镀锡用赫尔槽试验装置

介绍了一种具有制冷功能的镀锡用赫尔槽装置,用该装置进行酸性镀锡试验时,可保持镀液温度恒定。该装置主要由镀槽、温度控制器、冷却水箱和冷却水泵组成。镀槽侧壁内设有热电制冷片,镀槽侧壁外环绕有冷却水管,冷却水管与冷却水箱连接。镀槽内还设有热电偶,热电偶先感知镀液温度,随后通过温度控制器控制冷却水箱和热电制冷片的通断来调节镀液的温度,使镀液温度恒定。     

THEORETICAL SIMULATION OF HIGHLY EFFECTIVE COOLING WITH AN EVAPORATING ANNULAR FLOW IN A VERTICAL TUBE

A new concept is proposed for the highly effective cooling of a polymer electrolyte membrane fuel cell (PEMFC) using the downward annular two-phase flow of high-speed air and subcooled water in a small vertical tube. Numerical simulations based on the two-phase flow boundary layer model are performed to investigate the heat and mass transfer characteristics of the annular flow with uniform heat flux at the tube wall. The coupled heat transfer due to evaporation and convection and the effects of various relevant parameters on the temperature profiles on the wall and of the gas core are studied. It is shown that annular two-phase flow of air and subcooled water in a small vertical tube can provide high heat transfer rate through the evaporation of the water film, while still maintaining low wall temperature. This cooling method is found to be encouraging for use in the highly effective cooling of PEMFC.     

循环冷却水系统的黏附速率预测模型的研究

结垢是循环冷却水系统中常见的水质故障,人们常用水质判断指数来判断循环冷却水水质的结垢趋势。通过对某石化公司循环冷却水系统生产运行数据的分析,选取了对黏附速率影响较大的水质参数,借助神经网络的非线性映射、泛化及容错能力,基于BP神经网络建立了黏附速率的预测模型。利用该模型对循环冷却水系统一定周期黏附速率的预测结果较好,说明该方法可行,具有很好的应用前景。     

循环冷却水水质稳定性判断方法的研究综述

腐蚀和结垢是循环冷却水系统中主要的水质故障,人们常采用水质判断指数来判断循环冷却水水质的腐蚀和结垢趋势.主要研究了国内外判断循环冷却水水质稳定性的水质指数,并将其按照基于碳酸钙溶解平衡和基于多参数分析进行阐述,最后提出了一种基于数据的智能预测方法,旨在为准确、合理判断水质的腐蚀特性和结垢特性提供一个方向和参考.     

水质参数对交叉缩放椭圆管污垢的影响

采用对比的实验方法对交叉缩放椭圆管与光管的污垢热阻进行了分析,并重点研究了冷却水（松花江水）水质参数对污垢产生的影响。实验结果表明：在低流速时,交叉缩放椭圆管的污垢热阻渐近值比光管低,且没有明显的诱导期;实验中冷却水水质参数的变化对污垢影响明显。并深度分析了水质参数随时间的变化及水质参数变化对强化换热表面污垢特性的影响,为换热器提高换热效率提供了参考。     

肉桂醛臭氧化反应过程的碘量法跟踪

在肉桂醛臭氧化反应过程中 ,分别用碘量滴定法和气相色谱法测定臭氧和肉桂醛的浓度变化 ,两者的结果有良好的线性关系 ,其线性方程为 :Y =1 2 0 73X + 0 0 0 0 2 ,相关系数为 0 995 ,并根据臭氧化反应机理对线性方程进行了讨论 ,结果表明可用简单的碘量滴定法监控复杂的臭氧化反应     

The influence of the tacticity on thermal degradation of PVC. III. Verification by ozonization of degraded samples

Two sets of ozonization reactions, for 1 h and 24 h respectively, have been carried out at ?20°C on degraded samples of PVC having different contents of tactic sequences. The evolution of the polyene sequences distribution with the ozonization was followed by UV-Visible spectroscopy. The number of chain scissions of ozonized samples was calculated from the number average molecular weight measurements before and after ozonization. The observed increase of short polyenes relative to the long polyenes with ozonization was found to depend markedly on the content of syndiotactic sequences. On the other hand, the number of chain scissions after total ozonization was found to be the higher the lower the content of tactic sequences in PVC samples is.     

