嘉恒法-平流冲渣工艺

通过对嘉恒法及平流法渣处理工艺的剖析,取长补短后提出了嘉恒法-平流冲渣工艺的设计思路,重点解决了嘉恒法工艺缺少备用手段和系统设备磨损、堵塞的问题。

用人工模拟平流型低温鉴定橡胶无性系抗寒性方法的研究

以离体芽条和绿色树皮为材料,用人工模拟平流低温法鉴定已知抗性橡胶无性系的抗寒性,结果寒害级别与自然同类低温下的呈极显著相关,抗寒品系选对率达86.67％,高抗品系选对率达100％;高抗与中抗、中抗与低抗无性系之间,寒害级别差异达极显著水平;以绿色树皮为材料与以离体芽条为材料鉴定结果寒害级别呈极显著相关,而以绿色树皮为材科鉴定可以提高鉴定效率,提早获得鉴定结果,还可节省砧木用量,避免参试材料茎粗和物候不一致的影响,提高鉴定的可靠性。

平流隔油法的应用及效果

一、含油废水的来源及其特性我厂含油废水的主要来源于机械加工零部件的洗涤和冲压酸洗废水,每天排放这类废水在110顿左右,废水中油的主要存在状态是油滴的粒径大,浮于水面上。

嘉恒法在长钢9号高炉的应用实践

高炉渣处理工艺分为自然沉淀和机械脱水两种,嘉恒法作为机械脱水渣处理工艺的代表,具有设备紧凑、自动化程度高、系统安全性高以及更加环保等优点,但其存在设备磨损、堵塞、返渣二次脱水效率低、成品仓水渣板结等问题,因而长钢对嘉恒法进行必要的改进,保留嘉恒法工艺优点的同时,解决了嘉恒法存在的问题。

弧形翼-身组合体绕流流场数值模拟及实验研究

为了研究标准技术协作计划(TTCP)弧形翼-身组合体的空气动力学特性,对其在超声速下的三维绕流流场进行了数值模拟。应用雷诺应力湍流模型和平流迎风劈裂法离散格式,对弧形翼-身组合体在Ma∈[2.0,5.5]范围内的超声速绕流流场结构进行了分析。计算分析了弧形翼-身组合体的各气动力系数随马赫数、攻角的变化规律。阐述了弧形翼在零攻角状态下产生自诱导滚转力矩的机理。利用超声速风洞进行了标准TTCP弧形翼-身组合体在Ma=3.0条件下的吹风实验。实验结果与数值模拟结果的计算误差小于10%,验证了所采用数值模拟方法的可信度。

改进型INBA冲渣工艺在柳钢2号高炉的应用

针对INBA法中普遍存在的水回路中细渣多、热水池积渣严重以及各系统管道、泵阀磨损严重等问题,介绍结合了INBA法和平流沉淀法的改进型渣处理工艺,及其在柳钢2号高炉的应用特点和效果。

FLOW FIELD ANALYSES OF PLANE JET AT LOW REYNOLDS NUMBERS USING LATTICE BOLTZMANN METHOD

A two-dimensional（2-D） incompressible plane jet is investigated using the lattice Boltzmann method（LBM） for low Reynolds numbers of 42 and 65 based on the jet-exit-width and the maximum jet-exit-velocity. The results show that the mean centerline velocity decays as x-1/3 and the jet spreads as x2/3 in the self-similar region, which are consistent with the theoretical predictions and the experimental data. The time histories and PSD analyses of the instantaneous centerline velocities indicate the periodic behavior and the interaction between periodic components of velocities should not be neglected in the far field region, although it is invisible in the near field region.

Analysis of anthropogenic aluminum cycle in China

Anthropogenic aluminum cycle in China was analyzed by the aluminum flow diagram based on the life cycle of aluminum products. The whole anthropogenic aluminum cycle consists of four stages： alumina and aluminum production, fabrication and manufacture, use and reclamation. Based on the investigation on the 2003-2007 aluminum cycles in China, a number of changes can be found. For instance, resources self-support ratio （RSR） in alumina production dropped from 95.42%to 55.50%, while RSR in the aluminum production increased from 52.45%to 79.25%. However, RSR in the Chinese aluminum industry leveled off at 50%in the period of 2003-2007. The respective use ratios of domestic and imported aluminum scrap in the aluminum industry of 2007 were 5.38% and 9.40%. In contrast, both the net imported Al-containing resources and the lost quantity of Al-containing materials in aluminum cycle increased during the same period, as well as the net increased quantity of Al-containing materials in social stock and recycled Al-scrap. Proposals for promoting aluminum cycle were put forward. The import/export policy and reducing the loss of Al-containing materials for the aluminum industry in China in the future were discussed.

