Pub Date : 2025-02-15DOI: 10.1016/j.powtec.2025.120806
Yida Zhang, Shiliang Yang, Jianhang Hu, Hua Wang
Cyclone separators are extensively utilized in the mining, metallurgy, and energy industries due to their high efficiency in gas-solid separation. This study simulates gas-solid two-phase flow within a cyclone separator using the Eulerian-Lagrangian approach, with the mathematical model validated through experimental data. The influence of draft plates and inclination angle on flow patterns, particle dynamics, and separation efficiency is thoroughly investigated. The findings reveal that the incorporation of guide plates reduces energy losses and mitigates the detrimental effects of short-circuit flow on separator performance. Specifically, the pressure drop decreases as the draft plate angle increases, while a smaller draft plate angle significantly reduces short-circuit flow and enhances system stability. Moreover, draft plates effectively decrease the frequency of particle-wall collisions. At an optimal draft plate angle of 90°, the pressure drop is reduced by 71 %, and the short-circuit flow length decreases by 27 % compared to a traditional cyclone separator, indicating improved performance. Overall, this study demonstrates that the use of draft plates markedly enhances gas-solid phase interactions in cyclone separators.
{"title":"Impact of draft plate on the separation performance of gas-solid cyclone separator","authors":"Yida Zhang, Shiliang Yang, Jianhang Hu, Hua Wang","doi":"10.1016/j.powtec.2025.120806","DOIUrl":"10.1016/j.powtec.2025.120806","url":null,"abstract":"<div><div>Cyclone separators are extensively utilized in the mining, metallurgy, and energy industries due to their high efficiency in gas-solid separation. This study simulates gas-solid two-phase flow within a cyclone separator using the Eulerian-Lagrangian approach, with the mathematical model validated through experimental data. The influence of draft plates and inclination angle on flow patterns, particle dynamics, and separation efficiency is thoroughly investigated. The findings reveal that the incorporation of guide plates reduces energy losses and mitigates the detrimental effects of short-circuit flow on separator performance. Specifically, the pressure drop decreases as the draft plate angle increases, while a smaller draft plate angle significantly reduces short-circuit flow and enhances system stability. Moreover, draft plates effectively decrease the frequency of particle-wall collisions. At an optimal draft plate angle of 90°, the pressure drop is reduced by 71 %, and the short-circuit flow length decreases by 27 % compared to a traditional cyclone separator, indicating improved performance. Overall, this study demonstrates that the use of draft plates markedly enhances gas-solid phase interactions in cyclone separators.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120806"},"PeriodicalIF":4.5,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-15DOI: 10.1016/j.powtec.2025.120757
Jiaxin Liu , Zhongkui Wang , Yang Tian , Longchuan Li , Shugen Ma
The real-time modeling of interaction forces is essential for designing and controlling machines that traverse and manipulate granular materials. In a previous study, we analyzed the effects of motion-induced surface deformation at different depths and developed a depth-dependent drag force model based on the principles of resistive force theory (RFT). Through an energy variation analysis, we identified two primary factors that influence environmental changes: the generation of granular piles and changes in the local packing state. However, the role of object orientation has remained unexplored. In this study, we bridge this gap and extend the analysis to account for both depths and orientations, broadening the applicability of the model. To quantify the effect of orientation, we introduce the elastic potential energy as a measure of the packing state of granular media. This consideration contributes to integrating the induced surface deformation into the drag force model, providing physical insights into the prediction process. The model was validated through plate drag experiments and applied to predict the drag force of multi-connected plates, enhancing the accuracy of drag force prediction in scenarios involving significant surface changes. This real-time model offers a practical alternative to time-consuming computational methods, such as the discrete element method, enabling efficient analysis for a broader range of applications.