VCM聚合母液的综合利用

介绍了采用生化法与臭氧处理相结合的方法回收利用VCM聚合母液的工艺流程,采用该工艺处理聚合母液的运行费用为1．7元／m3,母液循环回用率为77％。     

臭氧—混凝法处理造纸废水

采用臭氧－混凝法处理造纸废水,COD、SS等主要污染物去除率均高达99％以上,各项指标超过一级排放标准,水质完全可以回收利用。为造纸废水处理提供了新的技术方案,可望使废水处理达到效益化运行。     

Synthesis and characterization of ozonized polyethylene

Polyolefins (LDPE and HDPE) can be ozonized with ozone/air gas flow to create peroxide and hydroperoxide groups on polymers. These reactive groups can be used to initiate radical polymerization of vinylic monomers and produce graft copolymers. In this study, the optimization of the experimental conditions and the explanation of the phenomena occurring during the ozonization of polyolefins in a fluidized bed have been studied. The most reproducible methods for placing peroxide and hydroperoxide groups onto polyolefins are the iodometric method and indirect titration by thiol. This work shows that it is necessary to control the temperature of the fluidized bed to avoid the acceleration of the reaction and the degradation of the polymers. Then, we studied the effect of different parameters such as the crystallinity and the granulometry of polymers, the time of ozonization and the effect of the load of the reactor on the quality of ozonization. Infrared spectroscopy and steric exclusion chromatography were used to characterize the ozonized polymers. We show that double bonds of PE, particularly vinyl groups, are very reactive to ozone and that ozonized HDPE leads essentially to the formation of hydroperoxide groups, whereas ozonized LDPE leads to the formation of peroxide groups.     

冷却塔配水管喷头流量的三维数值计算方法

冷却塔配水计算和优化可提高冷却塔的性能,目前通用的一维水力学方法没有考虑配水系统各部件的三维湍流影响。为准确计算冷却塔配水管喷头流量,提出了一种三维数值计算方法,该方法对配水管进行三维建模并对配水管内三维水流场进行模拟计算。采用该方法对1根典型的具有30个喷头的配水管实例进行数值模拟,计算得到喷头的流量分布合理,说明该方法是可行的,原则上该方法也可用于配水主管和竖井系统的配水计算和优化。     

铠装电缆用钢丝热镀锌工艺

介绍了在低碳钢丝倾斜引线热镀锌工艺的基础上,使用垂直引出法生产小直径铠装电缆用热镀锌低碳钢丝的工艺.其流程为:放线-退火—铅浴淬火-水冷-盐酸除锈-水洗-粘助镀剂-烘干-热镀锌—木炭粉抹拭-风冷-水冷-收线.详述了钢丝的热镀锌工艺参数的设定和钢丝镀锌采用垂直引出、木炭粉抹拭的方法.指出了预处理不当对镀层质量的影响.给出...     

循环冷却水的总碱度及其计算

不同条件下循环冷却水的总碱度有着不同理论和经验的计算。从化学热力学角度出发,考虑到浓缩倍数、离子强度和补水水质(包括总碱度、pH值和总溶解固体)等影响因素,在系统结垢之前,根据碳酸的离解平衡得到的循环冷却水的总碱度与实际较吻合。     

塑料模具异型水路制作与应用

传统的塑料模具模冷却水路加工往往依赖于钻加工,加工中必须避免干涉到模具机构,钻加工方式是直线型的,不能均衡地降低模温,无法解决塑料制品中许多缺陷。分析了模具中异型冷却水路的原理,并阐述了加工制造过程。对复合加工技术在模具中应用、结合浇口套实例做了介绍,采用异型冷却水路复合加工技术可达到模具均衡冷却,用以提高塑料制品质量。     

