Pub Date : 2025-01-10DOI: 10.1016/j.powtec.2025.120618
Langdon Feltner, Donovan Stumpf, Paul Mort
Particle size and shape distributions affect many aspects of powder processing; for example, shape and contact curvature are fundamental to the mechanics of powder spreading, packing, and sintering in powder-bed additive manufacturing. In this paper, we revisit the use of Fourier transforms for detailed shape characterization, including local curvature of particle perimeters and distributions thereof. Fourier transforms describe particles as symbolic functions that are differentiable, enabling direct mapping of curvature. Dynamic image analysis was used to collect 2D particle images of fine metal powders. Two types were compared, one made by gas atomization, and the other by a cold mechanical size reduction process, both suitable for additive manufacturing using laser powder-bed fusion. Global distributions in shape factors including contact curvature were analyzed. Results suggest the utility of curvature distributions as a unique and differentiating shape characteristic.
{"title":"On the use of the Fourier transform to determine contact curvature distributions in additive manufacturing powders","authors":"Langdon Feltner, Donovan Stumpf, Paul Mort","doi":"10.1016/j.powtec.2025.120618","DOIUrl":"10.1016/j.powtec.2025.120618","url":null,"abstract":"<div><div>Particle size and shape distributions affect many aspects of powder processing; for example, shape and contact curvature are fundamental to the mechanics of powder spreading, packing, and sintering in powder-bed additive manufacturing. In this paper, we revisit the use of Fourier transforms for detailed shape characterization, including local curvature of particle perimeters and distributions thereof. Fourier transforms describe particles as symbolic functions that are differentiable, enabling direct mapping of curvature. Dynamic image analysis was used to collect 2D particle images of fine metal powders. Two types were compared, one made by gas atomization, and the other by a cold mechanical size reduction process, both suitable for additive manufacturing using laser powder-bed fusion. Global distributions in shape factors including contact curvature were analyzed. Results suggest the utility of curvature distributions as a unique and differentiating shape characteristic.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"453 ","pages":"Article 120618"},"PeriodicalIF":4.5,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143157414","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}
Pub Date : 2025-01-10DOI: 10.1016/j.powtec.2025.120648
Charles E. Collins , Massih Pasha , Timothy A. Bell
In this study, complete bulk property characterization data was assembled for a collection of 28 materials of widely differing particle and bulk properties. Their FFC, internal friction angles, wall friction angles, and bulk density were all shown to vary as major principal stresses were increased to 30kPa and beyond, indicating the general inaccuracy of the use of a single parameter to summarize them. The practical significance on benchmarking was evaluated through inter- and intra-material comparisons of common flowability metrics including critical rathole diameter, critical mass flow angle, and FFC. These metrics were found to be sensitive to their method of calculation and inconsistent in their relationship to each other.
Legacy of Reg Davies
Reg Davies was an inspiring leader in the field of particle technology, and a passionate advocate for education, networking, and the development of people working in the field. All three of the authors of this paper were affected by him. Charles Collins is a graduate of the Masters program in particle technology at the University of Delaware. That program was created, in part, as a response to Reg's effective advocacy for academic training in the field. Massih Pasha came to DuPont (and subsequently Chemours) via the relationship between Reg's particle technology group at DuPont (PARSAT) and the faculty of the University of Leeds. Tim Bell was already working for DuPont when the PARSAT group was formed, but his transfer into PARSAT, and Reg's kind and thoughtful support, provided wonderful career opportunities. We are all in Reg's debt.
