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Nie W, Jiang C, Sun N, Guo L, Liu Q, Liu C, Niu W. CFD-based simulation study of dust transport law and air age in tunnel under different ventilation methods. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:114484-114500. [PMID: 37861825 DOI: 10.1007/s11356-023-30286-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 10/02/2023] [Indexed: 10/21/2023]
Abstract
To solve the problem of high-concentration dust pollution in a bored tunnel, we conducted a simulation study on the dust transport law and air age of the wind flow in a bored tunnel under different ventilation methods. Air age was innovatively introduced as an index for evaluating tunnel air quality. The results show that dust pollution is serious under conditions of press-in ventilation, which is unfavorable to personnel operations. Following the installation of an on-board dust-removal fan, an effective dust-control air curtain forms in the tunnel, and the high-concentration dust is essentially controlled within the range of Z = 13 m from the working face. The dust concentration in the working area on the left side of the tunnel is CD < 200 mg/m3, and the dust-control effect is obvious. At the same time, the air age on both sides of the tunnel is reduced by 35.5% following the use of the on-board dust-removal fan. Taking into account dust control by ventilation and dust removal by fan, spraying dust reduction measures are added, and we developed automated wind-mist synergistic wet high-frequency oscillation dust-capturing technology for tunnel boring. This could effectively improve the problem of high levels of coal dust pollution in tunnels.
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Affiliation(s)
- Wen Nie
- College of Safety and Environmental Engineering, Shandong University of Science and Technology, Shandong Province, Qingdao, 266590, China
- State Key Laboratory of Mining Disaster Prevention and Control Co-Found By Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao, 266590, China
| | - Chenwang Jiang
- College of Safety and Environmental Engineering, Shandong University of Science and Technology, Shandong Province, Qingdao, 266590, China
- State Key Laboratory of Mining Disaster Prevention and Control Co-Found By Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao, 266590, China
| | - Ning Sun
- College of Safety and Environmental Engineering, Shandong University of Science and Technology, Shandong Province, Qingdao, 266590, China
- State Key Laboratory of Mining Disaster Prevention and Control Co-Found By Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao, 266590, China
| | - Lidian Guo
- College of Safety and Environmental Engineering, Shandong University of Science and Technology, Shandong Province, Qingdao, 266590, China.
- State Key Laboratory of Mining Disaster Prevention and Control Co-Found By Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao, 266590, China.
| | - Qiang Liu
- College of Safety and Environmental Engineering, Shandong University of Science and Technology, Shandong Province, Qingdao, 266590, China
- State Key Laboratory of Mining Disaster Prevention and Control Co-Found By Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao, 266590, China
| | - Chengyi Liu
- College of Safety and Environmental Engineering, Shandong University of Science and Technology, Shandong Province, Qingdao, 266590, China
- State Key Laboratory of Mining Disaster Prevention and Control Co-Found By Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao, 266590, China
| | - Wenjin Niu
- College of Safety and Environmental Engineering, Shandong University of Science and Technology, Shandong Province, Qingdao, 266590, China
- State Key Laboratory of Mining Disaster Prevention and Control Co-Found By Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao, 266590, China
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Tan H, Wong KY, Othman MHD, Kek HY, Wahab RA, Ern GKP, Chong WT, Lee KQ. Current and potential approaches on assessing airflow and particle dispersion in healthcare facilities: a systematic review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:80137-80160. [PMID: 36194323 PMCID: PMC9531230 DOI: 10.1007/s11356-022-23407-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 09/27/2022] [Indexed: 06/04/2023]
Abstract
An indoor environment in a hospital building requires a high indoor air quality (IAQ) to overcome patients' risks of getting wound infections without interrupting the recovery process. However, several problems arose in obtaining a satisfactory IAQ, such as poor ventilation design strategies, insufficient air exchange, improper medical equipment placement and high door opening frequency. This paper presents an overview of various methods used for assessing the IAQ in hospital facilities, especially in an operating room, isolation room, anteroom, postoperative room, inpatient room and dentistry room. This review shows that both experimental and numerical methods demonstrated their advantages in the IAQ assessment. It was revealed that both airflow and particle tracking models could result in different particle dispersion predictions. The model selection should depend on the compatibility of the simulated result with the experimental measurement data. The primary and secondary forces affecting the characteristics of particle dispersion were also discussed in detail. The main contributing forces to the trajectory characteristics of a particle could be attributed to the gravitational force and drag force regardless of particle size. Meanwhile, the additional forces could be considered when there involves temperature gradient, intense light source, submicron particle, etc. The particle size concerned in a healthcare facility should be less than 20 μm as this particle size range showed a closer relationship with the virus load and a higher tendency to remain airborne. Also, further research opportunities that reflect a more realistic approach and improvement in the current assessment approach were proposed.
