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28. Numerical Analysis of Titanium Compounds in Blast Furnace Hearth During Titania Addition

Author

Komiyama, Keisuke, Guo, Bao-Yu, Zughbi, Habib, Zulli, Paul, Yu, Aibing, Komiyama, Keisuke, Guo, Bao-Yu, Zughbi, Habib, Zulli, Paul, and Yu, Aibing

Abstract

The longevity of an iron making blast furnace is largely limited by the erosion of hearth refractory. The addition of titanium (Ti)-bearing materials into the furnace may promote so-called Ti-rich scaffolds along the damaged hearth lining. A Computational Fluid Dynamics model is used to investigate the complex transport phenomena associated with the formation and dissolution of solid particles. Based on the modeling results, the isotherm of the equilibrium temperature of the incoming hot metal solution can be used as an indicator for the extent and phase of Ti compounds. It is proposed that the particles can be managed by controlling the location of this isotherm. This can be conducted by either (a) altering the Ti dosage and concentration or (b) altering the hot metal pool temperature. The effects of these parameters on the solids holdup along the hearth refractory linings are investigated. The equilibrium isotherm concept may provide a more suitable way to control the location of Ti-based particles for furnace operators.

Published
2015

29. In situconstruction of surface defects of carbon-doped ternary cobalt-nickel-iron phosphide nanocubes for efficient overall water splitting

Author

Gao, Wen-Kun, Yang, Min, Chi, Jing-Qi, Zhang, Xin-Yu, Xie, Jing-Yi, Guo, Bao-Yu, Wang, Lei, Chai, Yong-Ming, and Dong, Bin

Abstract

The ternary cobalt-nickel-iron phosphide nanocubes (P-Co0.9Ni0.9Fe1.2NCs) with high intrinsic activity, conductivity, defect concentration and optimized ratio have been realized through a facile phosphorization treatment using ternary cobalt-nickel-iron nanocubes of Prussian blue analogs (PBA) as a precursor. The scanning electron microscopy and transmission electron microscopy results show that the P-Co0.9Ni0.9Fe1.2NCs maintain a cubic structure with a rough surface, implying the rich surface defects as exposed active sites. The thermal phosphorization of the ternary PBA precursor not only provids carbon doping but also leads to the in situconstruction of surface defects on the NCs. The carbon doping from the PBA precursor lowers the charge transfer resistance and optimizes the electronic transformation. The synergistic effect among the ternary metal ions and rich defects contributes to the enhanced electrocatalytic performance. The P-Co0.9Ni0.9Fe1.2NCs achieve low overpotentials of −200.7 and 273.1 mV at a current density of 10 mA cm−2for the hydrogen evolution reaction and the oxygen evolution reaction, respectively. The potential of overall water splitting reaches 1.52 V at a current density of 10 mA cm−2. The long-term stability of the electrocatalysts was also evaluated. This work provides a facile method to design efficient transition-metal-based bifunctional electrocatalysts for overall water splitting. 本文以三元金属钴-镍-铁普鲁士蓝结构纳米立方体(Co0.9-Ni0.9Fe1.2NCs)为前驱体, 通过简单气相磷化处理, 得到优化比例的 P-Co0.9Ni0.9Fe1.2纳米立方体磷化物, 其具有高本征活性、导电性和高缺陷密度的特点. SEM和TEM结果表明, 碳掺杂型 P-Co0.9Ni0.9-Fe1.2保持了纳米立方体的结构, 其粗糙的表面结构意味着丰富的缺陷位, 暴露更多真实活性位. 三元金属普鲁士蓝前驱体的磷化处理不仅提供了碳掺杂, 而且原位构筑了立方体表面缺陷位. 碳掺杂降低了电荷传输的阻抗, 优化了电子传输速率. 三元金属离子之间的协同作用以及丰富的缺陷活性位有效提高了电催化的性能. P-Co0.9Ni0.9Fe1.2拥有极其高的HER和OER催化活性, 仅需要 −200.7 mV (HER) 和273.1 mV (OER) 过电位就可以达到 10 mA cm−2 的电流密度. 其全水分解仅需1.52 V就可以达到10 mA cm−2的电流密度. 此外, 本文还对催化剂的稳定性进行了测试. 本工作为设计高效过渡金属基双功能电解水催化剂提供了一种简便方法.