{"title":"Drag force modeling with induced surface deformation in granular media","authors":"Jiaxin Liu , Zhongkui Wang , Yang Tian , Longchuan Li , Shugen Ma","doi":"10.1016/j.powtec.2025.120757","DOIUrl":"10.1016/j.powtec.2025.120757","url":null,"abstract":"<div><div>The real-time modeling of interaction forces is essential for designing and controlling machines that traverse and manipulate granular materials. In a previous study, we analyzed the effects of motion-induced surface deformation at different depths and developed a depth-dependent drag force model based on the principles of resistive force theory (RFT). Through an energy variation analysis, we identified two primary factors that influence environmental changes: the generation of granular piles and changes in the local packing state. However, the role of object orientation has remained unexplored. In this study, we bridge this gap and extend the analysis to account for both depths and orientations, broadening the applicability of the model. To quantify the effect of orientation, we introduce the elastic potential energy as a measure of the packing state of granular media. This consideration contributes to integrating the induced surface deformation into the drag force model, providing physical insights into the prediction process. The model was validated through plate drag experiments and applied to predict the drag force of multi-connected plates, enhancing the accuracy of drag force prediction in scenarios involving significant surface changes. This real-time model offers a practical alternative to time-consuming computational methods, such as the discrete element method, enabling efficient analysis for a broader range of applications.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"455 ","pages":"Article 120757"},"PeriodicalIF":4.5,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438038","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}
Pub Date : 2025-02-14DOI: 10.1016/j.powtec.2025.120798
Yang Wang , Wei Guan , Yan Wang
Impact sampling on small bodies has been proven feasible. However, particle flow laws during regolith sampling are unclear, and existing sampling mechanisms have significant potential for improvement. In this study, the discrete element method and multi-body dynamics (DEM-MBD) coupling model is used to explore the particle flow laws, and an efficient impact sampling strategy is developed which can significantly improve the collected particle mass. Two projectiles are placed symmetrically around the end of the sampler and fired simultaneously. In the event that only one projectile is successfully fired, the collected mass is still 7.9 times higher than that of existing sampling method. As particles accumulate near the transporting pipe, a clogging state occurs and obstructs the particle flow, causing the mass flow rate to drop rapidly. Particle clogging can be effectively reduced using a sampling strategy in which the probe reaches the target position and then fires the projectiles. We show that the particle-probe interaction can interfere with position and attitude of the probe and eventually reduce the collected mass of particles. To solve this problem, a proportional derivative (PD) controller is designed to stabilize the attitude and position of the probe. An ejection angle of 54° can significantly improve the sampling efficiency by balancing the number of driven particles and vertical velocity, and the particle mass obtained is 31 times higher than that of the existing method.
{"title":"An efficient impact sampling strategy for small-body regolith: Dependence of collected mass on projectile ejection","authors":"Yang Wang , Wei Guan , Yan Wang","doi":"10.1016/j.powtec.2025.120798","DOIUrl":"10.1016/j.powtec.2025.120798","url":null,"abstract":"<div><div>Impact sampling on small bodies has been proven feasible. However, particle flow laws during regolith sampling are unclear, and existing sampling mechanisms have significant potential for improvement. In this study, the discrete element method and multi-body dynamics (DEM-MBD) coupling model is used to explore the particle flow laws, and an efficient impact sampling strategy is developed which can significantly improve the collected particle mass. Two projectiles are placed symmetrically around the end of the sampler and fired simultaneously. In the event that only one projectile is successfully fired, the collected mass is still 7.9 times higher than that of existing sampling method. As particles accumulate near the transporting pipe, a clogging state occurs and obstructs the particle flow, causing the mass flow rate to drop rapidly. Particle clogging can be effectively reduced using a sampling strategy in which the probe reaches the target position and then fires the projectiles. We show that the particle-probe interaction can interfere with position and attitude of the probe and eventually reduce the collected mass of particles. To solve this problem, a proportional derivative (PD) controller is designed to stabilize the attitude and position of the probe. An ejection angle of 54° can significantly improve the sampling efficiency by balancing the number of driven particles and vertical velocity, and the particle mass obtained is 31 times higher than that of the existing method.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"455 ","pages":"Article 120798"},"PeriodicalIF":4.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-14DOI: 10.1016/j.powtec.2025.120800
Yichen Shan , Shiyu Zhuang , Xiao Yu
Phosphorus slag is a potential high-valued mineral admixture of concrete, which can be ground into ultrafine powder to increase utilization efficiency. However, little is known about the impact of phosphorus slag fineness on the workability of cement paste. In this work, the influence of ultrafine phosphorus slag (UPS) on the workability of cement paste was in-depth investigated. Results show that with addition of UPS, the delay of hydration exothermic peak and the extension of setting time are more obvious than those with ordinary phosphorus slag (OPS). However, the fluidity and rheological properties show reverse trends. UPS paste exhibits a faster fluidity loss and a more rapid increase in yield stress compared with OPS paste. It reflected that in OPS paste, the chemical retarding effect of OPS on cement hydration is the primary factor driving the workability, while in UPS paste, it is the physical flocculation effect of UPS that plays an important role.
