导热型绝缘硅橡胶垫片的制备与性能研究

导热材料被广泛应用在电子电气领域中,既能为电子元器件提供安全可靠的散热作用,又能起到绝缘减震的作用。本文以加成型液体硅橡胶作为基体材料,SiC、Al2O3为导热填料,通过液体共混法制各出高导热绝缘硅胶复合材料,在单组份体系中,40μm Al2O3作为填料制各的垫片导热系数最高达到1．71w／（m·k）,在二元体系中,70μmAl2O3/10μm Al2O3／硅胶体系导热率最商达到2．7W／（m·k）,制品硬度均在20～35HA,且具有良好的稳定性以及电绝缘性。     

无机填料对环氧树脂胶粘剂的粘接性能的影响

选取了硅微粉、Al2O3、莫来石、氮化硼、滑石粉、云母、Si O2等无机填料作为改性环氧树脂胶粘剂的组分,讨论了不同类别的填料及用量对改性环氧树脂粘接强度和粘接界面的影响。每种无机填料对于粘接强度均有不同程度的提高,粘接强度随着填料用量的增加呈现先提高后降低的趋势,其中15份Al2O3的提高效果最佳,剪切强度和剥离强度分别可以达到22.42MPa和12.84N/cm。     

波纹板规整填料塔液体分布

将填料单元处理成立体节点网,根据节点网内网线液流和节点液流各自的运动方式建立了填料单元的液体分布模型.通过将填料与塔壁间的液体交换规范成填料节点网与塔壁节点网间的液量传递建立了填料单元对应塔壁区的流体分布模型.提出了规整填料塔液体分布问题的边界条件.2个描述填料单元及其对应塔壁区液体分布的数学模型与2类边界条件共同构成了波纹板规整填料塔的液体分布模型.采用单纯形法对3个模型参数进行了估计.模型计算结果与实验数据一致,表明模型能合理地描述波纹板规整填料塔的液体分布性能.     

填料式氧合器填料传质与溶血特性的研究

本文在直径5.2 cm的有机玻璃填料式氧合器中,分别填充几种自制小填料(6mm不锈钢O网环,6 mm PVC拉西环,以及7 mm PTFE拉西环等填料),进行血液-O_2的物理吸收实验。以体积传质系数k_Lα和溶血程度作为填料的性能指标,对所用填料进行综合评价与筛选。实验结果表明:在所选填料中,以7 mm PTFE拉西环的性能为最佳。     

超重力法回收火炸药厂的混合溶剂

为回收三元混合溶剂（丙酮、乙酸乙酯、水）对HMX转晶时挥发的部分溶剂（丙酮和乙酸乙酯）,采用高效传质的旋转填料床对其进行了回收利用。考察了转速、液体流量和循环时间对吸收效果的影响。结果表明,转速和液体流量对混合溶剂的吸收有明显影响,实验的最佳操作参数为转速1000r/min,液体流量2m^3/h,液体循环时间12h。旋转填料床对混合溶剂的吸收具有良好的环保和经济价值。     

大开孔率填料支承装置填料洗涤塔的设计与工业应用

介绍了填料洗涤塔的塔体、填料、填料支承装置和液体分布装置的结构和设计.目前已有数十套使用组合式液体分布装置和大开孔率填料支承装置的填料洗涤塔在运行中,最大塔径达4 800 mm,工业生产装置的实测数据表明,填料洗涤塔的烟气出口温度与进塔的液相温度相差1.5～2.0 ℃,填料洗涤塔的气相压力降为500～700 Pa.     

填充塔辅件

<正> 填充塔中除填料主体外,所谓辅件主要有填料支承板、液体分布器、液体再分布器、液体捕集器和填料压板等。这些辅件对于填充塔操作中流体的良好分布,提高分离效率,以及防止泛塔等起重要和保证作用。     

超重力法回收火炸药厂的混合溶剂

为回收三元混合溶剂(丙酮、乙酸乙酯、水)对HMX转晶时挥发的部分溶剂(丙酮和乙酸乙酯),采用高效传质的旋转填料床对其进行了回收利用.考察了转速、液体流量和循环时间对吸收效果的影响.结果表明,转速和液体流量对混合溶剂的吸收有明显影响,实验的最佳操作参数为转速1 000 r/min,液体流量2 m3/h,液体循环时间12 h.旋转填料床对混合溶剂的吸收具有良好的环保和经济价值.     

