焦炭塔内焦床影响塔壁变形的作用机理研究

通过对冷焦操作中水面温差弯曲应力、焦床与塔壁之间的周向应力、轴向应力的计算分析,讨论了焦床对塔体收缩的阻碍作用在周向与轴向的差异。发现水面引起的轴向弯曲应力和硬焦引起的轴向收缩受阻热应力是使塔体变形的两个主要因素,变形使得该处硬焦床直径进一步增大,产生更大的收缩应力和应变,形成"筒套锥效应"的恶性循环现象。对下锥体本体很少变形的原因也进行了分析。

焦炭塔内焦床变化温度场对塔壁变形的影响

将前苏联学者实测DN5500mm焦炭塔内焦床变化温度场的数据处理成操作时间、焦床半径、焦床高度等不同关联因素的曲线图,通过对这些曲线图的分析和热应力计算,提出了焦床温度场不均匀变化及其与塔壁变形的关系。塔壁下段受到轴向压应力的作用而上段受到拉应力的作用。

350kA铝电解槽焦床焙烧温度控制浅析

分析了焦床焙烧在温度控制方面的评价标准,统计了某厂焙烧升温情况,分析该厂温度控制方面的特点,并提出一些思考和建议。

Corex熔融气化炉煤焦混合料柱特性研究

在宝钢Corex工厂休风时,进行了熔融气化炉风口取样分析,得出了纯氧鼓风熔融气化炉煤焦混合料柱结构特点,并通过光学显微镜对粉末进行鉴别,得知料柱粒度分布结构形成的机理。利用XRD对风口水平焦的石墨化程度进行分析,并以此来推断其在炉内的高温历程。结果表明,气化炉料柱炉料的平均粒度小于7.7mm,是制约料柱透气性的关键因素,而块煤在炉内劣化严重,是导致料柱透气性差的主要原因。在此基础上,提出改善料柱结构和提高炉缸透气透液性的措施。

焦炭塔的套合效应研究

借助于有限元方法对一焦炭塔进行了瞬态热传导模拟,并将温度场顺次耦合于应力场,计算出了塔壁、焦床在降温完成后的应力场分布。将节点1800在无焦床作用时的各向应力与有焦床时的进行了对比分析,结果表明,降温阶段焦床与塔壁发生套合,使得塔壁内的周向、轴向应力大幅提高。为验证有限元计算的有效性,对套合效应进行了理论计算,得出了焦床对塔壁的周向套合应力值,结果同样表明,焦炭的套合作用显著,并且理论值与有限元值基本吻合。从而确定,焦炭塔的套合效应是继热机载荷之后,又一个对筒体鼓凸变形、焊缝开裂起决定性影响的因素。

高炉炉缸无焦区体积对炉墙切应力的影响

本文采用质量守恒和动量守恒方程对高炉炉缸在不同操作条件下的炉墙切应力进行数值求解。研究了不同焦床形状和位置对炉缸侧壁切应力的影响，结果表明所有类型的焦床形状对侧壁和炉缸底部的切应力都存在一个适宜的无焦区体积。处于坐落状态的圆锥形焦床若无焦区体积在48m^2以内，则对侧壁产生较大的炉墙切应力;处于悬浮状态的球形焦床当无焦区体积超过48m^2时，对炉墙的切应力最大；而研究的其它焦床形状对炉墙的应力是良性的。圆锥形焦床对炉缸底部产生的应力大于其他形状的焦床。

SO_2 emission characteristics from co-firing of petroleum coke and coal in circulating fluidized bed

Combustion and sulfur retention experiments of mixed fuel of petroleum cokeand coal were conducted on a pilot-scale circulating fluidized bed (CFB) combustor with the thermalinput of 0. 6 MW. The effects of several parameters, such as the primary air percentage, excess aircoefficient, bed temperature, Ca/S molar ratio and mass ratio of petroleum coke to coal on SO_2emission were verified. Experimental results show that when the ratio of petroleum coke to coal inthe mixed fuel increases, the SO_2emission increases. The maximum SO_2 emission appears when purecoke burns. The SO_2 concentration in flue gas reduces with the increase in the primary airpercentage, excess air coefficient and Ca/S molar ratio for all kinds of fuel mixtures. Therangebetween 830 t and 850 t is the optimal temperature for sulfur retention during co-firing ofpetroleum coke and coal with the mass ratio R of 1 and 3 in CFB.

