Characteristics and Application of Andalusite Material and Andalusite-Based Refractory

Andalusite material and Andalusite-based refractory are very popular in Europe and Japan, but its applications are restrained because of its low quality and misunderstanding in China. The paper introduced in detail the characteristics of andalusite material and andalusite-based refractory based on the authors‘ research work in recent years and on some references. Some information is illustrated clearly by figures and microstructure photographs. It is concluded the property of raw material and refractory is not determined by alumina content but by type and quantity of the impurities and microstructure.Mullitisation provide andalusite-based refractories more excellent macro and micro properties that guarantee itspopular application.     

China＇s Nonferrous Metallurgy Industry and Its Relevance to Refractories

As well known,there exists a reciprocal relationship betwween refractories industry and high temperature industries,in particular metallurgy industry,Refractories are consumed in many metallurgical processes of nonferrous metallurgy industry and closely associated with the tehcnological progress of this sector,In the past two decades,China‘s nonferrous metallurgy industry has kept fast growing,with much increased output,improved process technologies and more imported advanced equipment and technologies,which have put forward stringer requirements on refractories,not only in quantity,but in variety,performance and installation as well.This article,based on the authors‘ knowledge and information,reviews the development of China‘s nonferrous metallurgy industry in recent years and the related refractories issues.     

Sillimanite,Kyanite and Andalusite in China and Their Applications Part I .Their Reserve,Distribution and Characteristics

Sillimanite,kyanite and andalusite are advantageous natural refractory raw materials for aluminosilicate refactories to attain improved key properties.This paper are divided into parts to introduce their resource and technical characteristic in the first part,and their applications in refractories in the second aprt to be succeeded.In this part,based on authors‘ knowledge and sources,information on their reserve,distribution,composition and characteristic is provided,to bring it to light that China is rich in the reserve of them,in particular andalusite.The sillimanite group minerals are characterized by their phase transformation to form primary mullite and secondary mullite when added in high alumina system,accompanied by volume expansion,which can be taken use to improve creep resistances and thermal shock resistance of the related refractories.     

Scenario of Refractories Industry—World and China

The paper reviews the present situation of refractories industry on a worldwide basis,in terms of production volume,consumption in steel industry,marketing,trading and structural change,based on the information from the presentations at the World Refractories Congress Singapore‘2002 together with some newly revealed data on China‘s refractories industry.Authors‘ comments and suggestions on future development have been also provided in the paper.     

关于正常扩散Stefan-Maxwell 公式和 Grahan 扩散定律的注记

Certain prerequisite information on the component fluxes is necessary for solution of the Stefan-Maxwell equation in multicomponent diffusion systems and the Graham‘s law of diffusion and effusion is often resorted for this purpose. This article addresses solution of the Stefan-Maxwell equation in binary gas systems and explores the necessary conditions for definite solution of concentration profiles and pertinent component fluxes. It is found that there are multiple solutions for component fluxes in contradiction to what specified by the Graham‘s law of diffusion.The theorem of minimum entropy production in the non-equilibrium thermodynamics is believed instructive in determining the stable steady state solution out of infinite multiple solutions possible under the specified conditions.It is suggested that only when the boundary condition of component concentration is symmetrical in an isothermal binary system, the counter-diffusion becomes equimolar. The Graham‘s law of diffusion seems not generally valid for the case of isothermal ordinary diffusion.     

Polymorphism of D-mannitol: Crystal structure and the crystal growth mechanism

The polymorphism of D-Mannitol(mannitol) is reviewed in this paper. It was found that the structure of the stable form is consistent in most literatures, but different authors have given different information about the two metastable forms. Therefore the commonly used nomenclature of mannitol was summarized based on the crystal unit cell parameters with the help of X-ray powder diffraction. Moreover, the crystal growth mechanism of mannitol polymorphs was summarized. Considering the lack of kinetic data for the metastable form especially, a reported method was attempted to apply to δ mannitol in an aqueous cooling crystallization process based on the induction time previously measured, and it was identified that the growth of the δ form follows the two-dimensional(2D) nucleationmediated mechanism. The results also indicate that the method based on induction time and supersaturation should have the potential to be expanded to the metastable polymorphs for the growth property study in a bulk system.     