{"title":"Understanding the impact of ultrafine phosphorus slag on the workability of cement paste","authors":"Yichen Shan , Shiyu Zhuang , Xiao Yu","doi":"10.1016/j.powtec.2025.120800","DOIUrl":"10.1016/j.powtec.2025.120800","url":null,"abstract":"<div><div>Phosphorus slag is a potential high-valued mineral admixture of concrete, which can be ground into ultrafine powder to increase utilization efficiency. However, little is known about the impact of phosphorus slag fineness on the workability of cement paste. In this work, the influence of ultrafine phosphorus slag (UPS) on the workability of cement paste was in-depth investigated. Results show that with addition of UPS, the delay of hydration exothermic peak and the extension of setting time are more obvious than those with ordinary phosphorus slag (OPS). However, the fluidity and rheological properties show reverse trends. UPS paste exhibits a faster fluidity loss and a more rapid increase in yield stress compared with OPS paste. It reflected that in OPS paste, the chemical retarding effect of OPS on cement hydration is the primary factor driving the workability, while in UPS paste, it is the physical flocculation effect of UPS that plays an important role.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"455 ","pages":"Article 120800"},"PeriodicalIF":4.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-14DOI: 10.1016/j.powtec.2025.120808
Qinwen Liu , Wenqi Zhong , Aibing Yu
The oxy-fuel co-firing of coal and biomass in a pressurized fluidized bed (POFB), which integrates the benefits of pressurized oxy-fuel combustion, fluidized bed technology, and biomass as a carbon-neutral fuel, has been identified as a promising and innovative approach for low-cost CO2 capture and environmentally friendly waste disposal. However, experimentation and numerical simulations remain both challenging and limited. In this study, a 3D Eulerian-Lagrangian model based on the MP-PIC scheme was further developed, and was validated through our continuously running 10 kWth POFB tests. The effects of the combustion pressure (P) on gas–solid flow and reaction characteristics were analysed. The results showed that the model accurately predicted flow structure, temperature, and composition of CO2, CO, O2, NO, N2O, and SO2, under both atmospheric and pressurized combustion. When P increased, the POFB operated under both the CH mode (i.e., unchanged flow structure and heat input) and IH mode (i.e., unchanged local apparent gas velocity but increased heat input) constructed favourable gas–solid flow and chemical reaction conditions. Notably, increasing P under the IH mode enhanced the uniformity of the particle distribution along the axial direction and radial ring-core structure. The results demonstrated that increasing P not only led to a better temperature distribution and higher CO2 concentration in the flue gas but also reduced pollutants emissions. Overall, this study advanced the development of numerical models and obtained a series of results that are difficult to achieve through experiments, offering valuable support for the design, optimisation, and scaling up of POFB.