复合绝缘导热胶粘剂研究

以增韧的酚醛环氧树脂为基体树脂,氮化铝、氮化硼、氧化铝混杂粒子为导热填料制备了-新型绝缘导热胶粘剂。研究了填料用量对胶粘剂热导率、热阻、介电常数、体积电阻率等性能的影响,发现填料用量为40％时胶粘剂的热导率为O．99 W／mK,热阻为0．70℃／W,介电常数6,体积电阻率4．6×1012Ω·cm,20℃、200℃、250℃下的剪切强度分别为13．0MPa、10．0MPa、5．65MPa。研究结果表明该胶具备良好的电绝缘及力学性能,可以长期在150℃温度下使用,与不加导热填料的相同胶粘剂相比,具有良好的导热能力。     

基于液体弥散理论的规整填料塔液体扩散数值模拟

规整填料塔内液体弥散规律的研究对于气液吸收塔的布液装置设计、填料高度确定以及填料类型优选具有重要理论意义,目前关于液体弥散机理的理论描述和模型建立较为有限,本文为实现填料塔内液体扩散现象的准确预测,引入液体弥散机理。规整填料采用多孔介质简化,在考虑了机械弥散力、气液拖曳力、多孔介质阻力等基础上建立了二维CFD模型,模拟结果与实验结果吻合较好。在此基础上研究了液体扩散系数S、气体入口速度和液体入口速度对液体分布的影响。通过研究得出液体弥散机理中毛细管弥散作用影响较小,主要以机械弥散作用为主;液体扩散系数和液体入口速度对液体分布的影响显著,S/Dr的最佳比例为2,气体入口速度对液体分布影响很小。研究结果对其他类型填料的模拟研究有重要借鉴作用。     

不锈钢三角螺旋高效填料在水-氢交换工艺中的性能研究

对液相水-氢交换工艺中的小型高效三角螺旋填料进行脱脂除油、亲水等进行了表面处理;通过总有机碳方法 TOC分析,处理工艺对填料的脱油效果明显,扫描电子显微镜SEM分析表明该处理工艺明显改善了填料比表面积。在典型的水-氢交换工艺条件下,处理过后的小型高效填料与Pt-SDB催化剂分层填装,该处理方式显著提高了水-氢交换性能,等板高度HETP降低至13.46 cm;进一步实验测定水-氢交换柱流体力学性能:床层持液量为0.03 m3/m3、床层压降为20 Pa/m,与理论计算一致。     

新型规整填料的性能及其在硫酸工业中的应用

针对硫酸干吸塔研制出了TJ160X型陶瓷规整填料，通过试验研究和分析证明该填料比传统的散堆填料具有更大的比表面积、更大的通量，其效率高、压降低。该填料在相同的条件下，压降是散堆填料的1／3，通量提高2倍以上。结合先进的液体分布器，模拟设计了一套硫酸干吸塔。探讨了将先进的陶瓷规整填料塔技术用于硫酸干吸系统的途径和方法。     

复合板网填料性能研究

对一种新型的金属复合板网填料进行了研究,它是由三层板网贴合为复合基材后加工成波纹填料。在500冷模实验塔内对250Y型填料的测试结果表明复合板网填料具有显著的性能优势。三层复合板网填料的压降比常用的金属板波纹填料低60%以上,通量大20%～40%。氧解吸实验结果表明三层复合板网填料的分离效率明显高于单层板网填料,尤其在液气比低的工况下,效率可以倍增,和广泛应用的金属Mellapac填料相比,复合板网填料的分离效率能高30%左右。     

Models describing the behavior of new carbon fiber packings inn rectification processes

Many rectification processes are used to separate corrosive substances with high boiling points. This reports deals with a new type of structured column pacing mode of corrosion-resistant carbon fiber material. These column internals allows for low pressure drop at high throughput rated with reasonable column efficiency. Experiments in columns of 50 and 100 mm diameter have been carried out to investigated separation efficiency, pressure drop and liquid holdup of the packing even at low operation pressures. In the respective columns twp geometrical different types of packing have been tested using binary mixtures of chlorobenzene/ethylbenzene with a packing geometry similar to the Sulzer EX packing, the 100 mm diameter column was filled with elements of rougher structure and smaller specific surface. Basing on the experimental results, model equations are presented, which allow the calculation of the investigated performance characteristics.     

