Powder Technology最新文献

Simultaneous measurement of the 3D position, refractive index and droplet size of transparent spherical droplets using three-dimensional rainbow refractometry

IF 4.5 2区工程技术

Powder Technology Pub Date : 2025-02-28 DOI: 10.1016/j.powtec.2025.120818

Zhiwen Deng , Zhiming Lin , Xuecheng Wu , Yuxuan Zhao , Qiwen Jin , Yingchun Wu , Yongxin Zhang , Chenghang Zheng

{"title":"Simultaneous measurement of the 3D position, refractive index and droplet size of transparent spherical droplets using three-dimensional rainbow refractometry","authors":"Zhiwen Deng , Zhiming Lin , Xuecheng Wu , Yuxuan Zhao , Qiwen Jin , Yingchun Wu , Yongxin Zhang , Chenghang Zheng","doi":"10.1016/j.powtec.2025.120818","DOIUrl":"10.1016/j.powtec.2025.120818","url":null,"abstract":"<div><div>In this study, we investigate three-dimensional rainbow refractometry (TDRR) as a method for estimating the 3D position, refractive index, and droplet size of transparent spherical droplets. The principles governing the variation of rainbow signals with axial position under cylindrical lens modulation are elucidated, allowing for estimation of the droplet’s axial position based on fringe rotation angles. We also present a novel calibration technique for absolute scattering angles in TDRR measurements and propose an innovative data processing approach. A comprehensive TDRR system has been constructed to validate measurements of monodisperse water droplet flows. The results indicate that the error in 3D position measurement is less than 3%, while the absolute error in refractive index measurement is below 0.0015 and droplet size errors remain under 5%. As a new technique for simultaneous droplet positioning and multi-parameter assessment, TDRR offers significant advantages for investigating droplet interactions and dynamics in a large space.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120818"},"PeriodicalIF":4.5,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529344","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

Experimental study on the agglomeration of fire smoke by flow-sound-separation Hartmann whistle with swirl characteristics

IF 4.5 2区工程技术

Powder Technology Pub Date : 2025-02-24 DOI: 10.1016/j.powtec.2025.120835

Weihua Li, Guangxue Zhang, Shu Liu, Sirui Tong, Dingkun Yuan, Yunchao Li, Hailin Gu, Jiangrong Xu

引用次数: 0

Toward refinement and homogenization of heterogeneous metal nanoparticle prepared by electrical explosion with spatial filter

IF 4.5 2区工程技术

Powder Technology Pub Date : 2025-02-24 DOI: 10.1016/j.powtec.2025.120836

Ruoyu Han , Shuhan Liu , Jingran Li , Jie Bai , Xinxuan Xian , Chen Li , Jinhao Wu , Sichao Qin , Xi Chen

{"title":"Toward refinement and homogenization of heterogeneous metal nanoparticle prepared by electrical explosion with spatial filter","authors":"Ruoyu Han , Shuhan Liu , Jingran Li , Jie Bai , Xinxuan Xian , Chen Li , Jinhao Wu , Sichao Qin , Xi Chen","doi":"10.1016/j.powtec.2025.120836","DOIUrl":"10.1016/j.powtec.2025.120836","url":null,"abstract":"<div><div>The ability to synthesize nanoparticles (NPs) with desirable structural/compositional properties has been the driving goal of functional material applications. As a “one-step” evaporation-condensation method for NPs production, the electrical explosion can achieve ultrafast heating/quenching rates (d<em>T</em>/d<em>t</em> ∼ 10<sup>10</sup> K/s) of current-carrying metals. This study proposes a spatial filter to control explosion energy release and product quenching procedure. A supersonic plasma jet (>2 Mach) erupts through the small hole of the filter, forming a high-pressure homogenizer structure, enhancing the diffusion and cooling down of explosion products. Microscopic characterization indicates NPs size decreases from 46.3<sup>±16.7</sup> to 27.7<sup>±7.7</sup> nm. Structural study has yielded two assembly routes of NPs: the first involves the top-down approach (Cu particles >100 nm), while the second concerns the bottom-up way (Cu and Cu<sub>x</sub>O NPs <100 nm). The improved performance is attributed to the multi-stage control of explosion products, resulting in less instability development and a more reasonable evaporation-condensation process.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120836"},"PeriodicalIF":4.5,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529343","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 particle jet in supercritical water environment based on an improved coarse-grained CFD-DEM method

