新型耐酸性不锈钢波纹补偿器在莱钢煤气系统的应用

介绍了现波纹膨胀器在煤气管网运行中的腐蚀情况及原因,并从材质、结构上提出了解决腐蚀的改进措施,说明了该新结构、新材质的膨胀器在莱钢的使用效果。     

新疆八钢炼铁厂2号高炉投产

新疆钢铁公司八钢炼铁厂2号高炉(314m~3)于1987年10月25日建成投产。该高炉采用槽下过筛、PCⅢ型微机控制上料和称量误差补偿、歪咀空转布料器、自焙碳砖和高铝砖砌筑的综合水冷炉底、高效内燃式热风炉、热风支管波纹膨胀器和高温热风阀、     

韶钢新1号高炉通过竣工验收

韶钢新1号高炉(305m~3)已于1987年9月7日出铁,最近广东省组织了竣工验收。该高炉槽下与上料系统采用WAC—Ⅱ工业控制机进行自动控制,并有称重补偿、水分补偿等功能。炉顶装置及热风炉阀门、泥炮均为液压驱动,主卷扬马达采用可控硅调速。热风炉为改进内燃式,设支管与主管波纹膨胀器,还在烟道上并联了可再生热管     

浅谈波纹管膨胀器的安装,使用

１波纹管膨胀器及选型波纹管膨胀器是近年开发的管道膨胀器，其工作原理是通过金月波纹管的弹性变形来补偿管道的变形；波纹管通常是用不锈钢薄板液压或滚压成型，波纹管内装有钢成内衬筒，以减少流动介质对波纹管内部直接接触和防止进入管内凹陷处；膨胀器４个方向对称装有限位螺杆和定位螺杆各２根，用于调节、限制膨胀器的位移范围及运输定形。膨胀器有单式、复式、铰链式等；有法兰联接、焊缝联接等形式，可根据不同的使用场合选用．根据管道工作条件，经多方面考察、比较，在新建１０万ｍ３干式柜煤气管道上我们选用了单式普通型膨胀器…     

基于颗粒阻尼吸振的波纹辊轧机非线性垂振控制

轧机振动理论的研究一直是轧制成形领域的前沿科学问题，对板材的质量和设备的稳定运行至关重要。随着轧制复合成形技术的快速发展，波纹辊轧机作为一种具有特殊辊型的设备，在复合板制备上具有细化晶粒、改善板形、提高结合强度等突出优点，逐渐成为当前的研究热点，但是复杂辊型曲线所诱发的轧制力动态变化对轧机的稳定性控制提出了新的挑战。为了对波纹辊轧机的非线性垂振进行合理的控制，建立了考虑波平辊系之间的非线性刚度、波纹界面非线性阻尼和轧制力动态波动的非线性垂振方程，通过分岔图、最大Lyapunov指数、相轨迹和Poincare截面分析了轧制力的动态变化对系统稳定性的影响，发现轧制力的动态变化诱发系统产生了复杂的动力学行为。设计了一种颗粒阻尼吸振器对波纹辊轧机非线性垂振进行控制，运用多尺度法求解得到了安装颗粒阻尼吸振器系统的幅频特性曲线方程，分析了钢珠颗粒群质量、吸振器刚度系数、阻尼系数以及质量比对幅频特性曲线的影响，通过数值仿真研究了颗粒阻尼吸振器对非线性垂振的控制效果。最后，通过试验验证了颗粒阻尼吸振器设计的正确性和可行性，缩短动态过程调整时间的同时也减小了系统的振幅，为波纹辊轧机非线性动力学分析及稳定...     

基于动态轧制力的波纹辊轧机非线性振动

 金属层状复合板波纹辊轧制成形技术是一项变革性技术。为研究动态轧制力对波纹辊轧机振动特性和分岔行为的影响,考虑了波纹辊轧机动态轧制力、波纹界面间的非线性刚度和非线性阻尼,建立了基于动态轧制力的波纹辊轧机非线性振动数学模型。运用多尺度法求解了波纹辊轧机辊系在动态轧制力激励下的非线性振动幅频特性方程。分析了动态轧制力幅值、非线性刚度系数和非线性阻尼系数等参数对非线性振动的影响。通过最大Lyapunov指数、分岔混沌图、Poincaré截面和相轨迹等方法分析了轧制力的动态变化对系统稳定性的影响,设计了分岔反馈控制器对轧制力动态变化诱发的分岔行为进行控制,并且通过数值仿真验证了控制器设计的正确性和可行性。     