{"title":"Study on the gas-solid flow and reaction characteristics of oxy-fuel co-firing of coal and biomass in a pressurized fluidized bed by 3D Eulerian-Lagrangian modelling","authors":"Qinwen Liu , Wenqi Zhong , Aibing Yu","doi":"10.1016/j.powtec.2025.120808","DOIUrl":"10.1016/j.powtec.2025.120808","url":null,"abstract":"<div><div>The oxy-fuel co-firing of coal and biomass in a pressurized fluidized bed (POFB), which integrates the benefits of pressurized oxy-fuel combustion, fluidized bed technology, and biomass as a carbon-neutral fuel, has been identified as a promising and innovative approach for low-cost CO<sub>2</sub> capture and environmentally friendly waste disposal. However, experimentation and numerical simulations remain both challenging and limited. In this study, a 3D Eulerian-Lagrangian model based on the MP-PIC scheme was further developed, and was validated through our continuously running 10 kW<sub>th</sub> POFB tests. The effects of the combustion pressure (<em>P</em>) on gas–solid flow and reaction characteristics were analysed. The results showed that the model accurately predicted flow structure, temperature, and composition of CO<sub>2</sub>, CO, O<sub>2</sub>, NO, N<sub>2</sub>O, and SO<sub>2</sub>, under both atmospheric and pressurized combustion. When <em>P</em> increased, the POFB operated under both the CH mode (i.e., unchanged flow structure and heat input) and IH mode (i.e., unchanged local apparent gas velocity but increased heat input) constructed favourable gas–solid flow and chemical reaction conditions. Notably, increasing <em>P</em> under the IH mode enhanced the uniformity of the particle distribution along the axial direction and radial ring-core structure. The results demonstrated that increasing <em>P</em> not only led to a better temperature distribution and higher CO<sub>2</sub> concentration in the flue gas but also reduced pollutants emissions. Overall, this study advanced the development of numerical models and obtained a series of results that are difficult to achieve through experiments, offering valuable support for the design, optimisation, and scaling up of POFB.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120808"},"PeriodicalIF":4.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143519205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-14DOI: 10.1016/j.powtec.2025.120802
Gang Zhou , Zengxin Liu , Guochao Yan , Jingxu Chen , Biao Sun , Jianjun Yao , Xiangyan Zhang , Hanxu Guo
Quantifying the deposition of respirable dust in the respiratory tract under coal mining production conditions is essential for effectively improving industrial dust control technologies and developing occupational protective equipment. This study designed a series of test experiments to investigate dust exposure, with a focus on the impact of inhalable dust dispersion on the respiratory tracts of workers. The overall study encompassed three main components: the setup of respiratory parameters, fluorescence tracing experiments, and particle deposition tests in the respiratory tract. The validation of the experiments was carried out using bidirectional coupling simulations based on CFD-DEM. The study tested the performance of common dust-proof masks in coal mining using an occupational disease detection platform. The results indicate that the overall particle deposition is highest in the lobar bronchi, with the deposition rate in the right lobar bronchi showing the most significant variation with particle size. For particles smaller than 10 μm depositing in the respiratory tract, inertial impaction is the dominant factor. This phenomenon becomes more pronounced with increasing breathing intensity. The increase in flow velocity facilitates the dispersion and dilution of particles. The deposition rate of 1 μm particles is hardly influenced by breathing intensity. For particles smaller than 5 μm, the escape rate exceeds 90 %.
