高压电动机受潮现场处理

1高压电机受潮现象 我厂大型高压电动机较多，有时由于长时间停运或者环境的潮湿，导致电动机的绝缘水平下降，致使电动机不能再次正常启动；大型电动机是一个企业的关键设备．它的运行正常与否决定一个企业的生产是否能正常进行．所以本文拟想就高压电动机的绝缘问题作一下探讨。     

水泥厂6kV电动机继电保护和控制系统

水泥厂6kV电动机均为拖动工艺大型设备的主电动机,如生料磨、水泥磨、大型风机等,其设备的正常运行对工厂生产起到重要作用,所以6kV电动机的供配电、继电保护和控制系统是工厂电气设计中一个重要的环节。本文就6kV电动机的保护、控制、起动等方面作些论述,敬请指正。1 6kV电动机继电保护配置 继电保护装置是指:能反应电气设备发生故障或不正常工作状态作用于开关跳闸或发出信号的自动装置,由各种继电器组成,通过预防事故或缩小事故范围来提高系统运行的可靠性,最大限度地保证安全可靠的供电。     

电动机的安全运行条件

浅析了电动机必须具备的安全运行条件，对影响电动机不安全运行的因素进行了分析介绍，以便电动机动机正常运行。     

JQLX系列电动机常见故障和维修方法

文章介绍了ＪＱＬＸ系列电动机在生产过程中的常见故障及处理方法，保证该系列电动机正常、安全运行。     

生料磨高压电机过流一段动作事故的原因及处理

<正>大型电动机是大型工矿企业的重要电气设备。近年来投产的水泥企业一般都会安装配置合理的继电保护装置,监控和保护大型电动机的运行。随着技术的不断进步,微机电动机保护装置的功能越来     

高压电动机使用中应关注的几个问题

随着现代化水泥工业生产规模增大，生产设备越来越大型化，拖动电动机的功率也越来越大。水泥行业生产过程的特点为长周期运行，现代化大型水泥企业年运转率都超过９０％以上，这样就必须有高质量的、可靠的电气设备保证其生产过程的连续性，一旦故障停机就会造成巨大的经济损失。特别是大型高压电动机，一般都拖动球磨机、回转窑、风机等重载启动设备，对其制造质量和使用要求都很高，必须正确的安装、使用、维护、保养，才能保证长周期的运转。本文结合水泥企业生产的特点谈一谈６kV高压电动机在使用中应关注的几个问题。１高压电动机质…     

MRX—Ⅱ系列电机多功能节电器在破碎机上的应用

水泥企业的大部分电动机都不能保证在最佳负荷状态下运行,尤其是破碎机,特别是受γ射线料封信号控制的立窑熟料破碎机。其工作负荷波动很大,为了保证电动机能在最高负荷状态下正常运行,选用时都留有一定的富裕量。由于这一原因,造成电动机在运行中功率因数偏低,电能浪费较大。     

JQLX系列电动机常见故障和维修方法

文章介绍了ＪＱＬＸ系列电动机在生产过程中常见觉故障及处理方法，保证该系列电动机正常、安全运行。     

大型高压电动机主绝缘升级的探讨

大型高压电动机绝缘的可靠性是电机寿命长短及可靠性的重要标志。电机定子绕组是电机的心脏，其寿命直接影响电机的安全运行。我公司有高压电动机28台，其中同步电动机12台，异步电动机16台，均采用B级绝缘，除1台3#铜泵电动机为全封闭空冷电动机，绝缘良好外，其余高压电动机皆为开启式电动机，每逢阴南季节，定子绕组对地绝缘小于6MΩ，甚至降为0，严重影响生产。     

改造油管降低电动机轴瓦温度

我公司Ф3.2m×13m磨机配备的主电动机是绕线开启式异步电动机，规格型号YR1600-8/1430。2006年10月投入运行以来电动机一直不正常，经常因为轴瓦温度高而跳停，夏季最高时温度可达70℃，即使用风扇降温，也不能保证正常生产且浪费能源。     

与强者同场竞技 靠创新促进发展——访青岛福润德塑料挤出技术有限公司总经理赵炳仁先生

一年一届的中国国际塑料橡胶工业展览会(国际橡塑展),是全球多个行业寻找橡塑工业世界性商贸伙伴的机遇,也是企业开拓中国以至亚洲市场商机之"金钥匙"。在25届国     

Hydrogels reinforced with nanoclays with improved response rate

Two series of semiinterpenetrating networks (SIPN) based on linear hydrophilic poly(vinyl alcohol) (PVA) and thermo‐responsive poly(N‐isopropylacrylamide) (PNIPA), physically crosslinked with inorganic clay, are presented. The hydrogels with different crosslinking densities were prepared by varying the content of clay from 1 to 6 wt % and contained linear interpenetrant, PVA in the range of 0.5–1.5 wt %. The effect of clay content on swelling/deswelling behavior and phase transition in PNIPA gels, as well as the feasibility of reinforcing the gels with high molecular weight PVA, were analyzed. The thermal response of hydrogels, followed by DSC, confirmed that the insertion of hydrophilic PVA did not have a significant effect on the onset of the volume phase transition temperature, while the response was faster. The equilibrium degree of swelling of SIPNs and PNIPA hydrogels was in the range of 9–79 and decreased with increasing content of clay. The internal morphology and surface wettability of the hydrogels were investigated by scanning electron microscope analysis and contact angle measurements, respectively. The network structural parameters of the PNIPA and SIPN nanocomposites hydrogels, such as the average molecular weight between crosslinks, M_c, and effective crosslinking density, N_e, were determined by dynamic mechanical analysis. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44535.     