COREX C-2000操业的优化

对国外COREX-C2000操业技术优化进行了总结。为了优化COREX操业,结合高炉成熟的经验,对竖炉和气化炉炉顶布料设备、炉料的布料模式、气化炉的固定焦床高度等进行了革新,取得了较好的效果。

城市垃圾直接熔融炉喷吹可燃粉尘技术

在城市垃圾处理领域,焦床式竖窑对延长最终垃圾处理场的使用寿命和减少有害物质,如二恶英, 非常有效。然而,最近为了防止全球变暖和降低维护费用,需要降低直接熔融炉的耗焦量。开发出了通过直接熔融炉风口喷吹各种可燃物的技术。特别是由炉顶排放高温分解的可燃粉尘,以此来降低耗焦量。用试验装置和工业设施,进行了通过炉子风口喷吹可燃物的试验,取得的主要成果如下:(1)在熔融炉中可燃烧和熔融由下部风口喷入的可燃粉尘;(2)通过炉子的风口喷吹可燃粉尘,可保持炉渣具有较低的Pb浓度。此外改善了燃烧室中的燃烧性,抑制了二恶英的产生。

Modeling and Simulation of Coke Combustion Regeneration for Coked Cr2O3/Al2O3 Propane Dehydrogenation Catalyst

A heterogeneous model is developed for the regeneration of the Cr2O3/Al2O3 catalyst for the propane dehydrogenation process by considering the internal mass transfer and external mass/heat transfer during the coke combustion.Simulation shows that under practical operating conditions,multi-steady states exist for the catalyst pellets and the catalyst temperature is sensitive to gas temperature.However,at increased mass flow rate or lowered oxygen concentration,multi-steady states will not appear.Under the strong influences of film diffusion,the coke in the packed bed reactor will first be exhausted at the inlet,while if the film diffusion resistance is decreased,the position of first coke exhaustion moves toward the outlet of the reactor.

Feasibility of Combustion of Petroleum Coke in 230t/h Circulating Fluidized Bed Boiler

In order to reuse the high sulfur petroleum coke, the waste in chemical industry, as fuel of power plant for energy recovery, the combustion property of petroleum coke was researched experimentally in circulating fluidized bed (CFB) boiler. The performance of the boiler in burning mixed fuel with different ratios of coal to petroleum coke is obtained. Based on the experimental data, Factors influencing the stability of combustion,thermal efficiency of boiler, and emissions and desulphurisation are discussed. This study demonstrates that the combustion of petroleum coke in CFB boiler is applicable, and has great significance on the design and operation of CFB boiler to burn petroleum coke.

Fluidized-bed pyrolysis of waste bamboo

Bamboo was a popular material substituting for wood, especially for one-off commodity in China. In order to recover energy and materials from waste bamboo, the basic characteristics of bamboo pyrolysis were studied by a thermogravimetric analyzer. It implied that the reaction began at 190-210℃, and the percentage of solid product deceased from about 25% to 17% when temperature ranged from 400℃ to 700℃. A lab-scale fluidized-bed furnace was setup to research the detailed properties of gaseous, liquid and solid products respectively. When temperature increased from 400℃ to 700℃, the mass percent of solid product decreased from 27% to 17% approximately, while that of syngas rose up from 19% to 35%. When temperature was about 500℃, the percentage of tar reached the top, about 31%. The mass balance of these experiments was about 93%-95%. It indicated that three reactions involved in the process： pyrolysis of exterior bamboo, pyrolysis of interior bamboo and secondary pyrolysis of heavy tar.

