation of particle deposition on filter fiber in an external electric field

Particle deposition onto a filter fiber was numerically simulated when a uniform external electric field was applied. The effects of electric field strength, particle inertia, and electrical conductivity of particles on particle deposition characteristics such as particle loading patterns and collection efficiency were qualitatively investigated. As a result, the electrostatic forces between a newly introduced particle and the already captured particles on the fiber were found to have a great influence on the particle deposition patterns compared with the results where the electrostatic forces were neglected. Conductive particles and filter fibers lead to higher collection efficiency and more linear structure of particle deposits than those of dielectrics, and the particle inertia could also be more important to the collection efficiency of a fibrous filter when electric fields are present. The simulated particle deposits obtained from this work agreed well with the existing experimental results, in which the photographs of particle loaded fibers, within an external electric field, were reported.     

罐底油三相分离理论及实验研究

介绍了罐底油的现状及罐底油中渣颗粒和油滴及水在离心力场中的运动规律、受力情况,建立了相应的物理模型;推导出了渣颗粒的离心沉降分离速度、沉降层厚度和油滴的向心分离速度、向心层厚度的表达式;通过小型实验设备对罐底油进行了三相分离实验研究,分析了温度、分离转数等对分离效果的影响。实验与理论分析结果基本吻合,为罐底油的简单有效分离提供了依据。     

初始状态不确定的非线性过程系统状态估计的鲁棒粒子滤波方法

在过程系统的控制与故障检测等方面,状态估计发挥着重要作用。针对非线性过程系统状态估计过程中初始状态不确定性问题,提出一种鲁棒粒子滤波方法。该方法首先引入初始状态准确性间接判定准则,根据判定的结果来选择是否进行基于观测偏差反馈机制的初始状态迭代改进。初始值准确性较差时,可以通过初始状态迭代改进策略使最终的初始粒子更接近真实的初始状态,从而增加产生初始粒子的正确性概率,通过粒子滤波迭代得到更准确的状态估计结果。将提出的鲁棒粒子滤波方法与传统粒子滤波方法应用于两个非线性动态系统实例中,结果验证了所提出方法的有效性与鲁棒性。     

Effect of Milling on the Intrinsic Coercivity of Barium Ferrite Powders

The effect of milling on the intrinsic coercive force of Ba ferrite powders has been ascribed to (1) thermal fluctuations caused by superparamagnetic fine particles and (2) lattice defects introduced by milling. To test these interpretations, the Moessbauer absorption spectra and angular variation of coercive force for ball-milled powders were determined. With increasing milling time, the Moessbauer absorption spectrum becomes ambiguous, and the absorption lines are broadened; the quadrupole-split center line corresponding to superparamagnetic BaFe₁₂O₁₉ cannot be detected. The angular variation of coercive force shows that milling considerably lowers either the nucleation field of the reverse domain or the effective anisotropy field or both. It is concluded that lattice defects, rather than superparamagnetic fine particles introduced by milling, greatly affect the intrinsic coercive force of Ba ferrite powders.     

Effect of particle loading on the collection performance of an electret cabin air filter for submicron aerosols

Electret filters are composed of permanently charged electret fibers and are widely used in applications requiring high collection efficiency and low-pressure drop. We tested electret filter media used in manufacturing cabin air filters by applying two different charging states to the test particles. These charging states were achieved by spray electrification through the atomization process and by bipolar ionization with an aerosol neutralizer, respectively. Polydisperse solid NaCl particles with 0.1%, and 1% solutions or liquid dicotyl sebacate (DOS) particles were generated from an atomizer, and they were loaded on the filter media. The amount of charge, the mean particle size, and the particle material significantly affected the collection performance of the electret filter media for submicron particles. The collection efficiency of the electret filter media degraded as more particles were loaded, and showed minimum efficiency at steady state. The electret filter media captured the highly charged particles more efficiently during the transient state. At steady state, the filter media loaded with smaller NaCl particles showed lower collection efficiency. The filter media loaded with liquid DOS particles showed collection efficiency much lower than those loaded with solid NaCl particles.     

