Investigation on wet particle flow behavior in a riser using LES-DEM coupling approach

Tang, Tianqi; He, Yurong; Ren, Anxing; Zhao, Yunhua

doi:10.1016/j.powtec.2016.08.023

Cited by 12 publications

(2 citation statements)

References 39 publications

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“…The effects of the turbulence were ignored in most of previous numerical studies under different operating conditions, e.g., bubbling fluidized beds, − spouted beds, , and circulating fluidized beds . In several studies, − the large eddy simulation (LES) models were adopted to account for the turbulence of fluid phase. Nevertheless, there is still a lack of thorough understanding on the role of turbulence in the fluidized bed.…”

Section: Mathematical Methodsmentioning

confidence: 99%

Computational Fluid Dynamics/Discrete Element Method Investigation on the Biomass Fast Pyrolysis: The Influences of Shrinkage Patterns and Operating Parameters

Luo

Wang

et al. 2018

Ind. Eng. Chem. Res.

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In this study, we present a computational fluid dynamics/discrete element method (CFD-DEM) framework for biomass fast pyrolysis. With model validations against experiments, the effects of the particle shrinkage and superficial gas velocity on the pyrolysis process in the fluidized bed reactor are investigated. The results show that the shrinkage pattern has minor effect on the product yields, but it greatly affects the entrainment behaviors. It is found that the constant density shrinkage pattern leads to the longest residence time, and the constant size shrinkage pattern results in the shortest residence time. Interestingly, the time that biomass particles stay in the dense region shows a reverse trend. It is demonstrated that the gas velocity has a minor effect on the heat-transfer rate and chemical conversion rate of biomass particles, but it has a profound impact on the distributions of solid concentration and heterogeneous reactions.

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Section: Mathematical Methodsmentioning

confidence: 99%

Computational Fluid Dynamics/Discrete Element Method Investigation on the Biomass Fast Pyrolysis: The Influences of Shrinkage Patterns and Operating Parameters

Luo

Wang

et al. 2018

Ind. Eng. Chem. Res.

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“…In late years, studies on a highly-concentrated solid-liquid multiphase flow have became active by coupling a solver of the Navier-Stokes equation with DEM ( e.g. , Tang et al , 2016; 41 ) Mondal et al , 2016 42 ) ). The NWF, or the solver of liquid phase, enables the development of the computational science of the sediment transport by being coupled with DEM, or the solver of solid phase ( e.g.…”

Section: Calculation Of Sediment Transport With Numerical Wave Flumementioning

confidence: 99%

Computational wave dynamics for innovative design of coastal structures

Gotoh

Okayasu

2017

Proceedings of the Japan Academy. Ser. B: Physical and Biologic

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For innovative designs of coastal structures, Numerical Wave Flumes (NWFs), which are solvers of Navier-Stokes equation for free-surface flows, are key tools. In this article, various methods and techniques for NWFs are overviewed. In the former half, key techniques of NWFs, namely the interface capturing (MAC, VOF, C-CUP) and significance of NWFs in comparison with the conventional wave models are described. In the latter part of this article, recent improvements of the particle method are shown as one of cores of NWFs. Methods for attenuating unphysical pressure fluctuation and improving accuracy, such as CMPS method for momentum conservation, Higher-order Source of Poisson Pressure Equation (PPE), Higher-order Laplacian, Error-Compensating Source in PPE, and Gradient Correction for ensuring Taylor-series consistency, are reviewed briefly. Finally, the latest new frontier of the accurate particle method, including Dynamic Stabilization for providing minimum-required artificial repulsive force to improve stability of computation, and Space Potential Particle for describing the exact free-surface boundary condition, is described.

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Resistance characteristics and particle movement behavior of a petroleum coke particle packed bed in a vertical shaft calciner under different burden distribution methods

Huang,

Lu,

et al. 2024

Asia-Pacific J Chem Eng

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Because of the increasingly deteriorating quality of petroleum coke raw materials, abnormal furnace conditions, such as “firing and blasting”, frequently arise during the calcination of petroleum coke with a high powder/coke ratio in a vertical shaft calciner. This poses an urgent technical challenge that needs to be addressed. In iron and steel metallurgy, the burden distribution system is an important way to regulate blast furnace conditions and improve the permeability of a particle packed bed. In this work, advanced burden distribution concepts were introduced into the calcination process of petroleum coke in a vertical shaft calciner. Experimental devices were established to determine the resistance characteristics of a petroleum coke particle packed bed, along with a cold physical model of a 1/8 scale vertical shaft calciner. The influence of particle size and burden distribution methods on the resistance characteristics and particle motion behavior of the petroleum coke particle packed bed was systematically studied. The research findings indicate that both particle size and burden distribution methods significantly impact the resistance characteristics of petroleum coke particle packed beds. The smaller the particle size, the poorer the permeability of the bed. The layered burden distribution, symmetrical burden distribution, and dual‐particle mixed conventional burden distribution all contribute to improving the permeability of the petroleum coke particle packed bed in the vertical shaft calciner. Furthermore, employing symmetrical burden distribution in Bed‐3, which is packed with petroleum coke particles of diameters −3.2 + 2.5 mm and −1.0 + 0.8 mm, results in the smallest unit pressure drop, at only 1.7% of that of the conventional burden distribution of unscreened raw materials. This is the most effective means of improving the permeability of the bed. During the discharging process, particle size and symmetrical burden distribution have no significant impact on the motion characteristics of petroleum coke particles in the vertical shaft calciner. In general, in the calciner area, particles primarily move in a plug flow pattern and gradually transform into funnel flow in the cooling water jacket area. These research results provide the theoretical basis for addressing the technical challenges associated with powder coke calcination in vertical shaft calciners through reasonable burden distribution methods for fine and coarse particles.

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Investigation on wet particle flow behavior in a riser using LES-DEM coupling approach

Cited by 12 publications

References 39 publications

Computational Fluid Dynamics/Discrete Element Method Investigation on the Biomass Fast Pyrolysis: The Influences of Shrinkage Patterns and Operating Parameters

Computational Fluid Dynamics/Discrete Element Method Investigation on the Biomass Fast Pyrolysis: The Influences of Shrinkage Patterns and Operating Parameters

Computational wave dynamics for innovative design of coastal structures

Resistance characteristics and particle movement behavior of a petroleum coke particle packed bed in a vertical shaft calciner under different burden distribution methods

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