{"title":"The impact of simplification on the accuracy and benchmarking of powder flowability measurements","authors":"Charles E. Collins , Massih Pasha , Timothy A. Bell","doi":"10.1016/j.powtec.2025.120648","DOIUrl":"10.1016/j.powtec.2025.120648","url":null,"abstract":"<div><div>In this study, complete bulk property characterization data was assembled for a collection of 28 materials of widely differing particle and bulk properties. Their FF<sub>C</sub>, internal friction angles, wall friction angles, and bulk density were all shown to vary as major principal stresses were increased to 30kPa and beyond, indicating the general inaccuracy of the use of a single parameter to summarize them. The practical significance on benchmarking was evaluated through inter- and intra-material comparisons of common flowability metrics including critical rathole diameter, critical mass flow angle, and FF<sub>C</sub>. These metrics were found to be sensitive to their method of calculation and inconsistent in their relationship to each other.</div></div><div><h3>Legacy of Reg Davies</h3><div>Reg Davies was an inspiring leader in the field of particle technology, and a passionate advocate for education, networking, and the development of people working in the field. All three of the authors of this paper were affected by him. Charles Collins is a graduate of the Masters program in particle technology at the University of Delaware. That program was created, in part, as a response to Reg's effective advocacy for academic training in the field. Massih Pasha came to DuPont (and subsequently Chemours) via the relationship between Reg's particle technology group at DuPont (PARSAT) and the faculty of the University of Leeds. Tim Bell was already working for DuPont when the PARSAT group was formed, but his transfer into PARSAT, and Reg's kind and thoughtful support, provided wonderful career opportunities. We are all in Reg's debt.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"453 ","pages":"Article 120648"},"PeriodicalIF":4.5,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143156890","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}
Pub Date : 2025-01-09DOI: 10.1016/j.powtec.2025.120635
Vahid Delavari , Mohammad Rahmani
Gamma alumina possesses exceptional catalytic properties, making it a highly sought-after material in various industrial applications. The ability to control the size, shape, and morphology of these particles is crucial for optimizing their performance. The oil-drop method offers a promising technique for the synthesis of uniform and spherical particles. This research aims to enhance the understanding of the oil-drop method through a combined approach of numerical simulations and experimental validations. The results obtained from this study will contribute to the development of advanced techniques for the preparation of tailored gamma alumina macro particles with improved catalytic performance. Using Computational Fluid Dynamics (CFD) minimizes experimental time and costs by accounting for the process's physical dynamics and the characteristics of the liquid systems. This allows for precise control over the mixing and droplet formation processes. The results show that using this method, particles with a relatively narrow size distribution can be produced, allowing for the regulation of mean particle size and sphericity. After designing the experiment and conducting the modeling process, the objective is to achieve a droplet diameter of 1.8 mm and a maximum sphericity of 1.01. In order to meet these specific targets, it is necessary to adjust the effective parameters accordingly. The oil density should be set to 689.9 kg/m3, the oil viscosity to 0.02816 Pa.s, the sol density to 1194 kg/m3, the sol viscosity to 0.2412 Pa.s, the interfacial tension coefficient to 0.026 N/m, the contact angle to 2.4137 rad, and the injection speed to 0.0046 m/s.
{"title":"Numerical and experimental investigation of gamma alumina macro particle synthesis via the oil-drop method","authors":"Vahid Delavari , Mohammad Rahmani","doi":"10.1016/j.powtec.2025.120635","DOIUrl":"10.1016/j.powtec.2025.120635","url":null,"abstract":"<div><div>Gamma alumina possesses exceptional catalytic properties, making it a highly sought-after material in various industrial applications. The ability to control the size, shape, and morphology of these particles is crucial for optimizing their performance. The oil-drop method offers a promising technique for the synthesis of uniform and spherical particles. This research aims to enhance the understanding of the oil-drop method through a combined approach of numerical simulations and experimental validations. The results obtained from this study will contribute to the development of advanced techniques for the preparation of tailored gamma alumina macro particles with improved catalytic performance. Using Computational Fluid Dynamics (CFD) minimizes experimental time and costs by accounting for the process's physical dynamics and the characteristics of the liquid systems. This allows for precise control over the mixing and droplet formation processes. The results show that using this method, particles with a relatively narrow size distribution can be produced, allowing for the regulation of mean particle size and sphericity. After designing the experiment and conducting the modeling process, the objective is to achieve a droplet diameter of 1.8 mm and a maximum sphericity of 1.01. In order to meet these specific targets, it is necessary to adjust the effective parameters accordingly. The oil density should be set to 689.9 kg/m3, the oil viscosity to 0.02816 Pa.s, the sol density to 1194 kg/m3, the sol viscosity to 0.2412 Pa.s, the interfacial tension coefficient to 0.026 N/m, the contact angle to 2.4137 rad, and the injection speed to 0.0046 m/s.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"453 ","pages":"Article 120635"},"PeriodicalIF":4.5,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143157397","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}
Pub Date : 2025-01-09DOI: 10.1016/j.powtec.2025.120646
Haiming Yu , Yaowen Zhang , Yao Xie , Sen Xie , Peibei Wang
For the problem of serious dust pollution in the workface of integrated mechanized coal mining, this study proposes a new type of local negative pressure sealing dust prevention method. On account of the CFD-DPM approach, mechanisms of the impact of using a new method on dust pollution in diverse situations was studied. This study analyzed the diffusion of diverse sizes of dust. The results show that in the control group, the maximal dust loading in the footwalk void was above 500 mg/m3. During the coal cutting under a downwind or upwind situation, the cross-sectional size of the roadway where airflow passes through and the location of the coal mining wall altered, which resulted in a variation of the entering position and volume of the drum airflow into the footwalk void, thereby affecting the diffusion of dust. After using the new approach, under the downwind condition, the average value of dust load at the elevation of respiratory area in the footwalk void decreased by 93.2 %; under the upwind condition, the dust loading in the footwalk void should be controlled below 50.0 mg/m3. At an intake air speed of 1.5 m/s, the dust loading at the elevation of the pedestrian respiratory area is less than 156.6 mg/m3. The reduction in large particle dust reached 89 %, providing an innovative idea for coal mining operation dust reduction.
