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Fluidization and Transport of Vibrated Granular Matter:A Review of Landmark and Recent Contributions 被引量:1
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作者 Peter Watson Sebastien Vincent Bonnieu Marcello Lappa 《Fluid Dynamics & Materials Processing》 EI 2024年第1期1-29,共29页
We present a short retrospective review of the existing literature about the dynamics of(dry)granular matter under the effect of vibrations.The main objective is the development of an integrated resource where vital i... We present a short retrospective review of the existing literature about the dynamics of(dry)granular matter under the effect of vibrations.The main objective is the development of an integrated resource where vital information about past findings and recent discoveries is provided in a single treatment.Special attention is paid to those works where successful synthetic routes to as-yet unknown phenomena were identified.Such landmark results are analyzed,while smoothly blending them with a history of the field and introducing possible categorizations of the prevalent dynamics.Although no classification is perfect,and it is hard to distillate general properties out of specific observations or realizations,two possible ways to interpret the existing results are defined according to the type of forcing or the emerging(ensuing)regime of motion.In particular,first results concerning the case where vibrations and gravity are concurrent(vertical shaking)are examined,then the companion situation with vibrations perpendicular to gravity(horizontal shaking)is described.Universality classes are introduced as follows:(1)Regimes where sand self-organizes leading to highly regular geometrical“pulsating”patterns(thin layer case);(2)Regimes where the material undergoes“fluidization”and develops an internal multicellular convective state(tick layers case);(3)Regimes where the free interface separating the sand from the overlying gas changes inclination or develops a kind a patterned configuration consisting of stable valleys and mountains or travelling waves;(4)Regimes where segregation is produced,i.e.,particles of a given size tend to be separated from the other grains(deep containers).Where possible,an analogy or parallelism is drawn with respect to the companion field of fluid-dynamics for which the assumption of“continuum”can be applied. 展开更多
关键词 Granular materials vibrations fluidization FLOWABILITY symmetry breaking
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Influences of polymorphism of packed particles on bulk characterizations in fluidization realm
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作者 Quanhong Zhu Yalong Cao +4 位作者 Qiang Zhang Wankun Liu Hao Guan Donghui Liu Hengjun Gai 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第10期238-248,共11页
The characterization of a particle ensemble(rather than a single particle) is of paramount significance to various particle technologies and has long been a fundamental subject in the fluidization realm. However, many... The characterization of a particle ensemble(rather than a single particle) is of paramount significance to various particle technologies and has long been a fundamental subject in the fluidization realm. However, many of such bulk characterizations as loosely-packed density(ρbl), minimum fluidization velocity(Umf), sphericity(φ), discharge rate through orifice(q), angle of repose(β), and segregation index(S),were found to be poorly reproducible, making the reported results seldom comparable. Since these bulk characterizations started from the packed state of particles, such poor reproducibility was ascribed to the polymorphism of packed particles in this work. We observed that in the fluidized bed, the settled/packed state of particles varied monotonously with the settling rate(a) from complete fluidization to zero. This phenomenon confirmed the polymorphic characteristic of packed particles and further enabled us to systematically disclose/clarify its influences on the aforementioned bulk characterizations. Such influences could be comprehensively and intuitively reflected by the impacts induced by a. With the decrease of a, ρbl, φ and q first increased, then decreased, and finally leveled off while Umfand β showed an opposite trend. On the other hand, S first increased and then remained invariant. As per these findings and definitions of these bulk characterizations, benchmarks were indicated to unify the selection of settled state among future scholars and further make their outcomes become fairly comparable. Additionally, most packed states of the particle ensemble were proved to be metastable with their formation and behavior being identical to those of the amorphous state. 展开更多
