The fluidization behavior of silica gel was tested in a fluidized bed under different sound pressure levels and sound frequencies. It has been found that the particle mixtures can be fluidized smoothly with sound assistance at low sound frequency owing to the sound energy disrupting large size of agglomerates. The minimum fluidization velocity was found to decrease with increasing sound frequen...

............................................................................................................................. xi CHAPTER 1: INTRODUCTION ................................................................................................ 1 1.1 Motivation ............................................................................................................................. 1 1....

Fluidized bed has many advantages such as high heat and mass transfer rates, temperature homogeneity and good mixing property. However, conventional fluidized bed has some limitations; operation at high gas velocity leads to slugging and there exists minimum particle size for the uniform fluidization. Recently, a rotating fluidized bed (RFB) has attracted special interest, since it has a possib...

Gas–liquid-solid fluidized beds are broadly utilized in the petrochemical, pharmaceutical, refining, food, biotechnology, and environmental industries. Due to complex phenomena, such as particle-particle, liquid-particle, particle-bubble interactions, hydrodynamics, heat transfer of three-phase (gas-liquid-solid) beds, they incompletely understood. The ability accurately predict essential chara...

A mathematical model for the fluidization of polydisperse suspensions is developed. The stationary concentration configurations for a given fluidizing velocity are analyzed and a mixing condition for bed inversion is derived. A central finite difference scheme is applied to the simulation of the fluidization of a bidisperse suspension. The numerical simulations agree with the experimentally rep...

Liquid–solid fluidized beds have a wide range of applications in metallurgical processing, mineral extraction, and wastewater treatment. Great interest on their flow stability heterogeneous fluidization behaviors has been aroused research. In this study, various experiments were performed by adjusting the operating conditions particle size, density, liquid superficial velocity. For each case, s...

The conditions to improve performance of quartz tube silicon carbide (SiC) solid particle fluidized bed solar receiver was investigated with computational fluid dynamics (CFD) simulations. difficulty experimenting all possible operating overcome by preparing CFD base input appropriate models and parameters. amount SiC in the bed, size particles, air inlet velocity were considered as variables. ...

The present work is focused on the study of fluidization behaviour of biomass and sand mixtures in a laboratory scale test set up. The biomass materials used during the experimentation were rice husk, bagasse and sawdust. Two different particle sizes of silica sands were used in forming the mixture. The percentages of biomass in the mixtures were 2%, 5%, 10% and 15% by weight. The minimum fluid...

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...