300m~3高炉顶燃式热风炉设计

我国顶燃热风炉的试验研究已有多年的历史,特别是顶燃球式热风炉在100m~3以下高炉上得到广泛应用,但大、中型高炉配置顶燃热风炉的仅有首钢2号高炉。参照国内外有关方面的资料及实践经验,我们为三明钢铁厂3号高炉设计了顶燃式热风炉。其主要热工性能如表1。3号高炉顶燃式热风炉设计风温为1100～1150℃。为了实现交错并联送风,配置了四座热风炉,呈正方形布置,中心设垂直热风总(竖)管与各热风炉相联,热风支管上设置热风阀和波纹膨胀器(图1)。     

太钢三高炉热风炉易地大修工程热风管道设计的改进

本文结合对太钢三高炉热风管线设计,介绍了波纹补偿器及拉紧装置在热风管道的运用,热风管道内衬耐火材料的选择,热风管道系统采取这些措施后,可以消除因管道受热膨胀、热风支管法兰错位等造成的漏风现象,保证热风管道系统完全可靠的运行。     

波纹轨腰钢轨开发的实验研究

波纹钢腹板以其独特的受力特点,在工程建设领域得到极其广泛的应用,在波纹腹板H型钢的基础上,开发一种新型波纹腹板产品———波纹轨腰钢轨,介绍了这种钢轨的力学特性,并在燕山大学轧钢实验室三机架万能机组上进行的轧制试验,结果表明这种具有优越力学性能的波纹轨腰钢轨完全可以通过轧制方法生产,会有很好的开发前景。     

基于有限元法的回转式空气预热器波纹式弹性密封结构的优化设计

基于有限元法的优化设计方法,采用有限元通用软件ANSYS的优化设计模块对波纹式弹性密封进行三维参数化建模,并编制APDL命令流,建立优化设计分析文件对波纹式弹性密封结构进行了优化设计分析.结果显示.得到一组波纹式弹性密封的最优结构,波纹式弹性密封的弹性增加约68%.有限元法结合优化设计对选择波纹式弹性密封结构方案具有显著效益.     

The expression in vivo of a second isoform of pT alpha: implications for the mechanism of pT alpha action

Tissue expansion has enjoyed a wide range of applications since the technique was popularized by Radovan in 1978. A useful application of tissue expansion is in the reconstruction of the head and neck following burn injury. From July 1986 to March 1990, 25 patients underwent head and neck reconstruction for burn injury using tissue expanders. A retrospective chart review was undertaken. The average age was 24 years, and the age range was 9 months to 46 years. Fourteen males and 11 females were treated. A total of 51 expanders were placed, and the most common locations of the expanders were the cheeks, neck, and scalp. The time period from burn injury to reconstruction averaged 22.7 months. Operative time for placement of the expanders ranged from 40 to 180 minutes. The average time for full expansion was 86 days. Major complications were those that required an additional operative procedure, and included one dehiscence, one infection, and one port failure. The major complication rate was 12%. Minor complications were those that did not interrupt the expansion process or require any operative intervention. The minor complication rate was 32%, and included three cases of exposure, three cases of wound dehiscence, one seroma, and one ruptured implant. Minor complications were frequent, although when managed conservatively they did not compromise the overall outcome. Despite a major complication rate of 12%, final reconstruction was achieved in all patients. This retrospective review demonstrates that tissue expansion is a versatile adjunct in the treatment of burn injuries to the head and neck, and reconstruction in this area can be accomplished with excellent cosmetic results.     

Use of tissue expanders in final reconstruction of infrapubic midline scar, mons pubis, and vulva after bladder exstrophy repair

Two patients following bladder exstrophy repair presented for final cosmetic reconstruction with the characteristic lower abdominal midline scar, bisected mons pubis, and laterally displaced labia majora. Tissue expanders were used to obtain additional skin and subcutaneous tissue. After adequate serial expansion, the expanders were removed, scar tissue excised, and primary approximation of healthy tissues performed. A tension-free closure and esthetically pleasing midline incision, mons pubis, and vulva were obtained.     

