Gas-Liquid-Solid fluidized beds have emerged in recent years as one of the most promising devices for three phase operation. This operation generates considerable, intimate contact among the gas, liquid and solid particles in these systems. It provides substantial advantages for applications in physical, chemical or biochemical processing involving gas, liquid and solid phases. Such a device is of considerable industrial importance as evidenced in its wide use for chemical, petrochemical and biochemical processing. The successful design and operation of gas-liquid-solid fluidized bed systems depends on the ability to accurately predict the fundamentals properties of the system especially, the hydrodynamics, the mixing of the individual phases, and the heat and mass transfer properties. Identification of the flow regimes under which the bed operates is the crucial to an understanding of both the variations of these properties and the overall system performance.
[...] HYDRODYNAMICS OF GAS-LIQUID-SOLID FLUIDIZATION: Hydrodynamics of three phase fluidization means finding the pressure drop, bed expansion phase hold ups and mixing of the phases. All these factors are interdependent on each other that there are no particular equation had been found, but many models and empirical correlations have been proposed for finding these hydrodynamics and these are different for different mode of operation. Apart from the different modes present in three phase fluidized beds a single reactor system consists of three main sections as shown in fig The gas-liquid distributor section 2. [...]
[...] Based on the differences in flow directions of gas and liquid in contacting patterns between the particles and the surrounding gas and liquid, several types of operations for gas-liquid contact are possible. Taxonomy presented by Epstein for three phase fluidization. Here the three phase fluidization is divided into two types according to the relative direction of the gas and liquid flows, namely concurrent three phase fluidization and countercurrent three-phase fluidization. The concurrent three-phase fluidization, there are two contacting patterns characterizing different hydrodynamic conditions between the solid particles and the surrounding gas and liquid. These modes denoted as Mode a and Mode I-b. [...]
[...] Heat and Mass transfer of three phase fluidization: It has been reported in these fields that the heat transport phenomena have been analyzed by adopting two kinds of heat transfer systems; the one is wall-to-bed heat transport systems and the other is immersed heater-to-bed heat transfer systems. In spite of similar elementary mechanisms of heat transfer between the two, the value of heat transfer coefficient in each kind of heat transport system has been different from each other depending on the operational conditions. [...]
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