This paper presents an experimental and numerical investigation of solid-liquid fluidized beds consisting bonded spheres in very narrow tubes, i.e., when the ratio between tube grain diameters is small. In beds, high confinement effects have proved to induce crystallization, jamming different patterns, which can be intensified or modified if some grains are together. order investigate that, we ...

Hydrogen-based direct reduction of iron oxide powder in gas-fluidized beds has become an emerging technology. Agglomeration fine at elevated temperatures is however one key issue hindering the technological development. To obtain better knowledge high-temperature agglomeration mechanism, (de-)fluidization behavior micron-sized combusted particles experimentally studied this Part I. Effects vari...

Fluidization of initially segregated binary mixtures has been investigated for particle systems of the same material. This paper reports experiments conducted in 0.055m diameter fluidizes bed for binary mixtures composed of sands whose sizes ranged from 450 to 1450mm. An empirical relationship, Utf = 0.95 UF (dR)0.87, was derived in terms of the minimum fluidization of the smaller particle, UF ...

Introduction Over the last fifty years gas-solids fluidized beds have played a very important role in many areas in the process industry, especially in chemical and petroleum industries. The existence of different flow regimes in fluidized beds at different operating conditions has been known for a long time and numerous studies have been carried out to define the flow regimes [1-6]. It is well...

We use a dynamic finite-difference model to simulate martian landslides in the Valles Marineris canyon system and Olympus Mons aureole using three different modal rheologies: frictional, Bingham, and power law. The frictional and Bingham modes are applied individually. Fluidized rheology is treated as a combination of frictional and power-law modes; general fluidization can include pore pressur...

In recent years, the discrete element method (DEM) has gradually been applied to traditional fluidization simulation of fine particles in a micro fluidized bed (MFB). The application DEM simulating fast MFB not yet received attention. This article presents drag model that relies on surrounding environment particles, namely particle circumstance-dependent or PCDD model. Fast an is simulated usin...

A model is presented for the prediction of the fluid dynamic behaviour of binary suspensions of solid particles fluidized by Newtonian fluids. The equations of motion for the fluid and solid phases are derived by extending the averaged two-fluid equations of change for identical spheres in Newtonian fluids developed by Anderson and Jackson and Jackson. A new closure relationship for the fluid–p...

Convection and fluidization phenomena in vibrated granular beds have attracted a strong interest from the physics community since the last decade of the past century. As early reported by Faraday, the convective flow of large inertia particles in vibrated beds exhibits enigmatic features such as frictional weakening and the unexpected influence of the interstitial gas. At sufficiently intense v...

In the present work an attempt has been made to study the effect of the twisted tapes as bed internals, on the performance of the gas-solid fluidized beds. Experimental investigation has been carried out in cylindrical column with and without twisted tapes. Twelve numbers of twisted tapes of three different widths with four values of the twist ratios for each width were studied at different...

Various approaches to structure gas-solid fluidized beds are reviewed, followed by detailed discussion on the use of gas pulsation induce dynamic structuring. Granular media dissipative systems, which develop complex spatiotemporal patterns when excited an oscillating energy source. Here, we discuss how such perturbations initiate surface and these could propagate into a macroscopically organiz...