Particles distributions along a conical fluidized bed were predicted by an alternative arrangement of the minimum fluidization velocity equation. The proposed approach introduces two new equations which present the particle diameter in the bed as function of: height in the bed (Z), angle of inclination of the fluidized bed wall (θ), input flow rate (Qo), and gas distributor diameter (Do, 2ro). ...

A laboratory, fluidized-bed gasifier is being researched as a means to gasify feedstocks in a process to produce ethanol from biomass. Fluidization characteristics of the bed, especially minimum (Umf) and complete (Ucf) fluidization velocities, were measured because they are critical to the operation of the gasifier. Fluidization properties of sand and chopped switchgrasssand mixtures of differ...

Abstract The present study explores the relevance of physical properties biomass particles on determination minimum fluidization velocity ( U mf ) binary mixtures. Fluidization experiments were performed in a cold flow unit with diverse biomasses mixed sand different mass fractions. Gas and pressure drop across bed used to determine . Different correlations reported literature evaluated their a...

Nanoparticles (NPs) are applied in a wide range of processes, and their use continues to increase. Fluidization is one of the best techniques available to disperse and process NPs. NPs cannot be fluidized individually; they fluidize as very porous agglomerates. The objective of this article is to review the developments in nanopowder fluidization. Often, it is needed to apply an assistance meth...

The onset of surface fluidization of granular material in a vertically vibrated container, z = A cos (ωt), is studied experimentally. Recently, for a column of spheres it has been theoretically found [1] that the particles lose contact if a certain condition for the acceleration amplitude z̈ ≡ Aω/g = f(ω) holds. This result is in disagreement with other findings where the criterion z̈ = z̈crit = c...

A computational study has been carried out to assess the influence of pressure on the flow behaviors in dense gas-fluidized beds. Therefore the discrete particle simulation approach has been employed to study the regime transitions, local two-phase flow structures and the energy dissipation distribution. The results show that high pressure reduces the incipient fluidization velocity, widens the...

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...