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Affiliation(s)
- Huiyi Tan
- School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Johor, Malaysia
| | - Keng Yinn Wong
- School of Mechanical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Johor, Malaysia.
| | - Mohd Hafiz Dzarfan Othman
- Advanced Membrane Technology Research Centre (AMTEC), Universiti Teknologi Malaysia, Johor, Malaysia
| | - Hong Yee Kek
- School of Mechanical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Johor, Malaysia
| | - Roswanira Abdul Wahab
- Advanced Membrane Technology Research Centre (AMTEC), Universiti Teknologi Malaysia, Johor, Malaysia
- Department of Chemistry, Faculty of Sciences, Universiti Teknologi Malaysia, Johor, Malaysia
| | - Garry Kuan Pei Ern
- School of Health Science, Universiti Sains Malaysia, Kelantan, Malaysia
- Department of Life Sciences, Brunel University, Uxbridge, London, UK
| | - Wen Tong Chong
- Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia
| | - Kee Quen Lee
- Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia Kuala Lumpur, 54100, Kuala Lumpur, Malaysia
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Research on a New Drag Force Model for Cylindrical Particles in Fixed Bed Reactors. Catalysts 2022. [DOI: 10.3390/catal12101120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Fixed bed reactors play an important role in converting solid wastes to high-quality products. The solid wastes, as well as the corresponding catalysts, are often made into cylindrical particles. However, research on the drag force for cylindrical particles is still rarely reported. In this work, the fixed bed porosity was firstly predicted with the unresolved CFD-DEM method and validated against experimental data. Then, the Ergun model, Di Felice model, and Ganser model were evaluated against the reported pressure drop data for both the spherical and cylindrical particles, so that a more solid drag force theory could be selected as a candidate for cylindrical particles. Finally, a new Ganser model was proposed for cylindrical particle drag force prediction based on the reported experimental results and validated by other experimental data. It was found that, for the spherical particle bed, the relative prediction errors of the Di Felice model are approximately 10%, while those of the Ergun model are approximately 15%. For the cylindrical particle bed, the relative prediction errors of the Ganser model are approximately 10%, while those of the Di Felice model are much higher than 10%. With the new Ganser model proposed in this work, the maximum error between the predicted pressure drop and the experimental data can be lowered to approximately 5%. The research is of reference value for drag force model selection when simulating similar FBRs with cylindrical particles.
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Madlmeir S, Forgber T, Trogrlic M, Jajcevic D, Kape A, Contreras L, Carmody A, Liu P, Davies C, Sarkar A, Khinast J. Quantifying the Coating Yield by Modeling Heat and Mass Transfer in a Wurster Fluidized Bed Coater. Chem Eng Sci 2022. [DOI: 10.1016/j.ces.2022.117505] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Nijssen TM, Hoeks I, Manjunath V, Kuipers HA, van der Stel J, Adema AT, Buist KA. Experiments and simulations on a cold-flow blast furnace hearth model. CHEMICAL ENGINEERING SCIENCE: X 2022. [DOI: 10.1016/j.cesx.2022.100120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Li B, Zhang H, Saranteas K, Henson MA. A rigid body dynamics model to predict the combined effects of particle size and shape on pressure filtration. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.119462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Wang Z, Liu M. On the determination of grid size/smoothing distance in un−/semi-resolved CFD-DEM simulation of particulate flows. POWDER TECHNOL 2021. [DOI: 10.1016/j.powtec.2021.08.044] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Tian F, Liu S, Zhao Z, Lei M. Insight on micro bubbling mechanism in a 2D fluidized bed with Group D particles. INTERNATIONAL JOURNAL OF CHEMICAL REACTOR ENGINEERING 2021. [DOI: 10.1515/ijcre-2021-0070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
By CFD-DEM simulations, the present work is aimed to investigate the transient gas-solid bubbling mechanisms along a whole bubble lifecycle in a 2D fluidized bed from a micro perspective. Systemic comparisons with CCD measurements confirm the validity of current simulations. Afterward, the manner of particle motion and its driving mechanisms at various stages are investigated. In order to do that, external forces are analyzed at an individual particle level, including the drag, pressure gradient force, and their resultant acceleration together with gravity. Many interesting findings have been achieved. For example, a switch in directions of drag and pressure gradient forces at the root of an initial bubble enables its detachment. And, regarding their contributions to the burst of a bubble, the drag force is several times of the pressure gradient forces. Present efforts help to offer a novel view of particle dynamics during the bubbling fluidization.
