Powder Technology最新文献

{"title":"Simulating breakage by compression of iron ore pellets using the discrete breakage model","authors":"Horacio A. Petit ,&nbsp;Alexander V. Potapov ,&nbsp;Luís Marcelo Tavares","doi":"10.1016/j.powtec.2024.120433","DOIUrl":"10.1016/j.powtec.2024.120433","url":null,"abstract":"<div><div>Simulation of breakage embedded in the discrete element method (DEM) has evolved significantly in recent years, taking advantage of both greater computing power and novel approaches that have become available in both commercial and open-source packages. This work analyzes in detail the simulation of breakage using the discrete breakage model (DBM) in the commercial software Ansys Rocky. Breakage of iron ore pellets under slow compression was studied. After the selection of suitable contact parameters for the pellets, described as polyhedral particles, the model is used to describe their breakage considering fully resolved fragments from the beginning of the simulation. The effects of contact model, time step and number of elements on the ability of the model to represent average breakage response of iron ore pellets under compression is analyzed. An approach was then used to account for the variability in the breakage characteristics of the pellets, which provided a valid description when applied to another pellet sample, also showing capability to describe the size-scale effect on the breakage energy of pellets when applied to pellets of different sizes.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"449 ","pages":"Article 120433"},"PeriodicalIF":4.5,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653935","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}

{"title":"Role of particle shape in sheared granular media: Roundness and elongation","authors":"Usman Ali,&nbsp;Mamoru Kikumoto","doi":"10.1016/j.powtec.2024.120436","DOIUrl":"10.1016/j.powtec.2024.120436","url":null,"abstract":"<div><div>Particle shape is an intrinsic characteristic of soil particles that significantly influences mechanical responses. In this investigation, a meticulously calibrated and validated two-dimensional discrete element method (DEM) model of a biaxial shearing test was employed to simulate the shearing response of forty distinct particle shapes. The systematic evolution of particle roundness (R) and aspect ratio (AR) was achieved by utilizing idealized polygonal-shaped particles, aiming to comprehend their effects on the macro and micromechanical behaviors of granular materials. The results suggest that a reduction in R limits free rotations and enhances interlocking, thereby promoting relatively stable force transmission between particles and leading to a monotonic increase in shear strength. However, this effect diminishes as particles become more elongated. Conversely, a decrease in AR from 1.0 (increased elongation) constrains particle rotations, increases the coordination number, and enhances fabric anisotropy initially resulting in increased overall shear strength, reaching a maximum before exhibiting a decreasing trend, indicative of non-monotonic variation. For high elongations, notable fabric anisotropy impedes clear force transmission between particles thus facilitating interparticle sliding and overall strength diminishes. The extent to which AR impacts depends on the angularity feature of particles. Finally, a nonlinear equation has been proposed to predict the variation in critical state shear strength of granular samples, based on the R and AR values of the constituent particles.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"449 ","pages":"Article 120436"},"PeriodicalIF":4.5,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Generalizable classification methodology for quantification of atomized feedstock powder by 3D X-ray tomography data and machine learning","authors":"Daniel R. Sinclair,&nbsp;Eshan Ganju,&nbsp;Hamidreza Torbati-Sarraf,&nbsp;Nikhilesh Chawla","doi":"10.1016/j.powtec.2024.120432","DOIUrl":"10.1016/j.powtec.2024.120432","url":null,"abstract":"<div><div>Laser powder bed fusion (LPBF) is currently being applied to manufacture engineering-crucial components. To maintain consistent part quality, accuracy and speed in the quality assurance of atomized metal feedstock powder is critical. 3D x-ray tomography (XRT), coupled with machine learning algorithms, provides a transformative route to powder characterization and classification. A recycled AA7050 feedstock powder was studied through XRT to demonstrate a scheme for classification of highly deformed particles which vary both in geometric morphology and degree of surface irregularity. Manual, unsupervised, and supervised classification algorithms were optimized to reproduce visual classification, demonstrating how different approaches to algorithm training may provide a balance between the amount of training data and acceptable final accuracy. The reported approach provides a robust methodology that links 3D measurements and powder classification as means to control powder-induced defects and improve mechanical performance in printed parts.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"451 ","pages":"Article 120432"},"PeriodicalIF":4.5,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700228","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}