{"title":"Study on dust exposure levels and respiratory particle deposition patterns of workers in respirable dust environments","authors":"Gang Zhou , Zengxin Liu , Guochao Yan , Jingxu Chen , Biao Sun , Jianjun Yao , Xiangyan Zhang , Hanxu Guo","doi":"10.1016/j.powtec.2025.120802","DOIUrl":"10.1016/j.powtec.2025.120802","url":null,"abstract":"<div><div>Quantifying the deposition of respirable dust in the respiratory tract under coal mining production conditions is essential for effectively improving industrial dust control technologies and developing occupational protective equipment. This study designed a series of test experiments to investigate dust exposure, with a focus on the impact of inhalable dust dispersion on the respiratory tracts of workers. The overall study encompassed three main components: the setup of respiratory parameters, fluorescence tracing experiments, and particle deposition tests in the respiratory tract. The validation of the experiments was carried out using bidirectional coupling simulations based on CFD-DEM. The study tested the performance of common dust-proof masks in coal mining using an occupational disease detection platform. The results indicate that the overall particle deposition is highest in the lobar bronchi, with the deposition rate in the right lobar bronchi showing the most significant variation with particle size. For particles smaller than 10 μm depositing in the respiratory tract, inertial impaction is the dominant factor. This phenomenon becomes more pronounced with increasing breathing intensity. The increase in flow velocity facilitates the dispersion and dilution of particles. The deposition rate of 1 μm particles is hardly influenced by breathing intensity. For particles smaller than 5 μm, the escape rate exceeds 90 %.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120802"},"PeriodicalIF":4.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-14DOI: 10.1016/j.powtec.2025.120805
Jitao Liu , Xiaobing Liu , Xiao Chang , Bei Qin , Jiayang Pang , Zhenming Lai , Dengyun Jiang , Mengjun Qin , Bing Yao , Yongzhong Zeng
Turbine sediment erosion, which often leads to a reduction in turbine efficiency, damage to Pelton turbine, a reduction in operational stability (especially for 100 MW–500 MW turbines), and frequent overhauling, is a serious problem in plants with high sediment concentrations in the water, resulting in considerable economic losses. Hence, research into sediment erosion in Pelton turbines in sandy rivers aims to uncover the mechanism behind the sediment erosion of Pelton turbines. This investigation holds significant implications for the design and operation of Pelton hydropower plants to combat sediment erosion. In this study, a model turbine with a runner diameter of 400 mm was developed. Through numerical simulations of the model turbine's internal flow and the prediction of sediment erosion, the study analyzed the distribution of sediment volume fraction (concentration) on the bucket's working surface during the intake, retention, and discharge stages, as well as the sediment velocity distribution. Furthermore, the impact of silt particle size on sediment erosion in the Pelton turbine bucket was examined. The effects of silt and water velocity and metal material on the sediment erosion of Pelton turbine buckets were determined through sediment erosion tests, in conjunction with internal flow simulation results. Thus, the sediment erosion mechanism of Pelton turbine buckets was elucidated.
{"title":"Research on the mechanism of sediment erosion in the bucket of a large-scale Pelton turbine at a hydropower station","authors":"Jitao Liu , Xiaobing Liu , Xiao Chang , Bei Qin , Jiayang Pang , Zhenming Lai , Dengyun Jiang , Mengjun Qin , Bing Yao , Yongzhong Zeng","doi":"10.1016/j.powtec.2025.120805","DOIUrl":"10.1016/j.powtec.2025.120805","url":null,"abstract":"<div><div>Turbine sediment erosion, which often leads to a reduction in turbine efficiency, damage to Pelton turbine, a reduction in operational stability (especially for 100 MW–500 MW turbines), and frequent overhauling, is a serious problem in plants with high sediment concentrations in the water, resulting in considerable economic losses. Hence, research into sediment erosion in Pelton turbines in sandy rivers aims to uncover the mechanism behind the sediment erosion of Pelton turbines. This investigation holds significant implications for the design and operation of Pelton hydropower plants to combat sediment erosion. In this study, a model turbine with a runner diameter of 400 mm was developed. Through numerical simulations of the model turbine's internal flow and the prediction of sediment erosion, the study analyzed the distribution of sediment volume fraction (concentration) on the bucket's working surface during the intake, retention, and discharge stages, as well as the sediment velocity distribution. Furthermore, the impact of silt particle size on sediment erosion in the Pelton turbine bucket was examined. The effects of silt and water velocity and metal material on the sediment erosion of Pelton turbine buckets were determined through sediment erosion tests, in conjunction with internal flow simulation results. Thus, the sediment erosion mechanism of Pelton turbine buckets was elucidated.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"455 ","pages":"Article 120805"},"PeriodicalIF":4.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-14DOI: 10.1016/j.powtec.2025.120801
