scholarly journals Estimation of Bed Expansion and Separation Density of Gas–Solid Separation Fluidized Beds Using a Micron-Sized-Particle-Dense Medium

Separations ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 242
Author(s):  
Xuchen Fan ◽  
Chenyang Zhou
Keyword(s):  
Carbon Dioxide Emissions ◽  
Theoretical Basis ◽  
Fluidized Beds ◽  
Fine Particles ◽  
Energy Resource ◽  
Dense Medium ◽  
Carbon Neutrality ◽  
Separation Density ◽  
Chinese Policy ◽  
Bed Expansion

Coal is the dominant energy resource in China. With the Chinese policy of committing to reducing peak carbon dioxide emissions and achieving carbon neutrality, coal separation has recently become a hot topic, especially the fluidized separation of fine particles. In this study, micron-sized particles were introduced to ameliorate the properties of the traditional fluidized bed. The expansion characteristics of the micron-sized-particle-dense medium were explored. A bed expansion prediction model of the micron-sized-particle-dense medium was established, and the prediction error was about 10%, providing a theoretical basis for understanding the distribution characteristics of the bed. This model also helped predict the bed density in the presence of a micron-sized-particle-dense medium, and the prediction accuracy was between 85% and 92%, providing a theoretical basis for selecting and popularizing fluidized beds for industrial separation.

The effect of pressure on the flow of gas in fluidized beds of fine particles

1983 ◽  
Vol 38 (12) ◽  
pp. 1935-1945 ◽  
Author(s):  
G.F. Barreto ◽  
J.G. Yates ◽  
P.N. Rowe
Keyword(s):  
Fluidized Beds ◽  
Fine Particles ◽  
Effect Of Pressure

scholarly journals Study on Fluidization Characteristics of Magnetically Fluidized Beds for Microfine Particles

Minerals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 61
Author(s):  
Yakun Tian ◽  
Shulei Song ◽  
Xuan Xu ◽  
Xinyu Wei ◽  
Shanwen Yan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Fluidized Bed ◽  
Magnetic Field Strength ◽  
Fluidized Beds ◽  
Expansion Rate ◽  
Gas Velocity ◽  
Bed Height ◽  
Bed Expansion ◽  
The Magnetic Field

The bed pressure drop, minimum fluidized gas velocity, bed density, and bed expansion rate are important parameters characterizing the fluidization characteristics of gas-solid fluidized beds. By analyzing these parameters, the advantages and disadvantages of the fluidization state can be known. In this study, experiments were conducted to study the fluidization characteristics of a gas-solid magnetically fluidized bed for microfine particles by changing the magnetic field strength, magnetic field addition sequence, and static bed height. The experimental results show that when the magnetic field strength increased from 0 KA/m to 5 KA/m, the minimum fluidized gas velocity of particles increased from 4.42 cm/s to 10.32 cm/s, while the bed pressure drop first increased and then decreased. When the magnetic field strength is less than 3.4 KA/m, the microfine particles in the bed are mainly acted on by the airflow; while when the magnetic field strength is greater than 3.4 KA/m, the microfine particles are mainly dominated by the magnetic field. The magnetic field addition sequence affects the fluidization quality of microfine particles. The fluidized bed with ‘adding magnetic field first’ shows a more stable fluidization state than ‘adding magnetic field later’. Increasing of the static bed height reduces the bed expansion rate. The bed expansion rate is up to 112.5% at a static bed height of h0 = 40 mm and H = 5 KA/m. This will broaden the range of density regulation of a single magnetic particle and lay the advantage of gas-solid magnetically fluidized bed for microfine particles in the field of separation of fine coal.

scholarly journals The global trend towards decarbonization of the economy, the introduction of the Carbon Border Adjustment Mechanism in the EU and the possible consequences for Russia

2021 ◽  
Vol 129 ◽  
pp. 09021
Author(s):  
Vladimir Sh. Urazgaliev ◽  
V. Novikov Andrey ◽  
A. Menshikova Galina
Keyword(s):  
Carbon Dioxide Emissions ◽  
Economic Relations ◽  
Carbon Neutrality ◽  
Adjustment Mechanism ◽  
Reduce Carbon Dioxide ◽  
Energy Products ◽  
Climate Neutrality ◽  
The Impact ◽  
The Eu ◽  
Border Adjustment