微污染水源和城市供水臭氧生物活性炭处理工艺的应用

该文介绍了我国水源微污染的概况,评述了水源微污染的危害性,并提出了饮用水安全的目标——"全国城市饮用水安全保障规划2006～2020",要求在"十一五"期间重点解决205个设市城市及350个问题突出的城镇饮用水安全问题。综述了城市给水臭氧生物活性炭处理工艺的应用现状(全国仅1%的城市水厂及0.4%的供水采用臭氧生物活性炭处理工艺)、运行效果和运行中发现的问题等六个方面,其中微生物安全性(如剑水蚤)和臭氧化副产物溴酸盐是关注的热点。提出积极推动给水深度处理工艺的应用,加强对水源水质的检测,全面识别水中污染物的特性,有针对性地选择给水处理工艺。     

循环水含油监测分析管理的新思路

炼油厂循环水、外排污水含油监测采用同一方法,为了监督冷换设备的泄漏问题,检测人员一般采用的是通过感官判断和具体分析来判断,预见性差。如采用气相色谱-质谱法监测手段分析循环水中的含油组成,通过质量控制图,可以实现快速查出具体生产装置冷换泄漏设备。     

Experimental study on nozzle’s characteristics in secondary cooling zone of slab continuous casting

连铸钢坯的质量直接受到二次冷却的影响,二冷段喷嘴的冷却效果受喷嘴的种类、喷水压力、水流密度等因素的影响。本文设计了测试连铸二冷喷嘴性能的实验方案。实验测定了不同喷水条件下喷嘴的压力和水流量的关系、喷水密度的分布、不同喷嘴对喷水效果的影响,分析了不同喷嘴的性能曲线,实验结果为合理布置二冷段喷嘴、优化二冷制度提供一定的依据。     

混合补水水质的循环水处理

将焦作华润热电有限公司两种补充水根据不同比例进行混合,采用极限碳酸盐硬度法试验确定循环水系统所能容忍的最大极限碳酸盐硬度,对阻垢剂的阻垢机理进行了分析,并初步确定了现场循环水的一些控制指标.     

Reduction of nitrogen oxides by ozonization-catalysis hybrid process

Treatment of nitrogen oxides (NO_x) by using a hybrid process consisting of ozonization and catalysis was investigated. The ozonization method may be an alternative for the oxidation of NO to NO₂. It was found that nitric oxide (NO) was easily oxidized to nitrogen dioxide (NO₂) in the ozonization chamber without using any hydrocarbon additive. In a temperature range of 443 to 503 K, the decomposition of ozone into molecular oxygen was not significant, and one mole of ozone approximately reacted with one mole of NO. A kinetic study revealed that the oxidation of NO to NO₂ by ozone was very fast, almost completed in a few tens of milliseconds. When the amount of ozone added was less than stoichiometric ratio with respect to the initial concentration of NO, negligible NO₃ and N₂O₅ were formed. The oxidation of a part of NO to NO₂ in the ozonization chamber enhanced the selective reduction of NO_x to N₂ by a catalyst (V₂O₅/TiO₂), indicating that the mixture of NO and NO₂ reacts faster than NO.     

循环冷却水中生物黏泥的危害及对策

结合浮法玻璃生产特点,介绍常用两种形式的循环冷却水系统,在生产运行实践中,认识到黏泥的生成和存在的普遍性,审视黏泥的危害,重点叙述了减少和控制循环冷却水中黏泥的方法,旨在结合生产线的客观条件和水中杂质情况,采用一种或几种方法,减少和控制循环冷却水中黏泥的含量,以维护工艺设备安全,稳定生产过程,提高产品质量和数量,并能节水节能,降低生产成本,提高企业经济效益.