RESIDENCE TIME DISTRIBUTION IN A SCREW EXTRUDER

It has been studied that the residence time distribution(RTD)function in a screw extruder in relation to that in thescrew and that in the die.For a complex flow field such as that between screw and die,it was supposed that the RTDfunction in the screw and that in the die were almost independent on each other.Therefore,a probabilistic method wasused to predict the RTD function in a complete extruder from that in the screw and that in the die.The experiments fordetermining the RTD were based on a stimulus-response technique.The results predicted,both in single-screw extruderand in twin-screw extruder,were in good agreement with those experimentally obtained.     

Petrochemical Market Under the High Oil Price

Brisk production anddemand in domesticpetrochemical market in 20041. Drastic consumption increase of oilThe global oil supply shortage led to asustained price rise of crude oil in theinternational market in 2004.With the oilprice rise in the international market,theoil consumption in China made a dras-tic increase.According to the statisticsmade by the State Statistical Bureau,theprocessing amount of crude oil in Chinawas 273 million tons in 2004,an increaseof 13.7% over the previous year.The pro-cessing amount in Sinopec was 141 mil-lion tons(accounting for 52.2%),an in-     

多孔电极臭氧发生器氧化废水中有机物的吸收和反应动力学分析(英文)

A novel electrode design for the in situ generation of ozone in the reaction zone of a tubular reactor is described in this work.The ozone generator uses a porous inner electrode tube in the corona discharge assembly,and the ozone generated around the outer periphery of the porous tube diffuses into the tubular reactor and reacts with the contaminants in the fluid that is being treated.A mathematical model that includes absorption and second order reaction in the film is developed to describe ozonation kinetics of a contaminant dye in the tubular reactor.The model describes the experimental data for dye decolorization,oxidation byproducts,dissolved ozone,and ozone gas concentrations well.Model analysis indicates that the fast dye decolorization reaction occurs partly in the liquid film and partly in the bulk fluid.The model can be used in the selection of appropriate gas-liquid contactors for efficient oxidation of contaminants in effluents.     

Developing Status and Trend of the Refractories for Glass Furnaces in China

The developing course of refactories for glass furnaces in China is reviewed.Suggestions on their development trend in trms of improving in anticipation and meeting the requirements of glass industry in maximum degree are discussed.     

间歇化工过程和模型优化调度

Chemical batch processes have become significant in chemical manufacturing.In these processes,large numbers of chemical products are produced to satisfy human demands in daily life.Recently,economy globalization has resulted in growing worldwide competitions in traditional chemical process industry.In order to keep competitive in the global marketplace,each company must optimize its production management and set up a reactive system for market fluctuation.Scheduling is the core of production management in chemical processes.The goal of this paper is to review the recent developments in this challenging area.Classifications of batch scheduling problems and optimization methods are introduced.A comparison of six typical models is shown in a general benchmark example from the literature.Finally,challenges and applications in future research are discussed.     

Others

A Large Silicon Base to Be Set in Gansu ProvinceIt is reported that a large silicon base will be set in Gansu,a northwest province in China.Spanish Atlantic Metals and Alloys Inc,the world's first large scale multinational which produced silicon decided to pour CNY 6 billion in this project which would be its biggest investment in China.It is said that the project,which is divided into two phases,will be based in Kangding County and will begin to build in April 2009.The first phase is expected to churn o...     

BASF Constructs Coatings Plant in China

BASF is investing in a newpolyisocyanate plant in the ShanghaiChemical Industry Park in Caojing nearShanghai,China.Construction of theplant,with an annual capacity ofaround 8000 tons,is to begin in themiddle of 2005.It is scheduled to go     

Survey of Natural Gas Shortfall in China

<正> Natural gas users in many regions acrossChina experienced supply disruption in thepast winter. Statistics showed the gas gap atthe peak of use in the following cities andregions: 300 000 cubic meters in Hangzhou,eastern China, 600 000 cubic meters in Xi'an,western China, 700 000 cubic meters inWuhan, central China, 8 million cubic metersin Sichuan and Chongqing in southwesternChina. In total, the nationwide shortage of     

Rhodia Taking a Step Forward to Development in China

Rhodia celebrated its 25th anniversaryof its presence in China on April 21st,in Shanghai.Mr.J.P.Clamadieu,GroupCEO of Rhodia,paid a special visit toChina to host the event.Rhodia set up its first Representa-tive Office in Beijing in 1980,and hasmade great progress in the developmentin China within the recent decade.Bythe end of 2004,the total sales hadreached to US$420million in greater     

Investigation on characteristics of liquid self-diffusion in slit nanopores using simple quasicrystal model of liquid☆

Dynamical properties of liquid in nano-channels attractmuch interest because of their applications in engineering and biological systems. The transfer behavior of liquid confined within nanopores differs significantly from that in the bulk. Based on the simple quasicrystal model of liquid, analytical expressions of self-diffusion coefficient both in bulk and in slit nanopore are derived from the Stokes–Einstein equation and the modified Eyring's equation for viscosity. The local self-diffusion coefficient in different layers of liquid and the global self-diffusion coefficient in the slit nanopore are deduced fromthese expressions. The influences of confinement by porewalls, pore widths, liquid density, and temperature on the self-diffusion coefficient are investigated. The results indicate that the self-diffusion coefficient in nanopore increaseswith the porewidth and approaches the bulk value as the pore width is sufficiently large. Similar to that in bulk state, the self-diffusion coefficient in nanopore decreases with the increase of density and the decrease of temperature, but these dependences are weaker than that in bulk state and become evenweaker as the porewidth decreases. Thiswork provides a simplemethod to capture the physical behavior and to investigate the dynamic properties of liquid in nanopores.     

