大棒材钢丝捆扎机设计

目前对于直径φ60mm以上的热轧大棒的捆扎,由于温度高达700℃左右,使用直径φ60mm以下的棒材捆扎的打捆机很难在线应用,所以采用人工捆扎.为了减轻工人在恶劣环境下的劳动强度,研制了一种全新的棒材捆扎机,系统阐述了该捆扎机主要组成部分以及性能原理.该打捆机具有结构简单紧凑,占地面积小,价格低廉,易于操作和维护,能适应各种恶劣的工作环境,尤其适用于热轧大棒的捆扎.     

半连续式棒材轧机在线捆扎机及其工艺设置

上钢五厂于1986年与西德曼内斯曼·迪马克·萨克公司(以下简称M·D·S公司)签署了关于引进年产量为30万t的合金钢棒材轧制线的合同。但是,轧制后的棒材在线捆扎是一项待处理项目。根据30万吨棒材车间实际的生产工艺技术要求,笔者与北京冶金设备制造厂着手制订了在线捆扎机的设计方案,经双方多次讨论和技术论证,最终选择了以YSK6型钢丝捆扎机头为核心的捆扎机组。     

全液压立式钢丝捆扎机的PLC控制

全液压立式钢丝捆扎机的ＰＬＣ控制刘启水（宝钢集团北京冶金设备制造厂技术研究所北京１０００２９）在我国大部分钢铁企业中对各种冷热钢材的捆扎原来是由人工完成的。人工捆扎不仅劳动强度大，而且捆扎质量很差。为解决此问题，我厂于１９８９年研制成功了全液压立式钢...     

热轧带钢卷及型钢全自动捆扎机的创新设计

在考察了国内现有热轧带钢卷与型钢生产线的捆扎现状以及研究了国内外多种钢材打捆机的基础上,研制了一种全新的带钢卷、型钢全自动捆扎机。详细介绍了该捆扎机的整体结构;系统阐述了该捆扎机主要组成部分以及性能原理。该捆扎机结构巧妙,易于操作和维护,能适应各种恶劣的工作环境。     

装有精密控制系统的钢材生产线

装有精密控制系统的钢材生产线英国一家钢厂安装了一套拥有精密控制系统的钢材生产线，用于生产棒材及具有微合金钢特性的热卷线材。该生产线包括９台粗轧机架、３台剪切机、６台中间机架、１０机架连轧机组、快速冷却水箱、散卷装置、传送装置、矫直机及用于捆扎成品的打...     

棒材捆扎自动夹紧成形装置的研制

宣化钢铁公司为了解决棒材捆扎松散无形等产品包装质量问题 ,采用了棒材自动夹紧成形技术对半连轧棒材生产线包装系统进行了改造。改造后取得了明显效果。介绍了夹紧装置的组成结构、布置形式和改造内容。     

钢丝类打捆机线结特性分析

钢丝类打捆机用于对线材盘卷、棒材、钢管和小规格型钢等产品进行捆扎包装,捆线两端头的联结(称为线结)方式有多种,各种线结对应着不同的力学特性.线结类型的选择对捆扎质量有重要影响,结合生产实践及力学实验对各类线结的成形原理及力学特性进行分析比较,对提高捆扎质量以及打捆机的选型和设计具有一定的指导意义.     

英国将扩大钛的生产

今后两年,IMI钛公司的投资总额将达7.5百万英镑以上,以将其产量增加百分之六十。 该公司新扩大项目的经费将由威顿、伯明翰、沃纳威德及南威尔士等厂家分享,主要集中用于伯明翰新增加的熔炼,锻造及机加工产能,以及南威尔士工厂扩建其棒材轧制设备,工艺车间和精加工设备。 在威顿,对真空熔炼新增加的产能已配备了新的锻造预加热炉并增设了新的最后机加工的车床。在沃纳威德已安装了一台新的棒材精加工用的无心抛光设备。     

GH4169合金细晶棒材的径锻工艺及其组织与性能

介绍了我国第一台13MN液压式径锻机及其在国内首次研制出的中等规格系列GH4169合金10级左右晶粒细晶棒材的组织与性能。与传统的自由锻锤、快锻技术相比，径锻工艺生产的GH4169合金棒材在心部区域晶粒显著细化的同时，边缘冷变形组织也得以显著改善；不同部位晶粒度、6相的差异大幅度缩小，因而棒材各部位，尤其是近表面具有更良好的综合性能；工艺更稳定可控，棒材的平直度和表面质量也有明显改善，因而产品质量更稳定，成材率也有较大幅度的提高。     