典型非球形冰晶粒子的凝华增长数值模拟试验

在凝华增长过程中,冰晶的形状随着温度和湿度的改变而改变,准确模拟冰晶粒子的演变对于提高云模式的模拟能力起着非常重要的作用。在现有的云模式中,冰晶形状通常假设为球形,而在实际大气中,冰晶形状十分复杂。本研究中,我们根据冰晶凝华增长理论模型建立了一个单个冰晶粒子增长模型,模拟了温度分别为-1°C^-30°C时,单个典型非球形冰晶粒子的凝华增长过程。与风洞观测数据相对比,该模型能够抓住单个冰晶粒子的轴长,质量以及纵横比随温度和湿度的变化过程。我们进一步将该理论增长模型应用到群粒子的凝华增长过程的模拟。我们釆用欧拉二维正定平流输送法(MPDATA)模拟了典型非球形冰晶群粒子的凝华增长,并对比分析了在不同纵横比分辨率下的模拟效果以及温度变化对冰晶形状的影响,结果表明运用该数值方法可以合理地模拟出群粒子在凝华增长过程中纵横比的演变。与目前采用的拉格朗日—欧拉混合平流算法比较,该算法能够耦合到欧拉动力框架下的分档云模式中去,这对我们研究冰晶粒子形状对云微物理过程和动力过程的影响,以及它们对冰粒子凝华增长的反馈作用具有非常重要的科学意义。

改进型INBA冲渣工艺在柳钢2号高炉的应用

针对INBA法中普遍存在的水回路中细渣多、热水池积渣严重以及各系统管道、泵阀磨损严重等问题,介绍结合了INBA法和平流沉淀法的改进型渣处理工艺,及其在柳钢2号高炉的应用特点和效果。

HEURISTIC STUDY OF FLOWSHOP SCHEDULING TO MINIMIZE MEAN FLOW TIME WITH LOT TRANSFER CONSIDERED

Lot scheduling problem with idle time transfer between processes to minimize mean flow time is very important because to minimize mean flow time is to minimize work in process. But the problem is NP hard and no polynomial algorithm exists to guarantee optimal solution. Based the analysis the mathematical structure of the problem, the paper presents a new heuristic algorithm. Computer simulation shows that the proposed heuristic algorithm performs well in terms of both quality of solution and execution speed.

Energy Balance-Based SWAT Model to Simulate the Mountain Snowmelt and Runoff——Taking the Application in Juntanghu Watershed(China) as an Example

In order to predict long-term flooding under extreme weather conditions in central Asia, an energy balance-based distributed snowmelt runoff model was developed and coupled with the Soil and Water Assessment Tool(SWAT) model. The model was tested at the Juntanghu watershed on the northern slope of the Tian Shan Mountains, Xinjiang,China. We compared the performances of temperature-index method and energy balanced method in SWAT model by taking Juntanghu river basin as an application example(as the simulation experiment was conducted in Juntanghu River, we call the energy balanced method as SWAT-JTH). The results suggest that the SWAT snowmelt model had overall Nash-Sutcliffe efficiency(NSE) coefficients ranging from 0.61 to 0.85 while the physical based approach had NSE coefficients ranging from 0.58 to0.69. Overall, on monthly scale, the SWAT model provides better results than that from the SWAT-JTH model. However, results generated from both methods seem to be fairly close at a daily scale. Thestructure of the temperature-index method is simple and produces reasonable simulation results if the parameters are well within empirical ranges. Although the data requirement for the energy balance method in current observation is difficult to meet and the existence of uncertainty is associated with the experimental approaches of physical processes, the SWAT-JTH model still produced a reasonably high NSE. We conclude that using temperature-index methods to simulate the snowmelt process is sufficient, but the energy balance-based model is still a good choice to simulate extreme weather conditions especially when the required data input for the model is acquired.

