Powder Technology最新文献

{"title":"Turbulence effect on the determination of powders safety characteristics — A review on the experimental findings and simulation approaches","authors":"Maria Portarapillo ,&nbsp;Almerinda Di Benedetto ,&nbsp;Stefan H. Spitzer","doi":"10.1016/j.powtec.2025.120694","DOIUrl":"10.1016/j.powtec.2025.120694","url":null,"abstract":"<div><div>Safety characteristics are widely used in the process industry to design facilities in a safe way. For powders, they are normally investigated under turbulent conditions inside a spherical test vessel, the so called 20L-sphere, to disperse the dust in air. This has been the target of many researchers to either investigate the turbulence that is present during the standardized test conditions, to compare it to quiescent conditions or to manipulate it for the comparison to other conditions. The approaches have been numerous and while the focus used to be on obtaining different experimental results it has shifted more and more to different kinds of simulations. This review gives an overview about different simulation approaches and how they can be compared. It is also an overview over the experimental findings and compares it to data obtained for three different dusts while changing the pre-ignition turbulence level in a very fine way.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"454 ","pages":"Article 120694"},"PeriodicalIF":4.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143265839","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":"Study of the CO2 absorption with K2CO3 sorbents in gas-solid fluidized beds based on second-order moment model","authors":"Xi Chen,&nbsp;Shuyan Wang,&nbsp;Nuo Ding,&nbsp;Baoli Shao,&nbsp;Xuewen Wang,&nbsp;Yimei Ma","doi":"10.1016/j.powtec.2025.120708","DOIUrl":"10.1016/j.powtec.2025.120708","url":null,"abstract":"<div><div>K₂CO₃ is widely recognized as an effective CO₂ capture material due to excellent adsorption performance and reaction activity. In this study, the second-order moment (SOM) model is employed to simulate the CO₂ adsorption with K₂CO₃ sorbents in a fluidized bed reactor, considering the effect of particle velocity fluctuation anisotropy. The results indicate that the anisotropy can enhance the heterogeneous reaction and improve the CO₂ conversion rate in the reactor. Compared to the kinetic theory of granular flow (KTGF) model, the SOM model is better verified with the experimental results and can more accurately capture flow field heterogeneity and anisotropic characteristics. Quantities such as the particle concentration, velocities, particle second-order moments, Reynolds stresses, temperature and reaction characteristics are presented. Within a specific range, a higher temperature can intensify particle fluctuations and anisotropy, concurrently enhancing both reaction rates and CO₂ conversion rates. These findings provide theoretical insights for optimizing process conditions in CO₂ capture within fluidized bed reactors.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"454 ","pages":"Article 120708"},"PeriodicalIF":4.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103820","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":"Study on the differences in thermal physical properties of nanofluids formed by metal and metal oxide nanoparticles: A molecular dynamics simulation of Cu-H2O and CuO-H2O nanofluids","authors":"Chenghang Li,&nbsp;Zhumei Luo,&nbsp;Shan Qing,&nbsp;Wenlong Deng,&nbsp;Haoming Huang","doi":"10.1016/j.powtec.2025.120707","DOIUrl":"10.1016/j.powtec.2025.120707","url":null,"abstract":"<div><div>Nanofluids, known for their high thermal conductivity and excellent thermal physical properties, are widely used in various engineering fields. However, the impact of the type of nanoparticles on the thermal physical properties of nanofluids and the exploration of their microscopic mechanisms remain underexplored. This study employs molecular dynamics methods combined with various techniques (non-equilibrium molecular dynamics (NEMD), reverse non-equilibrium molecular dynamics (RNEMD), radial distribution function (RDF), phonon density of states (PDOS), etc.) to thoroughly investigate the differences in thermal physical properties between nanofluids formed by metals and their oxides in the same type of base fluid, using Cu-H₂O and CuO-H₂O nanofluids as examples. The study aims to provide a microscopic explanation and reveal the underlying mechanisms. The study found that under the consideration of practical factors such as temperature, nanoparticle shape (S/V ratio), and nanoparticle volume fraction in the nanofluid, the thermal conductivity of Cu-H₂O nanofluid is higher than that of CuO-H₂O nanofluid. For example, the thermal conductivity values are 0.83296 W/m·K (Cu-H₂O nanofluid, 2.5 %, 330 K, Cylinder) and 0.8288 W/m·K (CuO-H₂O nanofluid, 2.5 %, 330 K, Cylinder).Additionally, the viscosity of Cu-H₂O nanofluid is lower than that of CuO-H₂O nanofluid, as shown by the values 0.002284123 Pa·S (Cu-H₂O nanofluid, 280 K, 1.5 %, Platelets) and 0.0023976 Pa·S (CuO-H₂O nanofluid, 280 K, 1.5 %, Platelets).Subsequently, by comparing the phonon density of states (PDOS) overlap between nanoparticle atoms and base fluid atoms in both Cu-H₂O and CuO-H₂O nanofluids, the study elucidated the microscopic mechanism behind the higher thermal conductivity of Cu-H₂O nanofluid from the perspective of interfacial thermal conductance. The radial distribution function (RDF) was then used to explain the lower viscosity of Cu-H₂O nanofluid compared to CuO-H₂O nanofluid from the solid-liquid interface angle in the nanofluid, and to further elucidate the internal mechanism behind the higher thermal conductivity of Cu-H₂O nanofluid. This study fills a significant gap in the comprehensive comparative research of the thermal physical properties of nanofluids formed by metals and their oxides. It reveals the internal mechanisms behind the differences in thermal physical properties at a microscopic level, providing important guidance for the engineering application of nanofluids.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"455 ","pages":"Article 120707"},"PeriodicalIF":4.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377462","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":"Movement characteristics of mixed alfalfa and awnless brome seeds within a Venturi conveyor based on CFD-DEM","authors":"Yangyang Liao,&nbsp;Xiaoyi Zhou,&nbsp;Yong You,&nbsp;Decheng Wang,&nbsp;Yunting Hui","doi":"10.1016/j.powtec.2025.120735","DOIUrl":"10.1016/j.powtec.2025.120735","url":null,"abstract":"<div><div>The movement characteristics of mixed alfalfa and awnless brome seeds within a Venturi conveyor of an air-blown centralized seeding system were studied by using the CFD-DEM coupling method. A Venturi conveyor with curved tube structure was designed based on the principle of the brachistochrone curve, and the impact of various structural and working parameters on seed movement characteristics and airflow distribution was investigated. The results showed that the stability and uniformity of seed supply and transport of designed curvilinear feed tube were better than that of conventional linear tube, and the 50 mm mixed tube design significantly reduced the number of collisions between seeds and the tube wall, thereby enhancing transport performance. For a 1:1 ratio of alfalfa to awnless brome seeds, the optimal airflow velocity ranged from 24 to 28 m/s, and the suitable seed feeding rate was 1500–3000 seeds/s. When the ratio was adjusted to 1:2, the suitable airflow velocity was between 20–24 m/s, and the suitable seed feeding rate was 3000–4500 seeds/s. Bench tests confirmed that the optimized Venturi conveyor effectively improved its operational performance. The study outcomes contribute to a better understanding of the motion characteristics of mixed seeds in Venturi tubes and lay the groundwork for further device structure optimization.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"455 ","pages":"Article 120735"},"PeriodicalIF":4.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143394888","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 on spreading behavior and influencing parameters of particle-droplet collision","authors":"Jin Hou ,&nbsp;Botao Qin ,&nbsp;Qun Zhou","doi":"10.1016/j.powtec.2025.120702","DOIUrl":"10.1016/j.powtec.2025.120702","url":null,"abstract":"<div><div>This paper investigated the dynamic wetting characteristics during droplet impact on spherical particle as the main monitoring object, and analyzed the effects of droplet impact velocity, and surface tension on droplet spreading coefficient (Dc) and particle force. The droplet-particle collision condensation test platform designed and constructed in this paper. In addition, a novel particle-droplet collision numerical model was constructed by combining VOF, dynamic mesh and mesh adaptation techniques to assist the research. The results shown that the rate of increase of Dc increased with the increase of the collision velocity. When the collision velocity was less than 1 m/s, the attraction force generated by droplet on particle was greater than the resistance generated by surface tension, which results in adsorption force. The resistance of droplet to particle increased with the increase of velocity, while the effect of adsorption decreased. When the collision velocity exceeded 1 m/s, the effect of adsorption force was negligible, the particle and droplet could not produce adsorption mode of bonding and need to overcome the surface tension for wrapping. Reducing the surface tension could increase the encapsulation speed of the droplet to the particle, for example, the droplet with a surface tension of 28mN/m took only half as long as the surface tension of 76mN/m. The results of this study provide a basic theoretical basis for further exploration of the particle-droplet collision and coalescence mechanism.