What's New in Clinical Oncology? Highlights from the 2009 ASCO Annual Meeting

This review summarizes the major advances inclinical oncology presented at the 2009 ASCO annual meeting,with emphasis on studies that are potentially practice-changing.Emerging new drugs are also discussed.

Maintenance Chemotherapy of Stage Ⅲ Epithelial Ovarian Carcinoma-Focusing on Individualized Maintenance Chemotherapy

OBJECTIVE To investigate the role of maintenance chemotherapy on stage Ⅲ ovarian carcinoma. METHODS A retrospective analysis was conducted of 47 stage Ⅲ ovarian carcinoma patients with clinical complete remission after first-line chemotherapy. Among these patients, 21 cases were treated with maintenance chemotherapy, while the other 26 cases were free of treatment until progression. The 2 groups were compared with respect to progression-free survival （PFS） and overall survival（OS）. RESULTS The median PFS and OS were not significantly different between the 2 groups. For those patients, in a subgroup of suboptimal surgery （residual disease 〉2 cm）, the median PFS was 110 weeks and 56 weeks and the median OS was 223 weeks and 157 weeks for the maintenance and non-treated respectively. Both PFS and OS values favoured the maintenance group, P=0.004 and P=0.015 respectively. In a subgroup of optimal surgery （residual disease ≤2 cm）, the differences were not significant. CONCLUSION Patients with stage III ovarian carcinoma with clinical complete remission may benefit from maintenance chemotherapy, if the residual disease is 〉2 cm. To those with a residual disease ≤2 cm, the maintenance chemotherapy maybe of no value. So “individualized maintenance chemotherapy” should be conducted in the clinical setting.

Confocal laser endomicroscopy and immunoendoscopy for real-time assessment of vascularization in gastrointestinal malignancies

Gastrointestinal cancers represent a major cause of morbidity and mortality,with incomplete response to chemotherapy in the advanced stages and poor prognosis.Angiogenesis plays a crucial part in tumor growth and metastasis,with most gastrointestinal cancers depending strictly on the development of a new and devoted capillary network.Confocal laser endomicroscopy is a new technology which allows in vivo microscopic analysis of the gastrointestinal mucosa and its microvascularization during ongoing endoscopy by using topically or systemically administered contrast agents.Targeting markers of angiogenesis in association with confocal laser endomicroscopic examination(immunoendoscopy),as a future challenge,will add functional analysis to the morphological aspect of the neoplastic process.This review describes previous experience in endomicroscopic examination of the upper and lower digestive tract with emphasis on vascularization,resulting in a broad spectrum of potential clinical applications,and also preclinical research that could be translated to human studies.

Discussion on the mechanisms of BO's abdominal acupuncture therapy

This article discussed the mechanisms and precautions of abdominal acupuncture from three different perspectives. First, the relationship between Shénquè （神阙 CV 8） and zang-fu and eight extra meridians stated in the ancient literature explained that the theory of CV 8 as the theoretical core of abdominal acupuncture therapy had literature support and theoretical evidence; second, with emphasis on the diagnosis and treatment based on differentiation of syndromes, four methods for selecting the points, including the ones according to hologram, meridians and collaterals, the Ba-kuo （八 廓） and three energizer, meanwhile, the origin of method selecting the points according to Three Energizer and clinical experience was also addressed; third, some problems about the manipulation of abdominal acupuncture therapy were put forward, such as selection of depth, direction, needle tool, as well as personal ideas and precautions, in order to ensure the clinical effect.

