Powder Technology最新文献

{"title":"Discrete element simulation of dry adhesive granular flow in a vertical pipe","authors":"Xin Gao ,&nbsp;Eric J.R. Parteli ,&nbsp;Fengxian Fan","doi":"10.1016/j.powtec.2025.121079","DOIUrl":"10.1016/j.powtec.2025.121079","url":null,"abstract":"<div><div>The transportation and storage of granular materials with adhesive properties often involves particulate flow through narrow pipes, which is accompanied by still poorly understood dynamic behavior. Due to the difficulty in achieving a quantitative understanding of such flows based solely on experiments, here we perform particle-based numerical simulations of vertical pipe flows of adhesive granular materials using the discrete element method (DEM). Our simulations unveil different regimes of vertical pipe flow depending on the pipe-to-particle diameter ratio and the interparticle adhesive strength. Surprisingly, we find that the particle mass flow rate through the pipe increases substantially with this adhesive strength. This rather counterintuitive result is caused by an enhanced tendency of the particles to form stable agglomerates around the pipe symmetry axis, thus leading to reduced interaction of the particles with the frictional pipe walls. By contrast, incorporation of particle-wall adhesive interactions leads to exactly the opposite behavior, with such interactions dictating the granular dynamics in the pipe and leading to lower mass flow rate values compared to cohesionless flows. Furthermore, we show that the different flow regimes are associated with distinct spatiotemporal patterns of the granular solid fraction along the pipe axis (density waves). Therefore, our results provide theoretical references for future experimental research and application of adhesive granular flows through narrow pipes.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"460 ","pages":"Article 121079"},"PeriodicalIF":4.5,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143898693","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":"Corrigendum to “Capture characteristics comparison between magnetic and non-magnetic particles in centrifugal dry magnetic separation” [Powder Technology 458 (2025) 121005]","authors":"Xiaoqian Liu ,&nbsp;Luzheng Chen ,&nbsp;Xiangjun Ren ,&nbsp;Fan Yi","doi":"10.1016/j.powtec.2025.121060","DOIUrl":"10.1016/j.powtec.2025.121060","url":null,"abstract":"","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"460 ","pages":"Article 121060"},"PeriodicalIF":4.5,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144088988","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":"Minimum mesh quality for reliable morphology characterization of 3D soil particles","authors":"Chen-Xi Tong ,&nbsp;Jia-Jun Li ,&nbsp;Quan Sun ,&nbsp;Feng He ,&nbsp;Sheng Zhang ,&nbsp;Wan-Huan Zhou ,&nbsp;Daichao Sheng","doi":"10.1016/j.powtec.2025.121062","DOIUrl":"10.1016/j.powtec.2025.121062","url":null,"abstract":"<div><div>Remarkable advancements in computer-based optical imaging technology have greatly enhanced particle shape quantification and characterization with high efficiency. However, the varying sensitivity of different particle shape descriptors to mesh quality is often overlooked, which can affect the reliability and accuracy of particle shape characterization. In response to this issue, this study systematically investigates the impact of three-dimensional (3D) particle mesh quality on seven commonly used shape descriptors, showing that lower mesh quality can lead to greater deviations in 3D particle shape characterization. These shape descriptors are then categorized according to their scale and sensitivity to mesh quality. From this analysis, minimum mesh quality criteria are established to ensure reliable particle shape characterization. The applicability of the criteria to particles with diverse forms is evaluated, and further validation is conducted using four scanned morphologically featured particles. These findings provide essential technical guidance for determining acceptable levels of 3D particle mesh model simplification in geotechnical engineering applications.