Powder Technology最新文献_第2页

Influence of ballast gradation on repose angle using large-scale hopper flow tests and DEM simulation

IF 4.5 2区工程技术

Powder Technology Pub Date : 2025-02-27 DOI: 10.1016/j.powtec.2025.120852

Cheng Chen , Shao-shuo Li , Jun-feng Li , Lei Zhang , Juan Yang

{"title":"Influence of ballast gradation on repose angle using large-scale hopper flow tests and DEM simulation","authors":"Cheng Chen , Shao-shuo Li , Jun-feng Li , Lei Zhang , Juan Yang","doi":"10.1016/j.powtec.2025.120852","DOIUrl":"10.1016/j.powtec.2025.120852","url":null,"abstract":"<div><div>This study investigates the influence of ballast gradation on the repose angle through a series of large-scale hopper flow tests and discrete element method (DEM) simulations. Bulk-scale and micro analyses of the entire ballast pile formation process reveal three stages: platform-stacking, peak-stacking, and peak-shaving, with particle interlocking during these stages playing a crucial role in establishing the angle of repose. Results indicate that ballast gradation significantly affects the repose angle, the maximum repose angle is observed at <em>d</em><sub>50</sub> = 40.0 mm, within the tested range of 36.8 mm to 45.0 mm. As the gradation of the ballast transitions from uniform to non-uniform, the repose angle initially increases and then decreases, peaking at <em>d</em><sub>50</sub> = 40.0 mm and <em>C</em><sub>u</sub> = 1.46. The spatial distribution of particles within the ballast pile follows a distinct pattern, large particles within the ballast pile is relatively uniform, while small and medium particles are more concentrated in the core regions. A better particle gradation allows smaller particles to fill the voids between larger particles, thereby optimizing the load distribution between strong and weak force chains. This research underscores the importance of proper gradation for ensuring stability and effective load-bearing capacity in ballast systems.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120852"},"PeriodicalIF":4.5,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical simulation of proppant transport with multi-stage alternating injection in CO2 hybrid fracturing

IF 4.5 2区工程技术

Powder Technology Pub Date : 2025-02-26 DOI: 10.1016/j.powtec.2025.120840

Yong Zheng , Zhigang Wang , Haoyu Chen , Hai Huang , Jun Ni , Liangbin Dou , Haizhu Wang , Bin Wang

{"title":"Numerical simulation of proppant transport with multi-stage alternating injection in CO2 hybrid fracturing","authors":"Yong Zheng , Zhigang Wang , Haoyu Chen , Hai Huang , Jun Ni , Liangbin Dou , Haizhu Wang , Bin Wang","doi":"10.1016/j.powtec.2025.120840","DOIUrl":"10.1016/j.powtec.2025.120840","url":null,"abstract":"<div><div>Effective proppant placement has been one of the key objectives of reservoir stimulation. CO<sub>2</sub> hybrid fracturing is promising for the economic production of unconventional reservoirs, however, there is a lack of understanding of proppant transport within the rough fractures associated with it. In this study, a validated CFD-DEM model is used to simulate proppant transport with multi-stage alternating injection in CO<sub>2</sub> hybrid fracturing, focusing on evaluating the advantages of alternating injection within a rough fracture as well as the influence laws of key parameters. The simulation results show that the use of multi-stage alternating injection of proppant with different fluids in CO<sub>2</sub> hybrid fracturing can obtain better proppant placement than single fluid continuous pumping, with 36.4 % and 4.4 % higher proppant dune lengths, and 3.51 % and 2.3 % higher dune placement rate than single CO<sub>2</sub> pumping and water pumping, respectively. The optimal number of injection stages in multi-stage alternating injection of proppant is 4, while the optimal segment plug length ratio of CO<sub>2</sub> and water is 3:1. The best dune length and placement rate are obtained when the CO<sub>2</sub> segment plug is injected at a velocity of 0.1 m/s, but when the CO<sub>2</sub> segment plug is injected at a velocity of 0.2 m/s, it is favorable for the safety of the pipeline and equipment during fracturing operation.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120840"},"PeriodicalIF":4.5,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Two-stage synthesis of spherical iron powders from steel industry by product

IF 4.5 2区工程技术

Powder Technology Pub Date : 2025-02-25 DOI: 10.1016/j.powtec.2025.120851

Kameswara Srikar Sista , Abhijeet Premkumar Moon , Srinivas Dwarapudi , Siddhartha Misra , Chenna Rao Borra