Electrodialysis with brine solutions oversaturated with calcium sulfate

Electrodialysis (ED) was applied to concentrate brine solutions of various concentrations — similar to effluentsfrom the desalination of brackish and industrial water — to about 20%. The consequent reduction in effluent volumes would facilitate a reduction in disposal costs. The energy requirement for concentrating solutions from 70 to 300 mN (0.4-1.8%) to 3.9 N (20%) was in the range 1.5-7.1 kWh/m³, in contrast to approximately 25 kWh/m³ by thermal evaporation. With the aim of preventing precipitation of CaSO4 on the membranes, laboratory-scale ED experiments were carried out on solutions of different compositions to determine the conditions that would lead to the precipitation of excess gypsum on gypsum seeds in a separate precipitator. The results were then applied in a pilot-scale ED unit in which the brine that circulated through the ED brine cells passed through a separate CaSO, precipitator containing gypsum seeds.     

Biological studies with cyclopropenoids inactivated with fatty acids

Cyclopropenoids inactivated by reactingSterculia foetida oil with cottonseed oil fatty acids were fed at three dietary levels to growing rats and laying hens for 4 weeks. At the termination of the experiments, all animals were autopsied and examined microscopically for pathological lesions, but no pathology that could be related to dietary treatment was observed. Hemoglobin, packed cell volume and plasma cholesterol were similar in animals fed all of the diets. Growth rate of rats and egg production of hens fed the experimental diets were similar to those of animals fed the control diet. After 3 and 6 months of storage, eggs from hens fed the inactivated cyclopropenoids were normal and showed no evidence of the unusual characteristics of cyclopropenoid feeding. Lipids of heart, liver and adipose tissues of all the rats and hens varied little from the normal fatty acid composition. Small amounts of three unidentified fatty acids were found in the adipose tissues of rats fed the higher levels of inactivated cyclopropenoids. The results of these feeding studies suggest that inactivation of cyclopropenoids with fatty acids eliminates the unusual biological effects attributable to cyclopropenoids. Presented at the AOCS Meeting, New Orleans, April 1970.     

以创新谋发展 以协作促转型

复合肥行业的转型升级已被列为化肥行业"十三五"规划重要内容。介绍我国复合肥行业转型发展期的特征,并提出在此形势下复合肥行业的发展思路;以创新谋发展,促进行业技术水平提高;以协作促转型,助推行业转型发展。     

以创新铸就名牌 以名牌促进发展

介绍厦门正新橡胶工业有限公司在观念、产品、管理和技术方面开展创新活动的经验。观念创新是名牌战略的灵魂,相互理解与支持、创建伙伴关系是公司对外往来的原则,坚决实施名牌战略,坚持以人为本、适才适用的原则;产品创新是占领市场的法宝,根据市场需求不断适时开发新产品;管理创新是维护品牌形象的前提,各项试验均执行企业内控标准,严把产品质量关;技术创新是实施名牌战略的源泉,以自有技术开发各种轮胎。通过开展创新活动,公司利税指标一直位居国内前列。     

Crosslinking of styrene-butadiene rubber with polyurethanes bicapped with benzyocyclobutene

Summary A polyurethane prepared from 1,9-nonanediol and toluene-2,4-diisocyanate with M_n=11,840, was capped on both ends in a reaction with 4-(benzocyclobutenyl) methanol. The polyurethane was used to crosslink styrene-butadiene rubber through Diels-Alder reactions on the benzocyclobutene functionality. The synthesis and characterization of 4-(benzocyclobutenyl) methanol, a molecule not reported previously, is presented. The crosslinking reaction was carried out on intimate mixtures of the telechelic polyurethane and SBR at elevated temperature and pressure. Various physical properties of the crosslinked material were studied.Work done at the Department of Chemistry, University of Akron, Akron, OH 44325, USA     

Boundary-Layer Structure with Hydrogen Combustion with Different Injection Intensities

Results of numerical simulation of the influence of intensity of hydrogen injection through a porous surface in the case of hydrogen burning in the boundary layer are presented. Turbulent characteristics of the flow were simulated using the k–epsiv; turbulence model with Chien's modification for low Reynolds numbers. The diffusion model (infinitely large burning rate) was used to describe the chemical reaction process, but the difference in diffusion coefficients of different substances was taken into account. A comparison of injection with and without combustion shows that the presence of a heat-release front delays the laminar–turbulent transition and significantly deforms the profiles of density and viscosity of the gas mixture. As the injection velocity increases, the flame front is shifted from the porous surface toward the outer edge of the boundary layer. The contributions of injection itself and combustion to reduction of skin friction are analyzed. Key wrds: boundary layer, combustion, porous injection, heat and mass transfer, friction.     

纤维素酶协同作用蛋白质的研究进展

纤维素酶是木质纤维素原料降解的关键成本因素,综述了近年发现的一些与纤维素酶具有协同作用的蛋白质,及这些蛋白质的基本性质及协同作用的可能机理,以期望降低工业转化过程中纤维素酶的使用成本,并展望了木质纤维素制取燃料乙醇的发展前景。