铝电解槽覆盖料导热性能测试及散热分析

电解槽一半以上的散热量经由电解槽上部覆盖料层后，从烟气、槽罩和上部结构散出；而上部散热中，覆盖料层的热阻权重较大。拟采用平板导热仪测试电解槽覆盖料导热系数，以指导电解槽的设计与生产。对阳极上的破碎覆盖料、新鲜氧化铝粉进行取样及导热性能测试，对比了不同粒径的覆盖料导热性能，同时分析了不同阳极高度下电解槽覆盖层温度及散热。本文对电解生产管理在电解槽覆盖料粒径、配比、覆盖层厚度等精细化管理的选择上提出一定的建议，并建设性给出了一种新型的铝电解槽阳极覆盖方法。     

铝电解槽槽壳侧部散热计算方法的研究

本文借助ANSYS有限元分析软件,对某厂240 kA预焙阳极铝电解槽槽壳侧部散热进行研究,建立半槽切片有限元解析模型,对其电、热场进行耦合计算。该模型的计算结果与实测值吻合较好(槽壳各区域表面温度偏差在4℃以内),所计算的侧部散热量与实测值基本相符,与传统的公式计算相比,更能真实地反映铝电解槽实际运行的散热状况,为铝电解槽能量平衡的研究与优化设计提供精确、快速的研究手段。     

铝电解槽新型内衬材料导热系数的测量

工业铝电解槽内衬材料的导热系数是计算热平衡和温度场的重要数据之一.根据傅立叶定律和稳态平板法测量导热系数的原理设计了铝电解槽内衬材料导热系数的测量装置,阐述了此装置的测量原理和方法,测量了新型内衬材料氮化硅结合的碳化硅板、耐火混凝土砖在中低温度下的导热系数;用数学回归方法得到其与温度的线性关系式.     

谈保温涂料在铝电解槽上的应用

在铝电解生产过程中,除铝水平、电解质水平、分子比、槽电压等条件要达到一定的技术要求外,温度的保持也是关键的一环,也就是说热平衡要达到一个理想的状态,Q吸=Q放。电解槽吸热是通过电的做功来完成的,如果电解槽散热量少,则相应就不需要吸收过多的热量,只要达到相应的热平衡,电解槽就可以稳定生产。所以只要电解槽散热量少,就可以使电少做功,从而也就达到了节电的目的,使生产成本降低。电解槽的散热分为两大部分,一部分是壳面散热,另一部分是槽壳四周散热。要减少壳面散热,可以通过增加保温料的办法来实现。对于这一过程的实施各家都有一…     

铝电解槽在低电压下的能量平衡研究

铝电解生产过程中保持能量平衡是电解槽平稳高效运行的基本条件,特别是近年来随着无效应低电压技术、新型结构电解槽技术和异型阴极钢棒技术的出现,槽电压不断降低,在其生产过程中,对能量平衡的调整要求越来越高。本文通过分析能量平衡的原理,总结了四项低电压技术运行时能量平衡调整方向,即将内衬结构由散热型改为保温型设计、适当提高阳极电流密度、注重区域能量调整和合理匹配技术条件,并列举了完善焙烧启动制度、控制突发阳极效应、优化阳极更换作业、增加必要的外保温、适时调整烟气流量和加强日常生产管理六项能量平衡调整措施。中国铝业某企业在采用低电压技术过程中,通过合理的能量平衡措施,使普通电解槽的工作电压从4.15V降至3.90V,新型结构电解槽降低到3.77V,取得了明显的节能效果。     

500kA铝电解槽的能量平衡分析

对正常工况条件下500k A铝电解槽能量静态分布的测算及能量动态变化的科学测量和分析,有效了解了该槽型散热和效能平衡状况,对指导现实生产有积极意义。     

铝电解槽内衬材料导热系数的测定

在工业铝电解槽上,内衬材料占有很重要的地位。内衬材料的性能对铝电解槽的热量损失尤其重要,其导热系数是计算热平衡的重要数据之一。对于导热系数的测量方法有很多种,本文是根据YB/T059-91[1],在实验室原有仪器[2]的基础上设计了测量装置,并对某铝电解厂的筑炉和刨炉材料的导热系数进行了测量和分析。     

稀土电解槽内电解质导热系数的计算

根据混合熔盐导热系数计算原则,通过计算稀土电解槽内电解质单组分熔盐导热系数,从而预测稀土电解槽内三元系电解质熔盐导热系数,为稀土电解槽内温度场的研究提供了一个重要物性参数。     

3000A金属钕电解槽的能量平衡

对3000A金属钕电解槽的能量走向以及熔体发热与槽体散热的平衡进行计算,为槽型的改进和电解生产过程的节能降耗提供指导和建议.     

炼镁用预制球团填充层的有效导热系数研究

炼镁用预制球团煅烧后呈多孔形态,其传热特性与皮江法压制的球团完全不同.本文采用数值方法研究了预制球团煅烧后球团填充层的有效导热系数.结果表明:高温下,辐射传热起主要作用,可显著增加床层的有效导热系数;提高球团导热系数或增加球团直径均可提高床层的有效导热系数;球团直径相同时,皮江法球团填充层有效导热系数略优于预制球团.在1 473 K,球团直径为22.3 mm时,皮江法球团填充层的有效导热系数为1.3 W·m~(-1)·K~(-1),预制球团填充层的有效导热系数为1.1 W·m~(-1)·K~(-1).     

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。     

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.     

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。     

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。     

2008年中国电解金属锰发展态势浅析

对中国电解金属锰发展的市场态势、价格行情以及原材料供应情况作了初步分析,提出我国电解金属锰行业挑战与机遇并存,只要抓住机遇、迎接挑战、夯实基础、科技创新,电解金属锰行业前景将会更加光明。     

Replication of dimensions of locus of control.

Employed 120 male and 113 female undergraduates in a replication of H. L. Mirels's (see record 1970-10386-001) study which found 2 factors in analyzing responses to 23 items on Rotter's Internal-External Control Scale. The same polar dimensions of "luck" as the arbiter of life events as opposed to personal control were found as well as a 2nd dimension of degree of control over political and social institutions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)