关键词 fluidization fluidizED-BED Particle POLYMORPHISM Bulk characterization Comparability
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Behavior and mechanism of pre-oxidation improvement on fluidization in the fluidized reduction of titanomagnetite
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作者 Haoyan Sun Ajala Adewole Adetoro +1 位作者 Zhiqiang Wang Qingshan Zhu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第11期2458-2465,共8页
The direct reduction process is an important development direction of low-carbon ironmaking and efficient comprehensive utilization of poly-metallic iron ore,such as titanomagnetite.However,the defluidization of reduc... The direct reduction process is an important development direction of low-carbon ironmaking and efficient comprehensive utilization of poly-metallic iron ore,such as titanomagnetite.However,the defluidization of reduced iron particles with a high metallization degree at a high temperature will seriously affect the operation of fluidized bed reduction.Coupling the pre-oxidation enhancing reduction and the particle surface modification of titanomagnetite,the behavior and mechanism of pre-oxidation improvement on fluidization in the fluidized bed reduction of titanomagnetite are systematically studied in this paper.Pre-oxidation treatment of titanomagnetite can significantly lower the critical stable reduction fluidization gas velocity to 0.17 m/s,which is reduced by 56%compared to that of titanomagnetite reduction without pre-oxidation,while achieving a metallization degree of>90%,Corresponding to the different reduction fluidization behaviors,three pre-oxidation operation regions have been divided,taking oxidation degrees of 26%and 86%as the boundaries.Focusing on the particle surface morphology evolution in the pre-oxidation-reduction process,the relationship between the surface morphology of pre-oxidized ore and the reduced iron with fluidization properties is built.The improving method of pre-oxidation on the reduction fluidization provides a novel approach to prevent defluidization by particle surface modification,especially for the fluidized bed reduction of poly-metallic iron ore. 展开更多
关键词 fluidization direct reduction PRE-OXIDATION TITANOMAGNETITE iron whisker
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Extending homogeneous fluidization flow regime of Geldart-A particles by exerting axial uniform and steady magnetic field
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作者 Qiang Zhang Wankun Liu +1 位作者 Hengjun Gai Quanhong Zhu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第1期169-177,共9页
The homogeneous/particulate fluidization flow regime is particularly suitable for handling the various gas–solid contact processes encountered in the chemical and energy industry.This work aimed to extend such a regi... The homogeneous/particulate fluidization flow regime is particularly suitable for handling the various gas–solid contact processes encountered in the chemical and energy industry.This work aimed to extend such a regime of Geldart-A particles by exerting the axial uniform and steady magnetic field.Under the action of the magnetic field,the overall homogeneous fluidization regime of Geldart-A magnetizable particles became composed of two parts:inherent homogeneous fluidization and newly-created magnetic stabilization.Since the former remained almost unchanged whereas the latter became broader as the magnetic field intensity increased,the overall homogeneous fluidization regime could be extended remarkably.As for Geldart-A nonmagnetizable particles,certain amount of magnetizable particles had to be premixed to transmit the magnetic stabilization.Among others,the mere addition of magnetizable particles could broaden the homogeneous fluidization regime.The added content of magnetizable particles had an optimal value with smaller/lighter ones working better.The added magnetizable particles might raise the ratio between the interparticle force and the particle gravity.After the magnetic field was exerted,the homogeneous fluidization regime was further expanded due to the formation of magnetic stabilization flow regime.The more the added magnetizable particles,the better the magnetic performance and the broader the overall homogeneous fluidization regime.Smaller/lighter magnetizable particles were preferred to maximize the magnetic performance and extend the overall homogeneous fluidization regime.This phenomenon could be ascribed to that the added magnetizable particles themselves became more Geldart-A than-B type as their density or size decreased. 展开更多
关键词 fluidizED-BED fluidization Geldart-A particles Flow regimes EXTEND Magnetic stabilization