IF 4.5 2区工程技术

Powder Technology Pub Date : 2025-02-24 DOI: 10.1016/j.powtec.2025.120833

Chuan Zhang, Shenghui Guo, Fei Shang, Zhiwei Ge, Liejin Guo

{"title":"Numerical simulation of particle jet in supercritical water environment based on an improved coarse-grained CFD-DEM method","authors":"Chuan Zhang, Shenghui Guo, Fei Shang, Zhiwei Ge, Liejin Guo","doi":"10.1016/j.powtec.2025.120833","DOIUrl":"10.1016/j.powtec.2025.120833","url":null,"abstract":"<div><div>Supercritical water gasification is an innovative way to clean and green coal conversion. Nevertheless, the flow dynamics of the fluid-particle introduced into the reactor via the nozzle still require further investigation. In this study, the fluid-particle flow dynamics within the supercritical water environment are examined by an improved Coarse-grained CFD-DEM method. The fluid flow field, particle evolution process, particle velocity and temperature distributions, as well as the particle forces and energy variations during evolution are analyze. The primary findings indicate that the instability of the jet flow field in a supercritical water environment is amplified with a reduction in incident temperature, thereby enhancing heat transfer and mixing. The violent perturbations between the fluid and the particles result in a more complex particle evolution process. In contrast, incidence conditions of transcritical and supercritical have no significant effect on the particle velocity distribution. Furthermore, the variation of particle temperature along the jet axis approaches the incident temperature as the incident temperature increases. Additionally, the particle drag force accounts for 70 % of the total force, and its translational and rotational kinetic energy decreases with increasing incident temperature. This research reveals the mechanism of particle dispersion in supercritical water environment, and supplies a reference for optimized configuration of supercritical water gasification reactor and the improvement of model.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120833"},"PeriodicalIF":4.5,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512400","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

Tailored cellulose-based flocculants for microplastics removal: Mechanistic insights, pH influence, and efficiency optimization

IF 4.5 2区工程技术

Powder Technology Pub Date : 2025-02-24 DOI: 10.1016/j.powtec.2025.120838

Solange Magalhães , Magnus Norgren , Luís Alves , Bruno Medronho , Maria da Graça Rasteiro

{"title":"Tailored cellulose-based flocculants for microplastics removal: Mechanistic insights, pH influence, and efficiency optimization","authors":"Solange Magalhães , Magnus Norgren , Luís Alves , Bruno Medronho , Maria da Graça Rasteiro","doi":"10.1016/j.powtec.2025.120838","DOIUrl":"10.1016/j.powtec.2025.120838","url":null,"abstract":"<div><div>This study explores the performance of novel cellulose-derived sustainable flocculants in the flocculation of different model microplastics (MPs), including polyethylene (PE), polyethylene terephthalate (PET) and polyvinyl chloride (PVC). The influence of key parameters, such as pH, flocculant structure and concentration was evaluated by Laser Diffraction Spectroscopy (LDS) and optical microscopy to access their effects on flocculation performance, kinetics and floc structure. The results reveal that a bioflocculant concentration of 0.001 g·mL<sup>−1</sup> is ideal for effective flocculation, as lower concentrations lead to insufficient floc growth. While electrostatic interactions are a dominant factor in the flocculation process, the study also highlights the role of hydrophobic interactions, its contribution depending on the characteristics of the MPs. Overall, this research highlights the importance of understanding the key interactions governing the flocculation process. It further paves the way for designing and fine-tuning cellulose-based flocculants with improved efficiency and optimized dosages for effective MPs removal strategies.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120838"},"PeriodicalIF":4.5,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512396","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