紧扣生产主题 挖掘均热炉潜力

本文提出了科学组织生产,提高钢锭热锭率和热锭温度,合理装炉,减少均热炉待料和轧机待热时间,减少烧废,缩短修炉工期,以提高均热炉的生产能力,缓解均热炉能力低于轧机生产能力的矛盾.     

均热炉逆L烧钢法与节能

本文就均热炉而言,讨论烧钢工艺与节能的关系。生产实践表明,烧钢质量与烧钢工艺之间有着非常密切的关系,而烧钢工艺又与钢锭装炉温度有关,即不同的锭温应采用不同的烧钢方法。装入均热炉的钢锭,对同一锭温,采用不同的供热制度和温度制度,单位燃料消耗也大不一样。为此对同一炉型和烧咀结构,试验了三种不同的烧钢方法。     

钢锭凝固和冷却过程的计算

1.问题提出装入均热炉的热锭温度是确定均热炉加热制度的重要依据,是均热炉实现计算机最佳控制的基本原始数据,它直接关系到均热炉的产量、燃耗和钢锭加热质量等各项技术经济指标。影响热锭温度的因素很多,最主要的是钢锭的传搁时间,即钢锭从浇注完了到装炉所经历的时间。镇静钢钢锭装炉前不脱模,只在模内冷却。而沸腾钢和半镇静钢钢锭装炉前已脱模,模内冷却之后还有模外冷却。此外,钢锭尺寸、浇注时钢水温度、模壁厚度与材质等也都影响着钢锭的凝固和冷却过程。     

均热炉加热期热负荷的探讨

当前生产中,装到均热炉的钢锭温度大多为800～900℃。本文介绍在鞍钢二初轧厂使用回归正交试验法确定这类钢锭加热期热负荷的试验情况、所得的回归方程以及实际生产效果。重要结论是:均热炉燃料单耗与加热期热负荷之间存在最佳值,这一最佳值随入炉锭温成线性关系变化。在试验条件下,使平均燃料单耗下降37.4%。     

镇静钢锭液芯装炉的研究

缩短镇静钢锭在模内的时间,实行液芯装炉微能均热轧制,是增产节能的有效措施之一,经理论计算和生产试验证明,此法是可行的。该工艺的要点是:缩短镇静钢锭的注台镇静时间和模内时间,将模内时间由传统的90分钟缩短为60分钟;将镇静钢锭由传统的全凝固脱模、运送、装炉改为液芯脱模、运送和装炉,按罐定点脱模,对不脱模锭采用垫方铁顶脱法脱模;执行最佳均热工艺制度,降低均热炉温度20～30℃,减少钢锭在炉时间30～60分钟。与普通工艺相比,该工艺降低均热炉燃耗63％,提高均热炉生产能力60％,减少钢锭氧化损失3％;提高了炼钢厂注台、注车和线路的利用率,加速了钢锭模的周转,在不增加设备和投资的情况下,提高了炼钢厂的生产能力。     

TI560/565计算机在均热炉上的应用

一、7～10号炉均热仪表现状均热炉在初轧工序中用以加热钢锭,起炼钢与初轧机之间的枢纽作用,是能耗大户。1990年我厂烧钢量达开工以来最高纪录,年产量为268.3万吨。燃耗为1.018GJ/t锭,占初轧工序能耗的78％,比鞍钢二初轧均热炉燃耗高30％,为日本均热炉七十年代水平。 7～10号均热炉位于红锭进厂最优装炉     

水流量对热轧钢板层流冷却过程对流换热系数的影响

提高带钢层流冷却控制模型的精度,关键是建立精确的对流换热系数与冷却工艺之间的关系.采用有限差分法和反向热传导法,获得了实验条件下钢板表面的对流换热系数及表面温度.研究了不同水流量(0.9~2.1 m3·h-1)对换热系数与表面温度变化规律的影响.在层流冷却过程中,对流换热系数与表面温度呈非线性关系;在距离驻点70 mm内,水流量对换热系数随表面温度变化规律没影响;远离驻点70 mm外,对流换热系数比随远离冲击区驻点距离的增加而减小.采用所确定的换热系数计算得到的温降曲线与实测曲线吻合较好.      

钢锭零能少氧化均热轧制研究

根据计算机的辅助分析,采用新的钢锭传搁、铸后复合打水强制冷却、垫铁脱模与丙罐定点脱模等工艺后,入炉钢锭热焓已超过轧制需要,利用普通均热炉代替钢锭保温车,自然形成中性气氛保护,完全依靠钢锭潜热与显热均热,将过剩潜热用于弥补炉体和烟道热损失,对不同锭型与钢种,采用最佳的时问均热后出炉轧制,收到了与保温车均热钢锭直接轧制相同效果。     

四角烧嘴均热炉流场的改进

本文分析了方锭斜靠放置时的流场,并提出改进烧嘴的布置使炉内形成旋转气流的方案,分析了改进方案的优缺点及应注意的地方。计算结果表明:影响均热炉内气体流动方式的主要因素是烧嘴和烟道的布置,而钢锭的锭型和布置方式对总体流场影响不大。     

炉缸冷却壁对流换热系数计算及烘炉传热特性

 炉缸冷却壁冷却性能主要体现在冷却水与水管间的对流传热。因为工程上常用计算对流换热系数的经验公式不能满足不同的水流状态从而导致炉缸热应力分析误差较大，所以以某高炉炉缸结构为例，首先利用传热学准数方程推导出冷却水处于不同流动状态时对应的综合对流换热系数表达式，同时探讨了对流换热系数经验公式的适用范围；然后通过迭代计算推导出了冷却水处于层流状态下考虑衰减热阻时的综合对流换热系数表达式；最后对烘炉状态下炉缸侧壁传热模型进行瞬态传热与冷却分析，得到了微水烘炉甚至闭水烘炉的热工依据，可为初步制定高炉烘炉制度进行评估和完善。     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.     

Quality of life of relatives of mental patients

Usage of quality of life of psychiatric patients' relatives as the parameter of estimation of the quality of psychiatric care is considered. By means of standard questionnaire elaborated by the authors as well as by means of both individual and group conversations the quality of life was analyzed in 40 relatives which lived together with psychiatric patients. Different spheres of their life and difficulties (financial, social-psychologic, production) were examined in families with such patients. The defects of psychiatric care that had direct influence on the quality of life of the psychiatric patients' relatives are outlined.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。