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A developed transient gas-liquid-solid flow model with hydrate phase transition for solid fluidization exploitation of marine natural gas hydrate reservoirs
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作者 Geng Zhang Jun Li +3 位作者 Gong-Hui Liu Hong-Wei Yang Chao Wang Hong-Lin Huang 《Petroleum Science》 SCIE EI CAS CSCD 2023年第3期1676-1689,共14页
The multiphase flow characteristic is one of the most concerning problems during solid fluidization exploitation of marine natural gas hydrate reservoirs.In this research,a new transient gas-liquid-solid multiphase fl... The multiphase flow characteristic is one of the most concerning problems during solid fluidization exploitation of marine natural gas hydrate reservoirs.In this research,a new transient gas-liquid-solid multiphase flow model with hydrate phase transition was developed.Meanwhile,this model considered the coupling relationship among convective heat transfer,hydrate dynamic decomposition,and multi-phase flow.The model can simulate the change of flow pattern from solid-liquid to gas-liquid-solid flow,and describe the distribution character of volume fraction of phase,wellbore temperature and pressure,and hydrate decomposition rate during transportation.The simulation results indicate that the hydrate decomposition region in the wellbore gradually expands,but the hydrate decomposition rate gradually decreases during the solid fluidization exploitation of hydrate.When mining time lasts for 4 h,and the bottom hole pressure decreases by about 0.4 MPa.Increasing NaCl concentration in seawater helps expand hydrate decomposition regions and improves the wellbore hydrate decomposition rate.When the Nacl mass fraction in seawater reaches 15%,it will raise the hydrate decomposition regions to the whole wellbore.In addition,the higher the wellhead backpressure,the lower the decomposition area and decomposition rate of hydrate in the wellbore.When wellhead backpressure reaches 2 MPa,the volume fraction of gas near the wellhead will reduce to about 12%.This work is expected to provide a theoretical basis for the development of marine hydrate reservoirs. 展开更多
关键词 Gas-liquid-solid multiphase flow Solid fluidization Hydrate dynamic decomposition Convective heat transfer
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Fluidization characteristics of magnetic particles and determination of stable fluidization zone in magnetically fluidized bed 被引量:1
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作者 王迎慧 归柯庭 施明恒 《Journal of Southeast University(English Edition)》 EI CAS 2006年第4期523-527,共5页
To determine and calculate the stable fluidization zone in a magnetically fluidized bed, the fluidization characteristics of magnetic particles are investigated. Four kinds of magnetic particles with different average... To determine and calculate the stable fluidization zone in a magnetically fluidized bed, the fluidization characteristics of magnetic particles are investigated. Four kinds of magnetic particles with different average diameters, ranging from 231 to 512 μm, are fluidized in the presence of magnetic fields with specified values of the intensity in the range of zero to 7330 A/m, and the particle fluidization curves are plotted. For marking the stable fluidization zone in the curves, the minimum bubbling velocities of particles are measured by the pressure-drop fluctuation. Based on the fluidization curves, the influences of the average particle diameter and magnetic field intensity on the zone are analyzed and discussed. A correlation to determine the stable fluidization zone is derived from the experimental data, using three dimensionless numbers, i. e., the ratio of magnetic potential to gravity potential, the Reynolds number and the Archimedes number. Compared with available data reported, it is shown that the correlation is more simplified to predict relative parameters for the bed operating in the state of stable fluidization under reasonable conditions. 展开更多
关键词 magnetically fluidized bed fluidization characteristics stable fluidization minimum bubbling gas velocity pressure-drop fluctuation
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Study on Liquid-Phase Axial Dispersion in Converging Taper Liquid-Solid Fluidized Beds 被引量:1
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作者 夏素兰 朱家骅 胡新辉 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2000年第2期134-139,共6页
