Powder Technology最新文献

Numerical modelling on the ultra-low emission of NOx in hot blast stove-parametric study, optimization, mechanism, and solutions

IF 4.5 2区工程技术 Q2 ENGINEERING, CHEMICAL

Powder Technology

Pub Date : 2025-04-18 DOI: 10.1016/j.powtec.2025.121041

Deyu Yue , Zhong Li , Guangchao Wei , Meng Li , Chao Li , Guanyin Wu , Peng Han , Xizhong An , Hao Zhang , Haitao Fu , Xiaohong Yang , Qingchuan Zou

Aiming at the problem of ultra-low NOx emission from hot blast stoves in the ironmaking process, this paper takes the external combustion hot blast stove that used in a domestic steel plant as the research object. Through systematic numerical simulations, the influences of process parameters (e.g., the air excess coefficient α, preheating temperature of gas T_gas and air T_air, and gas flow rate V_gas) on the generation of NOx during the combustion process in the stove and the change of the composition of NOx in the flue gas were investigated. The mechanism of thermal NOx generation and the effective control scheme for high temperature combustion conditions are discussed. The NOx emission prediction model is established on this basis. The results show that when α is 1.02, the combustion effect is better, the gas is completely burnt out, and the NO emission is less. When α is about 1.60, the NO concentration is maximum. Increasing the preheating temperature can effectively increase the temperature in the stove. For every incremental preheating temperature with 100 K, the average temperature at the top of the regenerative chamber can be increased by about 20 K. When α is fixed, V_gas can reduce the retention time of the gas in the stove and the total amount of NO generation. It is proved that the prediction model based on the numerical results can achieve low NO emission under the condition of higher temperature in the stove, which will provide effective references for the research and industrial production of different types of hot blast stoves.

{"title":"Numerical modelling on the ultra-low emission of NOx in hot blast stove-parametric study, optimization, mechanism, and solutions","authors":"Deyu Yue , Zhong Li , Guangchao Wei , Meng Li , Chao Li , Guanyin Wu , Peng Han , Xizhong An , Hao Zhang , Haitao Fu , Xiaohong Yang , Qingchuan Zou","doi":"10.1016/j.powtec.2025.121041","DOIUrl":"10.1016/j.powtec.2025.121041","url":null,"abstract":"<div><div>Aiming at the problem of ultra-low NOx emission from hot blast stoves in the ironmaking process, this paper takes the external combustion hot blast stove that used in a domestic steel plant as the research object. Through systematic numerical simulations, the influences of process parameters (e.g., the air excess coefficient <em>α</em>, preheating temperature of gas <em>T</em><sub>gas</sub> and air <em>T</em><sub>air</sub>, and gas flow rate <em>V</em><sub>gas</sub>) on the generation of NOx during the combustion process in the stove and the change of the composition of NOx in the flue gas were investigated. The mechanism of thermal NOx generation and the effective control scheme for high temperature combustion conditions are discussed. The NOx emission prediction model is established on this basis. The results show that when <em>α</em> is 1.02, the combustion effect is better, the gas is completely burnt out, and the NO emission is less. When <em>α</em> is about 1.60, the NO concentration is maximum. Increasing the preheating temperature can effectively increase the temperature in the stove. For every incremental preheating temperature with 100 K, the average temperature at the top of the regenerative chamber can be increased by about 20 K. When <em>α</em> is fixed, <em>V</em><sub>gas</sub> can reduce the retention time of the gas in the stove and the total amount of NO generation. It is proved that the prediction model based on the numerical results can achieve low NO emission under the condition of higher temperature in the stove, which will provide effective references for the research and industrial production of different types of hot blast stoves.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"460 ","pages":"Article 121041"},"PeriodicalIF":4.5,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanical blending and microscopic image processing for evaluating homogeneity in nano- and micron-sized powder mixtures

IF 4.5 2区工程技术 Q2 ENGINEERING, CHEMICAL

Powder Technology

Pub Date : 2025-04-18 DOI: 10.1016/j.powtec.2025.121047

Ella L. Dzidziguri , Andrey A. Vasilev , Roman A. Vakhrushev , Konstantin N. Krestnikov , Evgeny A. Kolesnikov , Sergey A. Eremin , Leonid V. Fedorenko

