石钢3号高炉炉顶装料系统优化改造

石钢通过对3号高炉上料系统设备及程序的优化改造,提高了设备可靠性,增加了炉况调整手段,极大地促进了炉况的稳定运行,并使炉顶设备的检修工作量降低.     

中板轧机主电机优化设计改造

本文介绍原主电机设备绝缘老化容量不够,提出基础不动增容改造方案,并结合实际技术问题,优化设计,确定新电机的规格、技术参数,介绍电机改造实施过程,节约了大量宝贵的时间,设备的技术水平得到了很大提高。     

变频技术在风机、水泵上的应用

结合天津钢铁有限公司目前风机、水泵设备的特点及运行情况,分析了变频技术应用在风机、水泵上的先进性。介绍了低压系统除尘风机和动力厂水泵进行变频改造的方案。改造后提高了系统运行的安全性、可靠性,每年约可节电400万kWh,节能效果显著。     

高压氨水泵PID恒压控制改造

详细分析了高压氨水泵生产运行中存在的问题,阐述了PID恒压控制改造的具体方案设计及设备选型。改造方案实施后,有效地解决了原控制方式存在的问题,实现高压氨水的恒压控制,方便了设备的检修维护和日常操作,实现了系统节能和高效运行。     

高压电动机变频改造技术应用

分析了酒钢自备电厂2×300MW机组高压电动机变频改造前的现状和改造的必要性,通过对一次风机、凝结水泵节能测算方案的实施,变频改造前后相关数据的对比,分析出变频改造对降低综合厂用电率、提高设备运行可靠性及经济效益的积极作用。     

供水泵电机降压启动系统的改造

介绍唐钢炼铁厂三号炼铁高炉供水系统的水泵电机的启动方式,分析了电机烧毁的原因,制定了改造方案。     

PC机在制氧系统冷水塔轴流风机上的应用

上钢五厂制氧分厂有10台水泵(配用电机115kW)及与其配套的冷塔轴流风机10台(10极30kW电机)。因为风机转动惯性大,分别采用自耦降压起动。 在水泵系统大修中,为了简化起动设备的操作、提高可靠性、减少维护工作量,设想用一台起动控制设备对10台水泵、风机进行逐台起动,控制部分采用PC机来实现。但从可靠性出发考虑,一旦起动设备出故障,影响所有设备都不能起动,将危及生产。因此,首先在轴流风机上做试验。即把10台轴流风机分为两组,如果某台起动设备出故障,也只影响一组轴流风机不能用,另外一组轴流风机仍能确保制氧生产。 改造工艺方案如下…     

板坯连铸机一次切割车改造

济钢炼钢厂4号连铸机板坯切割车原为德国进口GEGA公司设备,以使用12年之久,存在机械电器元件老化严重、机械备件不通用等问题,故障率增高影响生产。板坯切割车通过维修改造,统一了机械备件,提高了通用性,重新选择了电器备件,解决了供应问题。改造后的板坯切割车运行良好并降低了检修次数和备件消耗。     

莱钢50 t超高功率电弧炉系统可靠性分析与改造

莱钢50t电炉原主体设备及液压系统，因使用时间长，严重老化，且原设计存在较多的缺陷，故障频发，系统可靠性大幅下降。为此，实施炉体装备、双液压缸倾动以及液压系统等改造措施，改造完成后，炉盖提升旋转时间缩短50％，炉衬寿命提高了200次，设备维护费用由12万元／月减少到4万元／月，系统设备运行的可靠性显著提高。     

高炉软水补水系统稳定性改造

改造前,股份1#高炉软水密闭循环系统补水设备主要由两台多级立式补水泵及变频器控制柜组成,遇系统回水压力波动较大时,补水泵频繁启停,整个管网压力处于不稳定状态,并增加了能耗。通过创新性实施管道改造,利用2#炉软水2台稳压罐为1#炉软水稳压等措施,实现了软水系统稳定节能运行。     

Cora valveless pulsatile rotary pump: new design and control

For decades, research for developing a totally implantable artificial ventricle has been carried on. For 4 to 5 years, two devices have been investigated clinically. For many years, we have studied a rotary (but not centrifugal) pump that furnishes pulsatile flow without a valve and does not need external venting or a compliance chamber. It is a hypocycloidal pump based on the principle of the Maillard-Wankel rotary compressor. Currently made of titanium, it is activated by an electrical brushless direct-current motor. The motor-pump unit is totally sealed and implantable, without noise or vibration. This pump was implanted as a left ventricular assist device in calves. The midterm experiments showed good hemodynamic function. The hemolysis was low, but serious problems were encountered: blood components collecting on the gear mechanism inside the rotor jammed the pump. We therefore redesigned the pump to seal the gear mechanism. We used a double system to seal the open end of the rotor cavity with components polished to superfine optical quality. In addition, we developed a control system based on the study of the predicted shape of the motor current. The new design is now underway. We hope to start chronic experiments again in a few months. If the problem of sealing the bearing could be solved, the Cora ventricle could be used as permanent totally implantable left ventricular assist device.     