It is found analytically that the parabolic radial profile of liquid velocity in cylindrical liquid-solid fluidized bed (LSFB) causes particles to circulate around some radial position. This is the main reason for liq... It is found analytically that the parabolic radial profile of liquid velocity in cylindrical liquid-solid fluidized bed (LSFB) causes particles to circulate around some radial position. This is the main reason for liquid-phase axial dispersions. The liquid-phase axial dispersion is depressed as the liquid velocity presents a flatter Bessel radial profile in a converging taper LSFB. The void fraction increases with axial distance in converging taper LSFB. The behavior produces less liquid-phase axial dispersion. Experimental results show good coincidence. 展开更多
关键词 converging taper liquid-solid fluidized bed liquid-phase axial dispersion radial profile of liquid velocity void fraction
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Fluidization: An Important Process in the Formation of the Qiyugou Au-bearing Breccia Pipes in Central China 被引量:5
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作者 ZHANG Yuanhou ZHANG Shihong Franco PIRAJNO 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2007年第2期226-238,共13页
Fluidization processes based on experiments are reviewed to gain some useful insights and comparisons with those that occur in hydrothermal systems. Field and petrographic work, and microscope observation were carried... Fluidization processes based on experiments are reviewed to gain some useful insights and comparisons with those that occur in hydrothermal systems. Field and petrographic work, and microscope observation were carried out on samples from the Qiyugou Au-bearing breccia pipes from the East Qinling region, Henan Province. Evidence from macro- and micro-textures suggests that the style of breccias in the Qiyugou area can be grouped into three types: (1) jigsaw fit-stockwork texture, in which the interval between clasts is marked by fractures or filled with calcite or quartz veins; (2) larger breccias that are supported by smaller breccias, rock flour and alteration materials; in this type clasts moved over short distances, creating open spaces; (3) fluidized texture, where the clasts of different lithologies have rounded shapes. These observations are compared with those resulting from experiments on fluidization processes. The results of this comparison suggest that fluidization is an important geological process in the formation of the Qiyugou Au-bearing breccia pipes and gold mineralization. In addition, fluidization processes such as expansion, bubbling, slugging, channeling and spouting must have contributed to the formation of the pipes and were conducive to the development of gold mineralization. In the Qiyugou breccia pipes, gold mineralization occurs as disseminations, in stockwork veins, and open space infills. The ore zones form subparallel sheets that are nearly perpendicular to the walls of the pipes. 展开更多
关键词 fluidization breccia pipe gold mineralization Qiyugou CRETACEOUS HENAN QINLING China
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Extending the EMMS/bubbling model to fluidization of binary particle mixture: Formulation and steady-state validation 被引量:3
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作者 Nouman Ahmad Yujie Tian +3 位作者 Bona Lu Kun Hong Haifeng Wang Wei Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第1期54-62,共9页
The EMMS/bubbling model originally proposed for fluidization of monodisperse particles is extended to fluidization of binary particle mixture in this study.The dense and dilute phases are considered to comprise of two... The EMMS/bubbling model originally proposed for fluidization of monodisperse particles is extended to fluidization of binary particle mixture in this study.The dense and dilute phases are considered to comprise of two types of particles differing in size and/or density.Governing equations and the stability condition are then formulated and solved by using an optimization numerical scheme.The effects of bubble diameter are first investigated and a suitable bubble diameter correlation is chosen.Preliminary validation for steady state behavior shows the extended model can fairly capture the overall hydrodynamic behaviors in terms of volume fraction of bubbles and average bed voidage for both monodisperse and binary particle systems.This encourages us to integrate this model with CFD for more validations in the future. 展开更多
关键词 EMMS BINARY mixture fluidization MESOSCALE structure
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Heat Transfer in a Liquid-Solid Circulating Fluidized Bed Reactor with Low Surface Tension Media 被引量:2
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作者 H.R.Jin H.Lim +2 位作者 D.H.Lim Y.Kang Ki-Won Jun 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第8期844-849,共6页