Experimental Study on Coal Multi-generation in Dual Fluidized Beds

An atmospheric test system of dual fluidized beds for coal multi-generation was built. One bubbling fluidized bed is for gasification and a circulating fluidized bed for combustion. The two beds are combined with two valves： one valve to send high temperature ash from combustion bed to the gasification bed and another valve to send char and ash from gasification bed to combustion bed. Experiments on Shenhua coal multi-generation were made at temperatures from 1112 K to 1191 K in the dual fluidized beds. The temperatures of the combustor are stable and the char combustion efficiency is about 98%. Increasing air/coal ratio to the fluidized bed leads to the increase of temperature and gasification efficiency. The maximum gasification efficiency is 36.7% and the calorific value of fuel gas is 10.7 MJ/Nm^3. The tar yield in this work is 1.5%, much lower than that of pyrolysis. Carbon conversion efficiency to fuel gas and flue gas is about 90%.

高出水标准下的再生水厂COD深度处理工艺比选

北京市某再生水厂设计规模为8×10^4m^3/d,出水水质执行北京市地方标准《城镇污水处理厂水污染物排放标准》(DB 11/890—2012)A标准。该厂采用多段进水A^2O+MBR工艺作为主处理工艺,由于其出水COD很难稳定达到京标A标准的要求(COD≤20 mg/L),需增加COD深度处理单元。对目前可选择的深度处理工艺——臭氧催化氧化、脉冲炭吸附、下向流炭吸附及活性焦吸附工艺就占地面积、投资、运行成本及工艺的实际应用情况进行了比较。结果表明,臭氧催化氧化工艺占地面积最小,脉冲炭吸附和下向流炭吸附工艺初期投资较低,活性焦吸附及下向流炭吸附工艺运行成本更低。臭氧催化氧化、脉冲炭吸附、活性焦吸附工艺均有实际应用案例。综合考虑,最终确定脉冲炭吸附和活性焦吸附工艺是现阶段较好的COD深度处理把关工艺。

Physicochemical Properties and Gasification Reactivity of the Ultrafine Semi-char derived from a Bench-scale Fluidized Bed Gasifier

Zhtmdong coalfield is the largest intact coalfield worldwide and fluidized bed gasification has been considered as a promising way to achieve its clean and efficient utilization. The purpose of this study is to investigate the phy- sicochemical properties and gasification reactivity of the ultrafme semi-char, derived from a bench-scale fluidized bed gasifier, using Zhundong coal as fuel. The results obtained are as follows. In comparison to the raw coal, the carbon and ash content of the semi-char increase after partial gasification, but the ash fusion temperatures of them show no significant difference. Particularly, 76.53% of the sodium in the feed coal has released to the gas phase after fluidized bed gasification. The chemical compositions of the semi-char are closely related to its particle size, attributable to the distinctly different natures of diverse elements. The semi-char exhibits a higher graphitization degree, higher BET surface area, and richer meso- and macropores, which results in superior gasification reactiv- ity than the coal char. The chemical reactivity of the semi-char is significantly improved by an increased gasifica- tion temperature, which suggests the necessity of regasification of the semi-char at a higher temperature. Conse- quently, it will be considered feasible that these carbons in the semi-char from fluidized bed gasitiers are rec- laimed and reused for the gasification process.

Electron microscopy:essentials for viral structure,morphogenesis and rapid diagnosis

Electron microscopy(EM) should be used in the front line for detection of agents in emergencies and bioterrorism,on accounts of its speed and accuracy.However,the number of EM diagnostic laboratories has decreased considerably and an increasing number of people encounter difficulties with EM results.Therefore,the research on viral structure and morphology has become important in EM diagnostic practice.EM has several technological advantages,and should be a fundamental tool in clinical diagnosis of viruses,particularly when agents are unknown or unsuspected.In this article,we review the historical contribution of EM to virology,and its use in virus differentiation,localization of specific virus antigens,virus-cell interaction,and viral morphogenesis.It is essential that EM investigations are based on clinical and comprehensive pathogenesis data from light or confocal microscopy.Furthermore,avoidance of artifacts or false results is necessary to exploit fully the advantages while minimizing its limitations.