Risk factors for complications in pediatric tissue expansion

Tissue expansion in children has been associated with complication rates of 20 to 40 percent. A critical analysis of 6 years' (1988-1993) experience with 180 expanders placed in 82 consecutive children was performed to identify those factors which predispose to complications. Major and minor complications each occurred in 9 percent of patients. The factors associated with a statistically significant increase in complications were burns and soft-tissue loss, patient age under 7 years, use of internal expander ports, and a history of two or more prior expansions. In addition, complications were significantly more likely to occur within the first 90 days than during any subsequent expansion. Factors that did not influence complication rate included patient gender, wound drainage upon expander insertion or removal, intraoperative use of antibiotic irrigation, number of expanders placed, use of customized expanders, and operating surgeon.     

热浸镀铝锌硅镀层云纹缺陷的分析及抑制

 对采用薄板坯连铸连轧工艺生产的热浸镀铝锌硅产品镀层横向云纹缺陷和纵向云纹缺陷进行了表面和截面结构的分析。结果表明,产生的云纹缺陷与气刀工作压力、气刀工作距离、气刀喷吹角度、锌液温度和钢板入锌锅温度有关;气刀工作压力过低及锌液温度过高时,易形成纵向云纹缺陷。气刀工作压力过大,气刀间距相应变大,形成镀层横向云纹缺陷;在一定温度下,调整各项参数将钢带抖动控制在3mm以下时,可以获得均匀的镀层厚度、表面锌花尺寸和色泽。     

基于转矩预测的感应电动机模糊直接转矩控制系统研究

针对传统直接转矩控制的转矩脉动大、低速性能差等缺点,采用转矩预测与模糊控制相结合的方法。根据转矩、磁链偏差值以及定子磁链所在扇区,通过模糊控制器推理得出所要输出的电压矢量,然后经过转矩预测单元计算得出所输出电压矢量的作用时间,在剩余采样周期的时间内输出零矢量,从而减小了转矩脉动。仿真结果证明与传统直接转矩控制相比转矩、磁链、电流脉动都有了明显的减小。     

Stress and strain in the flight muscles as constraints on the evolution of flying animals

The authors describes a new device for external tissue extension (ETE) which will be able to replace or complement tissue expanders. The device consists of many ETE units, each unit consisting of a needle and two friction stoppers counted on a silicone string. Application, optimal tension and final surgical procedure are described. The indications are the same as for tissue expanders, e.g. scars, naevi and previous skin grafts, and also concern the closure of acute fasciotomies. The advantages are numerous: very simple technique, application under local anaesthetics, faster cutaneous profits (5-6 days), inexpensive total treatment, low complication rate.     

Juvenile xanthogranuloma of the iris with bilateral spontaneous hyphema

Lengthening of the mandible by gradual distraction and ear reconstruction using tissue expanders were performed on nine young patients (6-11 years old) with unilateral hemifacial microsomia. The technique holds promise for reconstruction of ear and mandible at the same time. This is essentially a pilot clinical project. A late follow-up of these patients is necessary.     

再造鼓形膨胀器

介绍了本钢不停产安装再造煤气管道鼓形膨胀器的实践，并对制造、安装方法进行了叙述，特别是在结构上采用了独特的构槽密封焊缝和完整的安装程序，保证了实施的安全。     

Dynamics of Polymer Interdiffusion: The Ripple Experiment

We explore the interdiffusion of oppositely labeled triblock polystyrene chains, HDH/DHD, during welding in the melt using dynamic secondary ion mass spectroscopy (DSIMS) and specular neutron reflectivity (SNR). The HDH chains have the central portion of the chain deuterated (D) approximately 50% while the two ends (H) each have approximately 25% protonation; the DHD is oppositely labeled, but each set of chains contains about 50% deuteration. During welding, the deuterium depth profile exhibits "ripples" whose characteristic features, such as the time and molecular weight dependent shape, amplitude, and position, are very sensitive to the microscopic details of the polymer dynamics. The ripple experiment is especially sensitive to the presence, or absence, of topological constraints and anisotropic motion of chains. The current work significantly extends the molecular weight range up to 400 000. This allows greater separation of the six key ripple features used in deciphering the correct polymer dynamics model at the polymer-polymer interface. The DSIMS and SNR experimental results are compared to theoretical predictions and ripple simulations for Rouse, polymer mode-coupling, reptation (with and without tube broadening), and other phenomenological dynamics models. The six ripple characteristics were found to be perfectly correlated and convincingly consistent with the predictions of the reptation dynamics model. The ripple results are in significant disagreement with the polymer mode-coupling model proposed by Schweizer and other tubeless models. We conclude that the reptation model, proposed by DeGennes in 1971 with parallel developments by Edwards, is the correct model to describe the dynamics of polymer interdiffusion.