A Novel Mechanism for TRF of Plant-wide Material Flows in Process Industry MES

This paper is standing on the recent viewpoint originated from relevant industrial practices that well or-ganized tracing, representing and feedback （TRF） mechanism of material-flow information is crucial for system utility and usability of manufacturing execution systems （MES）, essentially, for activities on the side of multi-level decision making and optimization mainly in the planning and scheduling. In this paper, we investigate a key issue emphasized on a route of multi-level information evolution on the side of large-scale feedback, where material-flow states could evolve from the measuring data （local states） to networked event-type information cells （global states） and consequently to the key performance indicators （KPI） type information （gross states）. Importantly, with adapta-bilities to frequent structural dynamics residing in running material flows, this evolving route should be modeled as a suit of sophisticated mechanism for large-scale dynamic states tracking and representing so as to upgrade accu-racy and usability of the feedback information in MES. To clarify inherent complexities of this evolving route, the investigated issue is demonstrated from extended process systems engineering （PSE） point of view, and the TRF principles of the multi-level feedback information （states） are highlighted under the multi-scale methodology. As the main contribution, a novel mechanism called TRF modeling mechanism is introduced.     

利用计算流体力学方法研究精馏塔板上的液相流动

A computational fluid-dynamics model is presented for predicting the two-phase two-dimensional liquid phase flow on a distillation column tray based on the modification of Navier-Stokes Equation by considering both the resistance and the enhanced turbulence created by the uprising vapor. Experimental measurement of the local liquid phase velocity on an air-water simulator of 1.2 m in divaneter by using the hot film anemometer is briefly described. Two of the conventional fluid-dynamic constants are readjusted for the case of liquid flow on a tray byfitting the experimental data. The predicted local liquid phase velocity and direction of flow by the present model are confirmed satisfactorily by the authors‘ experimental measurements and by the data from literature. By the aid of the present model, the concentration field on the tray can be computed for the evaluation of the enhancement of liquid phase concentration across a tray. The advantages of applying computational fluid-dynamics to tray column design are discussed.     

超细粉在导向管喷动床中的固体循环速率

Ultra-fine powders are difficult to be fluidized due to the strong particle to particle cohesiveness.However, the authors‘ experiments showed that the ultra-fine powder CaCO3 could be stably fluidized in a spouted bed with a draft tube. The effects of geometric and operating parameters on solid circulation rate of ultra-fine powder CaCO3 were investigated in a 120 mm diameter transparent semicircular spouted bed with a draft tube. Three draft tubes with different sizes were used in this study. It was found that the solids circulation rate was mainly dependent on the drawing rate of the gas jet from the nozzle, then on the gas transport capacity in the draft tube. With increasing gas feed rate, distance between the nozzle and the draft tube inlet and draft tube diameter, the solids circulation rate could be increased. Based on the jet theory, a quantitative correlation was proposed for predicting the solid circulation rate of ultra-fine powders in a spouted bed with a draft tube by taking into account the gas transport capacity in the draft tube.     

To Readers

The15th International Congress on Coal Preparation will be held on October17,2006in Beijing.This is a magnificentassembly for those workingin the sector of coal preparationworldwide.China Association for Coal Processing and Utilization warmly welcome thefriendly participants,both domestic and from aboard and wish it be a successful gathering.For introducing to foreign friends and domestic colleagues such information as the posi-tion of coal in Chinese energy supply,the characteristics of …     

Advances in Modern Refractory Castables

Recent developments in terms of binding system, new material system, installation method and pre-cast shapes of refractory castables are introduced and discussed. In authors‘ view, binding system is advancing on the one hand towards “purification“ to minimize impurity components from binder materials, and on the other hand “stabilization“ to minimize the structure destroy by volatility and decomposition of binder materials. Challenges of higher service temperature, slag resistance, clean steel production and better thermal shock resistance have promoted the booming of new varieties of castables including MgO based, natural flake graphite containing and non-oxides like Sis N4, AION and SIMON containing castables. Installation technique is developing towards convenience, simplification and high efficiency. Advancement in installation and dry-out is of an incentive to the boost of selfflow castables, shotcreting castables, infiltration casting, quick dry-out castables and pre-cast shapes. Along wit hthe increased adoption of pre-cast shapes of castables, the boundary between “shaped“ and “ unshaped “ is becoming vague.     

