This paper examines the roles that granular flow theory might play in the modeling the solid-phase stresses in fluidized beds. It begins with a discussion of the historical limiting cases of the quasistatic and rapid-flow regimes. It then reviews the elastic granular theories that unify those two regimes. Finally it shows that measurements of solid-phase pressures cannot be explained by commonl...

Gas fluidization is widely used in industries and has been extensively studied either experimentally or mathematically. Recently, the coupled approach of discrete particle simulation (DPS) for solid phase and computational fluid dynamics (CFD) for gas phase has been proposed to study the heat transfer in fluidized beds at a particle level. The approach offers a convenient way to study the effec...

Petri nets are frequently used for modeling and analysis of discrete event systems. Similar to other modeling formalisms for discrete systems, it suffers from state explosion. Fluidification can be used to overcome this difficulty yielding fluid approximation of original Petri nets in the sense of behaviours and properties. This models are called continuous Petri nets. In this work, stochastic ...

Fluidization of cohesive pharmaceutical powders is difficult to achieve and typically requires the introduction external forces. This study investigates fluidization fine inhalation grade lactose (size range from 0.1-20 μm) that are specifically developed for dry powder (DPI) applications. The behaviour was evaluated under six conditions: without aids, with only vertical vibration (VFA), a down...

In this study, a Eulerian-Eulerian liquid-solid two-phase flow model combined with kinetic theory of granular was established to study the hydrodynamic characteristics and fluidization behaviors coarse coal particles in 3D fluidized bed. First, grid independence analysis conducted select appropriate parameters. Then, developed computational fluid dynamics (CFD) validated by comparing experiment...

The fluidization and reduction behavior of micron-sized iron oxide powder, produced by combustion, is studied in a lab-scale cylindrical fluidized bed. minimum velocity umf found to stabilize above normalized static bed heights 0.5 H/D (static height divided the diameter). measured as function temperature between 280 860 K for both H2 N2 fluidizing gas. experimental results start deviate from E...

This paper describes an experimental study on the extent of capture efficiency in a fluidized bed system under controlled conditions. Using aerosols as tracer compound, the capture efficiency in a fluidized bed was quantitatively measured as a function of contact distance (time). The paper presents the experimental technique as well as the results relating the capture efficiency to the bed hydr...

An experimental approach is proposed to investigate the gas-solid structure in the vicinity of a sparger nozzle in a fluidized bed. The local hydrodynamics were studied under injection velocities ranging between 0 and 100 m/s and three orientations. A fiber-optic probe was used to measure the instantaneous local particle holdup near the tip of the sparger nozzle. Under the investigated conditio...