Agglomeration detection by pressure fluctuation analysis during Cynara cardunculus L. gasification in a fluidized bed

2008 ◽

Vol 6 (1) ◽

Cited By ~ 8

Author(s):

Yong Zhang ◽

Baosheng Jin ◽

Wenqi Zhong

Keyword(s):

Fluidized Bed ◽

Pressure Fluctuation ◽

Visual Observation ◽

Fluctuation Analysis ◽

Mixing Ratio ◽

Dynamic Features ◽

Pressure Transducers ◽

Sand Mixture ◽

Wide Range ◽

Initial Packing

Fluidization, mixing and segregation of a biomass-sand mixture in a 3D gas-fluidized bed have been investigated by means of visual observation, pressure fluctuation analysis and the bed-frozen method. Three types of mixtures are considered, in which biomass is a thin long stalk, and sand belongs to the Geldart B category. Experiments are carried out in a segmented fluidized bed equipped with multiple pressure transducers. Three initial packing conditions and two experiment procedures are used. The fluidization velocity varies to cover a wide range. Results show that in the local fluidization region, the mixing and segregation patterns are sensitive to the initial packing condition. In the case of a fully segregated state with biomass at the bottom, the bed inversion can be significantly observed due to the great segregation tendency of biomass. Further analyses indicate that the mixing ratio exerts a subtle influence on the competition between mixing and segregation by disturbing the coalescence and break-up of the bubble. In addition, the pressure fluctuation signal proves to be helpful in understanding the dynamic features of the phenomenology.

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Pressure fluctuation analysis of solid exchange in a dual-leg fluidized bed

Powder Technology ◽

10.1016/j.powtec.2012.02.029 ◽

2012 ◽

Vol 224 ◽

pp. 69-75 ◽

Cited By ~ 10

Author(s):

Chunzhen Yang ◽

Yufeng Duan ◽

Haitao Hu ◽

Changsui Zhao

Keyword(s):

Fluidized Bed ◽

Pressure Fluctuation ◽

Fluctuation Analysis

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Pressure Fluctuation Analysis in Gas-Solid Fluidized Beds Using CFD Simulations

Volume 7: Fluids and Heat Transfer, Parts A, B, C, and D ◽

10.1115/imece2012-88632 ◽

2012 ◽

Author(s):

Mirka Deza ◽

Francine Battaglia

Keyword(s):

Binary Mixture ◽

Fluidized Bed ◽

Pressure Fluctuation ◽

Pressure Fluctuations ◽

Design Tool ◽

Fluctuation Analysis ◽

Valuable Insight ◽

Turbulent Regime ◽

Local Pressure ◽

Long Time

Reliable computational methods provide valuable insight into gas-solid flow processes and can be used as a design tool. Of particular interest is the hydrodynamics of a binary mixture of sand-biomass in a fluidized bed. Our study interprets the hydrodynamic states of a fluidized bed by analyzing the local pressure fluctuations of beds of sand and a mixture of cotton stalks and sand over long time periods. Standard deviation of pressure drop will determine different fluidization regimes at inlet gas velocities ranging from 2 to 9 times the minimum fluidization velocity. Bode plots will present the pressure spectra and reveal characteristic frequencies that describe the bed hydrodynamics for different fluidization regimes. This works contribution will present CFD as a useful tool to perform pressure fluctuation analysis, the study of pressure fluctuations in the turbulent regime and the analysis of a binary mixture using CFD.

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Pressure-fluctuation analysis of a Gas–Solid fluidized bed using the wigner distribution

AIChE Journal ◽

10.1002/aic.690430208 ◽

1997 ◽

Vol 43 (2) ◽

pp. 345-356 ◽

Cited By ~ 12

Author(s):

Zhen He ◽

Dongming Zhang ◽

Bochuan Cheng ◽

Weidong Zhang

Keyword(s):

Fluidized Bed ◽

Pressure Fluctuation ◽

Wigner Distribution ◽

Fluctuation Analysis

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The mutual effects between the interparticle forces and mechanical properties on fluidization of TiO2 nanoparticle agglomerates in a conical fluidized bed: nanoindentation and pressure fluctuation analysis

Journal of Nanoparticle Research ◽

10.1007/s11051-019-4640-0 ◽

2019 ◽

Vol 21 (9) ◽

Author(s):

Alireza Bahramian

Keyword(s):

Mechanical Properties ◽

Fluidized Bed ◽

Pressure Fluctuation ◽

Tio2 Nanoparticle ◽

Fluctuation Analysis ◽

Interparticle Forces ◽

Nanoparticle Agglomerates ◽

Conical Fluidized Bed

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Study on the Reduction of Pressure Fluctuation for a Double-Suction Centrifugal Pump With Staggered Blades

Volume 3: Fluid Machinery; Erosion, Slurry, Sedimentation; Experimental, Multiscale, and Numerical Methods for Multiphase Flows; Gas-Liquid, Gas-Solid, and Liquid-Solid Flows; Performance of Multiphase Flow Systems; Micro/Nano-Fluidics ◽

10.1115/fedsm2018-83118 ◽

2018 ◽

Author(s):

Qian-qian Li ◽

Da-zhuan Wu

Keyword(s):

Centrifugal Pump ◽

Pressure Fluctuation ◽

Cfd Simulation ◽

Stokes Equations ◽

Low Noise ◽

Living Environment ◽

Centrifugal Impeller ◽

Fluctuation Analysis ◽

Centrifugal Pumps ◽

Vibration Performance

Due to the distinctive characteristic of massive flow rates, double-suction centrifugal pump has been extensively applied in lots of perspectives, such as drainage, irrigation, transportation projects and other hydraulic engineering realms. Nevertheless, the significance of the pressure fluctuation inside the double-suction centrifugal pump, which is getting more and more prominent under the soaring demands for low noise and comfortable living environment, could not be underestimated. Consequently, how to reduce the pressure fluctuation as far as possible and enhance the running stability of the pump is always the research hotspot. In this study, the double-suction centrifugal impeller with abominable vibration performance is redesigned to improve the internal flow and reduce the flow-induced noise. What’s addition, the two redesigned impellers wearing splitter blades were compared in staggered arrangement with different angles for the purpose of ulteriorly decreasing the pressure fluctuation. On the basis of Realizable k-ε model and SIMPLEC algorithm, the unsteady Reynolds-averaged Navier-Stokes equations (URANS) were resolved by means of CFD simulation and the flow performance and the vibration performance were validated with the experiments. The results illustrate that the redesigned impeller with multi-blade could raise the hydraulic performance and reduce the pressure fluctuation inside the pump. When the impeller of each side was laid with the staggered angle of 12 degrees, the pressure distribution tended to be more uniform and the pressure fluctuation was well ameliorated. Through the pressure fluctuation analysis in time domain and frequency domain, the pressure change inside the pumps could be evaluated quantitatively and accurately, hence different pumps could be contrasted in detail. The consequences of this paper could provide reference for pressure fluctuation reduction and vibration performance reinforcement of double-suction centrifugal pumps as well as other vane pumps.

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