{"title":"Two-stage synthesis of spherical iron powders from steel industry by product","authors":"Kameswara Srikar Sista , Abhijeet Premkumar Moon , Srinivas Dwarapudi , Siddhartha Misra , Chenna Rao Borra","doi":"10.1016/j.powtec.2025.120851","DOIUrl":"10.1016/j.powtec.2025.120851","url":null,"abstract":"<div><div>Spherical iron powders are often used in high end applications like metal injection molding additive manufacturing, and soft magnetics due to their sphere morphology, high density and good flowability. Till date, manufacturing processes like gas atomization and carbonyl process are the only available routes for synthesis of spherical iron. In this work a novel approach of obtaining spherical iron powder via a two stage (reduction + plasma spheroidization) process by use of iron oxide by-product from steel industry is proposed. Physico-chemical characterization of powders reveals that irregular iron powders with high purity (Fe (T)- 98.2 wt%, Fe(M)- 96.8 wt%), low apparent density (1.1 g/cc) and high surface area (0.37 m<sup>2</sup>/g) are successfully synthesized at optimal conditions of reduction (850 °C, 300 min). Further, plasma spheroidization of this irregular iron powders at optimized process parameters (11.5 KW plasma power, 6.5 g/min feed rate) generated spherical powders with high purity (Fe (T)- 97.8 wt%, Fe(M)- 95.6 wt%), high apparent density (3.84 g/cc) and good flowability (8.8 s/50 g). Present work fosters a sustainable and scalable approach for synthesis of two different grades of iron powder having diverse applications from a single feed source.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120851"},"PeriodicalIF":4.5,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Powder bed fusion – Laser beam in reactive atmospheres – Ignition limits for Fe and Ti-6Al-4V powder blends in CO2 and N2

IF 4.5 2区工程技术

Powder Technology Pub Date : 2025-02-25 DOI: 10.1016/j.powtec.2025.120843

C. Felber , M. Köberl , E.A. Jägle

{"title":"Powder bed fusion – Laser beam in reactive atmospheres – Ignition limits for Fe and Ti-6Al-4V powder blends in CO2 and N2","authors":"C. Felber , M. Köberl , E.A. Jägle","doi":"10.1016/j.powtec.2025.120843","DOIUrl":"10.1016/j.powtec.2025.120843","url":null,"abstract":"<div><div>Powder bed fusion – laser beam (PBF-LB) in reactive CO<sub>2</sub> and N<sub>2</sub> atmospheres affect material properties, such as ductility and strength due to their uptake during processing. This can be exploited to manufacture in-situ particle reinforced materials. In Fe-based materials, in-situ precipitation is limited, thus Ti is added to increase the material-gas-interaction. However, the fraction of Ti in Fe-Ti blends must be limited, as laser exposure in these reactive atmospheres can lead to a strongly exothermic and self-sustained combustion reaction in the powder bed. In this study, the occurring combustion reaction and ignition limits are investigated. The laser power, speed, and spot size, as well as heat accumulation influence the onset of the combustion reaction. Based on our results, a lower limit for which no ignition occurs was determined to ca. 23 wt% Ti. At higher Ti concentrations, reasonable PBF-LB parameters may lead to ignition. The combustion products contain high numbers of oxides and carbides and consist of a combustion zone and a molten and sintered area below. These results show that undesired reactions in the powder bed can be controlled, and that Ti-containing powder blends are safely processable in CO<sub>2</sub> and N<sub>2</sub> atmosphere if the Ti fraction is limited.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120843"},"PeriodicalIF":4.5,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519206","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}

引用次数: 0

The effects of thermal properties on the interphase drag of supercritical water-particle flow

