The local solid flow structure of gas-solid bubbling fluidized bed was investigated to identify and characterize the particle clusters. Extensive mathematical calculations were carried out using the energy-minimization multi-scale (EMMS) approach for evaluating cluster properties including the velocity, the size and the void fraction of clusters in the dense phase of the bed. The results showed...

We report on the fluidization dynamics of an attractive gel composed of non-Brownian particles made of fused silica colloids. Extensive rheology coupled to ultrasonic velocimetry allows us to characterize the global stress response together with the local dynamics of the gel during shear startup experiments. In practice, after being rejuvenated by a preshear, the gel is left to age for a time t...

This paper provides a simple methodology for the design of air reactor chemical looping combustor to optimize its characteristics when it is employed connected turbo expander produce power. The process, given certain objective (e.g., electric power) defines specifics, namely height and diameter, taking into account following aspects: solids inventory reactor; gas velocity; transport disengaging...

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 ...

The modeling of the fluidization or sedimentation velocity a suspension solid particles is revisited by examining experiments conducted in either liquid gas. A general expression found case negligible fluid inertia, i.e. at low Reynolds Archimedes number. It built as product an isolated particle three non-dimensional corrections that each takes into account specific physical mechanism. first co...

INTRODUCTION To account for meso-scale phenomena in coarse grid simulations, Reynolds stress terms appearing in the filtered gas-solid flow equations have to be modeled. Filtered models for the gas-solid momentum transfer are focused on and possible approaches are discussed. Three-dimensional steady-state simulations of developing flow in the bottom section of a riser in which the solid phase i...

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 ...

This work investigates the effect of different conditions of PFO thermal cracking from two PFO samples on liquid, solid and gas product yield and asphaltene removal efficiency in a new designed experimental setup. No need to use a catalyst, simple operating system and experiment conditions, the ability to use water as a cheap carrier gas and high asphaltene extraction efficiency without the use...

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...