20t/h余热锅炉防灰管爆管原因分析

１问题的提出我公司现有２条Φ３．６m×７０m带余热发电的中空窑水泥生产线，窑尾装有２０t／h余热锅炉２台，分别于１９９０年及１９９２年投入运行。至１９９４年底防灰管共发生爆管事故１１次，累计停炉时间达２０多天。１．１爆管位置及爆口状况两台余热锅炉的上升管高度４．５m，每次爆管均发生在上部１．５m长度以内，其中１次发生在上升管的上集箱。防灰管共有４组，均发生过爆管。爆口为沿管道轴向方向，长度为３００mm左右，附近无缺陷。１．２上升管整体状况锅炉运行半年后，４组上升管即发生严重变形，无规律弯曲。上下集箱间距…     

提高窑尾电除尘器的收尘效率收尘效率的经验

我厂回转窑生产线为Φ３．０m／２．５m×４４m窑尾带五级旋风预热器窑。窑尾废气处理系统由五级旋风预热器、CZSΦ３．８５m×２６m增湿塔、１８００SIBB２４高温风机和CDPK－３０／３电除尘器等设备组成。１９９４年９月投产，１年多时间内设备运行良好，粉尘排放浓度低于１５０mg／m３。此后，由于设备本身的缺点及管理、技术改造工作缺乏先进性，在影响回转窑熟料产质量的同时，电除尘器收尘效率显著下降。为此，我们加强该系统工艺设备管理及技术改造，取得良好效果。１确保预热器吹堵系统高吹堵能力１．１吹堵能力与收尘效率之间…     

变频器在窑尾余热锅炉供水控制系统中的应用

１问题提出我厂Φ３．４m×６５m干法中空窑窑尾温度７００～８００℃，窑尾带余热发电，其锅炉供水系统给水泵型号２．５GC－６×９，流量１５～２０m３／h，电动机功率３０kW，连续恒速运行，并且流量的控制是通过调节水管道中调节阀实现的。采用调节阀调节时，由于阀门开度的减小，水泵出口压力会上升，阀门两边的压差将增大，不但会造成水泵能量的浪费，而且使该水泵的振动和磨损加大，进而寿命缩短。根据生产工艺的要求，决定对锅炉给水系统进行改造。其系统工艺流程见图１。图１系统工艺流程图２改造方案水泵的流量Q与转速N成正比，…     

水泥窑余热发电锅炉爆管事故的分析及解决措施

我厂３台干法中空回转窑余热锅炉发生过多起爆管事故，不仅影响了发电量，而且每次处理爆管事故都在３０h以上，造成水泥窑停产以及很大的经济损失。笔者曾对每起爆管事故进行了研究，包括每次爆管的部位、形状，爆管时的烟气温度和管内介质的温度、压力等。１原因分析１．１烟气温度高爆管多发生在过热器段，爆管部位几乎都在烟道中心处，即最热的部位；爆管处的形状也多为喇叭口状。我厂８０％爆管事故由烟气温度高引起。该回转窑原煤粉输送系统如图１。图１改造前煤粉输送系统流程示意煤粉由仓式泵送入煤粉仓中，由于空气与煤粉混合，在…     

余热锅炉的结构优化与效果

对余热发电窑生产线来说，其窑系统的协调、流畅、合理一方面可以充分利用窑尾余热多产蒸汽多发电，另一方面可以稳定窑内热工制度，多产优质熟料。其中窑尾锅炉的结构合理最为关键。我厂有3台4．0mx80m的中空回转窑，窑尾带HG－F2900－11余热锅炉（设计最大蒸汽量为26t／h，主蒸汽压力3．8MPa，温度450℃），于1994年12月投入运行。由于锅炉结构不合理，投产后造成其堵灰严重，各部位管子穿、漏频繁，制约了整个系统的正常运行。为此，我公司投资1200万元对这3台锅炉进行了技术改造，并拜了优化操作管理，效果显著。1改造内容针对锅炉结…     

Φ3m×11m水泥挤压联合粉磨系统的调试与生产

１系统简介我公司采用２台Φ３．０m×１１m和１台Φ２．４m×８m闭路水泥粉磨生产线。２００１年，公司将２条６００t／d预热器窑改造为１１００t／d预分解窑后，原水泥粉磨系统生产能力明显不足。为此，新增１条Φ３m×１１m挤压联合粉磨水泥生产线。工艺流程见图１。系统主要设备配置见表１。图１水泥挤压联合粉磨系统工艺流程示意表１水泥粉磨系统主要设备配置设备名称规格型号备注胶带输送机B６５０×１１．５m１３０t／h，１０kW交叉带式除铁器MC１２－８０９０L冷态消耗功率：２．６kW稳流称重仓２５００mm×２５００mm２２m３辊…     

