Mixing and migration rule of binary medium in vibrated dense medium fluidized bed for fine coal separation

Zhou, Enhui; Lu, Junyu; Wang, Quanqiang; Lv, Guannan; Zhao, Yuemin; Dong, Liang; Chen, Duan

doi:10.1016/j.apt.2020.06.029

Cited by 14 publications

(6 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Sieve analysis was performed on the resulting mixture of coal and ash to determine the initial mean particle diameter. The bed inventory considered Zhou et al [32] 0.2 0.8 500-900, 100-300 1200-2200 0.11, 0.15 The mixing of fine coal particles was investigated in a vibrated dense medium fluidized bed (VDMFB), wherein it was claimed that both vibration and bubbling dominated the mixing phenomena.…”

Section: Methodsmentioning

confidence: 99%

Modelling of binary fluidization of coal and ash and validation using radioactive particle tracking and densitometry

Roy

2022

Can J Chem Eng

View full text Add to dashboard Cite

Binary fluidization finds wide application in a variety of gas–solid catalytic and non‐catalytic industrial fluidization systems. In the present study, a three‐dimensional transient computational fluid dynamics (CFD) model was used to model the binary fluidization of coal and ash in a laboratory‐scale cold flow fluidized bed. In parallel, phase velocity measurements using radioactive particle tracking (RPT) and gamma‐ray densitometry were performed, which provided a rich database for validation of the CFD model. RPT being a time‐resolved Lagrangian technique, it was possible to extract velocity fluctuations and their correlations in addition to the mean velocity profiles. The latter provided additional validation for the CFD model, in addition to the typical validation that is done with time‐averaged profiles of phase velocity and volume fraction. The robust validation procedure opens up the possibility of expanding this model to a pilot plant‐scale fluidized bed.

show abstract

Section: Methodsmentioning

confidence: 99%

Modelling of binary fluidization of coal and ash and validation using radioactive particle tracking and densitometry

Roy

2022

Can J Chem Eng

View full text Add to dashboard Cite

show abstract

“…More recently, vibrated fluidized bed (VFB) and pulsation fluidized bed (PFB), which can strengthen the movement of particles, increase gas-solid contact rate, improve fluidization quality, and achieve fluidization of fine cohesive particles are applied for coal cleaning [ 202 , 203 ]. Vibrated dense medium fluidized bed (VDMFB) [ [203] , [204] , [205] , [206] ], gas-vibro fluidized bed (GVFB) [ 197 , 207 , 208 ], and pulsating air dense medium fluidized bed (PADMFB) [ 202 , 209 , 210 ] are the examples of these technologies. In these types of ADMFB, vibration energy weakened the influence of bubble that occurred in conventional ADMFB since the fluidization stability could flexibly adjust by the pulsating airflow [ 204 , 205 ].…”

Section: Dry-type Gravity Separation Technologiesmentioning

confidence: 99%

Conventional and recent advances in gravity separation technologies for coal cleaning: A systematic and critical review

Phengsaart¹,

Srichonphaisan²,

Kertbundit³

et al. 2023

Heliyon

View full text Add to dashboard Cite

“…This enables the separation of different components of raw coal. Excessive mixing of coal powder into the bed results in binary and dense medium segregation, increases the viscosity of the bed, and gives rise to abnormal fluidization phenomena such as ditch flow and dead zones [11]. The mixing, segregation, remixing, and directional migration of binary particles affect the homogeneity and stability of the fluidized bed, ultimately leading to a decline in the separation effectiveness of fine-grained coal [12].…”

Section: Introductionmentioning

confidence: 99%

Study on the Separation and Mixing Characteristics of Wide-Grained Dense Medium in Vibration Separation Fluidized Bed

Fan,

Guo,

Guo

et al. 2023

Preprint

View full text Add to dashboard Cite

Vibro-fluidized dry coal beneficiation involves the unavoidable mixing of -1 mm coal dust into the fluidized bed, which compromises the stability and homogeneity of the bed density and reduces the effectiveness of fine-grained coal separation. In order to understand the features of coal powder separation and mixing (-1 mm) in a vibrating fluidized bed, as well as to achieve a uniform and stable bed density, a wide-grained dense medium consisting of -1 mm coal dust and 0.3-0.15 mm magnetite powder was homogeneously mixed in this work. The degree of density separation in the entire bed was examined, as well as the local mixing properties of the Wide-grained Dense Medium. It was discovered that when low vibrational energy was introduced at the same gas velocity, particle separation was enhanced in comparison to the usual fluidized bed. Little bubbles were found to ensnare fine coal dust and migrate upward, increasing density separation. The introduction of high vibrational energy leads to particle disorder within the bed and an increase in the level of particle mixing. The beneficial effects of vibration on the bed are diminished when the gas velocity is gradually increased under specified vibration circumstances. This causes big bubbles to develop more frequently, which increases particle mixing. Among them, the 1-0.5 mm fine-grained coal exhibits the best mixing state; it is less impacted by variations in air velocity and vibration levels, whereas the -0.5 mm coal dust is more affected by each of these variables. Furthermore, a wide range of air velocity regulation without a significant segregation state change was discovered to be achievable by the particle system under vibration circumstances of f=25Hz A=1mm and f=25Hz A=2mm.

show abstract

Mixing and migration rule of binary medium in vibrated dense medium fluidized bed for fine coal separation

Cited by 14 publications

References 24 publications

Modelling of binary fluidization of coal and ash and validation using radioactive particle tracking and densitometry

Modelling of binary fluidization of coal and ash and validation using radioactive particle tracking and densitometry

Conventional and recent advances in gravity separation technologies for coal cleaning: A systematic and critical review

Study on the Separation and Mixing Characteristics of Wide-Grained Dense Medium in Vibration Separation Fluidized Bed

Contact Info

Product

Resources

About