This paper presents the results of mechanically blending AlSi₁₀Mg micropowder with Co₃O₄ nanoparticles, resulting in the formation of a nanoparticle coating on the surface of the coarse particles. An automated computer program was developed using Python's OpenCV library to process EDX elemental mapping images and evaluate the homogeneity of a mixture of nano- and micron-sized powders through surface analysis of sample images. The proposed methodology employs Otsu's thresholding technique to segment images into regions of interest and calculates quantitative data on the areas occupied by micron- and nanoscale components, which are key indicators for assessing powder mixture homogeneity. The developed technique is cost-effective and demonstrated its efficacy in measuring the homogeneity distribution of nanoparticles within a micropowder using a set of microscopy images. The only requirement for the method's applicability is a difference in the elemental composition of the powders. In this work, the homogeneity of micron-sized AlSi₁₀Mg powder mixed with varying concentrations of cobalt oxide nanoparticles was analyzed using the processing of elemental mapping images. The results showed that 8 h of blending in a planetary ball mill with grinding balls was sufficient to achieve a homogeneous powder mixture.

{"title":"Mechanical blending and microscopic image processing for evaluating homogeneity in nano- and micron-sized powder mixtures","authors":"Ella L. Dzidziguri , Andrey A. Vasilev , Roman A. Vakhrushev , Konstantin N. Krestnikov , Evgeny A. Kolesnikov , Sergey A. Eremin , Leonid V. Fedorenko","doi":"10.1016/j.powtec.2025.121047","DOIUrl":"10.1016/j.powtec.2025.121047","url":null,"abstract":"<div><div>This paper presents the results of mechanically blending AlSi<sub>10</sub>Mg micropowder with Co<sub>3</sub>O<sub>4</sub> nanoparticles, resulting in the formation of a nanoparticle coating on the surface of the coarse particles. An automated computer program was developed using Python's OpenCV library to process EDX elemental mapping images and evaluate the homogeneity of a mixture of nano- and micron-sized powders through surface analysis of sample images. The proposed methodology employs Otsu's thresholding technique to segment images into regions of interest and calculates quantitative data on the areas occupied by micron- and nanoscale components, which are key indicators for assessing powder mixture homogeneity. The developed technique is cost-effective and demonstrated its efficacy in measuring the homogeneity distribution of nanoparticles within a micropowder using a set of microscopy images. The only requirement for the method's applicability is a difference in the elemental composition of the powders. In this work, the homogeneity of micron-sized AlSi<sub>10</sub>Mg powder mixed with varying concentrations of cobalt oxide nanoparticles was analyzed using the processing of elemental mapping images. The results showed that 8 h of blending in a planetary ball mill with grinding balls was sufficient to achieve a homogeneous powder mixture.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"460 ","pages":"Article 121047"},"PeriodicalIF":4.5,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental investigation and analysis of the influence of the pipe diameter on pressure fluctuations in pneumatic conveying systems with fine bulk solids

IF 4.5 2区工程技术 Q2 ENGINEERING, CHEMICAL

Powder Technology

Pub Date : 2025-04-18 DOI: 10.1016/j.powtec.2025.121031

M. Dikty

When reducing the conveying gas velocity during the pneumatic transport of fine-grained bulk materials, the process goes through a wide variety of flow modes. If the conveying gas velocity is reduced to such an extent that a blockage occurs, the system-specific pressure limit has been exceeded. Along this reduction in velocity, there are pressure fluctuations of varying degrees, the so-called pressure pulsations. These have been intensively studied over the past 30 years, mainly about the associated flow mode. In this paper, the pressure pulsation is systematically investigated in dependence on the pipe diameter. For this purpose, conveying tests were carried out with different conveying air mass flows, starting with the dilute mode, and ending with the pipe blockage. Two different pipe diameters, 76.3 mm and 101.7 mm were investigated. The pressure values were sampled and evaluated at 5000 Hz. Criteria for assessing pressure pulsation are systematically related to the solid loading ratio (SLR), the Froude number and the Euler number based on a dimensional analysis. The resulting dependencies are evaluated qualitatively and quantitatively.