木材颗粒在卷烟滤嘴中的应用研究

通过电镜、比表面积及微孔物理吸附仪对木材颗粒表面形貌和比表面积进行表征。在卷烟对比实验中,研究木材颗粒复合滤棒和未采用木材颗粒醋纤滤棒的吸附性能。结果表明,木材颗粒表面呈鱼鳞状,具有介孔吸附材料特性;木材颗粒复合滤嘴可以降低卷烟主流烟气中的焦油和7种有害物质,对比未使用木材颗粒复合滤嘴下降幅度分别达到了焦油8.57%,CO 2.17%,B（a）P 22.22%,NNK 4.50%,巴豆醛3.49%,HCN 20.37%,氨离子3.77%和苯酚21.16%;木材颗粒复合滤嘴可以提升烟气浓度,增加烟香丰富性和改善舒适性。     

聚氯乙烯母液水中树脂颗粒回收新技术调试运行小结

介绍了新疆天业（集团）天辰化工有限公司407Yt／aPVC项目采用斜板式快沉槽与气动连续式砂滤器相结合处理、回收聚氯乙烯离心废水中PVC颗粒的技术。经现场试运行调试后，该装置运行正常，PVC母液水中PVC颗粒的回收率大大提高，实现了环保节能双收益。     

Antimicrobial Air Filtration Using Airborne Sophora Flavescens Natural-Product Nanoparticles

We investigated nanoparticle generation from a natural plant extract using the aerosol technique of the nebulization-thermal drying process, and tested its usefulness for antimicrobial air filtration. Sophora flavescens Ait. ethanolic extract was prepared as an antimicrobial natural-product suspension. Suspension droplets were generated using a single-jet Collison nebulizer, passed through an active carbon absorber to remove ethanol, and mixed and dried with sheath air. For drying, natural-product particles were exposed to 200°C for ～1 s. Finally, particles were introduced into a scanning mobility particle sizer, and their size distribution and morphology were analyzed. For application of natural-product particles to antimicrobial air filtration, the nanosized particles generated were deposited continuously onto air filter medium at various times. Physical characteristics (filtration efficiency, pressure drop, and fiber morphology by scanning electron microscopy), and biological characteristics (antimicrobial tests against Staphylococcus epidermidis, Bacillus subtilis, and Escherichia coli bioaerosols) were then evaluated. We also analyzed the chemical composition of particles deposited on the filter surface. The results showed that the nanoparticles generated were spherical and demonstrated a polydisperse size distribution, ranging from several tens to several hundred nanometers. Although the filter pressure drop increased with the amount of nanoparticle on the filter, the bioaerosol filtration efficiency and antimicrobial activity were enhanced. In particular, the S. flavescens natural-product nanoparticle-deposited filters were more effective for removal of Gram-positive than Gram-negative bioaerosols. These results are promising for the implementation of this new technology for control of air quality against hazardous bioaerosols.     

Numerical simulation of thermophoretic particle decontamination in clean rooms

In order to develop strategies for minimizing deposition of contaminant particles of diameters ranging from 0.1 to 1.0 μm on a wafer, the effect of thermophoresis on a particle deposition velocity was numerically studied. The angle between wafer surface and direction of free-stream flow was introduced as a system parameter. Convection, diffusion, sedimentation, and thermophoresis were included as particle transport mechanisms. Similarity transform was applied to the model equations and obtained equations with dimensions reduced by one. The results suggest that it is possible to enhance the removal of particles of diameter ranging from 0.1 to 1.0 μm by heating with a temperature difference of 10–30°C between wafer surface and the air stream. If the filter of a clean room removes well around 0.1 μm sized particles, the free-slream velocity or flow angle should be increased for the effective removal of particle by thermophoresis, but, if the filter is efficient in removing particles around 1 μm, the free-stream velocity or flow angle should be decreased.     

Improving the dewetability characteristics of hydrophobic fine particles by air bubble entrapments

The present study deals with the role of surface hydrophobicity and air bubble entrapment on filtration / dewatering of fine coal particles (− 0.5 mm). The experimental results showed that hydrophobizing reagents increased the contact angle (or hydrophobicity) and decreased the filtrate surface tension, cake formation time and moisture content of the fine particles. In addition to these, when the air bubbles were introduced to the hydrophobic fine coal particles in water, the cake formation time and moisture content of the filter cake were further reduced, which may be attributed to the fact that micro/nano size air bubbles were entrapped on the surface of the fine particles in a slurry and increased the dewetting characteristics of the fine particles. As a result, this process may lower the amount of moisture trapped during the dewatering fine particles and increase the efficiency of the filters.