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"460 ","pages":"Article 121062"},"PeriodicalIF":4.5,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143898695","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":"Application of data-driven methods to predict dynamic viscosity in nanofluids","authors":"Piaoyun Gu ,&nbsp;Xizhen Zhu ,&nbsp;Yiqin Fan","doi":"10.1016/j.powtec.2025.121072","DOIUrl":"10.1016/j.powtec.2025.121072","url":null,"abstract":"<div><div>Nanofluids have a wide variety of applications in various scientific and engineering fields. Dynamic viscosity (DV) is one of the important features of nanofluids that needs an accurate estimation. Therefore, the present study employed several white-box data-driven methods for estimating the DV of MWCNTs and aluminum oxide dispersed in an 80 % water and 20 % ethylene glycol solution. The white-box data-driven models, including classification and regression tree (CART), M5 model tree (M5MT), multivariate adaptive regression splines (MARS), gene expression programming (GEP), multi-expression programming (MEP), and group method of data handling (GMDH), were used. The main characteristic of the proposed methods is derived mathematical equations for predicting DV. The effective parameters, including solid volume fraction (SVF), temperature (T), and shear rate (SR), were used as input variables to predict DV. The equations obtained from the white-box models can be simply employed to estimate DV. In addition, sensitivity and Shapley Additive Explanation (SHAP) analyses were conducted to determine the impact of each input variable on DV. The CART, M5MT, GMDH, and MARS models provided simple and straightforward formulas for estimating DV. On the other hand, the MEP and GEP methods presented slightly more complex structures for the estimation of DV. For the overall evaluation of the accuracy of suggested methods, the Ranking Mean (RM) method was used. The RM values indicated that the MEP model (RM = 1.3) has the most accurate models, followed by MARS (RM = 1.9), GEP (RM = 3.1), M5MT(NLR) (RM = 4), GMDH (RM = 5.3), M5MT(LR) (RM = 5.6), and CART (RM = 7.0) models.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"460 ","pages":"Article 121072"},"PeriodicalIF":4.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143898694","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 of AP particle transport and breakage in a feed pipe","authors":"Yizhe Yu ,&nbsp;Wen Huang ,&nbsp;Kaixuan Chen ,&nbsp;Yang Qin ,&nbsp;Jie Liu","doi":"10.1016/j.powtec.2025.121077","DOIUrl":"10.1016/j.powtec.2025.121077","url":null,"abstract":"<div><div>The jet mill achieves particle refinement and classification through the shear collisions between high-speed airflow and particles, effectively meeting the demand for multi-scale ammonium perchlorate (AP) in composite solid propellants. However, the flow dynamics of the two-phase fine grinding system during the jet milling process still require further investigation. This paper employs the CFD-DEM method to analyze the dynamic behavior of the feed gas flow, the dynamic transmission of polyhedral particles, and the fracture mechanics of the true particles. The Ab-T10 model regards the particles as a single entity that is instantaneously decomposed into fragments by the Voronoi fracture algorithm after the impact energy accumulation is higher than the breakage energy. The visualization results show that the feed gas flow is subsonic inside the Venturi tube and reaches the sonic state at the nozzle outlet. As the jet continues to penetrate, the flow rate initially increases before subsequently decreasing. The increase of surface curvature will reduce the proportion of multi-stage collisions of particles, and it is difficult for the wall to form a long-term retardation of particle motion. The collision of low-curvature particles results in a greater normal contact force and a longer residence time on the wall, which can potentially cause mechanical damage to the feed pipe. Upon colliding with the wall, multiple large-scale cracks form in the initial deformation area, causing the original particles to break down into multi-scale fragments. The wall blocking reduces the velocity of the micro-particle fragments and forms a stable broken flow structure.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"460 ","pages":"Article 121077"},"PeriodicalIF":4.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143894529","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":"Copula-based dependency modelling of hydraulic properties for non-linear filtration through porous media","authors":"Subodh Shrivastava ,&nbsp;Ashes Banerjee ,&nbsp;Ashwin Singh ,&nbsp;Mritunjay Kumar Singh ,&nbsp;Srinivas Pasupuleti","doi":"10.1016/j.powtec.2025.121069","DOIUrl":"10.1016/j.powtec.2025.121069","url":null,"abstract":"<div><div>Predicting hydraulic parameters in porous media, such as Darcy and non-Darcy coefficients, is critical for understanding flow dynamics and designing hydraulic structures. This study develops a stochastic modelling framework using bivariate copula models to estimate these parameters, leveraging easily measurable quantities like packing diameter etc. A synthetic dataset, derived from experimental distributions reported in the literature, was utilized to overcome challenges associated with direct data collection. The analysis revealed that hydraulic radius is strongly correlated with Darcy (Kendall's tau = −0.74) and non-Darcy