{"title":"Experimental investigation and analysis of the influence of the pipe diameter on pressure fluctuations in pneumatic conveying systems with fine bulk solids","authors":"M. Dikty","doi":"10.1016/j.powtec.2025.121031","DOIUrl":"10.1016/j.powtec.2025.121031","url":null,"abstract":"<div><div>When reducing the conveying gas velocity during the pneumatic transport of fine-grained bulk materials, the process goes through a wide variety of flow modes. If the conveying gas velocity is reduced to such an extent that a blockage occurs, the system-specific pressure limit has been exceeded. Along this reduction in velocity, there are pressure fluctuations of varying degrees, the so-called pressure pulsations. These have been intensively studied over the past 30 years, mainly about the associated flow mode. In this paper, the pressure pulsation is systematically investigated in dependence on the pipe diameter. For this purpose, conveying tests were carried out with different conveying air mass flows, starting with the dilute mode, and ending with the pipe blockage. Two different pipe diameters, 76.3 mm and 101.7 mm were investigated. The pressure values were sampled and evaluated at 5000 Hz. Criteria for assessing pressure pulsation are systematically related to the solid loading ratio (SLR), the Froude number and the Euler number based on a dimensional analysis. The resulting dependencies are evaluated qualitatively and quantitatively.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"460 ","pages":"Article 121031"},"PeriodicalIF":4.5,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dispersion and secondary explosion model of propylene oxide droplets/aluminum powder under explosion driving: Considering the initial flow field

IF 4.5 2区工程技术 Q2 ENGINEERING, CHEMICAL

Powder Technology

Pub Date : 2025-04-16 DOI: 10.1016/j.powtec.2025.121045

Linghui Zeng , Jiafan Ren , Zhongqi Wang , Han Li , Xing Chen , Shenghua Fu

The dispersion and explosion characteristics of multiphase particles under explosion-driving hold significant importance for safety design and accident prevention in the chemical industry field. In order to solve the problems of discontinuity, incompleteness of flow field conditions and significant near-field errors in the existing numerical models, a dispersion and secondary explosion model of propylene oxide droplets/ aluminum powder under explosion driving is built. The model performs continuous computations for the four stages of initial dispersion, cloud development, concentration distribution, and secondary explosion. The model considers the initial flow field conditions, effectively reducing the near-field computational error to within 10 %. The dispersion and explosion processes of mixed fuel under three conditions (static, with wind speed and with falling speed) are studied through experiments and numerical models. The results show that under the initial wind speed, the dispersion radius of the downwind area extends by 16.8 %. The burnout rate increases by 15.0 %, and the peak overpressure of the secondary explosion rises by 4.2 %. Under the initial falling speed effect, the concentration distribution of the fuel cloud becomes more uniform. The proportion of the gas phase increases. It has been verified that the velocity change of the initial flow field can influence the stripping and evaporation effects of droplets, thereby strengthening the explosive properties of the cloud.

{"title":"Dispersion and secondary explosion model of propylene oxide droplets/aluminum powder under explosion driving: Considering the initial flow field","authors":"Linghui Zeng , Jiafan Ren , Zhongqi Wang , Han Li , Xing Chen , Shenghua Fu","doi":"10.1016/j.powtec.2025.121045","DOIUrl":"10.1016/j.powtec.2025.121045","url":null,"abstract":"<div><div>The dispersion and explosion characteristics of multiphase particles under explosion-driving hold significant importance for safety design and accident prevention in the chemical industry field. In order to solve the problems of discontinuity, incompleteness of flow field conditions and significant near-field errors in the existing numerical models, a dispersion and secondary explosion model of propylene oxide droplets/ aluminum powder under explosion driving is built. The model performs continuous computations for the four stages of initial dispersion, cloud development, concentration distribution, and secondary explosion. The model considers the initial flow field conditions, effectively reducing the near-field computational error to within 10 %. The dispersion and explosion processes of mixed fuel under three conditions (static, with wind speed and with falling speed) are studied through experiments and numerical models. The results show that under the initial wind speed, the dispersion radius of the downwind area extends by 16.8 %. The burnout rate increases by 15.0 %, and the peak overpressure of the secondary explosion rises by 4.2 %. Under the initial falling speed effect, the concentration distribution of the fuel cloud becomes more uniform. The proportion of the gas phase increases. It has been verified that the velocity change of the initial flow field can influence the stripping and evaporation effects of droplets, thereby strengthening the explosive properties of the cloud.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"459 ","pages":"Article 121045"},"PeriodicalIF":4.5,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Pore network modeling of iron ore agglomerates: Development of a methodology based on X-ray microtomography