装有精密控制系统的钢材生产线

英国一家钢厂安装了1套有精密控制系统的钢材生产线,生产棒材及具有微合金钢特性的热卷线材。该生产线包括9台粗轧机架、3台剪切机、6台中间机架、10机架连轧机组、快速冷却水箱、散卷装置、传送装置、矫直机及用于捆扎成品的打包机。尺寸为12.4ｍ×0.13ｍ×0.13ｍ的钢坯以40ｔ/ｈ的速度推入燃气加热炉加热至1020℃,每隔90ｓ将1根钢坯喂入粗轧机架。轧制过程用红外高温计首先测定粗轧机架中钢坯温度,然后测定棒、线材进入水箱前的温度。为了随意控制冷却速度,在前两个水箱后面装有附加夹送辊,通过保持线材张力控制冷却过程中水流速度。主控…     

热连轧厂钢卷打捆机的维护

钢卷打捆机是热轧带钢生产线重要的产品包装设备。打捆机能否正常使用将直接影响生产节奏和产品外观质量。对济钢热连轧厂打捆机的保养维护与故障处理进行了系统总结。介绍了全自动打捆机的机构性能。打捆头是打捆机的核心部件。重点对打捆头的结构原理、动作次序、保养维护及生产过程注意事项进行了阐述和总结。     

热轧带钢气动式打捆机控制优化

针对热轧带钢打捆机故障率高的现象,对打捆机PLC程序进行了优化控制,达到了提高打捆机作业率、降低运行成本及维护成本的目的。     

高炉重量布料准确度的提高

为提高高炉重量布料控制准确度,对称量罐测量环节进行研究,提出了称量系统的调整和维护方法。通过对称量系统进行分析和优化,使测量准确度满足了重量配料的要求,保证了高炉按重量布料方式的实现。     

Laparoscopic gastric banding for morbid obesity with expanded PTFE: technique and early results in the first 100 consecutive cases

BACKGROUND/AIMS: Surgery is the only effective treatment for the truly morbidly obese patient. Gastric banding was demonstrated to be a safe, effective, and easily reversible technique in the open surgical approach. METHODOLOGY: A five-puncture technique, developed by the authors, for laparoscopic gastric banding utilizing an expanded polytetrafluoroethylene (ePTFE) band is fully described and discussed. This technique was utilized in 100 consecutive patients operated on between October 1995 and November 1996. RESULTS: We recorded no mortality, no cases of conversion, a 1% rate of major complications, a low minor morbidity rate (10%), and an acceptable length of operative time (106+/-8 minutes). This was significantly related to body weight, B.M.I. and % of I.B.W. being longer in more obese patients, but not to the experience of the surgical team. Weight loss (35.0+/-5.1 kg), percentage of excess weight lost (55.3+/-5.3%), percentage of ideal body weight achieved (149.1+/-8.4%), and body mass index (33.8+/-2.0) were all significantly improved at 3, 6, 9 and 12-months follow-up. CONCLUSIONS: Early results of this series are promising, showing low morbidity and a rate of weight loss comparable to that achievable by means of open gastric banding or vertical banded gastroplasty. Any statement about long-term results deserves a longer follow-up.     

Accuracy and reliability of weight change determinations in a model infant weighing less than 750 grams

We designed a study to address the accuracy and reliability of the weighing process for tiny infants ( < 750 gm). A model was made with intravenous bags and stockinette and the following equipment was added: umbilical artery and venous catheters, endotracheal tube, pulse oximeter probe, electrodes, and orgastric tube. The models weight was changed in intervals of 2 to 43 gm and it was then weighed on two different types of scales. The measured weight on each scale was compared with the predicted weight (calculated as initial + added mass), and the mean absolute difference (MAD) was determined. All measurements were obtained by the same two nurses. For the bedside scale the MAD was 5 gm (range - 23 to + 10; n = 30). Similar results were obtained with a sling scale; the MAD was 3 gm (range - 13 to + 6 n = 30). The range of differences noted suggests that discrepancies between measurements may lead to a difference between weights that is in the range of 4% to 7% body weight. Interobserver variability was noted to affect the reliability of the weight determinations. When five experienced neonatal intensive care units nurses weighed the model the MAD was 9 gm (-33 to + 22; n = 15) and 6 gm (range - 11 to + 28; n = 15) for the bedside and sling scales, respectively. For the predicted weight, these discrepancies represent potential errors of 7.4% and 5.2%, respectively. These values are likely to underestimate the potential errors seen clinically inasmuch as we could not duplicate infant movement or anxiety of the person weighing the infant. These results should be considered when protocols are developed for weighing extremely small preterm infants.     