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"454 ","pages":"Article 120702"},"PeriodicalIF":4.5,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104257","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":"Multi-field coupling particle flow dynamic behaviors of the microreactor and ultrasonic control method","authors":"Lin Li ,&nbsp;Pu Xu ,&nbsp;Qihan Li ,&nbsp;Zichao Yin ,&nbsp;Runyuan Zheng ,&nbsp;Jiafeng Wu ,&nbsp;Jiaji Bao ,&nbsp;Wenyu Bai ,&nbsp;Huan Qi ,&nbsp;Dapeng Tan","doi":"10.1016/j.powtec.2025.120731","DOIUrl":"10.1016/j.powtec.2025.120731","url":null,"abstract":"<div><div>Microfluidic technology, known for its efficiency, safety, and precise control, has been extensively utilized in chip channel manufacturing and high-throughput drug screening. The design of the internal flow field and the distribution of particles are critical factors in enhancing mass transfer rates and reaction efficiency. However, uneven mixing processes and particle agglomeration hinder the widespread adoption of microreactors in industrial applications. To address these challenges, this paper proposes a multi-field coupling particle flow modeling and control method for microreactors, aimed at exploring the flow dynamic behaviors and particle cluster control modes. A computational fluid dynamics-discrete element method (CFD-DEM) based multi-field coupling particle flow model is set up to analyze particle distribution patterns under ultrasonic excitation. The fractal geometry analysis method is introduced to quantify the chaotic distribution of particles within the channels. Finally, a multi-field coupling mixing observation platform is constructed to validate the numerical results. The findings indicate that the proposed modeling strategy effectively elucidates the evolution mechanism of the multi-field coupling flow field. Ultrasound energy enhances the overall flow distribution and achieves uniformity in particle distribution. Moreover, the inlet flow rate and ultrasonic frequency have a significant impact on the evolution of the flow and the characteristics of particle distribution. This research provides valuable insights into the mechanisms of multi-field coupling in microreactors and supports the optimization of chip design for drug transport applications.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"454 ","pages":"Article 120731"},"PeriodicalIF":4.5,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143265850","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":"Enhancing system kinetics through size segregation in granular materials","authors":"Jian Guo ,&nbsp;Guodong Wang ,&nbsp;Yao Li","doi":"10.1016/j.powtec.2025.120706","DOIUrl":"10.1016/j.powtec.2025.120706","url":null,"abstract":"<div><div>The segregation process is a remarkable phenomenon in granular materials found in nature, occasionally accompanied by interlayer slippage. However, their impacts on system kinetic energy remain unclear. This study aims to quantitatively analyze the relationships between interlayer slippage, kinetic energy fluctuations, and fluidity during the segregation process of granular materials using three-dimensional Discrete Element Method simulations. The simulation parameters include size ratios (<em>S</em>_r: 0.5–1.0), volume ratios (<em>V</em>_r: 0.2–0.8), and inclination slopes (<em>δ</em>: 10°–30°). The results show that interlayer slippage at the top significantly reduces the degree of segregation, while slippage at the bottom has a smaller effect. A positive correlation is observed between kinetic energy and the degree of segregation, with the correlation being more pronounced on steeper slopes. Moreover, minimal vertical kinetic energy fluctuations induced by segregation significantly enhance granular fluidity, whereas interlayer slippage can reduce system kinetic energy by at least 50 %. These findings indicate that the widespread segregation process observed in long-runout landslides may promote their extreme mobility and destructive power by enhancing granular fluidity. This study may provide insights into granular system dynamics and practical guidance for landslide disaster prevention and mitigation.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"454 ","pages":"Article 120706"},"PeriodicalIF":4.5,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143266061","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 on the synergistic suppression effect of flame retardant-modified dry water on methane explosion","authors":"Jie Gao,&nbsp;Chuyuan Huang,&nbsp;Hao Zeng,&nbsp;Zuyang Du,&nbsp;Xianfeng Chen,&nbsp;Dongyang Qiu","doi":"10.1016/j.powtec.2025.120728","DOIUrl":"10.1016/j.powtec.2025.120728","url":null,"abstract":"<div><div>To reduce the occurrence of methane (CH₄) explosion accidents, this study successfully prepared a novel composite powder (CGDW) by adding magnesium hydroxide and zinc borate to the core solution of dry water (DW). Its physical properties, such as flowability, mechanical stability, particle size distribution, water retention, and bulk density were characterized separately. The effect of CGDW on the explosion characteristics of stoichiometric CH₄ was explored in a square explosion pipeline. The results showed that the physical properties of CGDW were significantly improved compared to DW. CGDW demonstrated excellent CH₄ explosion suppression performance due to its unique core-shell structure, which could simultaneously exert a solid-liquid two-phase suppression effect. After adding 15 g CGDW, the maximum explosion pressure decreased by 69.4 %, the peak temperature decreased by 97.8 %, and the explosion flame was isolated during propagation. In addition, the explosion suppression mechanism of CGDW on the CH₄ was explored in terms of physical effects (heat insulation, gas dilution, cooling) and chemical effects (interrupting the chain reaction). CGDW possesses green and high-efficiency characteristics, providing a new path to suppress CH₄ explosion and improve the safety of its usage.