Article
Engineering, Chemical
Salma Benzarti, Hatem Mhiri, Philippe Bournot
Summary: Fluidized beds have been crucial in processing industries for almost a century. However, their scaling up has been hindered by complex hydrodynamic behavior and diverse solids handling. This study simulated the hydrodynamic behavior of a 2D circulating fluidized bed under different superficial gas velocities and found that the gas/solid feeding configuration significantly affects the flow structure.
Article
Engineering, Chemical
Priyabrata Puhan, Asim Kumar Mukherjee, Arnab Atta
Summary: In this study, the impact of particle density difference on the expansion behavior of binary mixtures with varying size and density in an inclined fluidized bed is investigated. A transient multi-fluid Eulerian technique coupled with the Kinetic Theory of Granular Flow (KTGF) model is used. The effects of geometrical parameters, such as angle of inclination, width of the channel, and number of plates in the inclined section, on the flow behavior of the polydisperse mixtures are also studied. The results show that changes in the angle of the inclined bed, channel width, and number of channels significantly affect the flow behavior of the complex mixtures.
Review
Engineering, Chemical
Lei Zhang, Zhijie Fu, Jiantao Li, Ruixu Wang, Xiaotao Bi
Summary: This review paper provides a comprehensive understanding of the fundamentals and developments of multi-solids fluidized bed (MSFB) and discusses its hydrodynamic behavior, heat and mass transfer efficiency. The performance of MSFB in typical chemical processes is also evaluated.
Review
Engineering, Chemical
Pierre Sauriol, Javad Vahabzadeh Pasikhani, Jaber Shabanian, Jamal Chaouki
Summary: The high velocity injection of gas in a particulate system leads to the formation of a gas-solid structure characterized by enhanced momentum, mass, and heat transfers. This review focuses on the empirical correlations developed to predict the jet penetration length and half-angle at various operating conditions in different bed configurations in gas-solid fluidized beds. It also discusses the advances in modeling efforts, scale-up issues, and proposes an iterative approach for designing and scaling up injection systems in a gas-solid fluidized bed.
Article
Engineering, Chemical
Shijiao Li, Peng Zhao, Ji Xu, Li Zhang, Junwu Wang
Summary: This study investigates the fluidization of polydisperse particles in bubbling micro-fluidized beds using CFD-DEM. The study validates the method by comparing it with experimental measurements and then performs a detailed analysis of bed hydrodynamics. The results show that particle size distribution enhances fluidization quality and that significant axial segregation is observed only in the case of wide PSD. The study provides insights into the role of PSD in gas fluidization and the similarities and differences between micro and large fluidized beds.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Engineering, Chemical
Yandaizi Zhou, Jingrui Xu, Jesse Zhu
Summary: The gas-solid fluidized bed reactor with Group C+ particles showed higher reaction conversion and better contact efficiency compared to the one with Group A particles. This is attributed to the smaller bubbles, slower rise velocity, and longer residence time in the Group C+ fluidized bed, leading to improved fluidization quality and enhanced gas-solid contact.
Article
Engineering, Chemical
Bin Lan, Ji Xu, Peng Zhao, Zheng Zou, Junwu Wang, Qingshan Zhu
Summary: The study found that the pressure drop and particle residence time distribution in a laboratory scale fluidized bed can be reasonably predicted; the mean residence time of particles linearly scales with bed length under different solid feed rates; the mean residence time of particles can be inferred from CFD simulations and the mass fraction of particles at the inlet.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Engineering, Chemical
Timo Dymala, Tom Wytrwat, Stefan Heinrich
Summary: The study uses the MP-PIC method to simulate two pilot-scale circulating fluidized beds, demonstrating that the EMMS-based drag model shows better agreement and lower grid sensitivity compared to the homogeneous drag model. The necessity for a new meso-scale cluster correlation for the simulation of Geldart B particles is highlighted.
Review
Engineering, Chemical
Frederik Zafiryadis, Anker Degn Jensen, Weigang Lin, Elisabeth Akoh Hove, Morten Boberg Larsen, Hao Wu
Summary: This paper provides a thorough and up-to-date review of experimental and numerical investigations of gas-liquid sprays into gas-solid fluidized beds. It presents a phenomenological description of the prevalent mechanisms of gas-liquid injection under different operating conditions and identifies suitable computational fluid dynamic models for simulating the mechanisms involved in gas-liquid-solid interactions, along with recommendations for future work.
Article
Thermodynamics
Nan Zheng, Huang Liu, Jiabin Fang, Jinjia Wei
Summary: Mixed-size particles with low processing cost have potential in concentrated solar power plants but the research on heat transfer in gas-solid fluidized beds is limited. This paper determines the bed-to-tube heat transfer coefficient (HTC) numerically and investigates the distribution of local HTC for various particle systems. The results show that the HTC is influenced by solid volume fraction and particle size.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Energy & Fuels
David Bannon, Mirka Deza, Masoud Masoumi, Bahareh Estejab
Summary: Biomass, as a clean and renewable energy source, has great potential to address the global energy crisis. This study investigates the effects of varying RDF, FVM, phi, and SBF on the performance of TFM in accurately predicting the behavior of biomass particles. The results demonstrate the importance of using appropriate models, such as Ma-Ahmadi RDF and Schaeffer FVM, for accurately predicting the gasification behavior of biomass particles.
Article
Engineering, Chemical
Chengguo Liu, Chenyang Zhou, Zeneng Sun, Chenlong Duan, Jesse Zhu, Yuemin Zhao
Summary: GFBCB technology is an important technique for dry coal beneficiation, with the addition of ultrafine coal particles to adjust the hydrodynamics of the bed, lower the minimum fluidization velocity, increase bed expansion, and decrease bed density, providing a more desirable separation environment for coal beneficiation.
Article
Engineering, Chemical
Quanhong Zhu, Libo Zhang, Weikang Hao
Summary: This study aimed to define and determine the minimum fluidization velocity in magnetized fluidized beds (MFB) based on physics principles, resolving controversies in the field. Different methods and requirements for determining U-mf were identified for MFB with different types of particles. Experimental results showed that U-mf remained invariant in both types of MFB.
Article
Engineering, Chemical
Shanwei Hu, Xinhua Liu
Summary: The importance of bubble dynamics in fluidized beds has been highlighted by extensive experimental and numerical studies. However, previous coarse-grid CFD models have neglected the bubble dynamic evolution and its effects on sub-grid closures, especially for Geldart A particles. In this article, a population balance model with improved kernels was used to describe the bubble dynamic evolution in three-dimensional bubbling beds. The simulation results showed that the model can accurately predict the hydrodynamics and heterogeneous structures in three-dimensional bubbling beds of fine particles.
CHEMICAL ENGINEERING SCIENCE
(2023)
Review
Engineering, Chemical
Matteo Errigo, Christopher Windows-Yule, Massimiliano Materazzi, Dominik Werner, Paola Lettieri
Summary: Gas-solid fluidized-bed systems have advantages in terms of chemical reaction efficiency and temperature control, making them widely used in industrial applications. However, the design, scale-up, and optimization of these complex units are limited by the lack of deep physical understanding. Non-invasive and non-intrusive diagnostic techniques provide a way for researchers to study these systems without affecting the flow field or directly contacting the medium under study.