采煤机机电传动系统调速动态特性分析

为研究滚筒调速的可行性及调速对传动系统动态性能的影响,采用MATLAB/Simulink搭建了采煤机截割-牵引耦合机电传动系统动力学模型.针对截割部过载工况,综合考虑采煤机可靠运行和高效生产,制定了4种调速降载方案,并提出了通过截割电机电流计算目标切削厚度、依据目标切削厚度选择调速方案的方法.最后通过仿真对比了各种调速方案下电机和传动系统的动态响应特性,结果表明:当截割电机过载倍数较小时,采用滚筒调速方案能够在降低系统负载的同时使采煤生产率不受影响;当过载倍数较大时,采用牵引调速方案可获得较高的系统可靠性,而采用牵引-滚筒顺序调速方案可获得较高的采煤生产率.      

交流电机变频调速的应用

交流变频调束不但具有直流电机优良的调速特性，内时具备交流电机简单而坚固的结构，因而逐渐被广泛应用。介绍了鞍钢化工总厂硬质沥青加料泵皮带调速改为交流变频调束的实际应用过程。详细说明了调束原理及所带来的经济效益。     

Continued development of the Nimbus/University of Pittsburgh (UOP) axial flow left ventricular assist system

Nimbus and the University of Pittsburgh (UOP) have continued the development of a totally implanted axial flow blood pump under the National Institutes of Health (NIH) Innovative Ventricular Assist System (IVAS) program. This 62 cc device has an overall length of 84 mm and an outer diameter of 34.5 mm. The inner diameter of the blood pump is 12 mm. It is being designed to be a totally implanted permanent device. A key achievement during the past year was the completion of the Model 2 pump design. Ten of these pumps have been fabricated and are being used to conduct in vitro and in vivo experiments to evaluate the performance of different materials and hydraulic components. Efforts for optimizing the closed loop speed control have continued using mathematical modeling, computer simulations, and in vitro and in vivo testing. New hydraulic blade designs have been tested using computational fluid dynamics (CFD) and flow visualization. A second generation motor was designed with improved efficiency. To support the new motor, a new motor controller fabricated as a surface mount PC board has been completed. The program is now operating under a formal QA system.     

水泵电机高压软启动器的应用

水泵电机在矿山选矿系统中是不可或缺的重要设备,电机的启动方式也非常重要。经过实际应用证明,高压水泵电机使用软启动的方法有效可行,可以有效地提高水泵的使用寿命和供电可靠性。     

冷却塔风机的节能改造

用水轮机取代机械通风冷却塔的电机,由电力驱动改为水力驱动,使机械塔成为新型的节能型水动风机冷却塔,充分利用上塔泵的富余能量,经过改造以后,原水泵功率并不会增加太多,既能保证循环水冷却水温,还可省去冷却塔风机的电耗,在工业循环冷却水中应用具有可观的经济效益。     

SIEMENS主轴电动机在BECKHOFF数控系统中的应用

详细分析了SIEMENS主轴电动机与BECKHOFF驱动器的配置组态、参数优化技术,实现了SIEMENS主轴电动机在BECKHOFF数控系统中的应用,扩大了BECKHOFF数控系统的应用范围,对不同系统硬件的集成具有一定的借鉴意义。在同一控制系统中,利用不同品牌的工控产品进行＂混搭＂,既能实现生产工艺中一些特殊要求,又能使得整个数控系统的集成更经济、简洁,同时还能得到某一品牌的＂一站式＂全球技术服务,保障了设备使用过程中的维修技术支持。     

Ploidy results in prostatic carcinoma vary with sampling method and with cytometric technique

A cooperative effort between Baylor College of Medicine and NASA/Johnson Space Center is under way to develop an implantable left ventricular assist device for either pulmonary or systemic circulatory support for more than 3 months' duration. Using methodical evaluation and testing, an implantable axial pump has been systematically improved. These improvements include the addition of an inducer as a pumping element in front of the impeller and the construction of an efficient brushless direct current motor. To date, less than 10 W of power is required to generate 5 L/min flow against 100 mm Hg. An index of hemolysis of 0.021 g/100 L has been achieved. Two-day in vivo feasibility studies in calves are under way to evaluate the antithrombogenic nature of the pump. Further improvements in system efficiency, hemolytic performance, and the antithrombogenic nature of the pump are expected with the use of empirical studies, computer flow modeling, and in vivo testing in calves.     

液压泵驱动电机跳电分析

针对武钢高炉炉前液压系统液压站主电机启动频繁跳电的故障现象,对所选用电机的启动特性和电路控制方式进行了分析,对所选用液压泵的性能和泵源液压系统也进行了分析。根据分析的结果对电路保护装置和泵源液压系统进行了改进,从而提高了泵站启动的稳定性,消除了影响高炉生产的隐患。     

无刷无环起动器及应用

介绍了真空泵绕线式异步电动机应用无刷无环起动器取代庞大的频敏变阻器的特点,该装置适用于无变速要求的绕线式电动机,具有广泛的推广应用前景.