Rhodia to Increase IBCH Production Capacity in China

<正> Rhodia announces an increase in its IBCH production capacity in China in conjunction withthe transfer of its Wuxi plant to the group's new industrial platform located in Zhenjiang,Jiangsu province.IBCH is used by the perfumery industry.     

An Analysis of Contemporary Copper Recycling in China

Copper consumption increased very quickly in China in recent years, which could not be met by inland copper industry. In order to achieve a sustainable development of copper industry, an analysis of copper recycling in China was necessary. For the life cycle of copper products a copper-flow diagram with time factor was worked out and the contemporary copper recycling in China was analyzed, from which the following data were obtained. The average life cycle of copper products was 30 years. From 1998 to 2002, the use ratio of copper scraps in copper production, the use ratio of copper scraps in copper manufacture, the materials self-support ratio in copper production, and the materials self-support ratio in copper manufacture were 26.50%, 15.49%, 48.05% and 59.41%, respectively. The materials self-support ratios in copper production and manufacture declined year by year in recent years on the whole, and the latter dropped more quickly. The average index of copper ore and copper scrap from 1998 to 2002 were 0.8475 t/t and 0.0736 t/t, respectively; and copper resource efficiency was 1.1855 t/t. Some efforts should be paid to reduce copper ores consumption and promote copper scraps regeneration. Copper scraps were mostly imported from foreign countries because of shortage in recent years in China. Here the reasons related to copper scraps deficiency were also demonstrated. But we can forecast: when copper production was in a slow rise or in a steady state in China, the deficiency of copper scraps may be mitigated; when copper production was in a steady state for a very long time, copper scraps may become relatively abundant. According to the status of copper industry in China, the raw materials of copper production and manufacture have to depend on oversea markets heavily in recent years, and at the same time, the copper scraps using proportion and efficiency in copper industry should be improved.     

The New Year Message

Reviewing the past, we are full of confidence in our future. In the past years, a great changehas taken place in the world refractories industry. While consolidation by means of purchasingand merger has been surging forward in the world refractories industry, domestic refractoriesindustry has quietly immersed itself in hard work and has made a great progress both in pro-     

搅拌釡中层流流场的模拟

Stirred tanks are used extensively in process industry and one of the most commonly used impellers in stirred tanks is the R.ushton disk turbine. Surprisingly few data are available regarding flow and mixing in stirred-tank reactors with Rushton turbine in the laminar regime, in particular the laminar flow in baffled tanks.In this paper, the laminar flow field in a baffled tank stirred by a standard R.ushton turbine is simulated with the improved inner-outer iterative method. The non-inertial coordinate system is used for the impeller region, which is in turn used as the boundary conditions for iteration. It is found that the simulation results are in good agreement with previous experiments. In addition, the flow number and impeller power number calculated from the simulated flow field are in satisfactory agreement with experimental data. This numerical method allows prediction of flow structure requiring no experimental data as the boundary conditions and has the potential of being used to scale-up and design of related process equipment.     

Effect of Molding Press Direction on Properties of Periclase-spinel-carbon Brick

The effect of press direction on the thermal expansion,slag resistance,etc.of periclase-spinel-carbon brick has been studied in this article.The results show that the therma‘ expansion rate in the direction parallel to the press axis is larger than that in the direction perpendicular to the press axis and the slag resistance in the direction parallel to the press axis is much better than that in the perpendicular direction.The directional distribution of graphite in the specimen is observed with the microscope.     

Effect of Sudden Increase of Solid Feed Rate on the Arching in Hoppers Connected to a Standpipe with Interstitial Gas Flow

In this paper, a model is proposed for the prediction of the width of arching in hoppers resulted from sudden changes in solid feed rates. Such changes in solid feed rate usually come from the collision on the surface of the moving-bed in the standpipe. The model also takes into accountthe effect of the powder height in the standpipe of the hopper. The model proves to be adaptable for predicting operational conditions to avoid vxching by keeping constant powder height in the main standpipe wlth interstitial gas flow.     

Four Oil Giants Configure New International Competition Strategies

The crude oil price in the interna-tional market hit the new historicalrecord time and again in 2004 andprofound impacts were producedon large oil enterprises in China     

Trend in Monolithic Refractories Technology

This paper describes the trends in monolithic refractories echnology in terms of raw materials,binders and additives,water addition,installation and application,It is predicted that the application of unshaped refractories will be further extended in place of shaped refractories in the future.     

Upbeat about Caprolactam

<正> Caprolactam (CPL) is mainly used to producepolyamide 6 fibers, resins and films,which have extensive applications in thetextile, automotive, electronics and machinerysectors.Worldwide, caprolactam capacity was reportedly4.65 million t/a in 2008 and increasedto 4.754 million t/a in 2009 - growthof 2.24%.Total consumption in 2008 was3.788 million tons.China started commercial production ofcaprolactam in the late 1950s.It was howeveronly in the mid and late 1990s that