氧化铝蒸发工序能耗分析及节能措施

某铝业公司在低温拜耳法氧化铝生产中使用六效四闪管式降膜蒸发器,针对其蒸发过程中蒸汽用量高、热能浪费严重等情况,通过能源损失分析工具,提出了改善蒸发器进料方式、提高真空度、减少系统散热损失、提高蒸发原液温度、优化酸洗流程、进一步提高蒸发器的设备综合效率等节能措施,以提高蒸发效率、降低热能损失。节能改造后,实现了蒸发工序的有效节能,氧化铝的生产成本节约426万元/a。     

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。     

800m^2强制循环蒸发器大修工艺技术

简要介绍中州铝厂氧化铝分厂８００ｍ＾２强制循环蒸发器的结构特点和生产技术条件，重点叙述加热室换管大修施工过程中出现的一些技术问题及处理方法，并简要说明设备大修后的运行情况及存在问题。     

对外加热蒸发器结构改造的探索

在氧化铝生产过程中，母液蒸发是关键的工艺过程。多年来一直是各大氧化铝厂的薄弱环节。其中加热管的结垢、腐蚀和磨损，以及由此引起的加热管清理和更换，使蒸发器运转率和产能显著降低，制约着生产的稳产和高产。本文以外加热自然循环蒸发器为例，在结构上提出了自己的见解。     

颚式破碎机改造成功

山东铝业氧化铝厂投资2000万元研发管式降膜蒸发器的后续项目一强制循环蒸发器重大技改项目，于2004年12月2日正式投料、进汽。随着蒸发浓度的逐步提高，强制循环蒸发器进入平稳运行阶段，标志着该项目一次试车成功。对进一步减低蒸发汽耗，提高蒸发液浓度，降低流程碱耗，提高运行质量，具有极大的促进作用。     

氧化铝生产中提高高压溶出效率的途径

通过对目前氧化铝生产中高压溶出进料量、机组运转率及技术指标状况的分析，指出了各项指标未达标的原因，提出了相应的改进措施。提出通过加强生产管理、优化操作条件可使溶出系统提高产能，对实际生产具有指导意义。     

低温多效横管蒸发器在氧化铝生产中的应用

对比了传统蒸发器和低温多效横管蒸发器的特点,详细介绍了低温多效横管蒸发器在某氧化铝厂氧化铝生产中的建设规模、工艺参数、工艺及物料流程及主要设备和节能效果。     

浅析竖管降膜蒸发器与板式外流自由降膜蒸发器

降膜式蒸发器是一种新型的高效蒸发设备，在石油、化工、医药等行业得到了广泛的应用，近年来逐渐被氧化铝行业所认识和接受，引进技术和由国内自行研制的设备均在氧化铝生产蒸发系统得到了成功应用。本文对氧化铝生产中均巳得到应用的竖管降膜蒸发器和板式自由外流降膜蒸发器的特点、应用情况及投资等方面进行比较，为新建和改造旧有蒸发器提供借鉴。     

降低拜耳流程碳酸钠含量实践

针对拜耳流程碳酸钠含量升高的原因进行分析,山铝氧化铝厂优化改造原有设备,应用强制循环蒸发器二段蒸发技术形成高浓度蒸发析盐流程,同时增加赤泥洗液苛化流程配合结晶析盐运行,实现了短期内迅速降低拜耳流程溶液中碳酸钠含量的目的,降低了运行成本。     

氧化铝蒸发系统综合提产节能途径

蒸发是氧化铝生产的关键工序之一,其产能和消耗的水平直接关系到整个氧化铝生产水平和成本的高低,本文通过在原有设备和生产工艺的基础上提高真空系统的真空度;使用闪蒸器和改进生产作业方式等技术创新,达到了提高蒸发设备产能、降低运行成本和工人劳动强度的目的。实践证明改造效果明显,在一定程度上提高了蒸发器的产能,缓解了生产的矛盾,走出一条少投入、多产出的捷径。     

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.