新型垂直板规整填料流体力学及传质性能

采用氧解吸实验,在直径190 mm的有机玻璃塔内,液相喷淋密度10～38 m³·m^-2·h^-1,F因子0.2～3.2 m·s^-1·（kg·m^-3）^0.5的实验条件下测定了一种新型垂直板规整填料的流体力学及传质性能。实验结果表明：垂直板填料的操作压降及传质性能均显著优于商业波纹填料。通过与几种经改进的250型波纹填料相比发现,两者泛点F因子整体上相当;在较高液体喷淋密度下,垂直板填料传质性能及压降均高于改进250型波纹填料;在低喷淋密度下,垂直板填料可实现压降低于改进250型波纹填料,而两者传质性能相当。此外,对填料结构改进对其性能的影响进行了单因素考察。     

规整填料气体脱碳塔模拟计算

基于实际填料高度 ,本文首次建立了高效规整填料塔DEA活化热钾碱脱碳系统传质模型沿规整填料高度上CO2 气相浓度、溶液转化度、气液相CO2 分压等模拟计算结果与工业实例吻合很好     

Efficiency of Distillation Columns Containing Packed Sieve Trays

Abstract

The Murphree efficiency of the fifth tray in a six-sieve tray distillation column, 7.8 cm in diameter and 85 cm high, was increased from 37.5 to 90% when three disks of a wire mesh pad, 9 cm high, were placed on the tray. An acetone-methanol test system was used in this investigation. The pressure drop across the tower corresponding to this packing increased by 33%. Nine disks of Raschig rings of similar height increased the tray efficiency to 75% and the pressure drop by 16%. A model was used for the azeotropic system, and the overall tower efficiency was found to increase by about 20% due to the presence of packing on a single tray.     

Dehumidification of Air by Aqueous Lithium Chloride in a Packed Column

Abstract

A packed bed absorber-stripper system has been designed to dehumidify moist air by contact with aqueous solutions of lithium chloride. The packing material used in the study is 1.6 cm (5/8 inch) polypropylene Flexi rings, which have a surface to volume ratio of 342 m²/m³ (104 ft²/ft³). The absorber is capable of handling air face velocities from 3362.4 to 6746.4 kg/m²h and liquid flow rates from 2534.1 to 54648 kg/m²h. Solutions of 30% and 40% lithium chloride in water were employed as the dehumidifying agent. The minimum liquid flow rate calculated from the equilibrium data would be too low to wet the packing surface completely, and could not be used in the actual operating system. Therefore, liquid flow rates greater than the minimum wetting rate for the packing were used. Measured flooding conditions corresponded closely with exiting empirical correlations. Mass transfer coefficients ranged from 0.062 kmol/m³s at 40% flooding to 0.166 kmol/m³s at 80% flooding for the 40% lithium chloride solution. The height of a transfer unit calculated from the experimental data ranged from 0.340 m at a column efficiency of 71.6% to 0.617 m at a column efficiency of 50%.     

二段式吸收塔强化水洗技术提纯沼气过程

压力水洗技术已成为提纯沼气的关键技术之一。采用填料吸收塔进行CO₂脱除实验研究,考察了液气比、吸收压力、吸收温度、CO₂初始含量、填料层高度对CO₂脱除率的影响,以及液气比、沼气流量对总体积吸收系数的影响,并运用填料塔与喷雾塔结合的二段式吸收塔进行压力水洗提纯沼气的过程强化实验。实验结果表明,吸收压力和液气比的增大、吸收温度的降低、填料层高度的增加有利于CO₂的脱除,体积总吸收系数随着液气比及沼气流量的增加而增大。二段式吸收塔能够提高CO₂吸收效果,当沼气处理量为10 L·min^-1,填料层高度为100 cm,CO₂含量小于3%时,与填料塔相比二段式吸收塔可以减少约12%的吸收液用量,并且采用110 cm填料的二段式吸收塔获得最佳的提纯效果,CO₂脱除率达到97.4%。     

在高压下规整填料中的流动实验研究

Both distillation performance and hydrodynamic study for backmixing by tracer technique were carried out in a high-pressure packed column with 0.15 m inner diameter over a wide range of operating conditions. Isobutane and n-pentane are employed as test mixture in the distillation experiment and air/water is used for the hydrodynamic study. The column is installed with Mellapak 350Y structured packing and the total packing height is 2.0 m. With the increasing operating pressure, the separation efficiency increases slightly while the F-factor corresponding to the maximum efficiency at each pressure is descending. It is noted that, at all operating pressures, with the increase of F-factor, the packing efficiency is slightly higher up to the flooding point. The application of SRP model to high-pressure distillation gives much lower values of HTUOG than those obtained experimentally. An additional term, the height of mixing unit, is introduced to correct the SRP model and improve its accuracy at high pressure. From the tracer experiments, the height of mixing unit for gas phase was found to be larger than that for the liquid phase. From this viewpoint, it is believed that the gas phase backmixing gives more unfavorable influence on the separation efficiency in comparison with liquid phase.