检索结果-南通市图书馆

Particuology 2024年第8期91卷 72-87页

作者： Akshayveer Vijay M.Shinde MS2Discovery Interdisciplinary Research Institute Wilfrid Laurier UniversityWaterlooOntarioN2L3C5Canada Department of Chemical Engineering Indian Institute of Technology(BHU)Varanasi221005India

A CFD-DEM model is developed for chemical vapour deposition of silane in a fluidized bed reactor to investigate the effect of polydispersity on local phase dynamics,mass and heat transport,as well as the rate of Si *** gas-phase fines formation and heterogeneous deposition on the seed particle,as well as the scavenging effect for Si particle growth,are *** method is first validated against the experimentally measured Si deposition rate,percentage of fine production and minimum fluidisation ***,the properties,primarily particle intermixing,fluidisation behaviour and bubble dynamics along with the deposition process,are analyzed for several polydisperse beds under various operating *** effect of polydispersity of the bed on a fraction of the bubble size,dense phase expansion and interchange coefficient between various phases is thoroughly investigated to establish a correlation with reactor *** results show that broad-Gaussian particle size distribution(PSD)exhibits excellent improvement in fluidisation behaviour,resulting in a high deposition rate,and minimum formation of Si fines.

关键词： CFD-DEM method Chemical vapour deposition(CVD) Particle size distribution Silicon gas-solid fluidized bed

Heat transfer characterization and improvement in an external catalyst cooler fluidized bed

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2021年第3期19卷 103-112页

作者： Jiantao Li Xiuying Yao Lu Liu Xudong Zhong Chunxi Lu State Key Laboratory of Heavy Oil China University of Petroleum(Beijing)Beijing 102249China Luoyang R&D Center of Technology SINOPEC Engineering(Group)Co.Ltd.Luoyang 471003China

gas-solid fluidized beds have been widely used in heat transfer processes,and so there have been many studies focused on increasing heat transfer in such *** the present work,a pilot scale cold mode experimental rig was constructed to assess the effects of hydrodynamics on bed-to-wall heat transfer and to investigate various means of enhancing heat transfer in a dense gas-solid fluidized bed with external solid *** experimental results show that heat transfer in the dense region played a dominant role in total bed-to-wall heat transfer,accounting for more than 88%of the total heat transfer *** transfer could be lowered as a result of solids bypass that occurred because of external solids circulation,but this effect was weakened by the radial mixing of *** heat transfer characteristics identified in this study indicate that a specially designed baffle can be used to enhance bed-to-wall heat *** installing such baffles in the fluidized bed test structure,a 70%increase in the total heat transfer coefficient was obtained.

关键词： gas-solid fluidized bed Heat transfer Hydrodynamics Baffles Intensification

Injection of gas-liquid jets into gas-solid fluidized beds:A review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2023年第5期76卷 63-85页

作者： Frederik Zafiryadis Anker Degn Jensen Weigang Lin Elisabeth Akoh Hove Morten Boberg Larsen Hao Wu Department of Chemical and Biochemical Engineering Technical University of Denmark2800 Kongens LyngbyDenmark Topsoe 2800Kongens LyngbyDenmark

Injection of gas-liquid sprays into gas-solid fluidized beds finds application in many *** mixing and distribution of liquid feed and solid bed material is paramount to ensure an efficient and profitable *** its long-term use,the mechanism of liquid injection into gas-solid fluidized beds continues to raise questions and is only partially *** paper provides a thorough and up-to-date review of experimental and numerical investigations of gas-liquid sprays into gas-solid fluidized beds conducted over the past *** on the surveyed literature,a phenomenological description of the prevalent mechanisms of gas-liquid injection under different operating conditions is *** review identifies suitable computational fluid dynamic models for simulating the mechanisms involved in gas-liquid-solid interactions along with recommendations for future numer-ical and experimental work.

关键词： gas-liquid jet gas-solid fluidized bed Atomization Fluid catalytic cracking Fluid coking

FLOW DYNAMICS OF gas-solid fluidized bedS WITH EVAPORATIVE LIQUID INJECTION

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Particuology 2006年第1期4卷 1-8页

作者： W. Warsito Liang-Shih Fan Department of Chemical and Biomolecular Engineering The Ohio State University 140 West 19th Avenue Columbus OH 43210 USA

The electrical capacitance tomography （ECT） with neural network multi-criteria image reconstruction technique （NN-MOIRT） is developed for real time imaging of a gas-solid fluidized bed using FCC particles with evaporative liquid injection. Some aspects of the fundamental characteristics of the gas-solid flow with evaporative liquid injection including real time and time averaged cross-sectional solids concentration distributions, the cross-sectional solids concentration fluctuations and the quasi-3D flow structures are studied. A two-region model and a direct image calculation are proposed to describe the dynamic behavior in both the bubble/void phase and the emulsion phase based on the tomographic images. Comparisons are made between the fundamental behaviors of the gas-solid flows with and without evaporative liquid injection for various gas velocities ranging from bubbling to turbulent fluidization regimes. Significant differences are observed in the behavior of the gas-solid flow with the evaporative liquid injection compared to the fluidized bed without liquid injection.

关键词： gas-solid fluidized bed evaporative liquid injection electrical capacitance tomography real time imaging

Particle mixing rates using the two-fluid model

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Particuology 2018年第1期16卷 13-26页

作者： M. Banaei N.G. Deen M. van Sint Annaland J.A.M. Kuipers Multiphase Reactors Group Deportment of Chemical Engineering & Chemistry Eindhoven University of Technology 5600 MB Eindhoven The Netherlands Dutch Polymer Institute (DPI) 5600 AX Eindhoven The Netherlands Multiphase and Reactive Flows Group Department of Mechanical Engineering Eindhoven University of Technology 5600 MB Eindhoven The Netherlands

In this work, a new methodology is introduced to calculate the solids mixing rate in dense gas-fluidized beds using the two-fluid model. The implementation of this methodology into an existing two-fluid model code was carefully verified. The solids phase continuity equation was satisfied using our method, and the sensitivity of the computational results to the time step, computational cell size, and discretization scheme was investigated to determine the optimal simulation settings. Using these simulation settings, the degree of solids mixing was observed to rapidly （exponentially） increase with increasing operating pressure and linearly decrease with increasing bed diameter. Our novel methodology can be applied to analyze mixing processes in large lab-scale beds as an alternative to existing time-consuming simulation techniques such as computational fluid dynamics combined with the discrete element model.

关键词： gas-solid fluidized bed Simulation Two-fluid model solids mixing Pressure Scale up

CFD simulation in a cold-model jetting fluidized-bed gasifier with a binary system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CFD simulation in a cold-model jetting fluidized-bed gasifie...