{"title":"Dust removal method for open space of fully mechanized mining face: A cutting area pressure balance method","authors":"Haiming Yu , Yaowen Zhang , Yao Xie , Sen Xie , Peibei Wang","doi":"10.1016/j.powtec.2025.120646","DOIUrl":"10.1016/j.powtec.2025.120646","url":null,"abstract":"<div><div>For the problem of serious dust pollution in the workface of integrated mechanized coal mining, this study proposes a new type of local negative pressure sealing dust prevention method. On account of the CFD-DPM approach, mechanisms of the impact of using a new method on dust pollution in diverse situations was studied. This study analyzed the diffusion of diverse sizes of dust. The results show that in the control group, the maximal dust loading in the footwalk void was above 500 mg/m<sup>3</sup>. During the coal cutting under a downwind or upwind situation, the cross-sectional size of the roadway where airflow passes through and the location of the coal mining wall altered, which resulted in a variation of the entering position and volume of the drum airflow into the footwalk void, thereby affecting the diffusion of dust. After using the new approach, under the downwind condition, the average value of dust load at the elevation of respiratory area in the footwalk void decreased by 93.2 %; under the upwind condition, the dust loading in the footwalk void should be controlled below 50.0 mg/m<sup>3</sup>. At an intake air speed of 1.5 m/s, the dust loading at the elevation of the pedestrian respiratory area is less than 156.6 mg/m<sup>3</sup>. The reduction in large particle dust reached 89 %, providing an innovative idea for coal mining operation dust reduction.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"453 ","pages":"Article 120646"},"PeriodicalIF":4.5,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143100797","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}
Pub Date : 2025-01-09DOI: 10.1016/j.powtec.2025.120636
Lina Cayla Arianer , Mikel Leturia , Anne-Charlotte Robisson , Carine Ablitzer , Elias Daouk , Khashayar Saleh
This study focuses on the use of correlation matrices as a tool to investigate the relationship between the physical characteristics of powders and their flowability. The correlation coefficients are calculated for a dataset containing various types of powders, allowing the study of the influence of particle size, morphology and density on flow properties. Flowability is estimated through various tests such as the shear test, density ratio, powder rheometer and rotating drum. The analysis revealed that correlations between flowability indices are not strictly associated with specific flow regimes (quasi-static and dense regimes). Instead, the physical mechanisms of interparticle cohesion and friction appear to play a determinant role in these correlations. Further analysis involving the division of the dataset into fine and coarse powders provided additional insights, underscoring the different mechanisms governing the flow behavior of cohesive and non-cohesive powders. In a second step, this research work also incorporated data from existing literature, confirming the general trends observed with the initial dataset. Future research should focus on developing more sophisticated models that can account for multiple input parameters simultaneously and consider non-linear relationships, for example, through semi-empirical models or machine learning techniques.
