提高管式降膜蒸发器在拜耳法生产氧化铝中的运行效率

对管式降膜蒸发器在拜耳法生产氧化铝中的应用进行研究,分析了原液温度、蒸发器结疤、加热室面积等对管式降膜蒸发器蒸发效率的影响。通过优化改进,实现了管式降膜蒸发器低单耗、高蒸水量、高泛汽质量的高效运行。     

新型板式降膜蒸发器在氧化铝生产中的应用

板式降膜蒸发器具有蒸水能力大、汽耗低、回水比高等优点 ,但不宜蒸发有结晶析出的溶液。山西铝厂拜尔法母液中碳碱含量高 ,在蒸发过程中易析出。本文介绍了板式降膜蒸发器的工作原理、在山西铝厂试运行中达到的技术指标和出现的问题及取得的经济效益等情况 ,针对存在的问题 ,提出了改进措施。     

碳分母液高浓度蒸发技术的研究与应用

本文根据实验室试验,回归出了蒸发料浆全碱浓度与结晶量的关系;分析了溶液温度、化学成份及晶种对碳分母液中碳酸钠溶解度及碳酸钠析出结晶状态的影响;提出了“添加晶种、蒸发析盐、沉降分离、固液并送”的高浓度蒸发方案。在工业试验中,通过摸索一、二级蒸发器溶液温差,调整种子的加入量和加入位置,应用高效闪蒸器降低出料温度,使结晶量达到80g/l以上,使蒸发浆液浓度全碱在270g/l以上,并最大限度减少蒸发器结疤,蒸发效率和运转周期无明显下降。     

新型板式降膜蒸发器在氧化铝生产中的应用

板式降膜蒸发器具有蒸水能力大、汽耗低、回水比高等优点，但不宜蒸发有结晶析出的溶液。山西铝厂拜尔法母液中碳碱含量高，在蒸发过程中易析出，本文介绍了板式降膜蒸发器的工作原理、在山西铝厂试运行中达到的技术扶植和出现的问题及取得的经济效益等情况，针对存在的问题，提出了改进措施。     

降低硫酸镍蒸汽单耗生产实践

大冶有色30万t铜电解项目采用蒸发浓缩和冷冻结晶联合工艺生产粗硫酸镍,在生产运行中存在以下问题:两道工序之间由于生产周期不匹配,很难达到系统生产最大值;生产周期控制较难,系统非生产时间较多。针对以上问题,进行了以下改进措施:通过用蒸发浓缩产生的冷凝水加热蒸发前液,回收热量;优化生产组织,协调浓缩蒸发与冷冻结晶处理量一致性;清理结晶罐内壁,大幅提高热交换效率。改进后,硫酸镍蒸汽单耗由131 t/t NiSO_4·7H_20下降到116t/t NiSO_4·7H_2O,并提高了硫酸镍金属产能,降低了硫酸镍车间的生产成本。     

防治管式降膜蒸发器结垢的生产实践

针对用于烧结法碳分母液蒸发的管式降膜蒸发器加热管结垢形成的原因,采取了相应的改进措施。改进后蒸发器的蒸发效率显著提高,蒸汽消耗明显降低。     

防治管式降膜蒸发器结垢的生产实践

针对用于烧结法碳分母液蒸发的管式降膜蒸发器加热管结垢形成的原因。采取了相应的改进措施。改进后蒸发器的蒸发效率显著提高，蒸汽消耗明显降低。     

氧化铝生产多效蒸发器建模仿真

作为氧化铝生产过程的关键工序,多效蒸发工序的设备较多、操作复杂,蒸发过程涉及到的变量众多、变量之间的耦合关系很复杂,给现场操作带来了一定挑战。蒸发器蒸水量和汽水比(新蒸汽用量与蒸水量比值)是蒸发工序考核的重要指标,其数值大小直接影响到蒸发工序操作成本。尤其在蒸汽不足时,蒸发效果直接影响到母液浓度,甚至影响整个生产流程及产能,最终影响到企业的竞争力。调查发现,现场操作基本以经验为主,调整工艺参数未能到达预期目的,有时甚至出现相反效果,致使蒸发器潜能未能充分发挥,生产条件未能达到最优。基于物料衡算、能量衡算,借助流程模拟软件,搭建氧化铝生产逆流多效蒸发工艺等效物理模型,对拜尔法氧化铝生产多效蒸发工序工艺参数进行分析,探究不同工艺参数对蒸水量(汽耗)的影响规律,为蒸发工序实际操作提供理论指导,进而实现氧化铝生产节能、减排目的,助力氧化铝企业绿色低碳可持续发展。     

铜电解净化脱铜脱镍实现FMS的探讨

由于铜电解净化的硫酸铜系统与硫酸镍系统工艺、设备相近,从铜电解液中生产硫酸铜及硫酸镍,两者均采用蒸发浓缩、结晶工艺,有其共性,但硫酸镍作业含酸从400 g/L升高到500 g/L。因此通过将原钛材外热循环式蒸发器改为搪瓷反应缸,可实现同一蒸发器用于硫酸铜及硫酸镍蒸发,达到设备互换的作用。以30万t/a铜电解为例,硫酸铜系统处理量可从500 m~3/d增加到750 m~3/d,硫酸铜产量从54 t/d增加到81 t/d。硫酸镍系统处理量可从150 m~3/d增加到330 m~3/d,产量达到18 t/d。FMS柔性生产系统的应用可达到节约投资,灵活调节生产的目的。     

反循环蒸发技术在氧化铝生产中的开发与应用

针对强制循环蒸发器循环液量大、设备操作复杂、工艺条件不易控制、汽耗高、长时间高浓度操作结垢速度快运转率低等不足之处,通过改变循环泵的安装方式,将其传统的蒸发室切向进料方式改变为轴向进料,改变了物料的流向,实现蒸发室物料的反循环运转.结合在烧结法氧化铝生产实际应用中遇到的情况说明了反循环蒸发器在操作中的生产条件控制及应注意的事项.试验研究表明反循环结晶蒸发技术,在氧化铝生产母液蒸发工序推广应用,可以有效的延缓强制循环蒸发器加热管结疤速度,延长清理周期,提高传热效率,提高设备的运转率及生产能力,达到节约费用,提高产能,降低消耗,提高效益目的.     

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。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

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。     

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.