IF 4.5 2区工程技术 Q2 ENGINEERING, CHEMICAL

Powder Technology

Pub Date : 2025-04-16 DOI: 10.1016/j.powtec.2025.121046

Igor Nogueira Lima , Karen Soares Augusto , Marcos Henrique de Pinho Mauricio , Francisco José Rodrigues da Silva Junior , Richard Bryan Magalhães Santos , Bernardo Amaral Pascarelli Ferreira , Alei Leite Alcantara Domingues , Valdirene Gonzaga de Resende , Sidnei Paciornik

One of the most relevant characteristics of iron ore agglomerates is their porosity, which strongly impacts their performance in the steelmaking processes. This performance depends on a porous network allowing the gas to flow through its interior without compromising its integrity. However, there is a noticeable lack of research on the relationship between flow properties, absolute permeability, and the porous structure of agglomerates, especially for cold agglomerated iron ore. This work presents a methodology for characterizing iron ore agglomerates by identifying their pore network structure using X-ray microtomography (MicroCT) and Pore Network Modeling (PNM). The methodology was applied to iron ore pellets and cold agglomerates. Thus, the influence of the microstructure of these agglomerates on the variation of their porosity and permeability was evaluated. MicroCT provided a 3D visualization of the agglomerates' microstructure, allowing the pore space's discrimination. PNM was used to simulate the absolute permeability of the samples, correlating it with porosity, pore connectivity, and pore diameters and connections. The images were acquired with a 2 μm voxel size, and the obtained porosity was around 20 %. In addition, consistent results of the agglomerates' absolute permeability were found, ranging from 0.03 to 2.4 mD. From the developed methodology, it is possible to explore the relationship between porosity, permeability, and reducibility of agglomerates. Future research can use this approach to optimize process parameters and improve the efficiency of steel production by deepening the understanding of the influence of microstructure on the physical properties and performance of the reduction process.

{"title":"Pore network modeling of iron ore agglomerates: Development of a methodology based on X-ray microtomography","authors":"Igor Nogueira Lima , Karen Soares Augusto , Marcos Henrique de Pinho Mauricio , Francisco José Rodrigues da Silva Junior , Richard Bryan Magalhães Santos , Bernardo Amaral Pascarelli Ferreira , Alei Leite Alcantara Domingues , Valdirene Gonzaga de Resende , Sidnei Paciornik","doi":"10.1016/j.powtec.2025.121046","DOIUrl":"10.1016/j.powtec.2025.121046","url":null,"abstract":"<div><div>One of the most relevant characteristics of iron ore agglomerates is their porosity, which strongly impacts their performance in the steelmaking processes. This performance depends on a porous network allowing the gas to flow through its interior without compromising its integrity. However, there is a noticeable lack of research on the relationship between flow properties, absolute permeability, and the porous structure of agglomerates, especially for cold agglomerated iron ore. This work presents a methodology for characterizing iron ore agglomerates by identifying their pore network structure using X-ray microtomography (MicroCT) and Pore Network Modeling (PNM). The methodology was applied to iron ore pellets and cold agglomerates. Thus, the influence of the microstructure of these agglomerates on the variation of their porosity and permeability was evaluated. MicroCT provided a 3D visualization of the agglomerates' microstructure, allowing the pore space's discrimination. PNM was used to simulate the absolute permeability of the samples, correlating it with porosity, pore connectivity, and pore diameters and connections. The images were acquired with a 2 μm voxel size, and the obtained porosity was around 20 %. In addition, consistent results of the agglomerates' absolute permeability were found, ranging from 0.03 to 2.4 mD. From the developed methodology, it is possible to explore the relationship between porosity, permeability, and reducibility of agglomerates. Future research can use this approach to optimize process parameters and improve the efficiency of steel production by deepening the understanding of the influence of microstructure on the physical properties and performance of the reduction process.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"460 ","pages":"Article 121046"},"PeriodicalIF":4.5,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Chlorine-doping boosting Na+ transport kinetics of P2-type layered Na0.66Ni0.27Zn0.06Mn0.67O2 cathode for Na-ion batteries via regulating ion migration path 氯掺杂通过调节离子迁移路径促进 Na 离子电池 P2- 型层状 Na0.66Ni0.27Zn0.06Mn0.67O2 正极的 Na+ 迁移动力学