Heat transfer characteristics between the immersed heater and the bed content were studied in the riser of a liquid-solid circulating fluidized bed, whose diameter and height were 0.102 m (ID) and 2.5 m, respectively.... Heat transfer characteristics between the immersed heater and the bed content were studied in the riser of a liquid-solid circulating fluidized bed, whose diameter and height were 0.102 m (ID) and 2.5 m, respectively. Effects of liquid velocity, particle size, surface tension of liquid phase and solid circulation rate on the overall heat transfer coefficient were examined. The heat transfer coefficient increased with increasing particle size or solid circulation rate due to the higher potential of particles to contact with the heater surface and promote turbulence near the heater surface. The value of heat transfer coefficient increased gradually with increase in the surface tension of liquid phase, due to the slight increase of solid holdup. The heat transfer coefficient increased with the liquid velocity even in the higher range, due to the solid circulation prevented the decrease in solid holdup, in contrast to that in the conventional liquid-solid fluidized beds. The values of heat transfer coefficient were well correlated in terms of dimensionless groups as well as operating variables. 展开更多
关键词 heat transfer coefficient liquid-solid circulating fluidized bed liquid surface tension solid circulation rate particle size
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Effect of elevated temperature and silica sand particle size on minimum fluidization velocity in an atmospheric bubbling fluidized bed 被引量:3
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作者 A.Al-Farraji Haidar Taofeeq 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第12期2985-2992,共8页
The impact of temperature and particle size on minimumfluidizing velocity was studied and analyzed in a small pilot scale of bubbling fluidized bed reactor.This study was devoted to providing some data about fluidizat... The impact of temperature and particle size on minimumfluidizing velocity was studied and analyzed in a small pilot scale of bubbling fluidized bed reactor.This study was devoted to providing some data about fluidization to the literature under high temperature conditions.The experiments were carried out to evaluate the minimum fluidizing velocity over a vast range of temperature levels from 20℃ to 850℃ using silica sand with a particle size of 300-425μm,425-500μm,500-600μm,and 600-710μm.Furthermore,the variation in the minimumfluidized voidage was determined experimentally at the same conditions.The experimental data revealed that the Umf directly varied with particle size and inversely with temperature,whileεmf increases slightly with temperature based on the measurements of height at incipient fluidization.However,for all particle sizes used in this test,temperatures above 700℃ has a marginal effect on Umf.The results were compared with many empirical equations,and it was found that the experimental result is still in an acceptable range of empirical equations used.In which,our findings are not well predicted by the widely accepted correlations reported in the literature.Therefore,a new predicted equation has been developed that also accounts for the affecting of mean particle size in addition to other parameters.A good mean relative deviation of 5.473% between the experimental data and the predicted values was estimated from the correlation of the effective dimensionless group.Furthermore,the experimental work revealed that the minimum fluidizing velocity was not affected by the height of the bed even at high temperature. 展开更多
关键词 Minimum fluidization velocity VOIDAGE Elevated temperature Silica sand fluidized bed Bed height
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The Ejffect of Vertical Internal Baffles on Fluidization Hydrodynamics and Grain Drying Characteristics 被引量:3
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作者 LAWChungLim SitiMasrindaTASIRIN +1 位作者 WanRamliWanDAUD NGPinPin 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2004年第6期801-808,共8页
The effect of vertical internal baffles on the particle mixing and graindrying characteristics in a batch fluidized bed column is investigated. Experimental work wascarried out in a 3m high rectangular fluidized bed d... The effect of vertical internal baffles on the particle mixing and graindrying characteristics in a batch fluidized bed column is investigated. Experimental work wascarried out in a 3m high rectangular fluidized bed dryer of cross sectional area of 0.15 m x 0.61 mat different operating conditions using paddy, a group D particle, as the fluidizing material. Theresults of the study showed that the fluidized bed dryer system with vertical internal baffles gavebetter particle mixing effect in the bed of particles than that without vertical internal baffles.This is due to the fact that the vertical internal baffle act as gas bubble breakers by breaking upthe large gas