SCR 连铸连轧生产线在线称重系统研究与应用

结合 SCR 铜杆连铸连轧生产线产品称重计量实践,研究了 SCR 铜杆连铸连轧生产线称重计量磅差产生的原因,以及称重故障的影响因素,探讨了生产线称重系统的控制方法,通过设计在线称重系统,提高了称重计量的准确性,降低磅差投诉,为 SCR 连铸连轧生产线提质增效奠定了良好的基础。     

Tension pneumothorax precluding laparoscopic repair of diaphragmatic hernia

BACKGROUND: Central Europe and the Czech Republic are specific in the prevalence of obesity which has increased by 10-40% during the last 10 years. METHODS: In the Czech republic there is 30 years of experience of a comprehensive approach to obesity treatment which includes: dietary treatment; exercise; behavioral modification; drug treatment; and bariatric surgery. Each of these approaches has its place in complex obesity management. Since 1983 bariatric surgery has been established in the Czech Republic for the treatment of morbid obesity. Vertical banded gastroplasty (VBG), gastric banding, laparoscopic nonadjustable and adjustable gastric bandings have been used over the years. Since 1993 laparoscopic gastric banding has been the only method used in our department. RESULTS: The comprehensive approach for obesity treatment in the Czech Republic has resulted in the development of obesity management and research centers, regional obesity units, obesity out-patients clinics and weight reduction clubs. The surgical treatment is a well-established part of this system and the long-term results of surgical treatment are acceptable both in terms of weight loss and complication rate. There has been no statistical difference in weight loss results following VBG and laparoscopic gastric banding, but there is a significant decrease in morbidity, and shorter hospital stay associated with laparoscopic gastric banding. CONCLUSIONS: The surgical approach in obesity treatment has an important place in the comprehensive care of obese patients. Laparoscopic gastric banding in the hands of an experienced surgeon is a method with low morbidity, short hospital stay and long-term weight loss results which are fully comparable with the results of other surgical approaches.     

Maternal weight gain patterns and birth weight outcome in twin gestation

OBJECTIVE: To evaluate the association between maternal weight gain patterns, based on pregravid body mass index (BMI) and birth weight outcome in twins, and to make specific recommendations for maternal weight gain during twin gestation. METHODS: One hundred eighty-nine twin pregnancies were reviewed retrospectively. Weekly rates of maternal weight gain before 20 weeks, from 20 weeks to delivery, and for total gestation were calculated. Thresholds of weekly maternal weight gain were determined for underweight and normal-weight women. RESULTS: In underweight women, a higher weekly rate of gain before 20 weeks was associated with the birth of both twins weighing at least 2500 g (1.13 versus 0.70 lb/week, P = .017), when compared with mothers of at least one twin weighing less than 2500 g. A higher rate of weight gain from 20 weeks to delivery was associated with the delivery of twins weighing at least 2500 g in both underweight (1.92 versus 1.29 lb/week, P = .031) and normal weight (1.63 versus 1.29 lb/week, P = .046) women. No significant differences in weight gain patterns were found between overweight women delivering twins weighing less than 2500 g or at least 2500 g. A weekly rate of gain from 20 weeks' gestation to delivery of at least 1.75 lb/week in underweight women and at least 1.50 lb/week in normal-weight women was associated with the birth of both twins weighing at least 2500 g. After controlling for other potential determinants of birth weight, the threshold of 1.75 lb/week in underweight women showed a trend toward significance as an independent predictor of both twins weighing at least 2500 g (P = .06). CONCLUSION: Certain maternal weight gain patterns during twin pregnancy are associated with the birth of each twin weighing at least 2500 g. As with singletons, recommendations for maternal weight gain during twin pregnancy can be based on pregravid BMI.     

Melatonin in relation to the antioxidative defense and immune systems: possible implications for cell and organ transplantation

Inguinal hernia (IH) is relatively common in premature newborn infants, and the timing of surgical correction is controversial. We studied 40 premature infants who developed an IH and who were initially treated in a neonatal intensive care unit. Birth weight (BW) ranged from 492 to 2,401 g; 21 infants had a BW less than 1,000 g. The weight of the infants at operation ranged from 1,000 to 4,400 g. Twenty-one patients underwent herniotomy within 2 weeks after the diagnosis (short waiting group), in which 1 case of incarceration occurred; 19 waited longer than 2 weeks between diagnosis and surgery (long waiting group). Two cases of strangulation occurred in this latter group, and in 1 of those testicular necrosis occurred. Operation time was analysed in boys with bilateral herniotomy (n = 25): the short waiting group (n = 12) showed a significantly reduced operation time compared to the long waiting group (n = 13). Patients weighing less than 1,000 g at birth (n = 21) had a longer average waiting period for surgery. In the group of male patients with bilateral herniotomy, average operation time was longer in the group weighing less than 1,000 g at birth (n = 13) than in the group over 1,000 g (n = 12). Body weight at surgery did not affect operation time. It is concluded that early hernia repair should be considered in premature infants to avoid operative difficulties and gonadal ischaemia caused by incarceration.