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Affiliation(s)
- Fengguo Tian
- College of Environmental Science and Engineering , Donghua University , 2999 North Renmin Road, Songjiang District , Shanghai 201620 , China
| | - Shulei Liu
- College of Environmental Science and Engineering , Donghua University , 2999 North Renmin Road, Songjiang District , Shanghai 201620 , China
| | - Zifeng Zhao
- College of Environmental Science and Engineering , Donghua University , 2999 North Renmin Road, Songjiang District , Shanghai 201620 , China
| | - Ming Lei
- College of Environmental Science and Engineering , Donghua University , 2999 North Renmin Road, Songjiang District , Shanghai 201620 , China
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A Coupled CFD-DEM Model for Resolved Simulation of Filter Cake Formation during Solid-Liquid Separation. Processes (Basel) 2021. [DOI: 10.3390/pr9050826] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In cake filtration processes, where particles in a suspension are separated by forming a filter cake on the filter medium, the resistances of filter cake and filter medium cause a specific pressure drop which consequently defines the process energy effort. The micromechanics of the filter cake formation (interactions between particles, fluid, other particles and filter medium) must be considered to describe pore clogging, filter cake growth and consolidation correctly. A precise 3D modeling approach to describe these effects is the resolved coupling of the Computational Fluid Dynamics with the Discrete Element Method (CFD-DEM). This work focuses on the development and validation of a CFD-DEM model, which is capable to predict the filter cake formation during solid-liquid separation accurately. The model uses the Lattice-Boltzmann Method (LBM) to directly solve the flow equations in the CFD part of the coupling and the DEM for the calculation of particle interactions. The developed model enables the 4-way coupling to consider particle-fluid and particle-particle interactions. The results of this work are presented in two steps. First, the developed model is validated with an empirical model of the single particle settling velocity in the transition regime of the fluid-particle flow. The model is also enhanced with additional particles to determine the particle-particle influence. Second, the separation of silica glass particles from water in a pressurized housing at constant pressure is experimentally investigated. The measured filter cake, filter medium and interference resistances are in a good agreement with the results of the 3D simulations, demonstrating the applicability of the resolved CFD-DEM coupling for analyzing and optimizing cake filtration processes.
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Li B, Dobosz KM, Zhang H, Schiffman JD, Saranteas K, Henson MA. Predicting the performance of pressure filtration processes by coupling computational fluid dynamics and discrete element methods. Chem Eng Sci 2019; 208. [PMID: 31579324 DOI: 10.1016/j.ces.2019.115162] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
To obtain a fundamental understanding of the various factors affecting pressure filtration performance, we developed a coupled computational fluid dynamics (CFD) and discrete element method (DEM) model for simulating the effect of solvent flow through the solid particle cake. The model was validated using data collected by filtering mixtures of spherical glass beads and deionized water through a dead-end cell over a range of applied pressures. Numerical experiments were performed to study the effects of particle properties, liquid properties and operating conditions on filtration performance. The model predicted that the filtrate flow rate could be strongly affected by the mean size of the particles, the presence of small particles (i.e. fines) in the particle distribution, the viscosity of the liquid, and particle deformation leading to cake compression. Our study demonstrated that CFD-DEM modeling is a powerful approach for understanding cake filtration processes and predicting filtration performance.
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Affiliation(s)
- Boyang Li
- Department of Chemical Engineering and the Institute for Applied Life Sciences, University of Massachusetts, Amherst, MA 01003, USA
| | - Kerianne M Dobosz
- Department of Chemical Engineering and the Institute for Applied Life Sciences, University of Massachusetts, Amherst, MA 01003, USA
| | - Haitao Zhang
- Chemical Process Research & Development, Sunovion Pharmaceuticals Inc., Marlborough, MA 01752, USA
| | - Jessica D Schiffman
- Department of Chemical Engineering and the Institute for Applied Life Sciences, University of Massachusetts, Amherst, MA 01003, USA
| | - Kostas Saranteas
- Chemical Process Research & Development, Sunovion Pharmaceuticals Inc., Marlborough, MA 01752, USA
| | - Michael A Henson
- Department of Chemical Engineering and the Institute for Applied Life Sciences, University of Massachusetts, Amherst, MA 01003, USA
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Structural parameter optimization for novel internal-loop iron–carbon micro-electrolysis reactors using computational fluid dynamics. Chin J Chem Eng 2019. [DOI: 10.1016/j.cjche.2018.08.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Volk A, Ghia U, Liu GR. Assessment of CFD-DEM solution error against computational cell size for flows through a fixed-bed of binary-sized particles. POWDER TECHNOL 2018. [DOI: 10.1016/j.powtec.2017.11.051] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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