Discrete particle simulations are by now well established as an effective tool to study the mechanics of complex gas-solid flows in gas-fluidized beds. In this study, a state-of-the-art discrete particle model is used to explore the role of particle-particle interactions in bubbling gas-fluidized beds of Geldart A particles. We find that the particle-particle interactions, including inelastic p...

Modeling and measurement of bubble size in a rotating fluidized bed (RFB) were conducted. The model for predicting the bubble growth in RFB has been proposed based on the following concepts: (i) local centrifugal acceleration and excess gas velocity are considered as the parameters in the radial direction, and (ii) bubble volume flow locally changes depending on the radial distance. Bubbling be...

We demonstrate that a vibration-induced air inflow can cause vigorous bubbling in a bed of fine particles and report the mechanism by which this phenomenon occurs. When convective flow occurs in a powder bed as a result of vibrations, the upper powder layer with a high void ratio moves downward and is compressed. This process forces the air in the powder layer out, which leads to the formation ...

In the present study, dry reforming of methane (DRM) has been simulated in fluidized-bed reactors using multiphase particle-in-cell model. The model was meticulously built to investigate effect a wide range superficial gas velocities covering particulate, aggregative, and lean-phase flow regimes on bed hydrodynamics, conversion, yields product gases. Constant values for catalyst loading, CH 4 :...

The efficiency of fluidized bed reactors depends on bubble distribution, bubble size and bubble velocity within the reactor. The sizes and size distributions of particles used in the bed may lead to different bubble behaviour. The objective of this work is to study the influence of particle size distribution on bubble behaviour. The results from the experiments will be used for validation of CF...

UNLABELLED BACKGROUND The process of thermal decomposition of dichloromethane (DCM) and chlorobenzene (MCB) during the combustion in an inert, bubbling fluidized bed, supported by LPG as auxiliary fuel, have been studied. The concentration profiles of C6H5CI, CH2Cl2, CO2, CO, NOx, COCl2, CHCl3, CH3Cl, C2H2, C6H6, CH4 in the flue gases were specified versus mean bed temperature. RESULTS The...

We report initial NMR studies of gas dynamics in a particle bed fluidized by laser-polarized xenon (129Xe) gas. We have made preliminary measurements of two important characteristics: gas exchange between the bubble and emulsion phases and the gas velocity distribution in the bed. We used T2* contrast to differentiate the bubble and emulsion phases by choosing solid particles with large magneti...

The goal of this research is to determine how spectral analysis of pressure fluctuations can be used as a diagnostic and design tool for both bubbling fluidized beds (BFB) and circulating fluidized beds (CFB). Static pressure fluctuations are measured from two BFB models, two CFB models, and two Pyropower CFB boilers located at the ISU power plant/cogeneration facility. Analyzing the fluctuatio...

This is the first in a series of three papers describing combustion of biosolids in a 5-kW bubbling fluidized bed, the ash chemistry, and possible application of the ash produced as a fertilizing agent. This part of the study aims to clarify whether the distribution of main ash forming elements from biosolids can be changed by modifying the fuel matrix, the crystalline compounds of which can be...

The hydrodynamics in a 152 mm ID bubbling fluidized bed filled with 500-600 μm glass beads have been simulated using the computational fluid dynamics (CFD) code Fluent 6.3, and the results are compared to experimental data obtained using pressure measurements and 3D X-ray computed tomography. The grids in a Cartesian coordinate system used in simulations are made by 2D (8×8 mm, 4×4 mm, 2×2 mm, ...