Yingran Fang , Xinggao Li , Yidong Guo , Dalong Jin , Hongzhi Liu
The circulation system of the slurry Tunnel Boring Machine (TBM) plays a pivotal role in delivering the slurry to the excavation face and transporting the excavated rock particles to the ground. The severe vibration and significant wear induced by the transportation of large-sized particles in pressure pipelines constitute a complex multiphysics coupling problem. In this study, a numerical model of pressure pipeline conveying large-size rock particles is established based on CFD-DEM-FEM multifield coupling method with the background of a slurry TBM construction in Beijing. The engineering measured pipeline pressure loss and vibration data verified the reasonableness of the multifield coupling model. The U.S. pipeline vibration standard is introduced to systematically evaluate the vibration intensity of slurry TBM circulating pipeline. The effects of particle mass flow rate, particle size, slurry flow speed, slurry viscosity, pipeline wall thickness and fixed spacing on pipeline vibration and wear are investigated, and suggestions for the control of vibration and wear reduction in the circulating pipeline are proposed. The relevant conclusions can provide a reference for the long-term operation of slurry TBM circulation pipelines under complex geological conditions.
{"title":"Vibration and wear assessment of slurry TBM discharge pipeline transporting large sized rock particles: CFD-DEM-FEM multifield coupled simulation","authors":"Yingran Fang , Xinggao Li , Yidong Guo , Dalong Jin , Hongzhi Liu","doi":"10.1016/j.powtec.2025.120801","DOIUrl":"10.1016/j.powtec.2025.120801","url":null,"abstract":"<div><div>The circulation system of the slurry Tunnel Boring Machine (TBM) plays a pivotal role in delivering the slurry to the excavation face and transporting the excavated rock particles to the ground. The severe vibration and significant wear induced by the transportation of large-sized particles in pressure pipelines constitute a complex multiphysics coupling problem. In this study, a numerical model of pressure pipeline conveying large-size rock particles is established based on CFD-DEM-FEM multifield coupling method with the background of a slurry TBM construction in Beijing. The engineering measured pipeline pressure loss and vibration data verified the reasonableness of the multifield coupling model. The U.S. pipeline vibration standard is introduced to systematically evaluate the vibration intensity of slurry TBM circulating pipeline. The effects of particle mass flow rate, particle size, slurry flow speed, slurry viscosity, pipeline wall thickness and fixed spacing on pipeline vibration and wear are investigated, and suggestions for the control of vibration and wear reduction in the circulating pipeline are proposed. The relevant conclusions can provide a reference for the long-term operation of slurry TBM circulation pipelines under complex geological conditions.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"455 ","pages":"Article 120801"},"PeriodicalIF":4.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-13DOI: 10.1016/j.powtec.2025.120777
Shuqi Zhang , Jiangping Zhao , Yong Yang , YaChao Wang , Kainan Yu
To mitigate potential hazards of aluminum (Al) powder explosions, a green suppressant called MPP/ZB has been successfully produced using mechano-chemical technology. The suppressant consists of melamine polyphosphate (MPP) and zinc borate (ZB). This study examined the suppression effect of various mass concentrations of the composite suppressant on Al dust explosion. The results indicate that, with the addition of 100 wt% of MPP/ZB to the 300 g/m3 aluminum powder, Pmax and Kst decreased from 0.701 MPa and 8.7 MPa·m/s to 0.13 MPa and 0.2 MPa·m/s, respectively, effectively suppressing the explosions. Moreover, TG-DSC analysis of the suppressant and XPS/SEM examination of the explosion residues further revealed that the addition of ZB enhances the inhibitory effect of MPP on Al dust explosions. The H2O, Zn (OH)2 and ZnO produced by ZB decomposition reduce the concentration of NH3 generated by MPP decomposition, which may have a combustion promoting effect on Al dust.