提高辊压机联合粉磨系统产质量的措施

１工艺流程我公司年产１２０万t高标号水泥，粉磨系统引进KRUPPPOLYSIUS工艺生产技术和主机设备，其规格及参数见表１。表１主机设备参数名称规格生产能力电动机功率／kW设备来源喂料皮带B１０００１３０t／h５．５东莞煤机厂辊压机１５／８－５－S５００t／h２×８００德国提升机THG１０００５２９m３／h２×５５芜湖起重运输机械厂打散机IN型４５０t／h２×７５德国选粉机２５０／４－SVZC９０～１３０t／h３４２（风机）２１３（转子）德国球磨机Φ３．２m×１１m（单仓）８０～１２０t／h１４５０朝阳重型机械厂胶带斗提机B…     

Φ3.4m×7.5m生料磨单层篦板的改造

２００２年３月我厂对７００t／dNSF回转窑进行了改造，使之能力接近８００t／d。但与之配套的Φ３．４m×７．５m生料磨台时一直徘徊在４５t／h左右，远不能满足要求。为此采取通过扩大单层篦板通风面积来提高台时产量的措施，即：将原来的通风面积０．８６m２扩大为１．４２m２。表１是２００１年１０月至２００２年６月的生料磨台时产量对比。表１改造前后生料磨台时产量对比t／h改造前改造后１０月１１月１２月１月２月４月５月６月４５．９４５．３４５．７４５．１４５．８５２．３５３．６５３．２生料磨单层篦板改造前后的结构见…     

生料磨旋风除尘器回灰系统的技改

我厂新建的６００t／h熟料回转窑生产线，生料磨规格为Φ３．２m×（７＋１．８）m，产量为５０t／h。生料磨旋风除尘器回灰系统用空气输送斜槽与拉链机衔接。２００１年９月开始进行生产调试，由于当时原燃材料水分过大，烘干热风不足，导致出磨生料的水分在２％左右。按设计要求，磨内压力为５００～７００Pa，旋风除尘器的压力为－１．４～－１．６kPa。但当磨机产量达到２５t／h时，空气输送斜槽就发生阻料，严重影响生料磨的产量，只好增加磨内的压力为１２００～１６００Pa，旋风除尘器负压提高到－３．５～－３．８kPa，虽然产量可…     

PL450型提升机改进

我厂一台PL型４５０mm×１８．５６m板链式斗式提升机，用于提升Φ４m×６０m回转窑窑尾收尘系统回灰生料，其设计参数为：输送量８５t／h；料斗容量２２．４L；运行速度０．４m／s；配用电机J０２－６１－６，功率１１kW，转速９６０r／min。使用板链结构如图１a。１使用中存在的问题１．１结构复杂，零件技术要求高销轴两端开有四条对称且相互平行的固定卡板凹槽，其技术要求高，必须保证加工尺寸。否则，卡板与销轴能够相互转动，加剧磨损，卡板失去作用；内外卡板的卡槽尺寸也应严格要求，其定位作用好坏取决销轴、卡板及链板加工尺寸…     

乙苯,苯乙烯的生产及合成乙苯,苯乙烯催化剂的研究进展

苯乙烯是重要的石油化工原料。本文介绍了国内外苯乙烯生产的发展概况，合成乙苯，苯乙烯所用的催化剂种类，并就苯乙烯生产及催化剂的发展趋势提出了自己的观点。     

Synthesis and characterization of homopolymers and copolymers of various acrylates and acrylonitrile

Various homopolymers and copolymers of methyl acrylate, ethyl acrylate, butyl acrylate, and acrylonitrile in different feed ratios were synthesized. These were characterized by IR, ¹³C-NMR, DSC, DTA, and TGA. Spectroscopic characterization helped in differentiating copolymers of different mol ratios. Thermal analysis revealed different degradation patterns for homopolymers and copolymers. The temperature and energy changes associated with various phase transitions were dependent on the chemical composition of homo- and copolymers, as expected. © 1993 John Wiley & Sons, Inc.     