ZM-66, a New Podophyllotoxin Derivative Inhibits Proliferation and Induces Apoptosis in K562/ADM Cells

Objective To investigate the anti-tumor effect of ZM-66 on multidrug-resistant leukemic cell line K562/ADM. Methods The K562/ADM cells were treated with varying concentrations （0, 1, 2, 4×10^-3 mmol/L） of ZM-66 or etoposide for 24 hours. The proliferation was detected by Sulforhodamine B Sodium Salt （SRB） assay and apoptosis was detected by flow cytometry analysis and fluorescent staining. In addition, the expression levels of p53 and bax genes in K562/ADM cells were detected by RT-PCR analysis. The level of P-glycoprotein （P-gp）, P53 and Bax protein in K562/ADM cells were detected by Western blot assay. Results SRB assay demonstrated that etoposide had little inhibitory effect on K562/ADM cells, whereas ZM-66 （1, 2, 4×10^-3 mmol/L） had significantly inhibitory effect on K562/ADM cells （all P〈0.01）. The acridine orange/propidium iodide dual staining showed that there were typical condensation of chromatin and nuclear fragmentation nuclei with red color in ZM-66 treated cells. Flow cytometric analysis showed that there was a significantly increase of apoptotic cells i~ K562/KDM cells after treated with ZM-66. RT-PCR showed that the p53 and bax mRNA expression levels in K562/ADM cells treated with ZM-66 at 1, 2, 4×10^-3 mmol/L were higher than those in the cell without treatment. Western blot showed that the P53 and Bax protein expression levels in K562/ADM cells treated with ZM-66 at 2, 4x 10 s mmol/L were higher than those in the cell without treatment. But the P-gp protein expression level in K562/ADM cells treated with ZM-66 at 2, 4×10^-3 mmol/L was gradually lower than those in the cell without treatment. Conclusion ZM-66 is able to induce cell death by apoptosis in vitro, as a result of the reverse of theapoptosis resistance in drug-resistant K562/ADM cells by modulating expression of key factors associated with apoptosis induction.

3D Simulation of Flow with Free Surface Based on Adaptive Octree Mesh System

The technique of adaptive tree mesh is an effective way to reduce computational cost through automatic adjustment of cell size according to necessity. In the present study, the 2D numerical N-S solver based on the adaptive quadtree mesh system was extended to a 3D one, in which a spatially adaptive oetree mesh system and multiple particle level set method were adopted for the convenience to deal with the air-water-structure multiple-medium coexisting domain. The stretching process of a dumbbell was simulated and the results indicate that the meshes are well adaptable to the free surface. The collapsing process of water column impinging a circle cylinder was simulated and from the results, it can be seen that the processes of fluid splitting and merging are properly simulated. The interaction of second-order Stokes waves with a square cylinder was simulated and the obtained drag force is consistent with the result by the Morison＇s wave force formula with the coefficient values of the stable drag component and the inertial force component bein~ set as 2.54.

Simulation of Non-isothermal Injection Molding for a Non-Newtonian Fluid by Level Set Method

A non-isothermal injection molding process for a non-Newtonian viscous pseudoplastic fluid is simulated.A conservative interface capturing technique and the flow field solving method are coupled to perform a dynamic simulation.The validity of the numerical method is verified by a benchmark problem.The melt interface evolution versus time is captured and the physical quantities such as temperature,velocity and pressure at each time step are obtained with corresponding analysis.A"frozen skin"layer with the thickness increasing versus time during the injection process is found.The fact that the"frozen skin"layer can be reduced by increasing the injection velocity is numerically verified.The fountain flow phenomenon near the melt interface is also captured.Moreover,comparisons with the non-isothermal Newtonian case show that the curvatures of the interface arcs and the pressure contours near the horizontal mid-line of the cavity for the non-Newtonian pseudoplastic case is larger than that for the Newtonian case.The velocity profiles are different at different positions for the non-Newtonian pseudoplastic case,while in the case of Newtonian flow the velocity profiles are parabolic and almost the same at different positions.

Fatigue Life Assessment of Top Tensioned Risers Under Vortex-Induced Vibrations

The fatigue life of top tensioned risers under vortex-induced vibrations (VIVs) with consideration of the effect of internal flowing fluid on the riser is analyzed in the time domain.The long-term stress histories of the riser under VIVs are calculated and the mean stresses,the number of stress cycles and amplitudes are determined by the rainflow counting method.The Palmgren-Miner rule for cumulative damage theory with a specified S-N curve is used to estimate the fatigue life of the riser.The corresponding numerical programs numerical simulation of vortex-induced vibrations (NSVIV) which can be used to calculate the VIV response and fatigue life of the riser are compiled.Finally the influences of the riser's parameters such as flexural rigidity,top tension and internal flow velocity on the fatigue life of the riser are analyzed in detail and some conclusions are drawn.

