Time-series analysis of pressure fluctuations in gas–solid fluidized beds – A review

Ommen, J. Ruud van; Sasic, Srdjan; Schaaf, J. van der; Gheorghiu, Stefan; Johnsson, Filip; Coppens, Marc‐Olivier

doi:10.1016/j.ijmultiphaseflow.2010.12.007

Cited by 287 publications

(191 citation statements)

References 112 publications

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“…Many works have been done in this field and nowadays the pressure signal is routinely employed to obtain a large amount of information concerning the dynamics of a fluidised bed, c.f. the review by van Ommen et al (2011).…”

Section: Introductionmentioning

confidence: 99%

Experimental quantification of the particle–wall frictional forces in pseudo-2D gas fluidised beds

Hernández-Jiménez

Sánchez-Prieto

Soria-Verdugo

et al. 2013

Chemical Engineering Science

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Abstract:In this work a novel measurement technique for pseudo-2D fluidised beds is developed. The objective is to give an estimation of the overall frictional force between the solids and the front and rear walls of the bed. For doing this, the measured pressure signal in the bed is processed in combination with the solids distribution (i.e. centre of mass position, velocity and acceleration) obtained from digital image analysis of the optically accessible front view of the bed. This is performed by acquiring the pressure signal in the bed simultaneously to the digital images. Both the pressure and the digital images are connected through a simple force balance in the bed, and a particle-wall interaction coefficient is obtained assuming that the overall frictional force is proportional to the centre of mass velocity. The particle-wall interaction coefficient found using this technique is of the order of 40-120 kg/m 2 s in the bed tested, and the standard deviation of the frictional forces reaches more than 70% of the weight of the bed. Therefore, the results indicate that the contribution of the particle-to-wall friction on the fluctuation of the pressure drop in a pseudo-2D bed is not negligible.

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Section: Introductionmentioning

confidence: 99%

Experimental quantification of the particle–wall frictional forces in pseudo-2D gas fluidised beds

Hernández-Jiménez

Sánchez-Prieto

Soria-Verdugo

et al. 2013

Chemical Engineering Science

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“…Different bubble-related phenomena like bubble formation, bubble coalescence, bubble passage and bubble bursting can cause pressure waves in the bed. In addition, the oscillations in the bed surface and gas flow rate also cause pressure waves 15,16]. Time series of pressure fluctuations measured in the experiment and obtained from simulation at the same operating condition are shown in Fig.…”

Section: Rr (%) Lam and Det (%) Grid Size (Mm)mentioning

confidence: 98%

Validation of Eulerian modeling of gas-solid fluidized beds using nonlinear analysis

Norouzi¹,

Norouzi²,

Zarghami³

2015

AIP Conference Proceedings

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Abstract. In the present work, the new advanced method has been used for validation of twofluid method (TFM) for modeling of the hydrodynamics of gas-solid fluidized beds. While many investigations were addressed validation of the CFD codes, less effort has been made to validate the nonlinear dynamics of fluidized beds with nonlinear methods. In this work new advanced nonlinear methods of recurrence plot (RP) and recurrence quantification analysis (RQA) have been used to validate the hydrodynamics modeling of the gas-solid fluidized beds. Pressure fluctuations of inside the bed were selected for comparing the nonlinear dynamics of fluidized bed in experiments and simulations. Pressure fluctuations were measured in a rectangle fluidized bed containing Geldart's group B particles with sampling frequency 400 Hz. Simulations were done with the same operating condition and pressure fluctuations were recorded with the same sampling frequency. The superficial air velocity range was 0.25-0.73 m/s (bubbling regime) and two aspect ratios 1 and 1.5 were used. The results of experiments and simulations were analyzed by RP and RQA. The values of laminarity, determinism, and recurrence rate for both experiments and simulations are close to each other. The experimental and simulation results showed high values for determinism and laminarity which show predictable and periodic behaviors of both systems. High values of determinism and laminarity are one of the most important characteristics of bubbling regime in which bubbles are periodically produced and move in the bed. In the entire gas velocity, the values of determinism and laminarity were not changed significantly that shows that no regime change occurred in the bed.

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“…Among various methods available in the literature to identify flow regime transitions in multiphase reactors, a statistical analysis of time-series signals has been widely used due to its accuracy and repeatability [15,26] standard deviation, the coefficient of variation, and the higherorder moments, such as skewness (third-order moment) and kurtosis (fourth-order moment) are commonly used statistics for the identification of regime transitions. In the current work, the kurtosis was found to neatly discriminate the transition to pulse flow and it was computed from the WMS liquid saturation time-series data according to Eq.…”

Section: Low-to-high Interaction Regime Transitionmentioning

confidence: 99%

Offshore Floating Packed‐Bed Reactors: Key Challenges and Potential Solutions

2017

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Dedicated to Professor Rüdiger Lange on the occasion of his 65th birthdayThe influence of floating vessel motions on the hydrodynamic behavior of multiphase flows in porous media was studied using a hexapod ship motion emulator with an embarked packed column. The response of gas-liquid distribution, pressure drop, liquid saturation, and flow regime transition to column inclinations and roll motions was compared to those of the corresponding static vertical and inclined configurations. Two-phase flow patterns in terms of local liquid saturation distribution were visualized online by means of a capacitance wire-mesh sensor positioned firmly on the floating packed bed. The hydrodynamic performance of packed beds under roll motion deviates strongly from that of the static beds, indicating that the known characteristics of the conventional land-based tricklebed reactors cannot be transposed on a one-to-one basis for design and scale-up of the floating reactor configurations.

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Time-series analysis of pressure fluctuations in gas–solid fluidized beds – A review

Cited by 287 publications

References 112 publications

Experimental quantification of the particle–wall frictional forces in pseudo-2D gas fluidised beds

Experimental quantification of the particle–wall frictional forces in pseudo-2D gas fluidised beds

Validation of Eulerian modeling of gas-solid fluidized beds using nonlinear analysis

Offshore Floating Packed‐Bed Reactors: Key Challenges and Potential Solutions

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