IF 4.5 2区工程技术

Powder Technology Pub Date : 2025-02-25 DOI: 10.1016/j.powtec.2025.120849

Xiaoyu Li, Bowei Zhang, Yi Li, Hui Jin

{"title":"The effects of thermal properties on the interphase drag of supercritical water-particle flow","authors":"Xiaoyu Li, Bowei Zhang, Yi Li, Hui Jin","doi":"10.1016/j.powtec.2025.120849","DOIUrl":"10.1016/j.powtec.2025.120849","url":null,"abstract":"<div><div>The drag of particle clusters is important for the investigation of fluidized beds, but there is no accurate correlation available. The effects of nonlinear physical properties on the drag of particle clusters in supercritical water (SCW) fluidized beds cannot be overlooked either. This work conducts a simulation investigation on the interphase drag of SCW-particle flow. The results reveal that an increase in density leads to a decrease in the drag coefficient <em>C</em><sub><em>d</em></sub>. This results in a positive correlation between the drag coefficient and particle temperature. The effects of Reynolds number (<em>Re</em>) and void fraction (<em>ε</em>) on the density distribution further influence the normalized drag coefficient <em>C</em>. The distributions of dimensionless velocity and kinetic energy indicate that the conversion rate of pressure potential energy to kinetic energy in SCW is lower than that in constant property flow (CPF). The distributions of <em>C</em><sub><em>d</em></sub> and <em>C</em> of sub-particles show that downstream particles are most influenced by variations in density under different conditions. A model for the effects of nonlinear physical properties is established based on the <em>C</em>. Analysis of the results from CPF reveals that the exponent <em>β</em> in this work is primarily a function of <em>ε</em>. A correlation between the exponent <em>β</em> and <em>ε</em> is established. A drag coefficient model for particle flow in SCW is developed through the coupling of multiple models.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120849"},"PeriodicalIF":4.5,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Research on the pore structure and gas adsorption/desorption characteristics of tectonic coal in minor fault zone: Implications for coal and gas outbursts

IF 4.5 2区工程技术

Powder Technology Pub Date : 2025-02-25 DOI: 10.1016/j.powtec.2025.120846

Shangkun Shen , Haifeng Wang , Tianwei Ren , Zhiyuan Wang

{"title":"Research on the pore structure and gas adsorption/desorption characteristics of tectonic coal in minor fault zone: Implications for coal and gas outbursts","authors":"Shangkun Shen , Haifeng Wang , Tianwei Ren , Zhiyuan Wang","doi":"10.1016/j.powtec.2025.120846","DOIUrl":"10.1016/j.powtec.2025.120846","url":null,"abstract":"<div><div>Minor faults, widely prevalent as small-scale tectonism in mining work face, are one of the important factors influencing coal and gas outbursts (CGO). This paper examined the pore structure, gas adsorption and desorption characteristics of coal samples at varying distances from fault and analyzed their interrelationships. The results show that fault has a significant effect on modifying mesopore and macropore, with a lesser effect on micropore. As distance from the fault decreases, there is an increasing trend in the gas's maximum adsorption volume, desorption rate, desorption volume, expansion energy and initial emission speed. Micropore is not the sole factor influencing gas adsorption, coal mineral composition or other factors also affect gas adsorption performance, while mesopore and macropore control gas desorption characteristics. Powdering significantly enhances gas expansion energy, with gas expansion energy in 0.074–0.2 mm being 7.19 times that of 1-3 mm, greatly increasing the risk of CGO. The influence range of the hanging wall is 17.35 m, which is 1.16 times that of the footwall, indicating a notably stronger modification effect of the fault on the hanging wall. The research results reveal the mechanism of how minor fault affects the microphysical structure and macroscopic adsorption and desorption characteristics on outburst coal seams, providing a foundation for the prevention and control of CGO in coal seams containing minor faults.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120846"},"PeriodicalIF":4.5,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigating gas-solid flow hydrodynamics in spouted beds with a draft tube using XCT: The role of tube types, gas velocity, and diameter

IF 4.5 2区工程技术

Powder Technology Pub Date : 2025-02-25 DOI: 10.1016/j.powtec.2025.120850

Zhong Xiang , Xi Chen , Theodore J. Heindel

引用次数: 0

Measurement method for screw conveyors based on electrostatic primary and secondary frequency signals

IF 4.5 2区工程技术

Powder Technology Pub Date : 2025-02-25 DOI: 10.1016/j.powtec.2025.120842

Chao Wang, Guoji Ma, Hui Cao, Xueling Ji, Jiamin Ye

{"title":"Measurement method for screw conveyors based on electrostatic primary and secondary frequency signals","authors":"Chao Wang, Guoji Ma, Hui Cao, Xueling Ji, Jiamin Ye","doi":"10.1016/j.powtec.2025.120842","DOIUrl":"10.1016/j.powtec.2025.120842","url":null,"abstract":"<div><div>Screw conveyors are widely used in industries such as construction, grain processing, and mining due to their low cost, ease of operation, and simple structure. Real-time measurement of the operational status of screw conveyors is crucial for enhancing conveyor efficiency, reducing energy consumption, and ensuring the safety of the production process. However, effective real-time measurement methods are currently lacking. This paper designs an electrostatic sensor that synchronously accounts for the influence of screw blades and finds that the detected electrostatic signals contain distinct primary and secondary frequency information. The signals are extracted using Harmonic Wavelet Transform (HWT), and the coal powder particle signals and screw blade signals are distinguished based on the presence of time delays in the decomposed signals. The results indicate that the primary frequency primarily reflects the motion of the screw blades, while the secondary frequency mainly corresponds to the motion of the coal dust particles. Using the proposed velocity measurement method, the absolute value of the relative error for the measured screw rotation speed was less than 1 %, and the absolute value of the relative error for the coal dust particle lifting speed was less than 2 %.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120842"},"PeriodicalIF":4.5,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The influence of filling ratio and container geometry on granular convection and the dynamical mechanisms of three unconventional convection patterns in a vibrated granular bed