bubbles into smaller ones. The smaller bubbles cause a more vigorous mixing in the bedof particles before finally erupting at the bed surface. This improves the contacting efficiencyand enhanced the heat and mass transfer of the fluidized bed system. Thus a higher drying rate wasobtained in the falling rate period because the higher contacting efficiency increases theevaporation rate at the particle surface. However, the drying rate in the diffusion region showslittle improvement because the moisture diffusivity does not depend on the contacting efficiency.The fluidized bed dryer with vertical internal baffles could therefore be used in the initial rapiddrying stage in a two stage drying strategy for paddy. The insertion of vertical internal bafflesinto a fluidized bed system improves the processing of Group D particles in a fluidized bed systemespecially if the system is large in scale. 展开更多
关键词 bubble characteristics critical moisture content drying curves fluidization quality fluidized bed dryer group d particles PADDY
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Assessment of the TFM in predicting the onset of turbulent fluidization 被引量:1
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作者 Musango Lungu Haotong Wang +4 位作者 Jingdai Wang Ronald Ngulube Yongrong Yang Fengqiu Chen John Siame 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第5期979-992,共14页
Accurate prediction of the onset of turbulent fluidization still remains elusive owing to the dependence of the transition velocity on several factors including measurement methods and interpretation of results. In th... Accurate prediction of the onset of turbulent fluidization still remains elusive owing to the dependence of the transition velocity on several factors including measurement methods and interpretation of results. In this work, numerical simulations using the two fluid model (TFM) are performed in an attempt to predict the regime change reported by Gopalan etal.(2016) in a small scale pseudo-2D gas-solid fluidized bed containing Geldart D particles. Various time and frequency domain analyses were applied on predicted absolute and differential pressure time series data to reveal the bed dynamics. Numerical predictions of the transition velocity, Uc are in reasonably good agreement with experimental results from the small scale challenge problem. The literature correlations completely fail to predict the transition velocity for the system considered in this work. This work thus provides a different approach for validating the CFD model against experimental measurements. 展开更多
关键词 CFD fluidization REGIME identification SLUGGING TURBULENT WAVELET analysis
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EFFECT OF OPERATING TEMPERATURE AND PRESSURE ON THE TRANSITION FROM BUBBLING TO TURBULENT FLUIDIZATION 被引量:4
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作者 蔡平 陈沙鹏 +2 位作者 金涌 俞芷青 汪展文 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 1990年第1期122-132,共11页
Experiments have been carried out to investigate the effects of operating temperature(50 to 500℃)andpressure(1×10~5 to 8×10~5 Pa)on the transition from bubbling to turbulent fluidization by computer analysi... Experiments have been carried out to investigate the effects of operating temperature(50 to 500℃)andpressure(1×10~5 to 8×10~5 Pa)on the transition from bubbling to turbulent fluidization by computer analysisof the pressure fluctuation in dense phase.In order to reveal the influence of particle properties on the tran-sition process,eight kinds of particles were employed.A empirical correlaton which takes into accountthe effects of temperature and pressure is recommended for the prediction of transition 展开更多
关键词 TURBULENT FLUCTUATION dense fluidized empirical deviation AMBIENT camera BREAKING viscosity
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Characterizing the catalyst fluidization with field synergy to improve the amine absorption for CO2 capture 被引量:1
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作者 Yunsong Yu Chen Zhang +1 位作者 Zaoxiao Zhang Geoff Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第7期1608-1617,共10页