{"title":"Assessment of the influence of model powder characteristics on their flowability using correlation matrices","authors":"Lina Cayla Arianer , Mikel Leturia , Anne-Charlotte Robisson , Carine Ablitzer , Elias Daouk , Khashayar Saleh","doi":"10.1016/j.powtec.2025.120636","DOIUrl":"10.1016/j.powtec.2025.120636","url":null,"abstract":"<div><div>This study focuses on the use of correlation matrices as a tool to investigate the relationship between the physical characteristics of powders and their flowability. The correlation coefficients are calculated for a dataset containing various types of powders, allowing the study of the influence of particle size, morphology and density on flow properties. Flowability is estimated through various tests such as the shear test, density ratio, powder rheometer and rotating drum. The analysis revealed that correlations between flowability indices are not strictly associated with specific flow regimes (quasi-static and dense regimes). Instead, the physical mechanisms of interparticle cohesion and friction appear to play a determinant role in these correlations. Further analysis involving the division of the dataset into fine and coarse powders provided additional insights, underscoring the different mechanisms governing the flow behavior of cohesive and non-cohesive powders. In a second step, this research work also incorporated data from existing literature, confirming the general trends observed with the initial dataset. Future research should focus on developing more sophisticated models that can account for multiple input parameters simultaneously and consider non-linear relationships, for example, through semi-empirical models or machine learning techniques.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"453 ","pages":"Article 120636"},"PeriodicalIF":4.5,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143157413","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}
Regulating the structure of energetic materials to enhance safety performance has become a hot topic for researchers in recent years. This study prepared spherical co-aggregated CL-20/HMX with controllable microstructure using a combination of microfluidic and self-assembly strategies within a modular micro-reaction system. The morphology and agglomeration structures of CL-20/HMX particles were investigated with different mixing plates, solvent/nonsolvent flow rate ratio, and solvent content. Spherical co-aggregated CL-20/HMX co-crystals were prepared under optimized conditions, and the formation mechanism was analyzed. The impact of the spherical aggregation structure on the thermal properties and mechanical sensitivity was thoroughly studied. The results indicate that the spherical co-aggregated CL-20/HMX was assembled from lamellar nanoparticles, controlling CL-20 crystal morphology at the molecular level. CL-20/HMX co-aggregated microspheres exhibit higher mechanical safety and thermal stability than conventional reaction samples and physical mixing samples. Combining spherical aggregation structures and a microfluidic approach enhances thermal decomposition stability and improves safety. This research offers a novel strategy for developing and fabricating other energetic materials.
{"title":"Preparation of microstructure controlled spherical co-aggregated composite energetic materials: Synergistic enhancement of safety and thermal stability of CL-20","authors":"Wenyu Wu, Wenjie Liu, Meijie Li, Penglin Kang, Dongqian Fan, Xiaodong Li, Shuangqi Hu","doi":"10.1016/j.powtec.2025.120634","DOIUrl":"10.1016/j.powtec.2025.120634","url":null,"abstract":"<div><div>Regulating the structure of energetic materials to enhance safety performance has become a hot topic for researchers in recent years. This study prepared spherical co-aggregated CL-20/HMX with controllable microstructure using a combination of microfluidic and self-assembly strategies within a modular micro-reaction system. The morphology and agglomeration structures of CL-20/HMX particles were investigated with different mixing plates, solvent/nonsolvent flow rate ratio, and solvent content. Spherical co-aggregated CL-20/HMX co-crystals were prepared under optimized conditions, and the formation mechanism was analyzed. The impact of the spherical aggregation structure on the thermal properties and mechanical sensitivity was thoroughly studied. The results indicate that the spherical co-aggregated CL-20/HMX was assembled from lamellar nanoparticles, controlling CL-20 crystal morphology at the molecular level. CL-20/HMX co-aggregated microspheres exhibit higher mechanical safety and thermal stability than conventional reaction samples and physical mixing samples. Combining spherical aggregation structures and a microfluidic approach enhances thermal decomposition stability and improves safety. This research offers a novel strategy for developing and fabricating other energetic materials.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"453 ","pages":"Article 120634"},"PeriodicalIF":4.5,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143156147","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}
Pub Date : 2025-01-08DOI: 10.1016/j.powtec.2025.120629
Bin Wang, Jiahan Wang, Qinghong Cao
The three-electrode electrostatic precipitator (ESP) is a potentially effective purification technology for removing suspended particulate matter. In order to enhance the efficiency in the three-electrode ESP, a magnetic field was introduced, a theoretical coupling model was created for multiple physical fields, and the electromagnetic confinement effect in the ESP at various flue gas velocities and working voltages was simulated and analyzed using CFD software. Based on this, the electromagnetic confinement removal mechanism of PM2.5 is studied. The findings of the research demonstrate that the electromagnetic confinement effect can enhance the three-electrode ESP's capacity to remove dust, particularly when it comes to small-sized particle removal. When the voltage and velocity decrease, the electromagnetic confinement effect increases. The effectiveness of ESP dust removal steadily declines with rising voltage and velocity as the magnetic induction intensity rises. The findings of the research offer experimental evidence and theoretical backing for enhancing the three-electrode ESP's performance.