coefficients (Kendall's tau = −0.76), and an inverse relationship was observed between hydraulic radius and Darcy coefficient. For example, the probability of the Darcy coefficient not exceeding 2 s/m, 20 s/m, and 100 s/m was 10 %, 50 %, and 80 %, respectively, for a hydraulic radius of 0.005 m. Furthermore, the strong correlation between Darcy and non-Darcy coefficients (Kendall's Tau = 0.67) enables the use of the former as a predictor for the latter. For a Darcy coefficient of 50 s/m, the probability of the non-Darcy coefficient not exceeding 300 s²/m² and 750 s²/m² was approximately 50 % and 75 %, respectively. This approach provides designers and engineers with a probabilistic framework for selecting hydraulic parameter values with varying degrees of confidence. It offers practical applications in the design of hydraulic structures, such as rockfill dams, and in estimating discharge through fractures, allowing for more reliable assessments of head loss and stability. The findings underscore the potential of copula models in enhancing the predictive accuracy and practicality of hydraulic analyses in porous media.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"460 ","pages":"Article 121069"},"PeriodicalIF":4.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890487","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":"Preparation of magnetically separable NiFe2O4/conjugated poly(vinyl chloride) derivative nanocomposites for photocatalytic application","authors":"Ke Li,&nbsp;Jun Wang","doi":"10.1016/j.powtec.2025.121078","DOIUrl":"10.1016/j.powtec.2025.121078","url":null,"abstract":"<div><div>NiFe₂O₄ is a potential magnetically separable visible light photocatalyst, however its photocatalytic activity is unsatisfactory due to its speedy photogenerated charge recombination. Here, the conjugated derivatives (CPVC) derived from poly(vinyl chloride) (PVC) powder as well as waste PVC plastic film were exploited to enhance the photocatalysis of NiFe₂O₄. A variety of NiFe₂O₄/CPVC nanocomposites were prepared employing a simple composition-controllable method, by adjusting the synthesis conditions. Through photocatalyzing the reduction of Cr(VI) under visible light (λ &gt; 420 nm) and xenon lamp light, the photocatalytic capabilities of the prepared NiFe₂O₄/CPVC nanocomposites were evaluated. The outcome demonstrated that the optimized NiFe₂O₄/CPVC prepared using PVC powder (NiFe₂O₄/CPVC-2) possessed dramatically enhanced photocatalytic activity (4 and 5.3 times that of NiFe₂O₄ in visible light-driven photocatalytic reduction of Cr(VI) in water and the diluted passivation solution for copper alloys, respectively) and good stability, and can also be magnetically separated from water. According to the photoelectrochemical characterization results, it was deduced that the p-n heterojunction structure of NiFe₂O₄/CPVC-2 facilitated the photogenerated charge separation and transfer, playing a primary role in its improved photocatalysis. When the source material of CPVC used was waste PVC plastic film, the prepared NiFe₂O₄/CPVC nanocomposite showed an even more improved photocatalytic activity (2.4 times that of NiFe₂O₄/CPVC-2 and 6.3 times that of NiFe₂O₄). The current study not only has developed a new magnetically separable, efficient visible light photocatalyst for Cr(VI) wastewater treatment, but also offers a reference for recycling waste PVC plastics in constructing promising high value-added visible light photocatalysts.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"460 ","pages":"Article 121078"},"PeriodicalIF":4.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143882599","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":"Toward the influence of fluid convection on filtered drag force in fluidized gas-particle flows","authors":"Ju Jiang ,&nbsp;Shouzheng Yuan ,&nbsp;Xiao Chen ,&nbsp;Bolun Yang ,&nbsp;Qiang Zhou","doi":"10.1016/j.powtec.2025.121076","DOIUrl":"10.1016/j.powtec.2025.121076","url":null,"abstract":"<div><div>Mesoscale drag modeling for gas-solid flows is typically based on fully-periodic systems where fluid convection is insignificant. This study examines a series of 2D sudden-expanded fluidized beds (SEFBs) to investigate the effects of fluid convection on the filtered drag force. A priori analysis indicates that the volumetric force induced by convection has a notable impact on the filtered drag force, and correlations of drag force using traditional markers (such as solid volume fraction, slip velocity, and filter size) fail to provide accurate predictions. In contrast, the gas-phase pressure gradient shows a good correlation with drag force when strong convection is present. Posterior tests in the SEFBs with several existing drag models reveal that the predictive capacity of drag models constructed with traditional markers declines under conditions with strong convection, whereas the drag model incorporating the gas-phase pressure gradient still performs well.