Characteristics of pressure fluctuations and fine coal preparation in gas-vibro fluidized bed

Dong, Liang; Zhao, Yuemin; Peng, Liping; Zhao, Jie; Z, Luo; Liu, Qingxia; Chen, Duan

doi:10.1016/j.partic.2014.08.011

Cited by 19 publications

(12 citation statements)

References 29 publications

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“…According to this figure, the incoherent standard deviation is very small and independent of the gas velocity at low temperatures but increases slightly with increasing bed temperature. The incoherent standard deviation represents the intensity of the movement of bubbles and agglomerates. , At low temperatures, hydrophobic silica nanopowders become fluidized in the APF regime; i.e., bubbles do not exist, and the agglomerates are small. Therefore, the incoherent standard deviation is very small at low temperatures and remains approximately constant versus the superficial gas velocity.…”

Section: Resultsmentioning

confidence: 99%

“…A gas–solid fluidized bed includes two types of pressure waves: dynamic waves that travel fast and kinematic waves that travel slow. , The dynamic pressure wave corresponds to upward and downward fast waves. The upward fast waves arise from formation, coalescence, and abruption of bubbles and the downward fast waves are related to bubble eruption.…”

Section: Methods Of Data Anslysismentioning

confidence: 99%

“…Among different measuring methods, pressure fluctuation measurement is a promising and reliable technique that has been successfully utilized to characterize the hydrodynamics and quality of fluidization. − This technique is nonintrusive and inexpensive and can be employed in a wide range of operating conditions. , Pressure fluctuations include fast traveling (dynamic) and slow traveling (kinematic) waves. , Fast traveling waves originate from formation, coalescence, eruption, and abruption of bubbles and slow traveling waves correspond to local fluctuations caused by rising of bubbles or motion of particles.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Fluidization of Nanoparticle Agglomerates at Elevated Temperatures

Esmailpour

Mostoufi

Zarghami

2017

Ind. Eng. Chem. Res.

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The behavior of hydrophobic and hydrophilic nanoparticles was investigated. In a novel approach, the interparticle force (IPF) was altered by changing the temperature of the gas–solid fluidized bed in the range 25–110 °C. The hydrodynamic state of the bed was monitored by examining pressure fluctuations using coherent and incoherent analysis. Formation, coalescence, eruption, and mobility of bubbles in the fluidized bed were determined in addition to investigating the behavior of agglomerates. The diameter of the agglomerate was calculated from the incoherent output of the power spectral density of pressure fluctuations in the agglomerate particulate fluidization (APF) regime at various temperatures. No bubbles were detected in the bed of the silica nanopowder at low temperatures whereas small bubbles form at higher temperature. In contrast, hydrophilic titania nanopowder becomes fluidized in the ABF regime at lower temperatures and tends to fluidize at the APF regime with increasing bed temperature.

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Section: Resultsmentioning

confidence: 99%

Section: Methods Of Data Anslysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fluidization of Nanoparticle Agglomerates at Elevated Temperatures

Esmailpour

Mostoufi

Zarghami

2017

Ind. Eng. Chem. Res.

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“…The generation of a wake affects the efficiencies of the particle mixing, mass and heat transfer, chemical reaction, and drying processes. , A specific example where this effect is quite unfavorable is in the process of fluidized bed coal preparation, wherein the gangue left after separation is entrained in the wake and then rises to the bed surface, mixing with the clean coal products. This seriously affects the separation efficiency, particularly for fine coals. − Therefore, the present study aims to address this gap in the existing literature by considering the influence of the wake on the gas–solid distribution of the pulsed fluidized bed, which lays a foundation for its density control and numerical simulation.…”

Section: Introductionmentioning

confidence: 99%

Gas–Solid Distribution Theory in a Pulsed Fluidized Bed Based on the Intermediate Phase

Zhou

Zhang

et al. 2021

Ind. Eng. Chem. Res.

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Fluidized bed technology is widely used in chemical industries. The introduction of pulsating energy into a traditional fluidized bed can effectively reduce the generation of bubbles and improve the fluidization quality. The accuracy of gas−solid distributions has a significant influence on the density control of fluidized beds. Here, a gas−solid distribution model and bed expansion prediction model were established with the wake taken as the intermediate phase to make up for the lack of a gas−solid distribution theory in a pulsed fluidized bed. The correlation coefficient of the theoretical model was validated using data obtained from collapse experiments. The linear fitting correlation between the bed expansion height H (p) and correction coefficient Y is quite good. The error of the modified model of the bed expansion ratio was found to be within 20%, which enables it to provide theoretical guidance for industrial applications of pulsed fluidized beds.

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“…Thus, it is very important to give careful consideration to the advantages of dry separation. Moreover, dry coal separation has more advantages compared to wet coal separation [4][5][6][7][8][9][10][11], for example, it does not consume water resources, does not increase the moisture content of separated products, and does not pollute groundwater and ecological environment. As a result, it can reduce damage to the environment.…”

Section: Introductionmentioning

confidence: 99%

The Effect of the Characteristics of the Partition Plate Unit on the Separating Process of −6 mm Fine Coal in the Compound Dry Separator

Chen

Wang

et al. 2019

Minerals

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Although compound dry separation technology has been applied to industrial applications for +6 mm size fraction of coal separation, the technology has not been widely applied in the separation of fine coal (−6 mm). In this study, the effect of the partition plate unit characteristics on both the average density of particles in the bed uniformly and the final separation results in a fine coal separation process were studied. According to the results, the standard deviations of the corresponding density distribution were 0.08, 0.14, and 0.07 when the height of the partition plate was 2.5 cm, the partition plate angle was 35°, and the distance from the apex of partition plate on the backplane, was 12 cm, respectively, which were the lowest values at the same level. These results showed that the average density of particles in the bed was uniformly, and its corresponding density distribution contour map was more regular. When the amplitude was 2.8 mm, the frequency was 29 Hz, the height of the partition plate was 2.5 cm, the partition plate angle was 35°, and the distance from the apex of the partition plate to the backplane was 12 cm; as a result, the E value was 0.115 g/cm3, the yield of the concentrate was 69.24%, the ash content was 12.52%, and the separation effect was better. The characteristics of the partition plate unit have an important effect on the separating process of −6 mm fine coal in the compound dry separator.

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Characteristics of pressure fluctuations and fine coal preparation in gas-vibro fluidized bed

Cited by 19 publications

References 29 publications

Fluidization of Nanoparticle Agglomerates at Elevated Temperatures

Fluidization of Nanoparticle Agglomerates at Elevated Temperatures

Gas–Solid Distribution Theory in a Pulsed Fluidized Bed Based on the Intermediate Phase

The Effect of the Characteristics of the Partition Plate Unit on the Separating Process of −6 mm Fine Coal in the Compound Dry Separator

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