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"454 ","pages":"Article 120728"},"PeriodicalIF":4.5,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372256","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":"Characterization of nanoparticle agglomerate motion based on the TEMOM method","authors":"Juhui Chen ,&nbsp;Weikang Li ,&nbsp;Dan Li ,&nbsp;Qian Zhang ,&nbsp;Shilin Zhong ,&nbsp;Wentao Liu ,&nbsp;Zhuravkov Michael ,&nbsp;Siarhei Lapatsin ,&nbsp;Wenrui Jiang","doi":"10.1016/j.powtec.2025.120711","DOIUrl":"10.1016/j.powtec.2025.120711","url":null,"abstract":"<div><div>The investigation of nanoparticle agglomerates' dynamic behavior within fluidized beds constitutes a pivotal research avenue within the domains of aerosols and multiphase flows. Within this inquiry, the Thermo-Electrical Model of Moving Particle (TEMOM) is employed to scrutinize the efficacy of three distinct models, namely, the Sectional Moving Mesh (SMM), Quadrature Method of Moments (QMOM), and TEMOM itself, in elucidating particle dynamics within a fluidized bed. The findings underscore the superiority of the TEMOM model in congruence with experimental data about the simulation of bed pressure drop and expansion rate. Initially, during the phase of particle fluidization, particles ascend in a bulging configuration, engendering cyclic motion in conjunction with the descending particles along the walls. Over time, the particles attain a state of stable fluidization, manifesting a tendency towards the stabilization of agglomerated bulk fluidization distribution, albeit with the persistence of stratification phenomena. Within the bed's central region, particle agglomerate velocity attains prominence, with the discernible manifestation of Brownian condensation. Moreover, the continuous occurrence of agglomeration and fragmentation processes within the fluidized bed, particularly along the mid-bed wall, where aggregate diameter and axial velocity register higher values, is noted. The scrutiny of moment characteristics across each order of the particle phase elucidates the influence of particle number density on M₀, M₁, and M₂ moments, with the variation in particle number density directly impinging upon particle motion and agglomeration dynamics. After the attainment of a stable fluidization state by the fluidized bed, the moments' values for each particle order exhibit steady fluctuations, thereby reflecting the distributional and dynamic attributes of particles within the bed.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"455 ","pages":"Article 120711"},"PeriodicalIF":4.5,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143394690","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":"Mesoscopic flow simulation to understand the percolation through fine-ground electronic waste particle bed","authors":"Zachary Diermyer ,&nbsp;Yidong Xia ,&nbsp;Ahmed Hamed ,&nbsp;Jordan Klinger ,&nbsp;Vicki Thompson ,&nbsp;Zhen Li ,&nbsp;Jiaoyan Li","doi":"10.1016/j.powtec.2025.120703","DOIUrl":"10.1016/j.powtec.2025.120703","url":null,"abstract":"<div><div>Mechanical size reduction is a critical pretreatment for hydrometallurgical recovery of valuable metals in electronic waste. The particle size resulting from milling ranges from a few micrometers to a few millimeters, presenting challenges of achieving sufficient leaching percolation in portions occupied by fine particles. This work investigates the hydrodynamics of percolation through micrometer-sized fine particle beds by using many-body dissipative particle dynamics flow simulations. The results show that higher effective pore size resulting from high aspect-ratio particle packing contributes to higher permeability than spherical particle packing. Increasing surface wettability enhances maximum saturation rates but reduces permeability. Moreover, increasing tortuosity negatively impacts permeability and the degree of reduction in permeability caused by increased surface wettability decreases with increasing tortuosity. These findings imply possible complex relationships between tortuosity, pore size, and surface wettability that collectively impact percolation in loosely packed fine particle beds and can be used to guide improvement in pretreatment.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"454 ","pages":"Article 120703"},"PeriodicalIF":4.5,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104255","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}