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"460 ","pages":"Article 121076"},"PeriodicalIF":4.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886404","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":"Investigation of ash and slag deposition mechanisms in industrial-scale radiant syngas cooler for entrained-flow coal gasification","authors":"Weidong Xia ,&nbsp;Yan Gong ,&nbsp;Qinghua Guo ,&nbsp;Jinsheng Cao ,&nbsp;Guoyu Zhang ,&nbsp;Hantao Lu ,&nbsp;Guangsuo Yu","doi":"10.1016/j.powtec.2025.121061","DOIUrl":"10.1016/j.powtec.2025.121061","url":null,"abstract":"<div><div>Ash particles and slag deposit on the water wall tubes of radiant syngas cooler (RSC), resulting in increased thermal resistance and decreased efficiency of the gasification system. This study investigated deposition mechanisms at different heights of an industrial-scale RSC for a 2000 t/d entrained-flow coal gasifier. Ash and slag samples were comprehensively characterized through particle size analysis, XRF, XRD, and SEM-EDS. The results showed that the ash deposition process was influenced by particle size, temperature, and chemical composition. The deposition process consisted of three distinct stages. In the initial stage (near Wall-0 m), fine particles deposited through entrainment and formed the initial sticky layer of low-melting compounds that captured larger particles. In the development stage (near Wall-6.5 m), deposition was dominated by inertial impaction of larger particles (&gt;100 μm). Irregular particles were mainly composed of silicate or aluminosilicate with high melting temperature. In the stable stage (near the Wall-11.5 m and below), the deposition of fine particles (&lt;100 μm) enriched with FeS was primarily driven by thermophoresis, resulting in the formation of agglomerates and low-strength slag. The findings of this work are significant for deposition modeling and revealing the corrosion risks from Na and S enrichment in the RSC.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"460 ","pages":"Article 121061"},"PeriodicalIF":4.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143878890","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 comprehensive study on the effects of porous char particles on drag coefficients under combustion based on Micro-CT and pore-resolving simulation","authors":"Dongyu Liang","doi":"10.1016/j.powtec.2025.121073","DOIUrl":"10.1016/j.powtec.2025.121073","url":null,"abstract":"<div><div>This study examines the influence of real porous coal char particle morphology on drag coefficients under combustion conditions using micro-CT imaging and pore-resolving computational fluid dynamics (CFD) simulations. Traditional drag models, which rely on simplified geometries such as spheres, ellipsoids, and pipes, may not fully capture the aerodynamic behavior of real char particles. To evaluate these limitations, pore-resolving simulations were conducted at Reynolds numbers of 20, 40, 60, 100 and 200, comparing real char particles with various idealized shapes. Results demonstrate that the drag coefficient of real char particles, with irregular surfaces and complex internal pores, cannot be well represented by the ideal shapes. The poorly connected internal pores had negligible effects on drag, unlike well-connected pores in ideal pipe structures, which influenced aerodynamic behavior. Flow directionality along the same axis had minimal impact on drag for real particles, with less than 1 % error in most cases. However, different axes showed significant errors when <em>Re</em> is less than 200, ranging from 4.59 % to 31.98 %, emphasizing the need for realistic morphology and orientation in predictive models. As Reynolds number increased, discrepancies between drag coefficients of real and ideal particles diminished, suggesting potential use of simplified models at higher Reynolds numbers (with an overall error of 6.35 %). Four classical 1D models based on ideal shapes showed considerable errors in predicting drag coefficients, especially for complex orientations and porosities. While the Schiller model aligned better along the major axis with 10.41 % error and the Ouchene model along the minor axes with 10.08 % error, both still deviated significantly in predicting overall aerodynamic behavior. The need for optimizing drag coefficient models to incorporate realistic morphologies is emphasized in this research.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"460 ","pages":"Article 121073"},"PeriodicalIF":4.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143878892","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}