There are great interests to capture the CO2 to control the greenhouse gas emission.Amine absorption of CO2 is being taken as an effective way to capture CO2 in industry.However,the amine absorption of CO2 is cost-ine... There are great interests to capture the CO2 to control the greenhouse gas emission.Amine absorption of CO2 is being taken as an effective way to capture CO2 in industry.However,the amine absorption of CO2 is cost-ineffective due to great energy consumption and solution consumption.In order to reduce the capture cost,catalyst fluidization is proposed here to intensify the mass transfer and heat transfer.Catalyst fluidization with field synergy and DFT model is developed by incorporating the effects of catalyst reaction kinetics,drag force and multi-field into the mass transfer,heat transfer,fluid flow and catalyst collision.Experiments with an improved distributor are performed well to validate the model.The reaction kinetics is determined by the DFT simulation and experiment.The mass transfer coefficient in the fluidized reactor is identified as 17%higher than the conventional packed reactor.With the field synergy of catalyst fluidization,the energy consumption for CO2 desorption is reduced by 9%.Stepwise operation and inclination reactor are used to improve catalyst fluidization process. 展开更多
关键词 CO2 CAPTURE CATALYST fluidization Mass transfer DFT Energy CONSUMPTION Field SYNERGY
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Fluidization behavior and reduction kinetics of pre-oxidized magnetite-based iron ore in a hydrogen-induced fluidized bed 被引量:3
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作者 Heng Zheng Oday Daghagheleh +3 位作者 Thomas Wolfinger Bernd Taferner Johannes Schenk Runsheng Xu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2022年第10期1873-1881,共9页
The influence of different pre-oxidation temperatures and pre-oxidation degrees on the reduction and fluidization behaviors of magnetite-based iron ore was investigated in a hydrogen-induced fluidized bed.The raw magn... The influence of different pre-oxidation temperatures and pre-oxidation degrees on the reduction and fluidization behaviors of magnetite-based iron ore was investigated in a hydrogen-induced fluidized bed.The raw magnetite-based iron ore was pre-oxidized at 800 and1000℃ for a certain time to reach a partly oxidation and deeply oxidation state.The structure and morphology of the reduced particles were analyzed via optical microscope and scanning electron microscopy(SEM).The reaction kinetic mechanism was determined based on the double-logarithm analysis.The results indicate that the materials with higher oxidation temperature and wider particle size range show better fluidization behaviors.The lower oxidation temperature is more beneficial for the reduction rate,especially in the later reduction stage.The pre-oxidation degree shows no obvious influence on the fluidization and reduction behaviors.Based on the kinetic analysis,the reduction progress can be divided into three stages.The reduction mechanism was discussed combing the surface morphology and phase structure. 展开更多
关键词 magnetite-based iron ore prior oxidation fluidization behavior kinetic analysis hydrogen reduction
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Fluidization characteristics of different sizes of quartz particles in the fluidized bed 被引量:3
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作者 Zi-Jian Wang Jun Tang Chun-Xi Lu 《Petroleum Science》 SCIE CAS CSCD 2016年第3期584-591,共8页
Fluidization characteristics of quartz particles with different sizes are experimentally investigated in a fluidized bed with an inner diameter of 300 mm and height of 8250 mm.Results show that the average solid holdu... Fluidization characteristics of quartz particles with different sizes are experimentally investigated in a fluidized bed with an inner diameter of 300 mm and height of 8250 mm.Results show that the average solid holdup increases with the increase in superficial gas velocity and the decrease in initial solid holdup in the dense zone of the fluidized bed.The average cross-sectional solid holdup decreases with increasing bed height and superficial gas velocity.The bed expansion coefficient increases with the increase in superficial gas velocity and the decrease in solid holdup.Correlations of average solid holdup,average cross-sectional solid holdup and bed expansion coefficient are also established and discussed.These correlations can provide guidelines for better understanding of the fluidization characteristics. 展开更多
关键词 fluidization characteristic Solid holdup Axial average section solid holdup Bed expansion coefficient
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EMMS-based modeling of gas-solid generalized fluidization:Towards a unified phase diagram 被引量:2
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作者 Juanbo Liu Xinhua Liu Wei Ge 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第1期27-34,共8页