Published
2019
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31. Three-dimensional modelling of in-furnace coal/coke combustion in a blast furnace

Author

Shen, Yansong, Guo, Bao-Yu, Yu, Aibing, Austin, Peter R, Zulli, Paul, Shen, Yansong, Guo, Bao-Yu, Yu, Aibing, Austin, Peter R, and Zulli, Paul

Abstract

A three-dimensional mathematical model of the combustion of pulverized coal and coke is developed. The model is applied to the region of lance-blowpipe-tuyere-raceway-coke bed to simulate in-furnace phenomena of pulverized coal injection in an ironmaking blast furnace. The model integrates not only pulverized coal combustion model in the blowpipe-tuyere-raceway-coke bed but also coke combustion model in the coke bed. The model is validated against the measurements under different conditions. The comprehensive in-furnace phenomena are investigated in the raceway and coke bed, in terms of flow, temperature, gas composition, and coal burning characteristics. The underlying mechanisms for the in-furnace phenomena are also analysed. The simulation results indicate that it is important to include recirculation region in the raceway and the coke bed reactions for better understanding in-furnace phenomena. The model provides a cost-effective tool for understanding and optimizing the in-furnace flow-thermo-chemical characteristics of the PCI operation in full-scale blast furnaces

Published
2011

32. CFD Modeling and Analysis of The Flow, Heat Transfer and Mass Transfer in a Blast Furnace Hearth

Author

Guo, Bao-Yu, Yu, Ai-Bing, Zulli, Paul, Maldonado, Daniel, Guo, Bao-Yu, Yu, Ai-Bing, Zulli, Paul, and Maldonado, Daniel

Abstract

Understanding the complex phenomena in the BF hearth is essential to increasing furnace productivity and to extending furnace campaign. Numerical modeling provides a cost-effective tool to obtain such knowledge. We have developed several continuum-based mathematical/numerical models to simulate the flow, heat transfer and mass transfer in the lower part of BF and in the hearth. These models have generated an improved insight into the mechanisms for liquid drainage efficiency, lining erosion and wall protection in BF hearth under operational conditions. The current paper provides an overview of these studies, as well as dealing with three specific aspects: (a) Gas flow and pressure on the liquid surface, and its effect on the drainage characteristics; (b) Flow and temperature distributions of liquid iron in the hearth, and the temperature distribution in the refractories; and (c), Titania injection to form Ti(C,N)-rich scaffolds on the hearth refractory surface, to protect the hearth from erosion.

Published
2011

42. Towardthe Development of an Integrated Multiscale Model for ElectrostaticPrecipitation.

Author

Guo, Bao-Yu, Yang, Si-Yuan, Xing, Mao, Dong, Ke-Jun, Yu, Ai-Bing, and Guo, Jun

Subjects
*MULTISCALE modeling, *ELECTROSTATIC precipitation, *MATHEMATICAL models, *ELECTRIC fields, *ATMOSPHERIC deposition, *DISCRETE element method
Abstract

Thispaper reports our attempts in developing an integrated multiscalemathematical model to describe the wire-plate-type electrostatic precipitator(ESP), aiming to understand the underlying physics and to developa computer tool for process design and control. In the model, variousphenomena in a wide range of length/time scales related to the electricfield, gas-particle flow, dust deposition, cake formation, and theirinteractions are resolved. We apply different numerical methods fordifferent fields in different local regions, leading to various submodels,including a continuum-based electric field model, Euler–Lagrangegas-particle flow model, and discrete-based cake formation model.These submodels are eventually integrated to form an ESP process model,which can generate results useful for better understanding the phenomenaand assessing the ESP performance under different conditions. [ABSTRACT FROM AUTHOR]

Published
2013
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43. Profiling of differentially expressed chemotactic-related genes in MCP-1 treated macrophage cell line using human cDNA arrays.