大涡模拟研究两相燃烧的进展(Ⅱ)复杂气固流动和煤燃烧的大涡模拟(英文)

Large-eddy simulation(LES) is under its rapid development and is recognized as a possible second generation of CFD methods used in engineering.Large-eddy simulation of two-phase flows and combustion is particularly important for engineering applications.Some investigators,including the present authors,give their review on LES of spray combustion in gas-turbine combustors and internal combustion engines.However,up to now only a few papers are related to the state-of-the-art on LES of gas-particle flows and combustion.In this paper a review of the advances in LES of complex gas-particle flows and coal combustion is presented.Different sub-grid scale(SGS) stress models and combustion models are described,some of the main results are summarized,and some research needs are discussed.     

基于时段过渡分析的多时段间歇过程质量预测(英文)

Batch processes are usually involved with multiple phases in the time domain and many researches on process monitoring as well as quality prediction have been done using phase information. However, few of them consider phase transitions, though they exit widely in batch processes and have non-ignorable impacts on product qualities. In the present work, a phase-based partial least squares (PLS) method utilizing transition information is proposed to give both online and offline quality predictions. First, batch processes are divided into several phases using regression parameters other than prior process knowledge. Then both steady phases and transitions which have great influences on qualities are identified as critical-to-quality phases using statistical methods. Finally, based on the analysis of different characteristics of transitions and steady phases, an integrated algorithm is developed for quality prediction. The application to an injection molding process shows the effectiveness of the proposed algorithm in comparison with the traditional MPLS method and the phase-based PLS method.     

杂合基因算法在酵母中间代谢途径代谢通量分析中的应用

A scheme of investigating the intracellular metabolic fluxes in central metabolism of Saccharomyces cerevisiae based on isotope model and tracer experiment was developed. The metabolic model applied in this study includes the Embden-Meyerhof-Parnas pathway, the pentose phosphate pathway, the tricarboxylic acid cycle, CO2 anaplerotic reactions, ethanol and acetate formation, and pathways involved in amino acid synthesis. The approach of hybridized genetic algorithm combined with the sequential simplex technique was used to optimize a quadratic error function without the requirement of the information on the partial derivatives. The impact of some key parameters on the algorithm was studied. This approach was proved to be rapid and numerically stable in the analysis of the central metabolism of S.cerevisiae.     

Notes for Contributors

The Chinese Journal of Chemical Engineering is the official journal of the Chemical Industry and Engineering Society of China and published by the Chemical Industry Press. The aim of the journal is to develop the international exchange of scientific and technical information in the field of chemical engineering.Submission of Papers All papers will be submitted on line.     

KINETICS ON EPOXIDATION OF PROPYLENE WITH ETHYLBENZENE HYDROPEROXIDE

In the range of 76° to 1200C,Dalin and others studied the kinetics on molybdenum-catalyzed epoxi-dation of propylene with ethylbenzene hydroperoxide,proposed a mechanism model of this reaction andsuggested that effective concentration of catalyst is constant during the process of epoxidation.In thispaper the reaction has been studied experimentally based on Dalin's investigation.After analyzing thedata obtained in our experiment and those of Dalin,it is shown that the effective concentration of thecatalyst is not a constant but a variable,and its rate of consumption behaves in accordance with the firstorder reaction.Thus,the authors have modified the mechanism model in literature [3] and pointed outthat the deactivation mechanism of the catalyst is different from the inhibition mechanism described byFarberof.     

Notes for Contributors

The Chinese Journal of Chemical Engineering is the official journal of The Chemical Industry and Engineering Society of China and published by the Chemical Industry Press.The aim of the journal is to develop the international exchange of scientific and technical information in the field of chemical engineering.Submission of Papers All papers will be submitted on line.http://www.cjche     

Notes for Contributors

The Chinese Journal of Chemical Engineering is the official journal of the Chemical Industry and Engineering Society of China and published by the Chemical Industry Press.The aim of the journal is to develop the international exchange of scientific and technical information in the field of chemical engineering.Submission of Papers All papers will be submitted on line,http://www.cjche.com.cn