{"title":"Effect of electromagnetic confinement on three-electrode ESP dust-removal performance at various operating parameters","authors":"Bin Wang, Jiahan Wang, Qinghong Cao","doi":"10.1016/j.powtec.2025.120629","DOIUrl":"10.1016/j.powtec.2025.120629","url":null,"abstract":"<div><div>The three-electrode electrostatic precipitator (ESP) is a potentially effective purification technology for removing suspended particulate matter. In order to enhance the efficiency in the three-electrode ESP, a magnetic field was introduced, a theoretical coupling model was created for multiple physical fields, and the electromagnetic confinement effect in the ESP at various flue gas velocities and working voltages was simulated and analyzed using CFD software. Based on this, the electromagnetic confinement removal mechanism of PM2.5 is studied. The findings of the research demonstrate that the electromagnetic confinement effect can enhance the three-electrode ESP's capacity to remove dust, particularly when it comes to small-sized particle removal. When the voltage and velocity decrease, the electromagnetic confinement effect increases. The effectiveness of ESP dust removal steadily declines with rising voltage and velocity as the magnetic induction intensity rises. The findings of the research offer experimental evidence and theoretical backing for enhancing the three-electrode ESP's performance.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"453 ","pages":"Article 120629"},"PeriodicalIF":4.5,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143156150","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}
Pub Date : 2025-01-08DOI: 10.1016/j.powtec.2025.120637
Robert J. Macías , Juan C. Maya , Farid Chejne , Carlos M. Ceballos , Andrés F. Gómez
This work proposes a new scaling strategy for bubbling fluidized bed reactors. It is based on bubble size distribution, bubble coalescence phenomenon, and chemical reactivity, thus allowing us to deduct the dimensionless number which must remain around 0.45 at different scales to guarantee the fluidization regime. The proposed strategy is validated through computational simulations carried out under various operating conditions. Additionally, the limits for this scaling strategy to be valid were determined; they agree with those reported in the literature.
{"title":"A new scaling strategy for bubbling fluidized bed reactors based on population-balance model","authors":"Robert J. Macías , Juan C. Maya , Farid Chejne , Carlos M. Ceballos , Andrés F. Gómez","doi":"10.1016/j.powtec.2025.120637","DOIUrl":"10.1016/j.powtec.2025.120637","url":null,"abstract":"<div><div>This work proposes a new scaling strategy for bubbling fluidized bed reactors. It is based on bubble size distribution, bubble coalescence phenomenon, and chemical reactivity, thus allowing us to deduct the dimensionless number <span><math><mi>Φ</mi><mo>,</mo></math></span> which must remain around 0.45 at different scales to guarantee the fluidization regime. The proposed strategy is validated through computational simulations carried out under various operating conditions. Additionally, the limits for this scaling strategy to be valid were determined; they agree with those reported in the literature.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"453 ","pages":"Article 120637"},"PeriodicalIF":4.5,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143100449","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}
Pub Date : 2025-01-08DOI: 10.1016/j.powtec.2025.120622
Wan Dai , Guoping Qian , Huanan Yu , Jinguo Ge , Yixiong Zhong , Chao Zhang , Hongyu Zhou
This research analyzed the characteristics of aggregate contact chain networks based on complex network theory. The contact chain network was extracted using Digital Image Processing (DIP) technology and Three-Dimensional (3D) reconstruction technology. The change rule of the contact chain network of asphalt mixture was analyzed using the complex network theory. From the results of the analysis, the filling particles existed during the compaction. The 4.75–9.5 mm and 9.5–13.2 mm aggregates may rotate to increase the stability of the skeleton structure. The clustering coefficient of the aggregate increased as the asphalt mixture was compacted, and the aggregate with a small size had a larger clustering coefficient. The distribution of shortest path length in each compaction stage obeyed the Gaussian distribution. The average shortest path length decreased with the increase of the compactness of the specimen, indicating that there was a good correlation between shortest path length and compactness.