{"title":"Evaluation of a new three-phase fluidised bed flotation column for industrial experiment study","authors":"Ning Han ,&nbsp;Yifei Li ,&nbsp;Zhiyuan Zhang ,&nbsp;Jikang Han ,&nbsp;Peng Chen ,&nbsp;Yanfeng Li","doi":"10.1016/j.powtec.2024.120435","DOIUrl":"10.1016/j.powtec.2024.120435","url":null,"abstract":"<div><div>Three-phase fluidized bed flotation column (TFC) is a new type of separation flotation method with high efficiency and low energy consumption. In this paper, the industrial experimental effect of TFC is investigated. The influence of operating parameters on the flotation separation effect was investigated by adjusting the operating parameters such as gas velocity, liquid velocity, and bed height. In addition, when the sampling depth and sampling radius are increased, the ash content in the selection zone increases with it. The relationship between the amount of mid-coal circulation and the ash content was also investigated. The ash content of refined coal gradually decreased from 10.28 % to 9.28 % when the amount of middle coal circulating was increased from 0 % to 50 % of the feed. This study explores the separation effect of TFC from industrial experiment perspective, which lays a good foundation for future industrial-scale applications.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"449 ","pages":"Article 120435"},"PeriodicalIF":4.5,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654000","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}

{"title":"The effect of impeller speeds on the nanobubbles flotation efficiency of ultrafine coal particles","authors":"Hanyue Jiang ,&nbsp;Haichang Yang ,&nbsp;Yaowen Xing ,&nbsp;Yijun Cao ,&nbsp;Xiahui Gui","doi":"10.1016/j.powtec.2024.120431","DOIUrl":"10.1016/j.powtec.2024.120431","url":null,"abstract":"<div><div>Ultrafine particles exhibit poor flotation behavior due to the low collision efficiencies with conventional gas bubbles. Introducing nanobubbles are expected to improve the collision probability of ultra-fine particles with bubbles. However, it remains unclear whether nanobubbles can enhance flotation at high impeller speeds during flotation process as strong turbulence may scour away the nanobubbles from solid-liquid interface of particles. This study investigates the influence and the underlying mechanism of nanobubbles on flotation performance of ultrafine coal particles under varying impeller speeds. Specifically, the surface nanobubbles (SNBs) and bulk nanobubbles (BNBs) were utilized respectively, which were produced based on the temperature difference method and hydrodynamic cavitation, and characteristized by atomic force microscopy (AFM) and nanoparticle tracking analysis (NTA), respectively. The formation of ultrafine coal particle aggregates at different impeller speeds was analyzed through laser particle size analyzer (LPSA) and high-speed camera imaging. Result showed that as the impeller speed increases, the radius of the aggregates increases, and the number and radius of aggregates in SNBs/BNBs slurries is significantly larger than that in conventional slurry at varying impeller speeds from 1200 to 2800 rpm, which is consistent with the increased flotation recoveries and flotation rates. It is demonstrated that nanobubbles remain stable even at high impeller speeds, and thus promote aggregation and thereby enhance flotation performance. The findings of this study provide theoretical support and valuable insights for ultrafine particle separation technologies.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"449 ","pages":"Article 120431"},"PeriodicalIF":4.5,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653857","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}

