scholarly journals CFD-DEM Simulation of Spouted Bed Dynamics under High Temperature with an Adhesive Model

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2276
Author(s):  
Zhao Chen ◽  
Lin Jiang ◽  
Mofan Qiu ◽  
Meng Chen ◽  
Rongzheng Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Particle Surface ◽  
Particle Collision ◽  
Gas Velocity ◽  
Spouted Bed ◽  
Dem Simulation ◽  
Linear Spring ◽  
Adhesion Model ◽  
Adhesive Model ◽  
Damping Model

Particle adhesion is of great importance to coating processes due to its effect on fluidization. Currently, Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) has become a powerful tool for the study of multiphase flows. Various contact force models have also been proposed. However, particle dynamics in high temperature will be changed with particle surface properties changing. In view of this, an adhesion model is developed based on approaching-loading-unloading-detaching idea and particle surface change under high temperature in this paper. Analyses of the adhesion model are given through two particle collision process and validated by experiment. Effects of inlet gas velocity and adhesion intensity on spouted bed dynamics are investigated. It is concluded that fluidization cycle will be accelerated by adhesion, and intensity of fluidization will be marginally enhanced by slight adhesion. Within a certain range, increasing inlet gas velocity will lead to strong intensity of particle motion. A parameter sensitivity comparison of linear spring-damping model and Hertz-Mindlin Model is given, which shows in case of small overlaps, forces calculated by both models have little distinction, diametrically opposed to that of large overlaps.

DEM Simulation of the Particle Mixing in Spouted Bed of Three Solids Differing in Diameter

2011 ◽  
Vol 48-49 ◽  
pp. 362-365
Author(s):  
Wei Bing Zhu ◽  
Run Ru Zhu ◽  
Li Chao Xing ◽  
Xiao Bin Zhang
Keyword(s):  
Particle System ◽  
Three Dimensional ◽  
Rolling Friction ◽  
Equation Model ◽  
Particle Systems ◽  
Mixing Process ◽  
Gas Velocity ◽  
Spouted Bed ◽  
Dem Simulation ◽  
Particle Mixing

In this work, the mixing characteristic of ternary diameter particle system in a rectangular spouted bed was carried out three-dimensional discrete element method (DEM). In particular, the standard k- two-equation model and the Beer & Johnson equation were adopted to investigate the influence of turbulence and rolling friction, and Ashton mixing index was adopted to evaluate the dynamic mixing process of the ternary diameter particle systems. The particle velocity profiles, the gas-solid flow patterns, the particles distribution and the effect of gas velocity on mixing are discussed.

CFD–DEM simulation of fine particles in a spouted bed apparatus with a Wurster tube

Particuology ◽  
2019 ◽  
Vol 42 ◽  
pp. 114-125 ◽  
Author(s):  
Paul Breuninger ◽  
Dominik Weis ◽  
Isabell Behrendt ◽  
Philipp Grohn ◽  
Fabian Krull ◽  
...  
Keyword(s):  
Fine Particles ◽  
Spouted Bed ◽  
Dem Simulation

Surface area and microstructure of microwave activated crumb rubber modifier and its influence on high temperature properties of crumb rubber modifier binders

2020 ◽  
Vol 10 (2) ◽  
pp. 272-277 ◽  
Author(s):  
Bo Li ◽  
Xuwei Zhu ◽  
Xingjun Zhang ◽  
Xiaolong Yang ◽  
Xiuli Su
Keyword(s):  
High Temperature ◽  
Surface Area ◽  
Gas Adsorption ◽  
Treatment Time ◽  
Particle Surface ◽  
Microwave Treatment ◽  
Crumb Rubber ◽  
Adsorption Method ◽  
Temperature Performance ◽  
Mechanism Of Interaction

Crumb rubber pretreatment by microwave before blending with an asphalt matrix can address and improve the modification problem of of crumb rubber modifier (CRM) asphalt plant. In this research, the surface area and microstructure of microwave activated CRM and high-temperature performance of CRM asphalt were investigated to characterize the mechanism of interaction between activated CRM blends added and base asphalt. The surface area and microstructure of CRM were measured by gas adsorption method and the scanning electron microscopy (SEM) respectively when CRM was activated using microwave treatment time (30 s, 60 s, 90 s, 120 s and 150 s). The complex shear modulus (G*) and the phase angle (δ) of the CRM asphalt were measured by Dynamic Shear Rheometer (DSR) test. The results indicated that microwave treatment produced more porous structure and agglomeration phenomenon than control one for a given activated time of CRM. The flocculent structure was the most obvious one and agglomeration phenomenon was the most significant one for the particle surface microwave activated 90 s. The δ decreased and G* increased as CRM blends activated time increased before a certain time using the same frequency of microwave treatment. The G*/sinδ of CRM blends was the maximum when CRM activated for 90 s using microwave treatment. Both surface area and microstructure of the CRM influenced the high-temperature performance of CRM binders.