Research background: In the process of implementing the Paris Agreement (2015), Europe is a leader in the formation of new legislative initiatives in order to develop a set of effective measures to reduce greenhouse gas emissions in the atmosphere. The European Commission approved the European Green Deal (2015) - a strategy for achieving the EU parameters of climate neutrality through the transition to a clean circular economy. Its main goal is to reduce carbon dioxide emissions by 2030 by 50 - 55% from 1990 levels and achieve full carbon neutrality of the EU by 2050. As part of this strategy, the Carbon Border Adjustment Mechanism (CBAM) is being developed. The introduction of CBAM means a revolutionary transformation in the system of international economic relations. Purpose of the article is to identify and assess possible risks for producers and consumers, primarily of energy products after the introduction of CBAM, as well as the impact of these risks on Russian exports to Europe. Methods: The authors carried out a comparative analysis of scenarios for the implementation of CBAM in the sectorial and product segments of trade between Russia and the EU. Findings: The article contains comparative assessments of the beginning redistribution of international markets in the sectoral and product coverage of emissions, as well as an analysis of the unfolding contradictions in the verification of methods for determining the carbon footprint in the production chains of the real sector of the economy.

Fluid Dynamic and Mixing Characteristics of Biomass Particles in Fluidized Beds

2015 ◽  
pp. 54-91 ◽  
Author(s):  
Katia Tannous ◽  
Joana Bratz Lourenço
Keyword(s):  
Fluidized Beds ◽  
Fluid Dynamic ◽  
Eucalyptus Grandis ◽  
Technical Information ◽  
Thermal Conversion ◽  
Mixing Characteristics ◽  
Biomass Particles ◽  
Bed Expansion

The study of fluid dynamic and mixing characteristics of biomass particles in fluidized beds is fundamental for comprehension of thermal conversion processes. In this chapter a review of literature showed a large lacks of technical information about the quality of fluidization and representative models concerning binary mixtures (biomass and inert). A case study was presented involving Eucalyptus grandis wood and tucumã endocarp in order to obtain fluid dynamic parameters such as the characteristic fluidization, velocity and porosity, and the bed expansion. These parameters were more significant for mixtures with smaller diameter and mass fraction ratios, and sphericity ratio, due to the facility of beds to fluidize. A map was presented to identify the limits of effective mixtures considering four classes as a function of the complete fluidization Reynolds' and Archimedes' numbers. Empirical correlations have been proposed and showed a good agreement with the experimental work.

A CFD Study of Existing Drag Models for Geldart A Particles in Bubbling Fluidized Beds

2014 ◽  
Author(s):  
Bahareh Estejab ◽  
Francine Battaglia
Keyword(s):  
Experimental Data ◽  
Fluidized Beds ◽  
Fine Particles ◽  
The Other ◽  
Particle Interactions ◽  
Model Group ◽  
Drag Model ◽  
Numerical Studies ◽  
Solid Phases ◽  
Drag Models

In this study, seven drag models are examined to determine how they affect fluidization behavior of Geldart A particles of biomass and coal. Notwithstanding the notable number of numerical studies to find the best drag model for larger particles, there is a dearth of information related to drag models for finer Geldart A particles. Additionally, to our knowledge, these drag models have not been tested with a binary mixture of Geldart A particles. Computational fluid dynamics was used to model the gas and solid phases in an Eulerian-Eulerain approach to simulate the particle-particle interactions of coal-biomass mixtures and compare the predictions with experimental data. In spite of the previous findings that bode badly for using predominately Geldart B drag models for fine particles, the results of our study reveal that if static regions of mass in the fluidized beds are considered, these drag models work well with Geldart A particles. It was found that the seven drag models could be divided into two categories based on their performance. One category included the Gidaspow family of drag models (Gidaspow, Gidaspow-Blend, and Wen-Yu) and the Syamlal-O’Brien drag model; these models closely predicted the experiments for single solids phase fluidization. For binary mixtures, however, the other drag model group (BVK, HYS, Koch and Hill) yielded better predictions.

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