Accurate level set method for simulations of liquid atomization

Computational fluid dynamics is an efficient numerical approach for spray atomization study, but it is challenging to accurately capture the gas-liquid interface. In this work, an accurate conservative level set method is intro- duced to accurately track the gas-liquid interfaces in liquid atomization. To validate the capability of this method, binary drop collision and drop impacting on liquid film are investigated. The results are in good agreement with experiment observations. In addition, primary atomization （swirling sheet atomization） is studied using this method. To the swirling sheet atomization, it is found that Rayleigh-Taylor instability in the azimuthal direction causes the primary breakup of liquid sheet and complex vortex structures are clustered around the rim of the liq- uid sheet. The effects of central gas velocity and liquid-gas density ratio on atomization are also investigated. This work lays a solid foundation for further studvin~ the mechanism of s^rav atomization.

Investigation on a vertical radial flow adsorber designed by a novel parallel connection method

Due to the increasing global demand for industrial gas, the development of large-scale cryogenic air separation systems has attracted considerable attention in recent years. Increasing the height of the adsorption bed in a vertical radial flow adsorber used in cryogenic air separation systems may efficiently increase the treatment capacity of the air in the adsorber. However, uniformity of the flow distribution of the air inside the adsorber would be deteriorated using the height-increasing method. In order to reduce the non-uniformity of the flow distribution caused by the excessive height of adsorption bed in a vertical radial flow adsorber, a novel parallel connection method is proposed in the present work. The experimental apparatus is designed and constructed; the Computational Fluid Dynamics(CFD) technique is used to develop a CFD-based model, which is used to analyze the flow distribution, the static pressure drop and the radial velocity in the newly designed adsorber. In addition, the geometric parameters of annular flow channels and the adsorption bed thickness of the upper unit in the parallelconnected vertical radial flow adsorber are optimized, so that the upper and lower adsorption units could be penetrated by air simultaneously. Comparisons are made between the height-increasing method and the parallel connection method with the same adsorber height. It is shown that using the parallel connection method could reduce the difference between the maximum and minimum radial static pressure drop by 86.2% and improve the uniformity by 80% compared with those of using the height-increasing method. The optimal thickness ratio of the upper and lower adsorption units is obtained as 0.966, in which case the upper and lower adsorption units could be penetrated by air simultaneously, so that the adsorbents in adsorption space could be used more efficiently.

Optimization of assembly line balancing using genetic algorithm

In a manufacturing industry, mixed model assembly line(MMAL) is preferred in order to meet the variety in product demand. MMAL balancing helps in assembling products with similar characteristics in a random fashion. The objective of this work aims in reducing the number of workstations, work load index between stations and within each station. As manual contribution of workers in final assembly line is more, ergonomics is taken as an additional objective function. Ergonomic risk level of a workstation is evaluated using a parameter called accumulated risk posture(ARP), which is calculated using rapid upper limb assessment(RULA) check sheet. This work is based on the case study of an MMAL problem in Rane(Madras) Ltd.(India), in which a problem based genetic algorithm(GA) has been proposed to minimize the mentioned objectives. The working of the genetic operators such as selection, crossover and mutation has been modified with respect to the addressed MMAL problem. The results show that there is a significant impact over productivity and the process time of the final assembled product, i.e., the rate of production is increased by 39.5% and the assembly time for one particular model is reduced to 13 min from existing 18 min. Also, the space required using the proposed assembly line is only 200 m2 against existing 350 m2. Further, the algorithm helps in reducing workers fatigue(i.e., ergonomic friendly).

CFD Simulation of Flow and Mass Transfer in Structured Packing Distillation Columns

Detailed investigation of flow behavior in structured packing distillation columns is of great importance in accurate prediction of process efficiency and development of more efficient and optimal equipment internals. In this study, a three-dimensional two-phase flow model based on VOF method for simulating the hydrodynamics and mass-transfer behavior in a typical representative unit of the structured packing is developed. In the proposed model, the c 2 - ε c model is used for the closure of turbulent mass transfer equation. By solving the proposed model, the velocity distribution, phase fraction profile and concentration field are obtained. Using these data, the total liquid holdup, the wetted area and the separation efficiency [height equivalent to a theoretical plate (HETP)] are estimated. For testing the model validation, the simulated HETPs are compared with our previous experimental data obtained in a 150 mm-diameter column containing Mellapak 350Y operating at the pressures of 0.6-1.8 MPa. The compari-son shows that they are in satisfactory agreement, with an average absolute deviation (AAD) of 25.4%.