Prediction of pressure fluctuations and minimum fluidization velocity of binary mixtures of geldart group b particles in bubbling fluidized beds

Leu, Lii-Ping; Wu, Chih-Nan

doi:10.1002/cjce.5450780317

Cited by 9 publications

(4 citation statements)

References 12 publications

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“…In their turn, particles that tendency to float, in smaller size or lower density, were usually denominated as flotsam. During several years, this terminology has been applied for inert materials, e.g., corundum, glass, iron, polyethylene, polystyrene, steel, ceramic spheres, and sand [3][4][5][6], and currently for biomasses [7][8][9][10].…”

Section: Solid Particle Terminologymentioning

confidence: 99%

“…Modern procedures such as the evaluation of the pressure fluctuation in the time domain and the power spectrum calculated by the Fast Fourier Transform (FFT) in the frequency domain can also be applied. However, they are frequently used for homogeneous particles [36], since the mechanism of interaction between heterogeneous particles in these procedures is still not well understood [4,37]. The evaluation of these fluctuations allows a better understanding of the fluid dynamics states, consequently leading to the mechanism of mixing and segregation of the particles.…”

Section: Experimental Techniquesmentioning

confidence: 99%

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Experimental Study of Fluid Dynamic Behavior of Biomass Particles in Fluidized Beds: A Review

Tannous

Mitri

Mizonov³

2018

IVUZKKT

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Decease of natural resources and increase of price of fossil fuels at growing energy consumption, toughening of ecological standards and necessity of the increase of the level of energetics diversification motivates mankind to more wide usage of renewable energy resources including the solid fuel of biological origin. The potential of biofuel usage is rather considerable because the energy equivalent of the biomass harvest on the land exceeds the worldwide energy consumption several times as much. The biomass application as a renewable fuel is already a reality worldwide with the development of policies and technologies that turn viable the transformation of biomass into energy. The aims of this work is to present a literature experimental review on the studies concerning to the use of fluidized beds taking into account their design and scale-up. Initially, the usual solid particle terminology and some important biomass properties are presented. A brief description of conversion technologies and the fluidization phenomena are introduced, followed by an explanation of the different experimental techniques. The characteristic velocities (initial, apparent, of segregation, and complete) are discussed based on different biomass properties, as well as a number of empirical correlations for these velocities are described. Finally, some considerations are made about characteristic bed porosities (apparent and complete) and bed expansion. Based on the literature analysis, an improvement has been done on the understanding of the biomass fluidization phenomena, however, further research is needed to comprehend the effect of biomass characteristics on the bed operational parameters, besides more accurate and general correlations must be developed to improve these technologies. For citation: Tannous K., De Mitri A.G., Mizonov V. Experimental study of fluid dynamic behavior of biomassparticles in fluidized beds: a review. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 9-10. P. 4-14

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Section: Solid Particle Terminologymentioning

confidence: 99%

Section: Experimental Techniquesmentioning

confidence: 99%

Experimental Study of Fluid Dynamic Behavior of Biomass Particles in Fluidized Beds: A Review

Tannous

Mitri

Mizonov³

2018

IVUZKKT

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“…Furthermore, an important aspect in binary particle-based fluidized beds is that the minimum fluidization velocity varies non-linearly with bottom or top particles in contrast to a uniformly sized bed, and the particle velocity increases with an increase in the superficial velocity. A comprehensive literature review on the work carried out by the various authors using experimental techniques (Čársky et al, 1987;Hoffmann et al, 1993;Chehbouni et al, 1994;Gauthier et al, 1999;Leu and Wu, 2000;Harris et al, 2002;Ellis et al, 2004;Chew et al, 2010;Mazzei et al, 2010;Rao et al, 2010;Jayarathna and Halvorsen, 2011;Sau and Biswal, 2011;Di Maio et al, 2012;Obuseh et al, 2012;Lan et al, 2014;Philippsen et al, 2015;Leion et al, 2018;Menéndez et al, 2019;Penn et al, 2019;Chew and Cocco, 2021;Emiola-Sadiq et al, 2021;Gupta and De, 2021) and mathematical modeling/CFD (Cooper and Coronella, 2005;Du et al, 2006;Gao et al, 2009;Pei et al, 2010;Zaabout et al, 2010;Chang et al, 2012;Mostafazadeh et al, 2013;Benzarti et al, 2014;Sahoo and Sahoo, 2016;Bakshi et al, 2017;Agrawal et al, 2018;Chang et al, 2019;Daryus et al, 2019;Khezri et al, 2019;Shrestha et al, 2019;…”

Section: Introductionmentioning

confidence: 99%

CFD simulations to study bed characteristics in gas–solid fluidized beds with binary mixtures of Geldart B particles: II quantitative analysis

Ganguli

Bhatt

2023

Front. Energy Res.