IF 4.5 2区工程技术 Q2 ENGINEERING, CHEMICAL

Powder Technology

Pub Date : 2025-04-16 DOI: 10.1016/j.powtec.2025.121043

Chen Lu , Lin Xu , Guangpeng He , Bingqian Wang , Meiqi Zheng , Zhaohong Tang , Kaiwen Zhou , Wenwei Wu , Xuehang Wu

Sodium-ion batteries (SIBs) with high-energy-density require high-capacity and high-voltage cathode materials. Among various cathode materials, P2-type Na_0.66Ni_0.27Zn_0.06Mn_0.67O₂ (NNZMO) is attractive due to its high theoretical capacity, high working voltage, low production cost, and low toxicity. However, its cycle life and rate performance still need to be further enhanced for serving the needs of commercial applications. In this work, we demonstrate that Cl doping can effectively enhance the structural stability, working voltage, and capacity of the NNZMO-x (x = 0.03, 0.06), especially NNZMO-0.03, attributed that chlorine-doped NNZMO can provide more superior structural integrity, more favorable Na⁺ ion migration path, more electrochemical active sites. Such as, NNZMO-0.03 can provides a specific discharge capacity of 95.40 mAh g⁻¹ and a capacity retention of 86.26 % after 100 cycles at 100 mA g⁻¹, showing marked improvement compared with NNZMO (83.40 mAh g⁻¹ and 77.36 %). Besides, the rate performance of NNZMO-0.03 is also significantly improved after doping Cl⁻. Such as, specific discharge capacity of 81.5 and 76.1 mAh g⁻¹ for NNZMO-0.03 vs. that of 76.3 and 65.9 mAh g⁻¹ for NNZMO at 1000 and 2000 mA g⁻¹. Therefore, this work provides a new strategy by means of Cl doping to enhance the electrochemical performance of layered oxide cathode materials for SIBs

{"title":"Chlorine-doping boosting Na+ transport kinetics of P2-type layered Na0.66Ni0.27Zn0.06Mn0.67O2 cathode for Na-ion batteries via regulating ion migration path","authors":"Chen Lu , Lin Xu , Guangpeng He , Bingqian Wang , Meiqi Zheng , Zhaohong Tang , Kaiwen Zhou , Wenwei Wu , Xuehang Wu","doi":"10.1016/j.powtec.2025.121043","DOIUrl":"10.1016/j.powtec.2025.121043","url":null,"abstract":"<div><div>Sodium-ion batteries (SIBs) with high-energy-density require high-capacity and high-voltage cathode materials. Among various cathode materials, P2-type Na<sub>0.66</sub>Ni<sub>0.27</sub>Zn<sub>0.06</sub>Mn<sub>0.67</sub>O<sub>2</sub> (NNZMO) is attractive due to its high theoretical capacity, high working voltage, low production cost, and low toxicity. However, its cycle life and rate performance still need to be further enhanced for serving the needs of commercial applications. In this work, we demonstrate that Cl doping can effectively enhance the structural stability, working voltage, and capacity of the NNZMO-x (x = 0.03, 0.06), especially NNZMO-0.03, attributed that chlorine-doped NNZMO can provide more superior structural integrity, more favorable Na<sup>+</sup> ion migration path, more electrochemical active sites. Such as, NNZMO-0.03 can provides a specific discharge capacity of 95.40 mAh g<sup>−1</sup> and a capacity retention of 86.26 % after 100 cycles at 100 mA g<sup>−1</sup>, showing marked improvement compared with NNZMO (83.40 mAh g<sup>−1</sup> and 77.36 %). Besides, the rate performance of NNZMO-0.03 is also significantly improved after doping Cl<sup>−</sup>. Such as, specific discharge capacity of 81.5 and 76.1 mAh g<sup>−1</sup> for NNZMO-0.03 vs. that of 76.3 and 65.9 mAh g<sup>−1</sup> for NNZMO at 1000 and 2000 mA g<sup>−1</sup>. Therefore, this work provides a new strategy by means of Cl doping to enhance the electrochemical performance of layered oxide cathode materials for SIBs</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"460 ","pages":"Article 121043"},"PeriodicalIF":4.5,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Granular flow in screw conveyors: A review of experiments and discrete element method (DEM) studies