Author

Bian GX, Miao H, Qiu L, Cao DM, and Guo BY

Subjects
Chemotaxis drug effects, Chemotaxis immunology, Gene Expression immunology, Humans, Macrophages cytology, Macrophages drug effects, Neutrophils physiology, Reverse Transcriptase Polymerase Chain Reaction, U937 Cells, Chemokine CCL2 pharmacology, Chemotaxis genetics, Gene Expression Profiling, Macrophages physiology, Oligonucleotide Array Sequence Analysis
Abstract

Aim: To study the global gene expression of chemotactic genes in macrophage line U937 treated with human monocyte chemoattractant protein-1 (MCP-1) through the use of ExpreeChipHO2 cDNA array., Methods: Total RNA was extracted from MCP-1 treated macrophage line U937 and normal U937 cells, reversely transcribed to cDNA, and then screened in parallel with HO2 human cDNA array chip. The scanned result was additionally validated using RT-PCR., Results: The result of cDNA array showed that one chemotactic-related gene was up-regulated more than two-fold (RANTES) and seven chemotactic-related genes were down-regulated more than two-fold (CCR1, CCR5, ccl16, GRObeta, GROgamma, IL-8 and granulocyte chemotactic protein 2) in MCP-1 treated U937 cells at mRNA level. RT-PCR analysis of four of these differentially expressed genes gave results consistent with cDNA array findings., Conclusion: MCP-1 could influence some chemokine and receptor expressions in macrophages in vitro. MCP-1 mainly down-regulates the expression of chemotactic genes influencing neutrophilic granulocyte expression (GRObeta, GROgamma, IL-8 and granulocyte chemotactic protein 2), and the mRNA level of CCR5, which plays a critical role in many disorders and illnesses.

Published
2005
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44. [Effect of recombinant prothymosin alpha on secretion of IFN-gamma, IFN-alpha and TNF-alpha in vitro].

Author

Qiu L, Guo BY, Miao H, Dao SY, Zhang R, Yuan PQ, and Yang X

Subjects
Adjuvants, Immunologic pharmacology, Animals, Cell Separation, Female, Glutathione Transferase pharmacology, Lymphocytes metabolism, Macrophages drug effects, Macrophages metabolism, Mice, Mice, Inbred BALB C, Recombinant Fusion Proteins pharmacology, Spleen cytology, Interferon-alpha metabolism, Interferon-gamma metabolism, Macrophages, Peritoneal metabolism, Protein Precursors pharmacology, Thymosin analogs & derivatives, Thymosin pharmacology, Tumor Necrosis Factor-alpha metabolism
Abstract

Aim: To study the effect of prothymosin alpha (Pro T alpha) as a fusion protein on secretion of IFN-gamma, IFN-alpha and TNF-alpha in vitro., Methods: The in vitro study was carried out on the culture of splenocytes, splenic and peritoneal macrophages isolated from Balb/c mice. Splenocytes were incubated with various concentrations of Pro T alpha (1 x 10(-7)-1 x 10(-10) mol.L-1) with or without Con A (5 micrograms.mL-1) for 72 h. Splenic and peritoneal macrophages were respectively treated with Pro T alpha (1 x 10(-7)-1 x 10(-10) mol.L-1) in the presence of LPS (10 micrograms.mL-1) for 24 h. Then IFN-gamma, IFN-alpha and TNF-alpha levels in the supernatant were detected by ELISA., Results: Pro T alpha (1 x 10(-7) mol.L-1) was found to obviously increase IFN-gamma level (P < 0.05) in the supernatant of splenocytes compared with the control group. Moreover, Pro T alpha (1 x 10(-7) mol.L-1) significantly induced the secretion of IFN-alpha (P < 0.01) and TNF-alpha (P < 0.01) in splenic and peritoneal macrophages., Conclusion: In vitro, Pro T alpha could increase the secretion of IFN-gamma, IFN-alpha and TNF-alpha.

Published
2002

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