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Hydrodynamics of fluidized beds with binary mixtures of particles is important in many industrial applications. The binary particles are generally in the Geldart particle range. In our earlier work, (Part I) of this work simulations were carried out and qualitative analysis was presented. Quantitative predictions of gas velocity and particle velocity profiles have been presented in the present work, which is Part II of the two-part work on computational fluid dynamics (CFD) simulations of binary fluidized beds. It was observed that the dynamics of the bed vary for different binary mixtures and are a strong function of superficial velocity and bed height. Mixing and segregation in beds for two different initial bed heights and six different binary mixtures and superficial velocities have been identified. Segregation is prominent for binary mixtures with 20 wt.% and 80 wt.% of large particles, whereas mixing is observed in 40 wt.% and 60 wt.% large particle mixtures. Bypassing of gas near the walls is prominently seen for 60 wt.% large particles with gas velocities as high as 5 m/s. Time-averaged axial particle volume fractions have been observed to be lower in the dilute phase with large undulations in the middle whenever the bed is well mixed for central axial profiles. The axial volume fraction profiles also confirm the mixing and segregation for the 40 wt.% and 20 wt.% composition of large particles for the operating conditions considered for the study. Bed height expansion is linear until a certain superficial velocity with the increase or decrease depending on the superficial velocity or bed height of operation. Furthermore, correlations for minimum fluidization velocity and pressure drops from the literature have been compared with experimental results. The simulated data have been considered for the development of a correlation for minimum fluidization velocity. The predicted results match experimental data with a 10%–15% deviation.

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“…The standard deviation (SD) of pressure fluctuation was also used to determine the minimum fluidization velocity of the binary mixture of solids [31]. Lue and Wu (2000) used the sum of the SD of pressure fluctuation of each species to determine the SD of the binary mixture by multiplying the fraction of each species in the mixture to its corresponding individual SD under the same operating conditions [31]. Pressure fluctuation analysis has also been used to determine the combustion region in a fluidized bed reactor by studying the SD of the pressure fluctuation, and it was found that the combustion region was related to the regions that have high SD values [27].…”

mentioning

confidence: 99%

Systematic Study of Pressure Fluctuation in the Riser of a Dual Inter-Connected Circulating Fluidized Bed: Using Single and Binary Particle Species

Alghamdi

Peng

Luo³

et al. 2019

Processes

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This study systematically investigates the pressure fluctuation in the riser of a dual interconnected circulating fluidized bed (CFB) representing a 10 kW th cold-flow model (CFM) of a chemical-looping combustion (CLC) system. Specifically, a single-species system (SSS) and a binary-mixtures system (BMS) of particles with different sizes and densities were utilized. The pressure fluctuation was analyzed using the fast Fourier transform (FFT) method. The effect of introducing a second particle, changing the inventory, composition (i.e., 5, 10 to 20 wt.%), particle size ratio, and fluidization velocity were investigated. For typical SSS experiments, the results were similar to those scarcely reported in the literature, where the pressure fluctuation intensity was influenced by varying the initial operating conditions. The pressure fluctuations of BMS were investigated in detail and compared with those obtained from SSS experiments. BMS exhibited different behaviour; it had intense pressure fluctuation in the air reactor and in the riser when compared to SSS experiments. The standard deviation (SD) of the pressure fluctuation was found to be influenced by the fluidization regime and initial operating conditions, while the power spectrum density (PSD) values were more sensitive to the presence of the particles with the higher terminal velocity in the binary mixture.Processes 2019, 7, 890 2 of 25 beds are complex, primarily determined by the combined effects of solids' behaviour and bubbles' characteristics in terms of development, movement, and burst. The application of chemical-looping combustion (CLC) lies between these two points, i.e., it is both part of the chemical engineering application and in energy conversion and steam production.It has been well documented that utilizing a mixture of metal oxides significantly improves the oxygen storage capacity of oxygen carrier particles in CLC systems that consist of dual interconnected circulating fluidized bed (CFB) [3,4]. This mixture of oxygen carrier was used as a single particles carrier containing both ingredients. However, other systems utilize a binary-mixture system (BMS) as two separate species that differ in sizes and/or densities in bubbling fluidized beds [5][6][7][8][9][10][11][12][13][14][15][16], and in a single-column fluidized bed [17][18][19][20][21]. Utilizing a BMS that differs in size and/or density will raise a number of operational uncertainties associated with the mixing/segregation of particles and the hydrodynamics of these complex systems. Mixing and segregation of binary solids that differ in both size and density have been investigated previously, where an operating map was developed to avoid any type of segregation (i.e., local or components segregation) in CLC systems [22][23][24]. The hydrodynamics of BMS in a dual interconnected CFB are yet to be investigated extensively. Specifically, the effects of parameters including particle size and density, mixture composition, total solids inventory (TSI) on the pressure profile, solids holdup...

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Prediction of pressure fluctuations and minimum fluidization velocity of binary mixtures of geldart group b particles in bubbling fluidized beds

Cited by 9 publications

References 12 publications

Experimental Study of Fluid Dynamic Behavior of Biomass Particles in Fluidized Beds: A Review

Experimental Study of Fluid Dynamic Behavior of Biomass Particles in Fluidized Beds: A Review

CFD simulations to study bed characteristics in gas–solid fluidized beds with binary mixtures of Geldart B particles: II quantitative analysis

Systematic Study of Pressure Fluctuation in the Riser of a Dual Inter-Connected Circulating Fluidized Bed: Using Single and Binary Particle Species

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