IF 4.5 2区工程技术 Q2 ENGINEERING, CHEMICAL

Powder Technology

Pub Date : 2025-04-16 DOI: 10.1016/j.powtec.2025.121040

Milada Pezo , Lato Pezo , Biljana Lončar , Predrag Kojić , Milica Ilić , Aca Jovanović

Screw conveyors are essential in industries such as mineral processing, agriculture, chemicals, plastics, cement, and food processing, facilitating granular material transport and mixing. Despite their mechanical simplicity, the complex physics of granular flow poses challenges, including bridging, blockages, and inefficient mixing. This review examines transport mechanisms and mixing in screw conveyors through experimental studies and Discrete Element Method (DEM) simulations. DEM enables detailed analysis of particle interactions, capturing transport dynamics based on Newton's laws of motion. Key operational parameters—rotational speed, inclination angle, and fill level—significantly impact transport efficiency and mixing behaviour. Recent advancements in DEM, including integration with Computational Fluid Dynamics and Finite Element Analysis, have improved predictive accuracy and system optimization. These combined approaches enhance the modelling of fluid-solid interactions and mechanical stresses. Future research aims to refine particle models by integrating complex behaviours, including cohesion, breakage, and shape variations. The efficiency of simulations is expected to be further enhanced through high-performance computing and emerging technologies such as quantum computing, thereby reducing computational costs. Implementing of real-time data analytics and predictive maintenance is anticipated to facilitate adaptive system control, ensuring stable and efficient operation. Cross-disciplinary collaboration is crucial for refining validation techniques and improving software accessibility, aligning DEM simulations with experimental and industrial applications. An integrated approach to studying granular flow in screw conveyors bridges theoretical and practical insights, enhancing efficiency, reliability, and the broader applicability of DEM in optimizing screw conveyor performance across industries.

{"title":"Granular flow in screw conveyors: A review of experiments and discrete element method (DEM) studies","authors":"Milada Pezo , Lato Pezo , Biljana Lončar , Predrag Kojić , Milica Ilić , Aca Jovanović","doi":"10.1016/j.powtec.2025.121040","DOIUrl":"10.1016/j.powtec.2025.121040","url":null,"abstract":"<div><div>Screw conveyors are essential in industries such as mineral processing, agriculture, chemicals, plastics, cement, and food processing, facilitating granular material transport and mixing. Despite their mechanical simplicity, the complex physics of granular flow poses challenges, including bridging, blockages, and inefficient mixing. This review examines transport mechanisms and mixing in screw conveyors through experimental studies and Discrete Element Method (DEM) simulations. DEM enables detailed analysis of particle interactions, capturing transport dynamics based on Newton's laws of motion. Key operational parameters—rotational speed, inclination angle, and fill level—significantly impact transport efficiency and mixing behaviour. Recent advancements in DEM, including integration with Computational Fluid Dynamics and Finite Element Analysis, have improved predictive accuracy and system optimization. These combined approaches enhance the modelling of fluid-solid interactions and mechanical stresses. Future research aims to refine particle models by integrating complex behaviours, including cohesion, breakage, and shape variations. The efficiency of simulations is expected to be further enhanced through high-performance computing and emerging technologies such as quantum computing, thereby reducing computational costs. Implementing of real-time data analytics and predictive maintenance is anticipated to facilitate adaptive system control, ensuring stable and efficient operation. Cross-disciplinary collaboration is crucial for refining validation techniques and improving software accessibility, aligning DEM simulations with experimental and industrial applications. An integrated approach to studying granular flow in screw conveyors bridges theoretical and practical insights, enhancing efficiency, reliability, and the broader applicability of DEM in optimizing screw conveyor performance across industries.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"459 ","pages":"Article 121040"},"PeriodicalIF":4.5,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analytical solution for the polydisperse random close packing problem in 2D