{"title":"Numerical investigation on compaction operations of railway gravel ballast based on DEM-MBD coupling method","authors":"Zhihai Zhang ,&nbsp;Hong Xiao ,&nbsp;Qiang Liu ,&nbsp;Yang Wang ,&nbsp;Zhongxia Qian ,&nbsp;Mahantesh M. Nadakatti","doi":"10.1016/j.powtec.2024.120428","DOIUrl":"10.1016/j.powtec.2024.120428","url":null,"abstract":"<div><div>Compaction is an essential process in the maintenance of ballasted railways. However, unreasonable operating parameters can reduce compaction efficiency and increase maintenance costs. Previous studies have hardly addressed the impact of compaction on improving the mechanical properties of the ballast bed. In the study, the dynamic equations of compaction are established, and a novel model of compaction based on DEM-MBD coupling method is developed. Furthermore, the parameters of the compaction are optimized from a macro and micro perspective. The research results show that the compaction mainly increases the coordination number of the ballast in the upper area of the ballast shoulder, and the maximum growth rate is 17.45 %. The study reveals that there is no positive correlation between the compacting effect and the excitation frequency. The optimal frequency range for compaction is 25–32 Hz. This study can provide key theoretical support for the parameter selection of on-site compaction for line maintenance.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"449 ","pages":"Article 120428"},"PeriodicalIF":4.5,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653999","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}

{"title":"CFD-DEM simulation study on the bed dynamics of a binary mixture with super-quadric particles in a fluidized bed","authors":"Ju Wang ,&nbsp;Guirong Bao","doi":"10.1016/j.powtec.2024.120425","DOIUrl":"10.1016/j.powtec.2024.120425","url":null,"abstract":"<div><div>In biomass thermal conversion processes such as pyrolysis and gasification, biomass often takes on a cylindrical shape. However, most previous studies have modeled biomass as spherical, leaving the fluidization and mixing behaviors of non-spherical biomass particles with approximately spherical bed materials insufficiently explored. To bridge this gap, a super-quadratic particle model coupled with CFD-DEM was used to explore the fluidization characteristics and mixing dynamics of non-spherical binary mixtures. The numerical model successfully validated the pressure drop and spatial distribution within the binary mixture. The results indicate that particle mixing is primarily driven by the rise and movement of bubbles. The large aspect ratio of the cylindrical particles, combined with the narrow thickness of the 2D rectangular fluidized bed, leads to a significant interlocking effect during fluidization. This interlocking hinders both fluidization and mixing, resulting in poor overall performance for non-spherical particles. At a low superficial velocity (<em>U</em>_<em>g</em>), only the cylindrical particles in the lower part are fluidized as a result of the rising central bubble. The two particle types achieve effective mixing as the <em>U</em>_<em>g</em> rises to a high value. The mixing index increases from 0.78 to 0.94 as the <em>U</em>_<em>g</em> increases from 1.8 to 2.1 m/s. However, the stacking pattern of cylindrical particles creates a dead zone at the bed bottom, occupied solely by spherical particles, which limits local bed mixing and fluidization. As the <em>U</em>_<em>g</em> increases from 1.8 to 2.1 m/s and the dimensionless inventory height increases from 0.6 to 1.0, the axial dispersion coefficient of the cylinders increases from 1.17<span><math><mo>×</mo></math></span>10⁻³ to 4.35<span><math><mo>×</mo></math></span>10⁻³ m²/s and from 1.91<span><math><mo>×</mo></math></span>10⁻³ to 9.22<span><math><mo>×</mo></math></span>10⁻³ m²/s, respectively. This study provides new insights into the behavior of non-spherical particles, offering potential avenues for optimizing chemical engineering processes.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"449 ","pages":"Article 120425"},"PeriodicalIF":4.5,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654001","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}