{"title":"Characterization of contact chain network for asphalt mixture compaction process based on complex network theory","authors":"Wan Dai , Guoping Qian , Huanan Yu , Jinguo Ge , Yixiong Zhong , Chao Zhang , Hongyu Zhou","doi":"10.1016/j.powtec.2025.120622","DOIUrl":"10.1016/j.powtec.2025.120622","url":null,"abstract":"<div><div>This research analyzed the characteristics of aggregate contact chain networks based on complex network theory. The contact chain network was extracted using Digital Image Processing (DIP) technology and Three-Dimensional (3D) reconstruction technology. The change rule of the contact chain network of asphalt mixture was analyzed using the complex network theory. From the results of the analysis, the filling particles existed during the compaction. The 4.75–9.5 mm and 9.5–13.2 mm aggregates may rotate to increase the stability of the skeleton structure. The clustering coefficient of the aggregate increased as the asphalt mixture was compacted, and the aggregate with a small size had a larger clustering coefficient. The distribution of shortest path length in each compaction stage obeyed the Gaussian distribution. The average shortest path length decreased with the increase of the compactness of the specimen, indicating that there was a good correlation between shortest path length and compactness.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"453 ","pages":"Article 120622"},"PeriodicalIF":4.5,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143157394","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}
Pub Date : 2025-01-07DOI: 10.1016/j.powtec.2025.120632
Quanhong Zhu, Hao Guan, Donghui Liu, Yalong Cao, Hongbing Song
For coal dry beneficiation in air-fluidized beds, the sorted gangue particles can be discharged continuously from a side orifice underneath the gas distributor. The mass discharge rate (qm) was found to decrease with lo (orifice length) increasing from 0.003 to 0.010 m. The Beverloo equation worked well in correlating qm and do (orifice diameter) at all levels of lo. The independence of C and k on do was demonstrated by good linearity between and do. C was fitted as ∼0.20, irrelevant to lo or particle type. k was derived as >10, differing significantly from <2 for bottom orifices. The greater k was revealed to arise from a thick region with retarded particle flow at bottom of side orifices. Such a stagnant zone also explained why k increased with increasing lo and ρb (bulk density) or decreasing dp (particle size). lo is promising for adjusting qm and exploring the clogging/jamming phenomenon.
{"title":"Gravitational discharge of packed particles through side orifices with different lengths for continuous dry beneficiation of raw coal in fluidized beds","authors":"Quanhong Zhu, Hao Guan, Donghui Liu, Yalong Cao, Hongbing Song","doi":"10.1016/j.powtec.2025.120632","DOIUrl":"10.1016/j.powtec.2025.120632","url":null,"abstract":"<div><div>For coal dry beneficiation in air-fluidized beds, the sorted gangue particles can be discharged continuously from a side orifice underneath the gas distributor. The mass discharge rate (<em>q</em><sub>m</sub>) was found to decrease with <em>l</em><sub>o</sub> (orifice length) increasing from 0.003 to 0.010 m. The Beverloo equation worked well in correlating <em>q</em><sub>m</sub> and <em>d</em><sub>o</sub> (orifice diameter) at all levels of <em>l</em><sub>o</sub>. The independence of <em>C</em> and <em>k</em> on <em>d</em><sub>o</sub> was demonstrated by good linearity between <span><math><msubsup><mi>q</mi><mi>m</mi><mn>0.25</mn></msubsup></math></span>and <em>d</em><sub>o</sub>. <em>C</em> was fitted as ∼0.20, irrelevant to <em>l</em><sub>o</sub> or particle type. <em>k</em> was derived as >10, differing significantly from <2 for bottom orifices. The greater <em>k</em> was revealed to arise from a thick region with retarded particle flow at bottom of side orifices. Such a stagnant zone also explained why <em>k</em> increased with increasing <em>l</em><sub>o</sub> and <em>ρ</em><sub>b</sub> (bulk density) or decreasing <em>d</em><sub>p</sub> (particle size). <em>l</em><sub>o</sub> is promising for adjusting <em>q</em><sub>m</sub> and exploring the clogging/jamming phenomenon.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"453 ","pages":"Article 120632"},"PeriodicalIF":4.5,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143156149","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}
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