IF 4.5 2区工程技术 Q2 ENGINEERING, CHEMICAL

Powder Technology

Pub Date : 2025-04-15 DOI: 10.1016/j.powtec.2025.121008

Alessio Zaccone

An analytical theory for the random close packing density,

ϕ_{RCP}

, of polydisperse hard disks is provided using an equilibrium model of crowding (Zaccone, 2022) which has been justified on the basis of extensive numerical analysis of the maximally random jammed (MRJ) line in the phase diagram of hard spheres (Anzivino et al., 2023). The solution relies on the equations of state for the hard disk fluid and provides predictions for

ϕ_{RCP}

as a function of the ratio,

s

, of the standard deviation of the distribution of disk diameters to its mean. For a power-law size distribution with

s = 0.246

, the theory yields

ϕ_{RCP} = 0.892

, which compares well with the most recent numerical estimate

ϕ_{RCP} = 0.905

based on the Monte-Carlo swap algorithms (Ghimenti et al., 2024).

{"title":"Analytical solution for the polydisperse random close packing problem in 2D","authors":"Alessio Zaccone","doi":"10.1016/j.powtec.2025.121008","DOIUrl":"10.1016/j.powtec.2025.121008","url":null,"abstract":"<div><div>An analytical theory for the random close packing density, <span><math><msub><mrow><mi>ϕ</mi></mrow><mrow><mtext>RCP</mtext></mrow></msub></math></span>, of polydisperse hard disks is provided using an equilibrium model of crowding (Zaccone, 2022) which has been justified on the basis of extensive numerical analysis of the maximally random jammed (MRJ) line in the phase diagram of hard spheres (Anzivino et al., 2023). The solution relies on the equations of state for the hard disk fluid and provides predictions for <span><math><msub><mrow><mi>ϕ</mi></mrow><mrow><mtext>RCP</mtext></mrow></msub></math></span> as a function of the ratio, <span><math><mi>s</mi></math></span>, of the standard deviation of the distribution of disk diameters to its mean. For a power-law size distribution with <span><math><mrow><mi>s</mi><mo>=</mo><mn>0</mn><mo>.</mo><mn>246</mn></mrow></math></span>, the theory yields <span><math><mrow><msub><mrow><mi>ϕ</mi></mrow><mrow><mtext>RCP</mtext></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>892</mn></mrow></math></span>, which compares well with the most recent numerical estimate <span><math><mrow><msub><mrow><mi>ϕ</mi></mrow><mrow><mtext>RCP</mtext></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>905</mn></mrow></math></span> based on the Monte-Carlo swap algorithms (Ghimenti et al., 2024).</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"459 ","pages":"Article 121008"},"PeriodicalIF":4.5,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

GPU-DEM study of the flow and energy dissipation behaviors of burden materials in a full bell-less blast furnace charging system

IF 4.5 2区工程技术 Q2 ENGINEERING, CHEMICAL

Powder Technology

Pub Date : 2025-04-14 DOI: 10.1016/j.powtec.2025.121035

Patricio Jacobs-Capdeville , Shibo Kuang , Tim Evans , Sunny Song , Aibing Yu

The blast furnace bell-less top charging system involves multiple handling steps that affect burden distribution in the furnace throat. This study employs a GPU-DEM model to analyze particle motion and energy dissipation of burden materials from the belt conveyor to the furnace throat, providing insights into flow behavior, segregation, degradation, and erosion. Particle properties and size distributions strongly affect the flow structure. Pellets exhibit higher velocities than lumps, sinters, and coke, with differences decreasing in the rotating chute. Four regions of high energy dissipation were found, with coke and sinter degradation reaching 15 % of the feed and lump and pellet degradation remaining around 1 %. Wear intensifies with broader particle size distributions, driven by shear energy. Segregation before hopper filling is minimal, but in-hopper segregation significantly impacts in-furnace segregation, where larger particles accumulate at the periphery and top. Heap formation arises mainly from shifts between rolling and impact energy dissipation.