{"title":"Characteristics of powder charging behavior via forced triboelectric charging on an inclined chute","authors":"Mehran Javadi,&nbsp;Mohamed Abohelwa,&nbsp;Annett Wollmann,&nbsp;Alfred P. Weber","doi":"10.1016/j.powtec.2024.120400","DOIUrl":"10.1016/j.powtec.2024.120400","url":null,"abstract":"<div><div>This study presents a novel method for selective charging of powders by dry triboelectric forced charging utilized as the first stage of material sorting in an electric field. In forced triboelectric charging, a high voltage is applied to the copper chute in which particles are charged during their transportation. In this research, the effect of the operating parameters of the chute, including mass flow rate, angle of inclination, and length, on the specific particle charge of limestone powders was investigated. In addition, the behavior of the charged particles in an electrostatic sorter was analyzed by evaluating their charge distribution after sorting. The results reveal that as the length of the chute increases, the specific charge asymptotically approaches a saturation value, which is determined by the high voltage applied. Furthermore, for a given chute length, the high voltage influences the amount and the sign of the specific particle charge, including a high voltage value at which the particles are neutral on average, i.e., the so-called point of zero net charge (PZNC). This PZNC is of particular interest for sorting out a target component from a powder mixture. However, if the mass flow rate is increased above a certain value, the specific charge decreases as the number of particle wall contacts is reduced due to stratification. Bipolar charge distributions were observed for all investigated high voltages, with the distribution width increasing with particle size to the power of 2.1. The modal value of the charge distribution shifts according to the difference in voltage applied to the PZNC.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"449 ","pages":"Article 120400"},"PeriodicalIF":4.5,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on the design load of the flights of a rotary kiln based on thermal granular flow coupling","authors":"Yuan Chen ,&nbsp;Zhongliang Gong ,&nbsp;Jiantao Yu ,&nbsp;Yuhui Li ,&nbsp;Lincheng Luo ,&nbsp;Dan Huang","doi":"10.1016/j.powtec.2024.120430","DOIUrl":"10.1016/j.powtec.2024.120430","url":null,"abstract":"<div><div>The rotary kilns are widely used in chemical, food and metallurgical industries, and the design load of the internal flights has a significant effect on the drying efficiency of the rotary kilns. The motion of granular flow and heat absorption process inside the rotary kilns were simulated by establishing a coupled CFD and DEM model. The average heat absorption rate of granules was proposed to simulate the “L” type and three segments flights, and the results showed that the average heat absorption rate of granules was in accordance with the conclusions of previous scholars. We used the average heat absorption method of granules to optimize the structural parameters of the “J” type flights design load, the best parameter was obtained, and then compared with the “L” type and three segments of the flights, we found that the drying efficiency of “J” type flights is the best, followed by three segments and “L” type is found to be the worst. At the same time, the active region was divided to explore the relationship between the area occupied by the granules in different regions and the average heat absorption rate of granules, and it was found that under the same shape of the flights, the larger the area occupied by the granules in region 2, the larger the corresponding average heat absorption rate of granules.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"449 ","pages":"Article 120430"},"PeriodicalIF":4.5,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654004","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}

{"title":"A novel mesh algorithm to improve the packing efficiency of irregular-shaped particles in simulating cement paste's microstructure","authors":"Peng Gao ,&nbsp;Hongjie Liu ,&nbsp;Jingzhe Li ,&nbsp;Yang Yu ,&nbsp;Faquan Xie ,&nbsp;Haijun Lu ,&nbsp;Yanbo Hu ,&nbsp;Yonggan Yang ,&nbsp;Binggen Zhan ,&nbsp;Qijun Yu","doi":"10.1016/j.powtec.2024.120415","DOIUrl":"10.1016/j.powtec.2024.120415","url":null,"abstract":"<div><div>Irregular-shaped particle packing is important to simulate the cement paste microstructure. However, the efficiency of current packing models is relatively low. This study proposes a novel packing algorithm named the Mesh Optimization Packing (MOP) model inspired by the VOX and extent overlap box (EOB) methods. The MOP model's performance in terms of accuracy, uniformity, and randomness were evaluated. Meanwhile, compared to the Anm model 2.0 and the VOX model, the MOP model excels in simulating the initial microstructure of cement paste with high cement volume fractions. When the cement volume fraction is 56.03 %, the VOX model requires 124.68 h, while the MOP model only takes 18.80 h. By adding uniform-thickness shells to irregular-shaped particles, the MOP model integrates with the HYMOSTRUC3D-E model to simulate the evolution and uniaxial stretching process of the cement paste microstructure. This innovative modelling approach offers a promising solution for future simulations of cement paste microstructure.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"449 ","pages":"Article 120415"},"PeriodicalIF":4.5,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142654003","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}