IF 4.5 2区工程技术

Powder Technology Pub Date : 2025-02-25 DOI: 10.1016/j.powtec.2025.120841

Shukai Zhang , Xiaopeng Wang , Lu Zhang

{"title":"The influence of filling ratio and container geometry on granular convection and the dynamical mechanisms of three unconventional convection patterns in a vibrated granular bed","authors":"Shukai Zhang , Xiaopeng Wang , Lu Zhang","doi":"10.1016/j.powtec.2025.120841","DOIUrl":"10.1016/j.powtec.2025.120841","url":null,"abstract":"<div><div>Granular convection typically refers to the cyclic flow phenomenon observed in dense granular systems subjected to vertical sinusoidal vibration, where discrete particles descend along the container walls and rise in the center of the container. This process plays a crucial role in the overall transport and mixing of particles and has important applications in vibration processing techniques, such as Resonant Acoustic Mixing (RAM). However, current research on the changes in convection flow patterns and underlying mechanisms under conditions of low aspect ratio containers (< 1:4), high filling ratios of granular systems (nearly full), and inclined container walls is limited. Under these atypical conditions, the forms of granular convection and the associated dynamical mechanisms remain unclear. This study focuses on the effects of these three parameters on granular convection, employing the Discrete Element Method (DEM) to simulate and analyze granular convection phenomena in a 3D container. The results indicate that a multilayer convection pattern emerges under low aspect ratio conditions, a centrosymmetric convection pattern appears under nearly full-filling conditions, and a reverse convection pattern develops under inclined wall conditions. Furthermore, we analyze and explain the dynamical mechanisms behind these three unconventional convection patterns: the multilayer convection pattern arises from the longer time required for vibrations to propagate to higher positions in low aspect ratio conditions; the centrosymmetric convection pattern is caused by the top of the container becoming a new source of excitation; the dynamical mechanism of the reverse convection pattern not only involves shear forces along the walls but also considers the normal support force from the walls as a new driving force for convection. These findings are expected to provide theoretical support for granular convection control.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120841"},"PeriodicalIF":4.5,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cleaning performance of an electrodynamic dust shield under low-frequency vibrations

IF 4.5 2区工程技术

Powder Technology Pub Date : 2025-02-25 DOI: 10.1016/j.powtec.2025.120845

Ryudai Nitano , Shunsuke Mitsunaga , Shuntaro Yamato , Kosuke Tanaka , Hiroshi Kanamori , Masato Adachi

{"title":"Cleaning performance of an electrodynamic dust shield under low-frequency vibrations","authors":"Ryudai Nitano , Shunsuke Mitsunaga , Shuntaro Yamato , Kosuke Tanaka , Hiroshi Kanamori , Masato Adachi","doi":"10.1016/j.powtec.2025.120845","DOIUrl":"10.1016/j.powtec.2025.120845","url":null,"abstract":"<div><div>Dust mitigation is one of the most critical challenges in lunar exploration activities, and an electrodynamic dust shield (EDS) has been developed as a promising technology for dust removal. This paper presents an investigation combining an EDS with the assistance of low-frequency vibrations. Cleaning experiments were conducted on size-sorted particles of the lunar-regolith simulant using an EDS system mounted on vibrating stages, where the vibration frequency, amplitude, strength, and direction could be varied. Experimental results revealed that the assistance of horizontal vibration combined with the electrostatic force led to higher removal efficiencies for small- and medium-sized particles (with diameters less than 25 μm, in the range 50–75 μm, respectively). The horizontal vibration caused the rotational motion of aggregates of small- and medium-sized particles, enhancing their transport by the electrostatic traveling wave. The vibration itself was the dominant force that contributed to cleaning of the larger particles with diameters of 250–500 μm. Increasing the vibration intensity improved removal efficiency.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120845"},"PeriodicalIF":4.5,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0