高压变频器在红钢烧结除尘风机中的应用

红钢烧结厂260m~2 3号烧结机配套的4台除尘风机工频运行,风门开度均≤65%,导致电耗过高,同时风机工频运行振动大、运行噪声大,会缩短风机和电机的使用寿命,影响岗位人员身心健康。在不改变原有操作系统的前提下,进行高压变频器改造,该高压变频器将配置本地控制以及集中控制两路控制方案。变频改造后,烧结电耗从76.35kWh/t降至67.63kWh/t,取得良好的经济效益和社会效益。     

来稿摘登

首钢矿业烧结厂变革风机配置方式节能显著首钢矿业烧结厂共有6台烧结机,原设计中每台烧结机配有9000m3/min和1.3万m3/min风量的热风机、冷风机各1台。该厂的电量消耗占生产成本的15%,而烧结冷、热风机的用电量,占全厂总用电量的75%以上。因此,该厂把强化冷热风机的用电管理作为     

桃江锰矿使用节能风机效益明显

湖南省冶金矿山节能风机使用经验交流会在桃江锰矿召开。该矿节能风机的使用效益得到与会人员的肯定。桃江锰矿去年11月购置14台JK55-2№4(5.8kW)节能风机,并在两个工区一个车间使用,以取代原来的JF52-2(11kW)型风机。半年多来的使用实践表明:节能风机JK55-2№4与JF52-2型风机相比,风量要     

国产高压变频调速装置在铝电解烟气净化中的应用

中国铝业青海分公司动力厂8台6kV、500kW烟气净化引风机用于净化铝电解过程中产生的氟化物、二氧化硫和一氧化碳等有毒有害气体。引风机采用500kW／6kV高压电动机拖动，多数情况下6台引风机满足净化要求，风量控制采用手动节流调节方式。若节流阀开度不大，且风量风压足够，则停开1台引风机；否则再开启1台引风机，节流阀始终处于调节状态。为实现恒风压控制，节能，且改善风机控制特性，遂进行引风机的变频调速改造。     

恒风压变频调速模型在梅钢高炉出铁场除尘的应用

针对高炉不同的出铁工况,设计出一种高炉出铁场除尘恒风压变频调速模型,以满足高炉出铁过程中的正常风量需要,保持恒定的除尘总管风压;通过出铁场除尘阀门控制技术,将除尘控制设置在炉前泥炮操作室,完成对除尘阀门和风机的操作。梅钢5#高炉(4 070 m3,风机装机量2×2 240 k W)应用表明,出铁场除尘风机吨铁总电耗为5.78 k W·h,节能减排效果明显。     

调速液力偶合器在冶金工业节能中获广泛应用

冶金行业中交流电动机驱动的风机、水泵是主要的用电设备,其用电量约占总用电量的1/3～1/2。因此设法节约风机、水泵的电耗是冶金工业很重要的节能途径之一。在风机、水泵与电机之间装上调速液力偶合器,实现风机和水泵的调速运转,代替原先的阀门节流调节,既满足了变负荷工况的要求,又能取得巨大的节电效益。     

200 kA新型阴极结构电解槽系列生产工艺试验研究

详述了浙江华东铝业公司200 kA新型阴极结构电解槽系列生产的工艺与操作情况,包括:焙烧、启动过程,非正常生产与正常生产阶段的工艺技术参数调整与管理.94台新型阴极结构电解槽半年考核期间电解槽平均工作电压3.72 V,6个月的平均电流效率93.105%,对比的传统普通电解槽为93.001%.94台新型阴极结构电解槽6个月的平均直流电耗为12 043kW·h/t-Al,比普通槽降低1 024kW·h/t-Al.新型槽可比交流电耗为12 545kW·h/t-Al,平均铝锭综合交流电耗为12 790kW·h/t-Al,比2009年全国平均铝锭综合交流电耗的14 171kW·h/t-Al低1 381kW·h/t-Al,取得了巨大的节能成绩.在电解槽启动后的3个月阴极表面凸梁磨蚀消耗速度较快,达5 mm,但其后的消耗速度逐渐下降,统计数据给出,电解槽启动9个月后,其凸梁的磨蚀消耗仅为7.5 mm左右,预计凸梁年消耗速度可在10 mm/年之内.     

钢铁企业风机水泵节能工作实践

针对风机水泵电耗占比高,节能潜力大的情况,某钢铁企业通过工况优化、技术改造等途径,开展了风机水泵节能工作,取得了显著的效果。     

全国第二次炼钢节能学术会议论文选摘

提高除尘风机用电的合理性—(王刚),首钢炼钢厂在保证除尘效果的前提下,如何提高除尘设备用电的合理性,对降低吨钢电耗指标具有重要意义。首钢炼钢厂3座转炉配备除尘风机6台,总用电容量为1560kW(260kW三相异步电动机6台)。自1964年投产至1981年,风机风门一直处于常开(即不管炉子处于吹炼状态或非吹炼状态,风机均处于负荷运行状态)。然而,每炉钢的吹炼时间只有13min,辅助时间却为12或13min(目前为10min)。由于辅助时间内没有烟尘外排,不需要满风排尘,故这段时间内风机的用电包含着不合理的部分。但在每个冶炼     

汽动轴流风机冷却水串用的分析与研究

根据现场轴流风机冷却水系统的具体情况，通过两台风机冷却水的串用，降低2^#风机冷却水进水温度。提高2^#风机真空，在进口温度较低时，循环水泵由两台减少至一台，降低电耗；用控制极限碳酸盐硬度指标经验公式，判断2^#风机在低循环倍率下冷却水不进行水质化学处理的可能性与条件，同时节约水资源。     

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。     

显微维氏硬度测量不确定度评定

对显微维氏硬度测量不确定度进行评定，建立了不确定度计算的数学模型，确定了影响实验结果的各项因素，计算出了各因素的标准不确定度，得出结果的扩展不确定度，并给出最终测量结果的表达式。     

Concept of freedom of infection of animal flocks

Totally negative results of epidemiological investigation of random samples do not prove the absence of the infection as the pathogen may be restricted to only a few animals in the herd for a long time. The statement "absence of infection" is critical for such situations. The question is raised, whether the statement "absence of infection" should be generally avoided. Classification of herds and flocks according to the prevalence of the pathogen would be more valid for the implementation of control measures.     

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.     

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。     

Rehabilitation of disorders of the breaking of voice

The adolescent's breaking of the voice is the result of the substitution of the chest voice (or heavy mechanism) for the head voice (or light mechanism). In cases of late breaking, the voice is abnormally high-pitched and feeble, often with a distorted timbre, while the larynx is normal and pubescent. Such people are generally not fully aware of their voices' real nature. Therapy classically resorts to laryngeal manipulations, of which a new technique is put forward. Another therapeutic approach is based, on the one hand, on critical listening compared with a control male voice, thus enabling the subject to become aware of his own voice, and, on the other hand, on high intensity work which helps passing from head to chest voice.