生物质气化及生物质与煤共气化技术的研发与应用

总结了生物质原料的特点及生物质单独气化的缺点;介绍了国内外生物质气化技术及生物质与煤共气化技术的研发与应用现状;分析了在此领域国内外的发展趋势与前景;概括了开展生物质与煤共气化技术研发的意义。     

Electronic structures and reactivities of monometallic and bimetallic clusters of Au and Cu

The variation of the Au 4f binding energy of Au clusters with the cluster size has been established by measuring the binding energies of clusters whose size distributions were independently determined by HREM and STM. The binding energy increases significantly when the cluster size is less than 2 nm. Au-Cu bimetallic clusters of the composition Cu₃Au have been deposited for the first time on carbon substrates. The shifts in the core level binding energies of the bimetallic clusters show the effect of alloying in the case of large clusters, but show effects of both alloying and cluster size in the case of the small clusters. The interaction of CO with Cu₃Au clusters is stronger than with a bulk Cu metal. The interaction of CO with small Cu clusters also seems to be stronger than with bulk Cu or with large Cu clusters.     

钾盐资源及钾肥供需情况分析及预测

阐述了国内外钾盐资源及钾肥生产现状,对国内外钾盐的供需形势进行了分析及预测,从资源、原材料、国际市场三方面提出了解决我国钾盐短缺的措施。     

Kinetics and Mechanism of Oxidation of Mono- and Polyacetals

Abstract

Kinetics and mechanisms of oxidation of 6 acetals by molecular oxygen and ozone in liquid phase have been studied. Reaction with molecular oxygen (70°C, 15–16 hr) leads to the formation monoethers of the corresponding glycols with 68–90% selectivity. Salts of metals and complexes with crown-ethers have increased the reaction rate significally. Ozone have reacted with acetals with formation similar products. The mechanisms of intermediate stages have been proposed.     

Comparison of the Adhesion and Cohesion of Triblock and Random Copolymers of Styrene and Butadiene

A substantially greater detachment energy is required to strip a polyethylene tereph-thalate (Mylar) film from a styrene-butadiene-styrene (SBS) triblock copolymer compared to that for peeling from a random styrene-butadiene (SBR) copolymer. This is true even though the intrinsic interaction between the Mylar and each elastomer is expected to be similar because of their virtually identical chemical composition. It is proposed that this difference in peel strength (between the SBS and SBR) is a consequence of the much higher dissipative capacity of the former elastomer. Another manifestation of this is the higher cohesive tear strength of the SBS compared to the SBR. Extents of energy dissipation within each elastomer during detachment of the Mylar adherend are consistent with the hypothesis that the average maximum stress experience before detachment is some similar fraction of each elastomer's tensile strength.     

Wetting properties of homopolymers and copolymers of pentafluorostyrene and methylacrylate and homopolymer blends

Polypentafluorostyrene (PPFS), polymethylacrylate (PMA), and poly(pentafluorostyrene-co-methylacrylate), poly(PFS-co-MA) were prepared and the wetting characteristics of polymer blends of PPFS and PMA were compared with that of poly(PFS-co-MA) via contact angle measurements. The critical surface tension of polypentafluorostyrene was found to be 22.6 dyne/cm, which is comparable to the value reported for polytrifluoroethylene (22 dyne/cm). The critical surface tension of poly(PFS-co-MA) is not linearly related to its composition. The polymer blends of PPFS and PMA exhibit significant surface enrichment of the fluoropolymer. The harmonic-mean method¹ was employed to determine surface tensions of these polymers and many known polymers. It is found that the method produces useful surface tension data provided the contact angle values are derived from testing liquids of dissimilar polarity.     

责任和责任心的涵义与结构

责任是人应主动承担的角色义务和对其因过失所造成后果应承担的责罚.有两层涵义:一是义务;二是后果.责任心是个体自觉做好分内事务和履行道德义务的心理倾向,是个性心理品质成分中自我特征维度上的重要内容.责任心具有两个方面的涵义:一是角色分内职责;二是角色道德义务.责任心是一种通过责任认知、责任个性和责任适应的动态形式表现出来的静态品质,责任心是责任心过程结构与责任心关系结构相互制约、相互影响的统一体.     

二甲基二烯丙基氯化铵和丙烯酰胺的合成及应用

用复合引发体系(过硫酸盐-偶氮类引发剂)和脂肪胺类氧化还原体系引发,在实验室获得了单体转化率≥98%,特性粘数高于13.6 dL/g的阳离子共聚物PDA,探讨了控制聚合物分子量的影响因素.