基于响应曲面法的氨法烟气脱硫效率预测模型

采用响应曲面法对某化工厂燃煤锅炉烟气氨法脱硫装置的脱硫效率进行了建模分析,得到氨法脱硫效率的预测模型.方差分析结果表明:模型P值＜0.000 1,该预测模型可以很好地描述脱硫效率与SO2入口浓度、浆液pH值、液气比以及烟气流速等重要操作参数之间的关系.因素分析表明:SO2入口浓度对脱硫效率的影响最大,同时SO2入口浓度...     

铜冶炼高温电除尘试验研究

为了实现铜冶炼高温烟气粉尘的高效脱除，本文分析高温烟气领域除尘技术研究现状，搭建了基于铜冶炼烟气工况的高温电除尘中试装置，分析了炼铜粉尘的形貌、粒径等特性，研究了不同烟气流速、电压对除尘效率的影响，得出电除尘关键参数最佳设置方法。结果表明，高温电除尘器烟气流速为0.48 m/s时，烟气颗粒既不会造成高温电除尘器严重积灰，也不会导致大量颗粒大量逃逸，除尘效率最佳；电场电压越高，出口粉尘浓度越低，除尘效率越高，实践中要在满足除尘效率的前提下寻找能耗最低的电压值。在福建某铜冶炼厂进行高温电除尘技术工程应用试验，测试结果表明，高温电除尘器出口烟气含尘浓度由2.19 g/m³降至62 mg/m³,除尘效率大于97.1%。     

高温换热器烟气侧传热特性的研究

本文通过计算和实验的方法，对高温换热器的烟气侧传热特性进行了分析。得出了换热器中换热管合理的纵、横向间距是S1／d≥2．0，S2／d≥1．5的结论；提出了用金属辐射网强化高温烟气传热的有效方法；并用实验的方法讨论了烟气流速及温度等对换热器综合传热系数的影响。认为对流传热方式在烟气侧的传热中仍占有重要的地位。     

正压水煤气立式余热锅炉流动传热特性

利用Fluent 2020R2软件,针对正压水煤气立式余热锅炉,重点研究了炉内流动传热特性。研究结果表明:炉内两直角转弯处流场均匀性变差;烟气流经膨胀节后流通截面减小,烟气流速增大,强化了换热;余热利用率随入口烟温上升呈现出先增大后减小趋势,最佳入口烟温为1 223 K;炉内横截面温度呈现Π型分布特征,会造成并列管束吸热不均。     

基于CFD的闪速炼铜余热锅炉内部流场分布研究

闪速炉余热锅炉炉膛内的烟气流动过程十分复杂,与烟气的初始流入条件、炉膛的结构及挡板、管屏的尺寸及布置方式均密切相关。因此,研究其内部的流场分布规律对于闪速熔炼的工艺优化具有积极的指导作用。本文采用计算流体力学（CFD）数值模拟方法,对某闪速炼铜余热锅炉炉膛内的流场分布规律进行了数值模拟及分析。研究结果表明：建立的余热锅炉流场数值分析方法,能够较准确反映炉膛内的流场分布情况,模型收敛性较好,模拟结果有保证;锅炉辐射室整体流速较低,对流室整体流速较高;进入辐射室的烟气分三部分流动,如何增加流过挡板的烟气动量、减小涡旋的产生是优化炉膛结构的重点。盐化风的高速射入起到了有效打散烟气团的作用,可以防止烟气大量聚集而影响辐射室内烟气的流动和换热,也可以有效保护炉膛顶部,并防止积灰。辐射室挡板的尺寸和布置方式是改变烟气入口处流场的重要因素,合理优化挡板、管屏的设计方案对于保障余热锅炉正常运行及闪速熔炼工艺的顺利进行具有重要的意义。     

烟化炉前排风机入口阀门的改造实践

为减少前排风机停机清灰对烟化炉正常生产的影响,实施了2台前排风机入口阀门的前移改造,生产中2台风机平稳倒换,实现备用风机在线清灰,减少风机入口阀门前管道内的积灰,保证了前排风机正常运行,提高了烟化炉系统的生产效率。     

脱硫废水烟道喷射的数值模拟

以某电厂300 MW燃煤机组为例,对脱硫废水烟道喷射系统进行CFD数值模拟,研究了雾化粒径、烟气温度、烟气流速和喷枪布置方式对液滴蒸发的影响。结果表明:雾化粒径明显影响液滴群蒸发质量百分比和蒸发时间,在较低的烟温下(140℃),需要较小的雾化粒径(≤50μm)才能保证液滴完全蒸发;烟气温度对液滴群蒸发质量百分比和蒸发时间的影响显著,随着烟气温度升高,液滴蒸发速率加快,蒸发时间明显减少;烟气流速对液滴蒸发特性影响不大,随着烟气流速升高,烟气量增大,液滴群蒸发时间会降低,而液滴群蒸发质量百分比变化不大;在烟道同一截面处,不同喷枪布置方式对液滴蒸发影响小。     

冶金炉窑高温烟尘结焦机理分析及解决方案探讨

介绍了冶金炉窑高温烟气余热利用装置的积灰、结焦情况,分析了高温烟气、烟尘物理化学结焦的机理,并针对余热利用装置高温烟气、烟尘结焦问题,提出了有效可行的具体措施。     

烧结机除尘系统优化

针对承钢公司烧结机除尘器系统近年来存在的内部积灰严重、电气故障等问题,对电场1~4的积灰现象进行分析,找出了除尘器漏风的原因。通过治理多处漏风点,逐步解决了烧结电除尘器存在的漏风问题。通过日常工作中加强保养,可以提高除尘效率,最大限度地减少能源消耗;另外,在除尘器后端加设了烟气脱硫系统,使烧结机排放的烟气达到了国家标准,实现了大气污染的有效治理。     

基于气固两相流的电除尘器数值模拟研究

通过商业CFD软件,模拟计算了某电除尘器烟气量分配、气流均布、颗粒相质量流量分配、粒径分布等气固两相流参数。模拟结果表明:采用合适的导流板布置方案,不仅可使电除尘器各进口烟道内烟气流量、颗粒相质量流量偏差均在±5%以内,各室入口截面烟气流速相对均方根差均不超过0.25,还可使颗粒相粒径分布的均一性得到大幅改善。研究可为烧结烟气、窑炉烟气等电除尘器的超低排放改造提供一种技术思路。     

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。     

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.     

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。     

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.