{"title":"GPU-DEM study of the flow and energy dissipation behaviors of burden materials in a full bell-less blast furnace charging system","authors":"Patricio Jacobs-Capdeville , Shibo Kuang , Tim Evans , Sunny Song , Aibing Yu","doi":"10.1016/j.powtec.2025.121035","DOIUrl":"10.1016/j.powtec.2025.121035","url":null,"abstract":"<div><div>The blast furnace bell-less top charging system involves multiple handling steps that affect burden distribution in the furnace throat. This study employs a GPU-DEM model to analyze particle motion and energy dissipation of burden materials from the belt conveyor to the furnace throat, providing insights into flow behavior, segregation, degradation, and erosion. Particle properties and size distributions strongly affect the flow structure. Pellets exhibit higher velocities than lumps, sinters, and coke, with differences decreasing in the rotating chute. Four regions of high energy dissipation were found, with coke and sinter degradation reaching 15 % of the feed and lump and pellet degradation remaining around 1 %. Wear intensifies with broader particle size distributions, driven by shear energy. Segregation before hopper filling is minimal, but in-hopper segregation significantly impacts in-furnace segregation, where larger particles accumulate at the periphery and top. Heap formation arises mainly from shifts between rolling and impact energy dissipation.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"459 ","pages":"Article 121035"},"PeriodicalIF":4.5,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143835387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Deep oxidation and rupture processes in the aging of boron particles by time-sequenced slicing approach

IF 4.5 2区工程技术 Q2 ENGINEERING, CHEMICAL

Powder Technology

Pub Date : 2025-04-14 DOI: 10.1016/j.powtec.2025.121033

Yuanjian Li , Li Yang , Sicheng Chen , Yi Ding , Ji-Min Han

The energy performance of boron-based energetic materials gradually deteriorates over time, primarily influenced by the formation and evolution of the oxide layer on boron particle surfaces. However, accurately characterizing the structural evolution of this oxide layer remains challenging due to its nanoscale characteristics and inward growth, thereby limiting a comprehensive understanding of the aging process. To address this, this study integrates accelerated aging experiments with micro-nanostructure processing techniques and develops a time-sequenced slicing approach for systematically analyzing the oxidation evolution of boron particles. Experimental results indicate that the growth of the boron oxide layer follows a two-stage process: an early slow-growth phase dominated by boron‑oxygen diffusion, followed by a mid-stage accelerated growth phase driven by structural degradation. The growth rate constants of these two modes differ by approximately a factor of 17.7. During oxidation, the chemical composition of boron undergoes a transformation from elemental boron to mixed boron oxides and eventually to boric acid (B → B_nO_m → H₃BO₃), leading to a decrease in surface density, an enhancement of oxidation-induced expansion, and the formation of cracks and voids. These structural changes directly influence oxidation kinetics and account for the variation in oxidation rates between the early and mid-aging stages. This study elucidates the microscopic structural evolution mechanism of boron particles under storage conditions, providing critical theoretical insights for optimizing energy performance assessment and storage stability.

{"title":"Deep oxidation and rupture processes in the aging of boron particles by time-sequenced slicing approach","authors":"Yuanjian Li , Li Yang , Sicheng Chen , Yi Ding , Ji-Min Han","doi":"10.1016/j.powtec.2025.121033","DOIUrl":"10.1016/j.powtec.2025.121033","url":null,"abstract":"<div><div>The energy performance of boron-based energetic materials gradually deteriorates over time, primarily influenced by the formation and evolution of the oxide layer on boron particle surfaces. However, accurately characterizing the structural evolution of this oxide layer remains challenging due to its nanoscale characteristics and inward growth, thereby limiting a comprehensive understanding of the aging process. To address this, this study integrates accelerated aging experiments with micro-nanostructure processing techniques and develops a time-sequenced slicing approach for systematically analyzing the oxidation evolution of boron particles. Experimental results indicate that the growth of the boron oxide layer follows a two-stage process: an early slow-growth phase dominated by boron‑oxygen diffusion, followed by a mid-stage accelerated growth phase driven by structural degradation. The growth rate constants of these two modes differ by approximately a factor of 17.7. During oxidation, the chemical composition of boron undergoes a transformation from elemental boron to mixed boron oxides and eventually to boric acid (B → B<sub>n</sub>O<sub>m</sub> → H₃BO₃), leading to a decrease in surface density, an enhancement of oxidation-induced expansion, and the formation of cracks and voids. These structural changes directly influence oxidation kinetics and account for the variation in oxidation rates between the early and mid-aging stages. This study elucidates the microscopic structural evolution mechanism of boron particles under storage conditions, providing critical theoretical insights for optimizing energy performance assessment and storage stability.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"459 ","pages":"Article 121033"},"PeriodicalIF":4.5,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143829488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0