Hydrodynamic features of gas-solid generalized fluidization can be well expressed in the form of phase diagrams,which are important for engineering design.Mesoscale structure presents almost universally in generalized... Hydrodynamic features of gas-solid generalized fluidization can be well expressed in the form of phase diagrams,which are important for engineering design.Mesoscale structure presents almost universally in generalized fluidization and should be considered in such phase diagrams.However,current phase diagrams were mainly proposed for cocurrent upward flow according to experimental data or empirical correlations with homogeneous assumption.The energy-minimization multiscale(EMMS)model has shown the capability of capturing mesoscale structure in generalized fluidization,so EMMS-based phase diagrams of generalized fluidization were proposed in this article,which describe more reasonable global hydrodynamics over all regimes including the important engineering phenomena of choking and flooding.These characteristics were also found in discrete particle simulation under various conditions.For wider range of application,the typical hydrodynamic parameters of the phase diagrams were correlated to non-dimensional numbers reflecting the effects of material properties and operation conditions.This study thus shows a possible route to develop a unified phase diagram in the future. 展开更多
关键词 fluidization Phase diagram Dimensionless correlation MESOSCALE Mathematical modeling EMMS
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Review on the nanoparticle fluidization science and technology 被引量:14
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作者 Xiaolin Zhu Qiang Zhang +1 位作者 Yao Wang Fei Wei 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2016年第1期9-22,共14页
Gas fluidization has an ability to turn static particles to fluid-like dense flow, which allows greatly improved heat transfer among porous powders and highly efficient solid processing to become reality. As the risin... Gas fluidization has an ability to turn static particles to fluid-like dense flow, which allows greatly improved heat transfer among porous powders and highly efficient solid processing to become reality. As the rising star of current scientific research, some nanoparticles can also be fluidized in the form of agglomerates, with sizes ranging from tens to hundreds of microns. Herein, we have reviewed the recent progress on nanomaterial agglomeration and their fluidization behavior, the assisted techniques to enhance the fluidization of nanomaterials,including some mechanical measures, external fields and improved gas injections, as well as their effects on solid fluidization and mixing behaviors. Most of these techniques are effective in breaking large agglomerates and promoting particulate fluidization, meanwhile, the solid mixing is intensified under assisted fluidization. The applications of nanofluidization in nanostructured material production and sustainable chemical industry are further presented. In summary, the fluidization science of multidimensional, multicomponent and multifunctional particles, their multi-phase characterization, and the guideline of fluidized bed coupled process are prerequisites for the sustainable development of fluidized bed based materials, energy and chemical industry. 展开更多
关键词 Nanomaterial Nanoparticle fluidization Agglomerate Assisted technique Solid mixing Application
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Effect of Gas Distributor Structure on Fluidization Characteristics in a Gas-Solid Fluidized Bed 被引量:2
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作者 Jang Kwangbyol Feng Yali Li Haoran 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2020年第2期102-110,共9页
In the present paper,the experimental method and computational fluid dynamics(CFD)method were used to investigate the effect of gas distributors with different orifice sizes and orifice pitches on fluidization charact... In the present paper,the experimental method and computational fluid dynamics(CFD)method were used to investigate the effect of gas distributors with different orifice sizes and orifice pitches on fluidization characteristics in a gas-solid fluidized bed.The Euler-Euler two fluid model(TFM)approach based on the kinetic theory of granular flow(KTGF)and the standard k-epsilon turbulence model was employed in the numerical simulation by using ANSYS Fluent 15.0.The results showed that the orifice size and the orifice pitch of gas distributor had a significant influence on the flow characteristics in the gas-solid fluidized bed.With a decreasing orifice size and orifice pitch of gas distributor having the same opening area,the distributor pressure drop,the initial bubble size,and the height of dead zone just above the distributor were decreased,and the bed pressure drop was increased more than that of the larger orifice size and orifice pitch of distributors,the distribution of solid volume fraction was also more homogeneous for the smaller orifice size. 展开更多
关键词 fluidized bed gas distributor orifice size BUBBLE numerical simulation
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