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本文对不锈钢冷连轧机组所用张力辊的几何参数、材质、传动功率进行了计算选型,避免了电机功率不够而导致的带钢打滑或电机功率过大而造成的浪费。 相似文献
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舞钢炼钢厂连铸机拉矫机电气控制系统使用了西门子公司生产的6RA22XXX系列带有微处理器的双闭环可控硅直流调速装置,整个拉矫机部分有三组该类型装置控制驱动。第一组SCR_1(即第一组可控硅),控制25#上辊、25#下辊、27#上辊、27#下辊、30#上辊、30#下辊,共6台直流电动机运行(功率Pe=6kW/台),电动机的负载端联接拉矫机的扇形段驱动辊的减速机。另一端安装有园盘制动器(园盘制动器常称作电磁抱闸)。第二组SCR_2(即第二组可控硅),控制35#上辊、40#上辊、45#上辊、52#上辊及52#下辊,5台直流电动机运行(功率Pe=10kW/台)。 相似文献
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某新建连退机组清洗段采用的是双张紧辊组配置方式,其中1号张紧辊位于清洗段入口,作为速度主控制辊;2号张紧辊位于清洗段出口,用于清洗段张力控制(张力计在清洗段入口);其他辅助辊子(沉没辊、转向辊)也采用速度控制。在此控制方式下,出现过张力控制不稳定,2号张紧辊过载及带钢跑偏的问题。针对某连退机组的清洗段出现的这些问题,提出对张力控制的建议,主要是:在设计上尽量减少张力计与2号张紧辊之间的距离,同时辅助辊参与张力调节,提高控制快速性;平衡清洗段各辊子电机负荷,以降低辊子磨损和跑偏,防止2号张紧辊电机过负载。 相似文献
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鞍钢7#、11#高炉(2580m3)脱水器为110kW单电机驱动。几年来,通过生产实践考察和参数分析计算,电机110kW偏大,脱水器在生产运行过程中还存在一些缺点,需要改进。功率是脱水器非常重要的基本参数,零部件的选择计算都要以功率参数为依据。为了使鞍钢新建5#高炉脱水器具有优越的性能,对脱水器功率进行分析计算。为验证分析计算的正确性,采用了两种计算方法,其结果两种方法的数据基本一致。通过分析计算成果将单电机改为双电机加液力耦合器传动方案,实现脱水器软启动。经一年多生产实践考核,不仅节约了电能,且证明计算是正确的,改进是成功的。 相似文献
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为了使板坯连铸机扇形段的传动系统运行稳定,根据扇形段传动辊的物理关系计算各个传动辊的速度给定值,并利用传动辊的负荷平衡原理计算速度补偿量,用速度给定值加补偿量作为传动辊的速度控制量;为了得到准确可靠的实际拉速,采用计算平均速度的方法计算实际拉速,即先优选出合理的传动辊速度,再计算这些优选速度的平均值,把这种方法计算的平均速度作为实际拉速来应用。结果表明扇形段各个传动辊受力平衡,控制系统运行稳定,实际拉速应用也完全满足工艺要求。 相似文献
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倪志安 《Canadian Metallurgical Quarterly》2011,23(3)
马克思主义唯物论是一种物本主义形态的唯物论,还是一种超越物本主义形态、从实践理解世界的本质相关问题的实践的唯物主义的唯物论?这是一个我们必须搞清楚的有关马克思主义唯物论的本质规定性和精神实质的重大问题.在考察物本主义的唯物论及其思维方式的局限性的基础上,揭示了马克思主义唯物论是现代的、实践的唯物主义,并重点研讨了马克思主义唯物论关于从实践理解世界的物质性和自然世界的先在性的原理,以期为马克思主义唯物论进一步阐明人类世界的实践性原理奠定基础. 相似文献
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D. N. Reznikov 《Metallurgist》1962,6(12):535-537
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The data are presented on changes in the rat arcuate nuclear neuron ultrastructure after using cyproheptadine (peritol, Egyt Pharmaceutical Works, Hungary) in a water suspension at a dose of 20 mg/kg once daily during 7 successive days and twice a day within 10 days. It was shown that cyproheptadine decreases the functional activity of the arcuate nuclear neurons, depending on the total amount of the drug used. Cyproheptadine-induced inhibition of the forming neurohormone release from neurons is likely to be one of the mechanisms of its therapeutic effect in Itsenko-Cushing's disease. 相似文献
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Vasomotor responses from the nasal mucosa and tongue, and contractions of the nictitating membrane, were recorded on stimulation of the cervical sympathetic or internal carotid nerves. Preganglionic sympathetic nerve fibres which elicited a membrane response possessed a lower threshold than those which evoked nasal vasoconstriction, while the latter displayed a lower threshold than fibres which evoked tongue vasoconstriction. The sympathetic vasodilator fibres to the tongue whose activity was revealed after alpha-receptor blockade, had a similar threshold to the vasoconstrictor fibres. Membrane contraction, nasal vasoconstriction and occasionally tongue vasoconstriction could be evoked by stimulating the internal carotid nerve. The postganglionic fibres innervating the nasal mucosa had a similar threshold to those of the nictitating membrane, which may indicate that there are small myelinated fibres innervating the mucosa. The preganglionic compound nerve action potential had four major components, S1-S4. S1, S2 and usually S3 fibres were associated with membrane contraction; S2, S3 and sometimes S1 fibres were associated with nasal vasoconstriction; and S3, usually S2 and occasionally S1 fibres were associated with vasoconstriction in the tongue. It is concluded that each of these three groups of nerve fibres, but not S4 fibres, may include fibres associated functionally with the three effectors. There was a considerable difference between the relative amplitude of the responses of the three effectors elicited by stimulation of the cervical sympathetic nerve at frequencies between 0.2 and 2 Hz. Vasoconstrictor responses were relatively larger than membrane contractions suggesting differences in the mechanisms of neurotransmission at the neuroeffector junctions. 相似文献
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