CFD–DEM simulation of a pseudo-two-dimensional spouted bed comprising coarse particles

Particuology ◽  
2019 ◽  
Vol 43 ◽  
pp. 171-180 ◽  
Author(s):  
B. Mahmoodi ◽  
S.H. Hosseini ◽  
G. Ahmadi
Keyword(s):  
Coarse Particles ◽  
Two Dimensional ◽  
Spouted Bed ◽  
Dem Simulation

Study on Particle Surface Modification Using a Spouted Bed Plasma Reactor

2018 ◽  
Vol 44 (4) ◽  
pp. 236-241
Author(s):  
Nobusuke Kobayashi ◽  
Baiqiang Zhang ◽  
Kengo Hanai ◽  
Yoshinori Itaya
Keyword(s):  
Surface Modification ◽  
Plasma Reactor ◽  
Particle Surface ◽  
Spouted Bed

Research on Electrochemical Properties of LiMnPO4 Synthesized by High Temperature Solid-Phase Method

2012 ◽  
Vol 487 ◽  
pp. 714-718 ◽  
Author(s):  
Sheng Kui Zhong ◽  
Ying Mei Zhang ◽  
Wei Li ◽  
Yue Bin Xu
Keyword(s):  
High Temperature ◽  
Solid Phase ◽  
Raw Materials ◽  
Particle Surface ◽  
Lithium Ion ◽  
Xrd Analysis ◽  
Spherical Particles ◽  
Phase Method ◽  
Solid Phase Method ◽  
Olivine Structure

LiMnPO4cathode material for lithium ion batteries was synthesized by high temperature solid-phase method using MnCO3, Li2CO3, NH4H2PO4as raw materials. The structure of samples was identified by XRD analysis and the particle surface morphology was examined by SEM. The results of XRD showed that the LiMnPO4sample sintered at 700°C for 20h had single ordered olivine structure. The SEM pattern showed that spherical particles distributed uniformly. Respectively, it figured out that the initial charge and discharge capacities of the samples at 0.05C rate were 133.9 and 66.4mAh•g-1.

Comparison of Euler-Euler and Euler-Lagrange Approaches for Simulating Gas-Solid Flows in a Multiple-Spouted Bed

2019 ◽  
Vol 17 (7) ◽  
Author(s):  
Meng Chen ◽  
Malin Liu ◽  
Yaping Tang
Keyword(s):  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Basic Mechanism ◽  
Hydrodynamic Characteristics ◽  
Cycle Period ◽  
Mechanism Analysis ◽  
Gas Velocity ◽  
Spouted Bed ◽  
Particle Velocities ◽  
Lagrange Approach

Abstract In this work, a comparative study of Euler-Euler and Euler-Lagrange approaches for modeling gas-solid flows in the multiple-spouted bed has been carried out to investigate the hydrodynamics of gas-solid flows. The influence of inlet gas velocity on the hydrodynamics of gas-solid flows in the multiple-spouted bed is investigated as well. Hydrodynamic characteristics of gas-solid flows such as flow behaviors, solid volume fraction, particle velocity and particle trajectory are analyzed and discussed in detail, providing some basic mechanism analysis of the gas-solids in the multiple-spouted bed. It is found that the central spout gas jet is a little confined by the auxiliary gas jets, and the hole-to-hole synergy is quite obvious when the auxiliary spout gas velocity is higher than the central spout gas velocity. When central/auxiliary gas velocity is 10/20 m/s, the maximum vertical particle velocities predicted by Euler-Euler and Euler-Lagrange approaches are 452 mm/s and 721 mm/s at the height of 10 mm respectively. A typical cycle period of a single particle is about 1.25 s, and the residence time in the spout regions is about 0.14 s in one cycle period in auxiliary dominant pattern. The curves of bed expansion height versus time calculated by Euler-Lagrange approach rise and fall periodically, while the curves calculated by Euler-Euler approach keep steady with little change. It is much easier for particles to be blew in the multiple-spouted bed using the Euler-Lagrange approach. The simulation results obtained from two models can provide some guidance for modifying the multiple-spouted bed to optimize physical operations such as drying and coating in the multiple-spouted bed.

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