{"title":"Suppression effect and mechanism of melamine polyphosphate /zinc borate composite suppressant on aluminum dust explosion","authors":"Shuqi Zhang , Jiangping Zhao , Yong Yang , YaChao Wang , Kainan Yu","doi":"10.1016/j.powtec.2025.120777","DOIUrl":"10.1016/j.powtec.2025.120777","url":null,"abstract":"<div><div>To mitigate potential hazards of aluminum (Al) powder explosions, a green suppressant called MPP/ZB has been successfully produced using mechano-chemical technology. The suppressant consists of melamine polyphosphate (MPP) and zinc borate (ZB). This study examined the suppression effect of various mass concentrations of the composite suppressant on Al dust explosion. The results indicate that, with the addition of 100 wt% of MPP/ZB to the 300 g/m<sup>3</sup> aluminum powder, P<sub>max</sub> and K<sub>st</sub> decreased from 0.701 MPa and 8.7 MPa·m/s to 0.13 MPa and 0.2 MPa·m/s, respectively, effectively suppressing the explosions. Moreover, TG-DSC analysis of the suppressant and XPS/SEM examination of the explosion residues further revealed that the addition of ZB enhances the inhibitory effect of MPP on Al dust explosions. The H<sub>2</sub>O, Zn (OH)<sub>2</sub> and ZnO produced by ZB decomposition reduce the concentration of NH<sub>3</sub> generated by MPP decomposition, which may have a combustion promoting effect on Al dust.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"456 ","pages":"Article 120777"},"PeriodicalIF":4.5,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-13DOI: 10.1016/j.powtec.2025.120789
Dong Yan , Hongzhong Li , Qingshan Zhu , Zheng Zou
The heterogeneous structure is considered to improve the theoretical prediction of gas-solid hydrodynamics in pressurized bubbling fluidized beds. The two-fluid simulation shows that the traditional unmodified Gidaspow model overestimates the gas-solid coefficient and bed expansion. As a comparison, the simulations which consider the meso-scale structures predict the reduced gas-solid drag coefficients and the reasonable bed expansions especially at high superficial gas velocities. The decrease in the dimensionless gas-solid drag coefficient with the elevated pressure indicates that the drag modification based on the heterogeneous structure is essential. The parameter sensitivity analysis demonstrates that the effect of the elevated pressure on the gas-solid drag force should be mainly attributed to the changes in minimum fluidization velocity, while the bubble behaviors contribute slightly. Moreover, the gas-solid slip velocity shows a surprisingly uniform distribution, which verifies the dynamic steady state of gas-solid interaction in bubbling fluidized beds.
{"title":"Theoretical analysis and numerical simulation of the gas-solid hydrodynamics in pressurized bubbling fluidized beds","authors":"Dong Yan , Hongzhong Li , Qingshan Zhu , Zheng Zou","doi":"10.1016/j.powtec.2025.120789","DOIUrl":"10.1016/j.powtec.2025.120789","url":null,"abstract":"<div><div>The heterogeneous structure is considered to improve the theoretical prediction of gas-solid hydrodynamics in pressurized bubbling fluidized beds. The two-fluid simulation shows that the traditional unmodified Gidaspow model overestimates the gas-solid coefficient and bed expansion. As a comparison, the simulations which consider the meso-scale structures predict the reduced gas-solid drag coefficients and the reasonable bed expansions especially at high superficial gas velocities. The decrease in the dimensionless gas-solid drag coefficient with the elevated pressure indicates that the drag modification based on the heterogeneous structure is essential. The parameter sensitivity analysis demonstrates that the effect of the elevated pressure on the gas-solid drag force should be mainly attributed to the changes in minimum fluidization velocity, while the bubble behaviors contribute slightly. Moreover, the gas-solid slip velocity shows a surprisingly uniform distribution, which verifies the dynamic steady state of gas-solid interaction in bubbling fluidized beds.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"455 ","pages":"Article 120789"},"PeriodicalIF":4.5,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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